JPH11298848A - Digital camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a photographed image with image quality as being imagined by a photographer. SOLUTION: The afterglow mode is set to the digital camera. In the afterglow mode, an image signal received by an image pickup section 3 is processed as specified and stored in an image memory 209. A thumbnail image generating section 219 and a preview image generating section 220 read image data from the image memory 209, adjust white balance by using adjustment values with different characteristics to generate pluralities of sample images with different colors, and the resulting image is displayed on a liquid crystal display LCD display section 10 in a form of a matrix. A photographer selects a desired sample image by operating a prescribed switch in a switch group 215. When a sample image is selected, the thumbnail image generating section 219 reads the image data from the image memory 209 and adjusts white balance of the data by using same characteristic values as those of the selected sample image and stores the result to a memory card 18. Pluralities of sample images are displayed and desired image processing is selected based on the sample image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital camera that photoelectrically converts a subject light image into an image signal, captures the image signal, performs predetermined image processing on the image signal, and records the image signal on a recording medium.

[0002]

2. Description of the Related Art Conventionally, in a digital camera, an LCD (Liquid Crystal Display) display section is provided in a camera body, a plurality of captured images recorded from a recording medium are read, and these captured images are processed into thumbnail images. rear,
It is known to arrange them in a matrix and display an index on an LCD display unit.

In image processing by a personal computer, an image captured from an image reading device such as a scanner is subjected to image processing using a plurality of types of γ characteristics, color tone characteristics, and the like, thereby obtaining gradation characteristics and saturation characteristics. It is known that a plurality of different images are created, and these images are arranged in a matrix and displayed on a display device such as a CRT (Cathode Ray Tube) or an LCD.

[0004]

By the way, in photographing with a digital camera, for example, in the case of photographing a sunset scene, the finish of a photograph imaged by the photographer differs depending on the photographer. It is more convenient to provide a fixed width so that the photographer can select a desired image processing among them, because the operability of the digital camera is improved. In this case, a sample image based on a plurality of thumbnail images having different finishing conditions with respect to the photographed image is displayed in a matrix on an LCD display unit provided in the camera body, so that the photographer can select image processing while monitoring the finishing state. preferable.

However, in a conventional digital camera, an image signal captured by an image pickup device such as a CCD (Charge Coupled Device) is applied to an image signal relating to various image qualities such as white balance adjustment, gradation adjustment, saturation adjustment, and contour correction. After the processing is performed, the image is recorded on a recording medium such as a memory card.In general, each image processing such as white balance adjustment is performed based on predetermined characteristics set in advance, and the captured image is adjusted. Is automatically processed in the camera.

As described above, in computer image processing, there is known a technique of displaying a plurality of images having different finishes on a monitor in order to determine a correction process regarding the image quality of a captured image. No such technique has been proposed. Even in a digital camera having the above-described LCD display unit and displaying a plurality of thumbnail images in a matrix on the LCD display unit, only a plurality of captured images recorded on a recording medium are displayed as an index. However, a plurality of image quality sample images having different finishing conditions are not displayed on the monitor in order to select.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and displays a plurality of sample images having different image processings on a photographed image so that a desired image processing method can be selected from the displayed images. By doing so, it is possible to provide a digital camera that can obtain a photographed image that matches the photographed image of the photographer.

[0008]

According to the present invention, there is provided an image pickup means for photoelectrically converting a subject light image into an image signal, a display means for displaying an image, and temporarily storing the image signal taken by the image pickup means. A first storage unit that reads the image signal from the first storage unit, performs image processing using a plurality of preset characteristic values, and creates a plurality of image quality sample images having different image qualities. An image creation unit, a display control unit that displays the plurality of image quality sample images created by the sample image creation unit on the display unit, and one of the plurality of image quality sample images displayed on the display unit 1
Image selection means for selecting the image quality sample image, image processing means for reading the image signal from the first storage means, and performing image processing with the same characteristic values as the image quality sample image selected by the image selection means. And second storage means for storing the image signal subjected to the image processing by the image processing means (claim 1).

According to the above arrangement, the image signal taken by the image pickup means is temporarily stored in the first storage means. The image signal stored in the first storage means is read out, and image processing is performed with a plurality of preset characteristic values to create a plurality of image quality sample images having different image qualities. The images are arranged in a matrix and displayed on the display means. Then, when one of the image quality sample images is selected by the image selection means from the image quality sample images displayed on the display means, the image signal is read from the first storage means, and the selected image quality sample image is read. After the image processing is performed with the same characteristic value as that of the image, the image signal is stored in the second storage unit.

Further, according to the present invention, in the digital camera, a predetermined photographing mode set in advance can be set, and when the photographing mode is set, the sample image forming means, the display control means and the image processing means can be set. This enables processing by each means (claim 2).

According to the above configuration, when a predetermined photographing mode is set and a photograph is taken in the photographing mode, a plurality of image quality sample images having different image qualities are created based on the image signals captured by the image pickup means. The image quality sample images are arranged in a matrix and displayed on the display means.
Then, when any one of the image quality sample images is selected by the image selection means from the image quality sample images displayed on the display means, the image is displayed with the same characteristic values as the image quality sample images selected for the image signal. After the processing is performed, the image signal is stored in the second storage unit.

On the other hand, when a photograph is taken in a state where a predetermined photographing mode is not set, a plurality of image quality sample images having different image qualities are created based on the image signals captured by the image pickup means, and the image quality sample images are created. Is not displayed.
Therefore, the image signal captured by the imaging unit is stored in the second storage unit after image processing is performed with a predetermined characteristic value set in advance.

Further, according to the present invention, in the above digital camera, the photographing mode is a sunset mode for photographing a sunset scene, and the image processing performed by the sample image creating means is a white balance adjusting process. ).

According to the above arrangement, in the sunset mode, when an image is taken by the image pickup means, a plurality of image quality sample images are created by processing the image with a plurality of preset white balance adjustment values different from each other. Then, the information is displayed on the display means in a matrix form. For example, in addition to an image having a standard color balance, a plurality of image quality thumbnail images whose color balance is lost such as an image having a strong reddish color and an image having a strong orange color are displayed on a monitor. Then, when any one of the image quality sample images is selected from the sample image quality images, the captured image is white-balance-adjusted to the same color balance as the sample image and stored in the second storage means.
For example, when a reddish image quality sample image is selected, the captured image is finished to a reddish color balance image quality.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A digital camera according to the present invention will be described with reference to the drawings. FIG. 1 is a front view of a digital camera according to the present invention, and FIG. 2 is a rear view of the digital camera. 3 and 4 are a top view and a bottom view, respectively, of the digital camera.

The digital camera 1 comprises a box-shaped camera body 2 and a rectangular parallelepiped imaging section 3. The imaging unit 3 is detachably mounted on the right side of the camera body 2 when viewed from the front, and is rotatably mounted in a plane parallel to the right side. Further, the imaging unit 3 can be connected to the camera main unit 2 via a dedicated connection cable. In the present embodiment, the imaging unit 3 is attached to the right side of the camera body 2, but may be attached to the left side of the camera body 2.

The image pickup unit 3 rotates within a range of approximately ± (90 + α) ° within the side surface of the camera body 2 with reference to the set position in FIGS. 1 and 2 (hereinafter, this position is referred to as a rotation reference position). You can do it. The imaging unit 3 includes a photographing lens including a macro zoom and a CCD (Charge Cou
It has an imaging device including a photoelectric conversion element such as a pled device, and converts an optical image of a subject into an image signal (an image signal composed of a charge signal photoelectrically converted by each pixel of a CCD) and captures the image signal. .

On the other hand, the camera body 2 is provided with an LCD (Liquid
A display unit 10 (see FIG. 2) composed of a Crystal Display).
It has a mounting portion for a memory card 18 (see FIG. 6) and a connection terminal 13 (see FIG. 2) to which a personal computer is externally connected, and mainly performs predetermined signal processing on the image signal captured by the imaging unit 3. Thereafter, processing such as display on the LCD display unit 10, recording on the memory card 18, and transfer to a personal computer is performed.

The image pickup unit 3 has a substantially rectangular parallelepiped shape having substantially the same length as the length of the camera body 2 in the height direction, and having substantially the same size as the width of the camera body 2. The image pickup section main body 3A is provided with a mounting section 3 for mounting the image pickup section 3 to the camera body section 2 on one side surface of the image pickup section main body 3A.
B is protruded.

As shown in FIG. 5, a macro zoom lens 301 is provided inside the image pickup section main body 3A, and an image pickup circuit 302 having a CCD color area sensor 303 at an appropriate position behind the macro zoom lens 301. Is provided. In addition, a dimming circuit 304 including a dimming sensor 305 that receives the reflected light of the flash light from the subject is provided at an appropriate position in the imaging unit 3. The light control sensor 305 is
It is arranged at an appropriate position on the front end face of the mounting portion 3B (see FIG. 3).

On the other hand, as shown in FIG. 2, a side parallel to the back surface of the camera body 2 (the upper side when the imaging unit 3 is rotated + 90 ° from the rotation reference position) is provided outside the imaging unit body 3A, as shown in FIG. A zoom lever 306 for changing the zoom ratio of the macro zoom lens 301 and switching between zoom and macro is provided on the side surface). A lock release lever 307 is provided to enable the user to detach the camera.

The zoom lever 306 is moved in the horizontal direction (the imaging unit 3).
With a lever that can slide in the direction perpendicular to the optical axis of
The zoom ratio of the macro zoom lens 301 is changed by sliding the zoom lever 306 laterally left and right at the zoom position PZ. In addition, the zoom lever 306 is slid rightward beyond the zoom position PZ to set the macro position PM.
Is set, the macro zoom lens 301 is switched to the macro lens. At the macro position PM, an image can be taken as close to the subject as about 50 cm.

As shown in FIG. 1, on the front surface of the camera body 2, a grip 4 is provided at an appropriate position at the left end, and a flash 5 is provided at an appropriate upper portion at the right end. As shown in FIG. 2, an LCD for displaying a monitor of a captured image (corresponding to a viewfinder) and reproducing and displaying a recorded image is provided on the rear surface of the camera body 2 as shown in FIG.
A display unit 10 is provided. Also, the LCD display unit 10
An FL mode setting switch 11 for flash emission and a shooting mode setting switch 16 for selectively setting a plurality of shooting modes, which will be described later, are provided above the flash memory.
A compression ratio setting switch 12 for switching and setting a compression ratio K of image data recorded in the personal computer and a connection terminal 13 to which a personal computer is externally connected are provided. FL
Mode setting switch 11 and shooting mode setting switch 1
Reference numeral 6 denotes a push switch, and the compression ratio setting switch 12 includes a two-contact slide switch.

As shown in Table 1 below, the digital camera 1 is capable of selectively setting ten kinds of preset photographing modes. The photographed image is subjected to predetermined image processing according to the set photographing mode. Is to be done. When the photographing mode setting switch 16 is pressed, the currently set photographing mode is displayed on the LCD display unit 10. Each time the photographing mode setting switch 16 is pressed, the display is changed from (1) to (1).
The mode is cyclically switched in the order of 0), and the desired photographing mode is displayed on the LCD display unit 10 so that the photographing mode can be set.

[0025]

[Table 1]

Each of the photographing modes in Table 1 includes: (1) a standard mode; a photographing mode in which a standard image quality is obtained; (2) a portrait mode; a photographing in which an appropriate image quality is obtained for a portrait photograph of a person or the like. Mode (3) Landscape mode; a shooting mode in which an appropriate image quality can be obtained for a landscape photograph in which a natural or artificial landscape is the subject. (4) Night landscape mode; for a night landscape photograph photographed with a night landscape in the background. (5) Slow synchro mode; a shooting mode that provides appropriate image quality for images shot with open flash (6) Sunset mode; appropriate for images shot in sunset scenes (7) Macro mode; shooting mode that provides appropriate image quality for close-up photos (8) Gray scale mode; Shooting mode (9) sepia mode to finish the image; shooting mode (10) solarization mode to finish the captured image to the toning Sepia or reddish brown; has a content of the mode to finish a photographed image to solarization image.

The respective processes in Table 1 are: (a) edge emphasis process; process for emphasizing an edge portion or reducing high-frequency noise by changing the frequency characteristic of a photographed image; (b) signal at low luminance Amplification processing; processing for compensating for underexposure by image signal (analog signal) amplification processing in a low-luminance scene exceeding the range in which exposure control is possible. (C) Gradation processing; processing for adjusting contrast by γ correction. (E) WB processing; adjusting the white balance to adjust the overall color balance of the captured image.

The specific image processing related to the above (a) to (e) will be described later. The description in the remarks column means that shooting is performed with the focus position of the macro zoom lens 301 fixed at infinity. In the night view mode, shooting is performed with flash emission prohibited to make use of the night view atmosphere. In the slow synchro mode, it is assumed that the flash photography is assumed, and thus the flash is forcibly emitted to perform photography.

The digital camera 1 has an "automatic emission mode" in which the flash 5 is automatically emitted according to the subject brightness as a mode relating to flash emission, and a "forced emission" in which the flash 5 is forcibly emitted regardless of the subject brightness. A flash mode setting switch 11 and a flash mode 5 are provided.
Each time is pressed, each mode of "automatic light emission", "forced light emission" and "light emission inhibition" is cyclically switched, and any one of the modes is selectively set. Note that when the night view mode and the slow sync mode are set as the shooting modes, the mode setting by the FL mode setting switch 11 is ignored, and the “flash off mode” is set in the night view mode, and the “forced flash mode” is set in the slow sync mode. Is automatically set.

The digital camera 1 has 1/8 and 1 /
For example, when the compression ratio setting switch 12 is slid to the right, the compression ratio K = 1/8 is set, and when it is slid to the left, the compression ratio K = 1/20. Is set. In the present embodiment,
Although two types of compression ratios K can be selected and set,
Three or more types of compression ratios K may be selectively set.

Further, a recording / reproduction mode setting switch 14 for switching and setting between "recording mode" and "reproduction mode" is provided at the upper right end on the rear surface of the camera body 2. The recording / reproduction mode setting switch 14 is provided. A main switch 17 for turning on a main power supply is provided on the left side of the main switch. The recording mode is a mode for taking pictures, and the playback mode is
In this mode, the captured image recorded on the memory card 18 is reproduced and displayed on the LCD display unit 10. The recording / playback mode setting switch 14 also includes a two-contact slide switch.
For example, sliding to the right sets the playback mode, and sliding to the left sets the recording mode. The main switch 17 includes a push switch. When the switch is pressed in the on state, the power of the digital camera 1 is turned on. When the switch is pressed in the off state, the power is turned off.

On the upper surface of the camera body 2, as shown in FIG. 3, image processing (white balance adjustment processing) is selected at the time of photographing in the sunset mode at substantially the center, and a recorded image is reproduced. In this case, switches 6 and 7 for performing frame feed are provided. An erasure switch 8 for erasing an image recorded on the memory card 18 is provided on the left side of the switch 7 when viewed from the rear side, and a shutter button 9 is provided on the upper right of the switch 6.

In the sunset mode, the digital camera 1 performs a plurality of preset white balance adjustments (WB adjustments) on a photographed image in a sunset mode as described later, and a plurality of thumbnail images having different WB adjustments. Is displayed on the LCD display unit 10 so that the photographer can
Adjustment values can be selected.

Switches 6 for shooting in the sunset mode
The selection of the image processing by 7 means that the user designates the thumbnail image on which the desired WB adjustment has been performed by operating the switches 6 and 7 while visually recognizing the thumbnail image displayed on the LCD display unit 10 on the monitor. The method for specifying the thumbnail image will be described later.

On the other hand, the frame advance of the recorded image by the switches 6 and 7 at the time of reproduction means the LCD display unit 1 in the reproduction mode.
At 0, the image recorded on the memory card 18 is displayed together with the frame number, and the frame image displayed on the LCD display section 10 is displayed in the ascending direction (the direction of the photographing order) or the descending direction (the direction opposite to the photographing order). Direction).

The switch 6 is used to increase the number of the thumbnail image displayed on the LCD display section 10 when selecting the WB adjustment value, and to advance the frame in the direction in which the frame number increases when changing the frame number. Switch (hereinafter, UP
It is called a switch. The switch 7 reduces the number of the thumbnail image displayed on the LCD display unit 10 when selecting the WB adjustment value, and switches the frame number in the direction in which the frame number decreases when the frame number is changed. (Hereinafter referred to as DOWN switch).

A touch panel switch is provided on the LCD display unit 10, and the touch panel switch is used to operate the LCD.
The thumbnail image displayed on the display unit 10 may be selected.

As shown in FIG. 6, a battery loading chamber for a power battery E and a memory card 1 are provided on the bottom of the camera body 2.
8 card loading chambers are provided, and the loading ports of both loading chambers are
It is configured to be closed by a clamshell type lid 15.

FIG. 7 is a block diagram of a control system of the digital camera 1. In the figure, the same members as those shown in FIGS. 1 to 6 are denoted by the same reference numerals.

The macro zoom lens 301 in the image pickup section 3 is provided with an aperture member (fixed aperture) having a fixed aperture. A signal processing circuit 308 and a timing generator (TG) 309 are components of the imaging circuit 302. CCD area sensor 303 (hereinafter, CC)
Abbreviated as D303. ) Is an image sensor composed of a CCD color area sensor, which converts the light image of the subject formed by the macro zoom lens 301 into R (red), G (green), B
The image signal is photoelectrically converted into an image signal of a (blue) color component (a signal composed of a signal sequence of pixel signals received by each pixel) and output. The timing generator 309 generates various timing pulses for controlling driving of the CCD 303.

The exposure control in the image pickup unit 3 is performed by adjusting the exposure amount of the CCD 303, that is, the charge accumulation time of the CCD 303 corresponding to the shutter speed, since the stop is a fixed stop. If you cannot set an appropriate shutter speed when the subject brightness is low,
By adjusting the level of the image signal output from 303, improper exposure due to insufficient exposure is corrected. That is, when the luminance is low, exposure control is performed by combining the shutter speed and the gain adjustment (see the signal amplification processing at the time of low luminance in Table 1). The level adjustment of the image signal is performed in the gain adjustment of the AGC circuit 308b in the signal processing circuit 308 described later.

The timing generator 309 controls the CCD 3 based on the reference clock transmitted from the camera body 2.
03 is generated. The timing generator 309 is, for example, a timing signal of integration start / end (exposure start / end), a read control signal of a light receiving signal of each pixel (horizontal synchronization signal, vertical synchronization signal, transfer signal, etc.).
, And outputs it to the CCD 303.

The signal processing circuit 308 performs predetermined analog signal processing on an image signal (analog signal) output from the CCD 303. The signal processing circuit 308
DS (correlated double sampling) circuit 308a and AGC
(Auto gain control) circuit 308b,
The noise of the image signal is reduced by the CDS circuit 308a, and the level of the image signal is adjusted by adjusting the gain of the AGC circuit 308b.

The gain of the AGC circuit 308a is automatically set by the main body control unit 201. However, as shown in Table 1, when the photographing mode is the night scene mode or the slow sync mode, the signal processing circuit 308 Gain adjustment is prohibited, and exposure control is performed only by the charge accumulation time of the CCD 303. In the night view mode and the slow synchro mode, the brightness of the subject is considerably low, so that the charge accumulation time of the CCD 303 becomes long, and the dark noise included in the image signal output from the CCD 303 increases. Even if the image signal from the CCD 303 is amplified by the AGC circuit 308b even in the night view mode and the slow synchro mode, there is a possibility that the image quality may be deteriorated due to the effect of the amplified dark noise. AGC
The gain adjustment by the circuit 308b is prohibited.

The light control circuit 304 controls the light emission amount of the flash 5 in flash photography to a predetermined light emission amount set by the main body control unit 201. In flash photography, the reflected light of the flash light from the subject is received by the light control sensor 305 at the same time as the start of exposure, and when the amount of received light reaches a predetermined light emission amount, the light control circuit 304 provides the light in the camera body 2. The light emission stop signal STP is output to the FL control circuit 214 thus set. FL control circuit 214
Stops the light emission of the flash 5 in response to the light emission stop signal STP, whereby the light emission amount of the flash 5 is controlled to a predetermined light emission amount.

The switch group 310 is a switch group for detecting a set position of the zoom lever 306 of the macro zoom lens 301 and a set position of the image pickup unit 3 in the image pickup direction.

In the camera body 2, a reference clock generating circuit 202 is a circuit for generating a reference clock.
The timing control circuit 203 includes the timing generator 3
09 and the A / D converter 205
Is a circuit for generating a clock CLK2 with respect to. Reference clock generation circuit 202 and timing control circuit 203
Is controlled by the main body control unit 201.

The RTC 204 is a clock circuit for managing the shooting date and time. The RTC 204 is driven by a power supply battery (not shown) different from the main power supply battery.

The A / D converter 205 converts each pixel signal of the image signal input from the imaging section 3 into a 10-bit digital signal. The A / D converter 205 converts each pixel signal (analog signal) based on the A / D conversion clock CLK2 input from the timing control circuit 203.
Into a 10-bit digital signal.

The black level correction circuit 206 corrects the black level of the A / D converted pixel signal (hereinafter referred to as pixel data) to a reference black level. The WB circuit 207 performs level conversion of pixel data of each of the R, G, and B color components so that the white balance is also adjusted after the γ correction. The WB processing in Table 1 is performed by the WB circuit 207. The WB circuit 207 converts the level of the pixel data of each of the R, G, and B color components using a level conversion table having the characteristics shown in FIG.

In the case of the standard processing shown in Table 1, the conversion coefficient (gradient of the characteristic) of each color component in the level conversion table is set by the main body control unit 201 for each captured image. on the other hand,
When the night view mode and the slow synchro mode are set, most of the reflected light from the subject is the flash light from the flash 5, so the level of the image data of each of the R and B color components is the color temperature of the flash light. Is set in the WB circuit 207 so as to be converted into a predetermined level that matches the flash light level. Therefore, “WB for FL” in Table 1 indicates that dedicated WB processing for flash light is performed.

Further, in the sunset mode, the photographed image is usually considered to be an image of a sunset scene. In this case, too, in order to emphasize the redness of the sunset, a predetermined WB is set so that the white balance collapses to a reddish color. Adjustment value (for example, B
/ G = 1, R / G = K (> 1)). Of course,
A plurality of WB adjustment values are prepared in advance so that an atmosphere close to the sunset scene imaged by the photographer can be expressed,
The photographer can select and set a desired WB adjustment value from these WB adjustment values. Therefore, Table 1
“Fixed value processing” is a predetermined WB adjustment value that breaks the white balance into a reddish color, and indicates that processing is performed using a predetermined WB adjustment value selected by the photographer.

The γ correction circuit 208 corrects the γ characteristics of the pixel data. The gradation processing in Table 1 is performed by the gamma correction circuit 208. As shown in FIG. 10, the γ correction circuit 208 has five types of γ correction tables having different γ characteristics, and performs γ correction of pixel data using a predetermined γ correction table according to a set photographing mode. Note that this γ
In the correction processing, 10-bit pixel data is converted into 8-bit (256 gradation) pixel data. The reason why the image data before the γ correction processing is 10-bit data is as follows.
This is to prevent the image quality from deteriorating when the γ correction is performed with the γ characteristic having strong nonlinearity.

The image data of each of the R, G, and B color components is subjected to a predetermined level conversion by the WB circuit 207, and these image data are respectively converted into γ by a γ correction table.
to correct.

In FIG. 10, the characteristic is γ = 0.45.
Characteristic of the LCD display unit 10 (γ =
(Having 2.2 γ characteristics). The LCD display unit 10 has a function as a view finder. When the digital camera 1 is in a standby state for release, the LCD display unit 10 operates similarly to the video camera.
The subject is imaged every 1/30 (second) by D303,
The captured images are sequentially displayed on the LCD display unit 10 on a monitor. In the image processing of the captured image in the monitor display, γ correction is performed according to the characteristics so that the image quality of the monitor image is suitable.

The characteristic is a γ characteristic of γ = 0.55, and a captured image of a standard photographic scene is stored in the memory card 1.
8 is applied to image processing when recording. In Table 1, it is applied in “standard processing”. In the digital camera 1, a personal computer 19 can be connected to an external device, and the captured image recorded on the memory card 18 is normally reproduced on a monitor (having a γ characteristic of γ = 1.8) via the personal computer 19. Since it is considered that the image is displayed, the captured image for which the recording to the memory card 18 is instructed by the release is subjected to the γ correction according to the characteristic, so that the image quality of the image reproduced on the monitor becomes suitable.

The characteristic has a smaller γ value than the characteristic, and the quality of the reproduced image is softer than that when the captured image is subjected to the γ correction with the characteristic. An image with high delineation of the highlight portion is obtained. For this reason, the characteristic is applied to an image captured in the portrait mode (see “soft tone” in the gradation processing in Table 1).

When the input level of the γ characteristic is divided into three regions of “high (bright)”, “medium” and “low (dark)”, the characteristics are changed from the “middle” level region to the “high” level region. In the “low” level region so that the slope of γ is larger than the characteristic. When the captured image is γ-corrected with the characteristic, the image quality of the reproduced image is higher and the contrast is stronger than when the γ-correction is performed with the characteristic, but the image has a tighter dark portion. For this reason, the characteristics are applied to images captured in the landscape mode, the night scene mode, the slow synchro mode, and the macro mode (see “high contrast” in the gradation processing in Table 1).

The characteristics have substantially the same characteristics as the characteristics, but a predetermined input level V in the "medium" level region.
As described above, the γ coefficient is made negative. With this characteristic,
The gradation characteristic is inverted at a predetermined input level V or higher, and a solarized image is obtained. Therefore, the present invention is applied to a solarization mode.

Returning to FIG. 7, the image memory 209 is a memory for storing the pixel data output from the gamma correction circuit 208. The image memory 209 has a storage capacity for one frame. That is, the image memory 209 has a CCD
When the pixel 303 has n rows and m columns of pixels, it has a storage capacity for pixel data of n × m pixels, and as shown in FIG. 11, each pixel data G (i, j) (i = 1 , 2 ... n, 1,
,... M) are stored at corresponding pixel positions (i, j).

The VRAM 210 is a buffer memory for image data reproduced and displayed on the LCD display unit 10. VR
The AM 210 has a storage capacity for image data corresponding to the number of pixels of the LCD display unit 10.

In the photographing standby state, each pixel data of the image picked up by the image pickup unit 3 every 1/30 (second) is A
After being subjected to predetermined signal processing by the / D converters 205 to γ correction circuit 208, the signals are stored in the image memory 209, transferred to the VRAM 210 via the main body control unit 201, and displayed on the LCD display unit 10. . Thus, the photographer can visually recognize the subject image from the image displayed on the LCD display unit 10. In the playback mode, after the image read from the memory card 18 is subjected to predetermined signal processing by the main body control unit 201, the VRAM 21
0 and is reproduced and displayed on the LCD display unit 10.

The switch group 211 includes an UP switch 6, a D
OWN switch 7, erase switch 8, FL mode setting switch 11, compression ratio setting switch 12, recording / playback mode setting switch 14, and shooting mode setting switch 16
Is a switch corresponding to.

The card I / F 212 is a memory card 18
An interface for writing image data into and reading image data from the memory. Also, communication I / F
Reference numeral 213 denotes an interface compliant with, for example, the RS-232C standard for externally connecting the personal computer 19 in a communicable manner.

The FL control circuit 214 is a circuit for controlling light emission of the flash 5. The FL control circuit 214 controls the light emission of the flash 5, the light emission amount, the light emission timing, and the like based on the control signal of the main body control unit 201, and emits the light of the flash 5 based on the light emission stop signal STP input from the dimming circuit 304. Control the amount.

The main body control section 201 is composed of a microcomputer, and controls the driving of each member in the image pickup section 3 and the camera main body section 2 in an organic manner so as to control the photographing operation of the digital camera 1 overall. is there.

Further, the main body control section 201 includes a luminance determination section 21 for setting an exposure control value (shutter speed).
5 and a shutter speed (SS) setting unit 216. In the photographing standby state, the luminance determination unit 215
The brightness of the subject is determined by using an image captured by the CD 303 every 1/30 (second). That is, the brightness determination unit 215 determines the brightness of the subject using the image data that is renewedly stored in the image memory 209.

As shown in FIG. 11, the luminance determining section 215 stores the storage area of the image memory 209 in nine blocks B
(1), B (2),... B (9), and each block B (r) (r =
The luminance data BV (r) representing each block B (r) is calculated using the pixel data G _G (k, h) of the G (green) color component included in 1, 2,... 9).

The shutter speed setting section 216 sets the shutter speed Tv (the integration time of the CCD 303) based on the result of the brightness determination of the subject by the brightness determination section 215. The shutter speed setting unit 216
It has a table in which a plurality of shutter speeds Tv are set in advance.

The shutter speed Tv is initially set to a predetermined value (for example, 1/128 (second)) when the camera is started.
In the shooting standby state, the shutter speed setting unit 216
Changes from the initial value to the high-speed side or the low-speed side one step at a time in accordance with the determination result of the brightness of the subject by the luminance determination unit 215.

As a result, when the brightness of the subject determined based on the image captured at the shutter speed Tv of 1/128 (second) is too bright, for example, the shutter speed is increased by one step to the next speed. Is taken, and the brightness of the subject is determined again based on this image. And, if this determination result is still too bright, for example,
The shutter speed Tv is further increased by one step to capture the next image, and thereafter, after an elapse of a certain time period in which the subject brightness determination and the resetting of the shutter speed Tv are alternately repeated, an appropriate shutter speed Tv is obtained. Is set.

The main body control section 201 includes a frequency processing section 217 for performing a predetermined frequency processing on the photographed image in accordance with the photographing mode set by the photographing mode setting switch 16 and a saturation processing section for performing a predetermined saturation processing. 218. The frequency processing unit 217 changes the frequency characteristic of the captured image using a digital filter to correct the image quality.
This correction process performs a process corresponding to the “edge enhancement process” in Table 1 according to the set shooting mode.

FIG. 8 is a block diagram showing an embodiment of the circuit configuration of the frequency processing section 217.

As shown in FIG.
Are the Y signal generation circuit 217A and the C signal generation circuit 217
B, an LPF circuit 217C, an HPF circuit 217D, a coring circuit 217E, adders 217F and 217G, and output circuits 217H and 217I.
The image signals of the G and B color components are represented by a luminance signal Y and a chroma signal C.
On the other hand, the luminance signal Y is subjected to predetermined frequency processing, which will be described later, to generate two types of luminance signals Y1 and Y2.
A first image signal composed of the luminance signal Y1 and the chroma signal C and a second image signal composed of the luminance signal Y2 and the chroma signal C are output.

The first signal comprising the luminance signal Y1 and the chroma signal C
Is an image signal in which the high frequency component of the captured image is increased to emphasize the edge portion. In the present embodiment, the HPF
By changing the filter characteristic of the 217D, edge enhancement can be performed in two stages of "standard edge enhancement" and "strong edge enhancement". When the standard mode, the sunset mode, the gray scale mode, the sepia mode, and the solarization mode are set, the first image signal subjected to the standard edge enhancement processing is output from the frequency processing unit 217, When the shooting mode of the landscape mode and the macro mode is set, the frequency processing unit 217 outputs a first image signal on which a stronger edge enhancement process has been performed. In the landscape mode and the macro mode, strong edge enhancement is used to emphasize the outline of the image in a landscape photo, so that the image feels sweet, so that the outline is emphasized and a clear image is obtained. The details of the main subject are expressed as clearly as possible.

On the other hand, the second image signal composed of the luminance signal Y2 and the chroma signal C is obtained by removing noise components contained in the high-frequency components of the captured image. When the photographing modes of the portrait mode, the night scene mode, and the slow sync mode are set, the frequency processing unit 217 outputs the second image signal on which the noise removal processing has been performed. In portrait mode, the captured image (portrait photo)
In order to achieve smooth image quality of human skin with soft focus, normal edge enhancement is not performed and high-frequency noise components are removed so that the outline portion is softly expressed. In the night scene mode and the slow synchro mode, dark noise increases as the charge integration time of the CCD 301 increases, so that noise removal processing is performed as a measure to reduce dark noise.

The Y signal generation circuit 217A is a circuit for generating a luminance signal Y from image signals of R, G, B color components, and the C signal generation circuit 217B is a circuit for generating an image signal of R, G, B color components. Is a circuit for generating a color signal C. The Y signal generation circuit 217A adds and synthesizes the respective color components of R, G, and B at a predetermined ratio, and outputs a luminance signal Y (= KrＲR + Kg ・ G + Kb).
B, Kr, Kg, and Kb are coefficients). The C signal generation circuit 217B calculates the luminance signal Y using each of the R, G, and B color components, and calculates the luminance signals Y and R,
The color difference signals (RY) and (BY) for each color component of B are calculated, and these color difference signals (RY) and (BY) are output as a color signal C.

The luminance signal Y output from the Y signal generation circuit 217A is input to the LPF circuit 217C, the HPF 217D and the adder 217G, and the color signal C output from the C signal generation circuit 217B is output from the output circuits 217H and 217I.
Is input to

The LPF circuit 217C is a digital low-pass filter for extracting a low frequency component of a luminance signal.
H217D is a digital high-pass filter that extracts a high-frequency component of a luminance signal. The LPF circuit 217C is a digital low-pass filter having the filter coefficients shown in FIG. 12, for example, and the HPF circuit 217D is a digital high-pass filter having two types of filter coefficients for standard edge processing and strong edge processing. . The filter coefficients for stronger edge processing are, for example, as shown in FIG.

Further, the coring circuit 217E is a HFP
This is a circuit that removes a component having a predetermined level or less from the high-frequency components of the luminance signal Y extracted by the circuit 217D. That is, the circuit removes a noise component included in the high-frequency component by removing a certain low-level component from the high-frequency component. Coring circuit 21
7E has the level conversion characteristic shown in FIG. 14, and converts the level V of the luminance signal Y input from the HPF circuit 217D with the level conversion characteristic and outputs the result. As is clear from FIG. 14, since the levels of all the luminance signals Y of −V2 ≦ V ≦ + V1 become “0”, the coring circuit 217E
Outputs a high-frequency component from which noise components in this level range have been removed.

The low frequency component of the luminance signal Y output from the LPF circuit 217C is input to the adder 217G,
The high frequency component of the luminance signal Y output from the F circuit 217D is input to the coring circuit 217E and the adder 217F. The high-frequency component of the luminance signal Y after the coring process output from the coring circuit 217E is input to the adder 217G.

In the adder 217F, the luminance signal Y and the high-frequency component of the luminance signal Y are added and mixed to generate a luminance signal Y1, and this luminance signal Y1 is input to the output circuit 217I. Since the luminance signal Y1 is mixed with a high-frequency component in the original captured image to increase the high-frequency component of the image, the output circuit 217I outputs an image signal in which an edge portion is emphasized. The adder 217G adds and mixes the low-frequency component of the luminance signal Y and the high-frequency component subjected to the coring process to generate a luminance signal Y2.
Is input to the output circuit 217H. The luminance signal Y2 reduces the high frequency component of the image by mixing the low frequency component of the original captured image and the high frequency component from which the noise component has been removed,
Since high-frequency noise has been removed, the output circuit 217H outputs a soft and smooth tone image signal.

The output of the image signals from the output circuits 217H and 217I is controlled by the photographing mode setting signal set by the photographing mode setting switch 16, and is controlled by the selector controlled by the photographing mode setting signal at the subsequent stage of the output circuit. An image signal is output from one of the output circuits 217H and 217I. That is, when the shooting mode of the portrait mode, the night view mode, and the slow synchro mode is set, an image signal of a soft and smooth tone is output from the output circuit 217H, and if any other shooting mode is set, The output circuit 217I outputs an image signal whose edges are emphasized (see Table 1).

The saturation processing section 218 uses the image signals of each of the R, G, and B color components stored in the image memory 209 and the luminance signal Y output from the frequency processing section 217 in accordance with the shooting mode. It performs predetermined processing relating to colors, such as saturation enhancement, hue rotation, and monochrome processing. This processing corresponds to the “saturation processing” in Table 1.

The saturation processing section 218 includes a frequency processing section 217
Using the color difference signals (RY) and (BY) output from the CPU, arithmetic processing such as saturation enhancement, hue rotation, and monochrome processing is performed by the following arithmetic expression (1).

[0086]

(Equation 1)

In the above equation (1), a to f are variables,
By adjusting these values, the color difference signal (R-
The saturation of (Y) ', (RY)' is adjusted. In Table 1, “normal emphasis” and “flashy emphasis” are (a, b,
The adjustment is performed by appropriately adjusting the variables c, d, e, and f). For example, increasing the value of a enhances red, and increasing the value of d enhances blue. In this case, the value of the correction term (e, f) is usually (0, 0).

Further, since the "saturation removal processing" in the gray scale mode is a processing for eliminating the tint,
(A, b, c, d, e, f) = (0, 0, 0, 0, 0,
This is performed by calculating equation (1) as 0). The “fixed value processing” in the sepia mode is processing for fixing the hue of the captured image to a predetermined hue of sepia or reddish brown, so (a, b, c, d, e, f) =
This is performed by calculating equation (1) as (0, 0, 0, 0, E, F). At this time, (E, F) is set to a color difference signal (fixed value) corresponding to a previously set sepia color or reddish brown, and the color difference signal (RY) ′ = E by calculating equation (1). , (BY) ′ = F.

In the sunset mode, the main body control unit 201 displays a plurality of thumbnail images SG1 to SG9 (images of the image quality adjustment sample) having different WB adjustment degrees in a matrix on the LCD display unit 10, as shown in FIG. Thumbnail image creation unit 219 for creating the thumbnail images SG1 to SG9 and thumbnail image creation unit 219
And a preview image creation unit 220 that creates a display image (hereinafter, this image is referred to as a preview image) by arranging the plurality of thumbnail images SG1 to SG9 created in the above in a matrix.

The thumbnail image creation unit 219 has a level adjustment circuit and a WB adjustment circuit (not shown). When the sunset mode is set, image data is roughly sampled from the image memory 209 at a predetermined pixel pitch. In addition to creating a thumbnail image, the thumbnail image is subjected to predetermined level adjustment and WB adjustment to create a thumbnail image having a different color tone of the sunset image. In the present embodiment, nine different tones are prepared as the tone of the color of the sunset image, and the thumbnail image creation unit 219 roughly samples the image data nine times from the image memory 209 and performs thumbnail images SG1 to SG9. Are generated, and the thumbnail images SG1 to SG9 are subjected to level adjustment and WB adjustment processing shown in Table 2 below, and are sequentially output to the preview image creation unit 220.

When the photographer selects the adjustment values of the level adjustment and the WB adjustment of the photographed image to be recorded by the photographer, the thumbnail image creation unit 219 reads out all the image data from the image memory 209 and sets the image data. Level adjustment and WB adjustment are performed based on the adjusted values, and output to the frequency processing unit 217.

The preview image creating section 220 creates a preview image by sequentially transferring the thumbnail images SG1 to SG9 input from the thumbnail image creating section 219 to a predetermined storage area of the VRAM 210. That is, the thumbnail images SG1 to SG9 are sequentially arranged in the VRAM 210 such that an image in which the thumbnail images SG1 to SG9 are arranged in a predetermined matrix (in this embodiment, a 9 × 9 array) is created in the storage area of the VRAM 210.
The data is transferred to 210 and displayed on the LCD display unit 10.

[0093]

[Table 2]

In the WB adjustment, when R / G is made larger than 1.0, an image having a strong red tint is obtained. On the other hand, B / G
Is smaller than 1.0, an image having a strong yellow tint (an image having a weak blue tint) is obtained. Therefore, in Table 2, the thumbnail images SG1 and SG4 indicate sample images having a strong red tint, and the thumbnail images SG3 and SG6 indicate sample images having a strong yellow tint. Further, R / G is set to be larger than 1.0, and B /
If G is smaller than 1.0, the image becomes orangeish, so the thumbnail images SG2 and SG5 show sample images with strong orange color. Also, thumbnail images SG7, SG
Reference numeral 8 denotes a thumbnail image SG2 in which the overall brightness is suppressed, and thumbnail image SG9 denotes a thumbnail image SG5 in which the overall brightness is suppressed. Therefore,
In the thumbnail images SG7 to SG9, images are obtained that emphasize the orange sunset at dusk.

In the sunset mode, when a photograph is taken, first, a sample image of the sunset enhancement process based on the thumbnail images SG1 to SG9 shown in FIG. In FIG. 15, the double line display of the thumbnail image SG1 indicates that the thumbnail image SG1 is initially selected as the adjustment value of the WB adjustment and the level adjustment. The photographer confirms the finish of the image with this sample image, and operates the UP switch 6 and the DOWN switch 7 to display the thumbnail images SG1 to SG1 displayed on the LCD display unit 10.
When one of SG9 is selected, the adjustment values of the WB adjustment and the level adjustment of the captured image to be recorded on the memory card 18 are set. Each time the UP switch 6 and the DOWN switch 7 are operated, the selection display (double line display) moves sequentially from the thumbnail image SG1 in ascending or descending order.
By simultaneously operating the P switch 6 and the DOWN switch 7, the selection of the selected and displayed thumbnail image is determined.

When the adjustment values for the WB adjustment and the level adjustment are set, all the image data of the photographed image is read out from the image memory 209 to the thumbnail image creation unit 219, and
After the WB adjustment and the level adjustment are performed with the set adjustment values, the output is output to the frequency processing unit 217.

In the present embodiment, in order to make the sample images easy to see, sample images are created with thumbnail images, and these thumbnail images are collectively displayed on the LCD display 10 in a matrix. To make it easier to see the thumbnail images, the size of the thumbnail images may be increased, and the thumbnail images may be divided into a plurality of images and displayed in a matrix.
You may make it display on the D display part 10.

Further, the main body control unit 201 includes a recording image generation unit 221 for generating a compressed image for image recording when recording a photographed image and an image recorded on the memory card 18 as an LC.
A reproduction image generation unit 222 that generates a reproduction image is provided for reproduction on the D display unit 10.

In the recording mode, when the photographing is instructed by the shutter button 9 in the recording mode, the main body control unit 201 performs predetermined image processing on the image data taken into the image memory 209 after the photographing instruction, and then performs the image recording. Information about the captured image (frame number, exposure value, shutter speed, compression ratio K, etc.)
Together with the data on the memory card 18.

[0100] The recording image generation unit 221 includes the frequency processing unit 2
17 and a JPEG image such as two-dimensional DCT transform, Huffman coding, etc.
(Joint Photographic Coding Experts Group) performs predetermined compression processing to generate image data of a compressed image having a compression ratio K set by the compression ratio setting switch 12,
This image data is recorded on the memory card 18.

The reproduction image generation section 222 reads out image data from the memory card 18 and
Then, a captured image to be reproduced and displayed is generated. Memory card 1
The image recorded in 8 is the γ coefficient for monitoring (= 0.55)
The recorded image is directly converted to LC
When the image is reproduced on the D display unit 10, the contrast becomes strong due to the mismatch between the γ coefficient and the γ coefficient for LCD display (= 0.45).
Re-corrects the γ characteristic of the reproduced image when generating an image for reproducing the recorded image. That is, the reproduced image generation unit 222
Expands the image data of the compressed image read from the memory card 18 to generate image data for display, performs γ correction on the image data with a γ characteristic of γ = 0.82,
The data is sequentially transferred to the VRAM 210 and the recorded image is reproduced and displayed on the LCD display unit 10.

Next, shooting control in the recording mode of the digital camera 1 will be described. First, regarding shooting control when a shooting mode other than the sunset mode is set,
This will be described with reference to the flowcharts shown in FIGS.

The photographing control mainly comprises viewfinder processing, exposure control and image processing. The viewfinder process is a process of displaying a subject image on the LCD display unit 10 so that the photographed content can be visually recognized. In the viewfinder processing, a suitable adjustment of the shutter speed is also performed.

When the recording mode is set by the recording / reproduction mode setting mode 14, the control unit 204 determines the shooting mode set by the shooting mode setting switch 16, and determines various parameters of image processing corresponding to the shooting mode. Is initially set in the corresponding processing unit. The parameters correspond to the above-described circuits of the AGC circuit 308b, the WB circuit 207 and the γ correction circuit 208, and the
And processing parameters required for each processing unit of the saturation processing unit 218.

Thereafter, first, the shutter speed Tv is set to the initial value (1/128 (second)) (# 2), and γ = 0.
After the γ characteristic (the characteristic in FIG. 10) of 45 is set (#
4) Exposure by the CCD 303 is started (# 6).
When a predetermined exposure time (Tv = 1/128 (second)) has elapsed (YES in # 8), the image signal captured by the CCD 303 is read out (# 10), and the signal processing circuit 30
8. After predetermined image processing is performed by the A / D converters 205 to γ correction circuit 208 (# 12), the image memory 20
9 (# 14). The image data stored in the image memory 209 is immediately read out to the VRAM 210 and displayed on the LCD display unit 10 as a monitor (# 16).

Subsequently, the brightness data of the captured image is calculated (# 18), and it is determined whether or not the shutter speed Tv is appropriate based on the brightness data (# 20). The luminance data is obtained by dividing the captured image into nine blocks B (1) to B (9) (see FIG. 11), and each block B (i) (i = 1, 2,...).
For each 9), the average value BV (i) of the pixel data of the G (green) color component included in the block B (i) is calculated. Then, is the nine brightness data BV (1) to BV (9) a too bright overall imaging image compared respectively with thresholds BV _L threshold BV _H and a low level of a predetermined high level (overexposed ), Whether the captured image is too dark (underexposure) as a whole, or appropriate.

If the captured image as a whole is too bright or too dark, it is determined that the shutter speed Tv is inappropriate (NO in # 20), and the shutter speed Tv is changed in accordance with the brightness of the captured image. (# 22) Then, the process returns to step # 6 to determine whether the shutter speed Tv is appropriate. That is, when the captured image is entirely too bright (overexposure), the shutter speed Tv is changed to a value smaller by one step, and when the captured image is entirely too dark (underexposure), the shutter speed Tv is changed. Tv is changed to a value one step higher, and the process returns to step # 6.

Then, the loop of steps # 6 to # 22 is repeated, and when the shutter speed Tv is set to an appropriate value (YES in # 20), subsequently, it is determined whether or not the photographing mode has been changed during this time. If it is determined (# 24) that the shooting mode has been changed (YES in # 24), various parameters of image processing corresponding to the changed shooting mode are changed and set to the corresponding processing unit (# 26). On the other hand, if the shooting mode has not been changed (NO in # 22), step # 24 is skipped.

Subsequently, it is determined whether the shutter button 9 has been pressed and the release switch has been turned on (# 2).
8) If the release switch is not turned on (#
(NO at 28), the process returns to step # 2, and enters the release standby state (loop of # 6 to # 28).

Since the CCD 303 captures a frame image every 1/30 (second), the processes of steps # 6 to # 28 are performed for each frame image, and the shutter speed Tv is increased by one stage from the initial value. Alternatively, the shutter speed Tv is adjusted at the same time as the viewfinder processing. When the shutter speed Tv is renewed to a large value by the loop process of steps # 6 to # 28 and exceeds 1/30 (second), the process proceeds to step #.
The shutter speed Tv at 22 is fixed at 1/30 (second), and the gain of the AGC circuit 308 b in the signal processing circuit 308 is adjusted. However, if the shooting mode is set to the night view mode or the slow synchro mode, the AG
The gain adjustment of the C circuit 308b is prohibited.

In a release standby state, when the shutter button 9 is pressed and the release switch is turned on (# 2)
After a predetermined shutter speed Tv is set (# 30), exposure control is performed (# 32, # 3).
4). When a predetermined exposure time Tv has elapsed and the exposure is completed (YES in # 34), an image signal is read from the CCD 303 (# 36), and the signal processing circuit 308, A / A
D converter 205 to γ correction circuit 208, frequency processing unit 21
7 and predetermined image processing according to the shooting mode set by the saturation processing unit 218 (# 38).

Here, the predetermined image processing corresponding to the shooting mode is an image processing corresponding to the shooting mode shown in Table 1 above. Characteristic image processing in each shooting mode is as follows.

(1) Standard Mode Since the standard mode is a mode for finishing a captured image to a standard image quality, each process is performed with standard values. In other shooting modes, the strength of the processing content is set relatively based on the processing in the standard mode.

(2) Portrait mode The portrait mode is a mode in which a portrait photograph of a person is mainly created, and a photographed image is mainly required to have an image quality such that the main character looks soft and beautiful.
As compared with the standard mode, edge enhancement by frequency processing and gradation correction by gamma correction are different. In portrait mode, the gamma correction is performed with weak gamma characteristics so that the texture of human hair is not impaired, and the low-frequency component of the captured image and the high-frequency component from which noise has been removed are added and mixed. By changing the frequency characteristics so as to make the skin part of the person soft and smooth.

(3) Landscape Mode The landscape mode is a mode for mainly creating a landscape photograph, and since the subject is far away, the image is focused at infinity. Also, since the sharpness of the distant view image is relatively reduced due to the resolution of the CCD 301, image processing is performed so that the image quality becomes clearer than in the standard mode. In landscape mode, γ correction is performed using the γ characteristic with high contrast, and the high frequency component of the captured image is added to the original captured image to change the frequency characteristic so that the high frequency component is emphasized. And finished to be clear. In addition, the vividness of the colors of the landscape photograph can be enhanced by emphasizing the color saturation.

(4) Night view mode The night view mode is a mode for mainly photographing a night scene or a person with a night scene as a background.
A shooting scene with a low subject brightness is set as a shooting target. In such a shooting scene, the dark area occupies a large proportion in the shadow screen, and in the night view mode, the flash emission is prohibited so as not to impair the atmosphere of the night view, so the contrast in the dark part is crushed and it feels full The image quality tends to be remarkably reduced in dark portions. Therefore, in the night scene mode, while performing the γ correction with the γ characteristic having a strong contrast, the contrast in the dark portion is utilized, and the frequency characteristic is added and mixed with the low frequency component of the photographed image and the high frequency component from which noise has been removed. , The high-frequency component of the dark noise is removed, and the deterioration of the image quality in the dark part is suppressed. In addition, sharpness of the night view photograph can be enhanced by emphasizing the saturation vividly.

(5) Slow Synchro Mode The slow synchro mode is a mode in which a slow shutter is set to perform flash photography, and differs from the night view mode only in the presence or absence of flash emission. Therefore, in the image processing, the same processing as in the case of the night scene mode is performed.

(6) Macro Mode The macro mode is a mode for taking a close-up shot of a main subject such as a flower or an insect. In the macro mode, it is desired that the photographed image be sharp and clear so that the main subject is expressed lively. Since such an image quality request is similar to the image quality request in the landscape mode, the same image processing as in the landscape mode is performed in the macro mode except for the saturation processing. In the macro mode, if the saturation is excessively emphasized, the color of the main subject becomes rather unnatural, so that the normal enhancement processing is performed in the saturation processing.

(7) Gray Scale Mode The gray scale mode is a mode for expressing a color image in monochrome. For this reason, in the gray scale mode, the same image processing as in the standard mode is performed except that the color components of the captured image are removed by the saturation processing.

(8) Sepia Mode The sepia mode is a mode in which the color of a photographed image is adjusted to a specific color of sepia or reddish brown. The grayscale mode is similar to the grayscale mode in that the color of the color image is changed. The sepia mode differs from the grayscale mode in that the color of the captured image is adjusted to a specific color of sepia or reddish brown by saturation processing.

(9) Solarization Mode The solarization mode is a mode for changing a photographed image to a solarized image. Since the solarization image is a special effect image using the inversion characteristic in the high level region of the γ characteristic, the same image processing as in the standard mode is performed except for the gradation adjustment.

In the above-described embodiment, the edge enhancement is stronger in the landscape mode and the macro mode than in the standard mode. However, in these modes, the standard edge enhancement similar to that in the standard mode is performed. You may make it simple.

Returning to FIG. 17, when predetermined image processing is performed in step # 38, predetermined image data for recording is generated by the recording image generation unit 221 (# 40), and this image data is stored in the memory card 18. The transferred image is recorded (# 42). Then, the photographing operation is completed by recording the image data on the memory card 18, and the process returns to step # 2 to perform the next photographing.

Next, photographing control when the photographing mode of the sunset mode is set will be described with reference to the flowchart shown in FIG.

The sunset mode is a shooting mode for shooting a sunset scene. In the sunset mode, a reddish white balance is adjusted, and a saturation adjustment is performed so as to emphasize a red-based hue, thereby creating an atmosphere of a sunset. The sunset mode is different from the other shooting modes in that a WB adjustment value that can obtain the image quality imaged by the photographer can be selected from an image sample processed with a plurality of WB adjustment values.

Therefore, in the sunset mode, FIGS.
In the flowchart of FIG.
Are performed in place of the processing of steps # 38-1 to # 38-11 shown in FIG. Therefore, in the following description, FIG.
Only the processing shown in FIG.

In the sunset mode, photographing is performed by the CCD 303, and when an image signal is read out from the CCD 303 (# 36), the image signal is subjected to predetermined noise reduction processing and level adjustment processing by the signal processing unit 308. After that, it is input to the camera body 2. The image signal input to the camera body 2 is subjected to pre-image processing by the A / D converters 205 to γ correction circuit 208, and then the image memory 20
9 (# 38-1, # 38-2). That is,
The image signal is converted into a digital signal by an A / D converter, the black level is adjusted by a black level correction circuit 206, and a standard WB set in advance by a WB circuit 207.
White balance adjustment is performed using adjustment values (for example, R / G = 1 and B / G = 1). Further, the image data is temporarily stored in the image memory 209 after the γ correction is performed by the γ correction circuit 208 using standard γ characteristics (see FIG. 10).

Subsequently, the image data is roughly sampled from the image memory 209 to create a thumbnail image. Color adjustment is performed using the WB adjustment value and the level adjustment value of 1 to generate a thumbnail image GS1 as an image quality sample (# 38-3). This thumbnail image GS1 is transferred to a predetermined storage area of the VRAM 210 to create a preview image for an image quality sample (# 38-4).

Subsequently, it is determined whether the creation of the preview image has been completed (# 38-5). This time, only the first thumbnail image SG1 was created (# 38-
(NO at 5), returning to step # 38-3 to create the second thumbnail image SG2. And No. 9
Is created, and when this thumbnail image SG9 is transferred to the VRAM 210 (# 38)
-5, YES), the creation of the preview image ends, and LC
A preview image is displayed on the D display unit 10 (# 38)
-6, see FIG. 15).

Subsequently, the photographer selects a desired thumbnail image S from the preview image displayed on the LCD display section 10.
When the selection of Gi (i = 1, 2,... 9) is confirmed (# 38-
7) All the image data is read from the image memory 209 (# 38-8), and the WB is adjusted with the same adjustment values as the WB adjustment and the level adjustment performed on the selected thumbnail image SGi.
Adjustment and level adjustment are performed (# 38-9). For example, no. If one thumbnail image SG1 is selected,
The white balance of the image data is readjusted so that R / G = m1 and B / G = 1 (that is, to enhance the red tint).

Subsequently, the image data after the WB readjustment is subjected to standard edge enhancement processing by frequency processing and to red-based color enhancement by saturation adjustment processing (# 38-10, # 38-10). 38-11), compression processing is performed and recorded on the memory card 18 (# 40, # 42).

As described above, in the sunset mode,
Sample images with different atmospheres of the sunset scene are created with a plurality of WB adjustment values, displayed in a matrix on the LCD display unit 10, and the photographer selects a desired sample image from these sample images to final record. Since the WB adjustment value of the photographed image can be determined, a sunset photograph imaged by the photographer can be obtained.

In the above embodiment, the photographed image after the γ correction is temporarily stored in the image memory 209. However, in FIG. The WB circuit 207 may be arranged at a stage subsequent to the level correction circuit 206 and perform WB adjustment of each sample image and WB adjustment of a captured image for recording in the sunset mode. In this case, the thumbnail image creation unit 219 and the preview image creation unit 220 in the main body control unit 201 can be omitted, and the main body control unit 201
09, the image data is read from the WB circuit 207 and γ
By controlling the image processing of the correction circuit 208 and the transfer of the image data from the γ correction circuit 208 to the VRAM 210, the thumbnail image creation and the preview image LCD are controlled.
Display on the display unit 10 is performed.

Further, in the above embodiment, the digital camera 1 which enables a plurality of photographing modes to be selectively set and performs image processing corresponding to the photographing mode selected for the photographed image, in the sunset mode As described above, in a mode in which the sunset scene to be imaged by the photographer is different, a plurality of image quality adjustment values are prepared, and the photographer selects a desired adjustment value from among them, but as a simpler configuration. Even when a plurality of shooting modes are not selectable, a plurality of image quality adjustment values may be prepared so that the photographer can select the image quality adjustment values.

For example, when a plurality of γ characteristics of the γ correction circuit 208 are prepared and a photograph is taken, a plurality of thumbnail images having different γ corrections (that is, a plurality of thumbnail images having different contrast adjustments) are displayed on the LCD display section 10. When a desired gamma characteristic is selected from these sample images by a matrix display and the photographer selects a desired gamma characteristic, the photographed image may be gamma-corrected with the gamma characteristic and recorded on the memory card 18. In this method, a plurality of sample images having different contrasts from the captured image are displayed, and the photographer can select a desired contrast from the sample images.

Based on the same concept, a plurality of finishing conditions of the edge emphasizing process and the noise removing process in the frequency processing unit 217 and a plurality of finishing conditions of the chroma emphasis and the color rotation in the chroma adjusting unit 218 are prepared, and photographing is performed. Then, a plurality of sample images having different finishing conditions of the frequency adjustment and the saturation adjustment are displayed in a matrix on the LCD display unit 10 so that a photographer can select a desired frequency adjustment value and a saturation adjustment value from these sample images. It may be.

In the case where the photographer can select the image quality without providing the photographing mode, a mode in which the photographer can select the image quality and a mode in which the photographer cannot select the image quality can be set in consideration of the operability of the camera. Only when the image quality selectable mode is set, the display of the sample image with the above image quality and the selection of the sample image may be enabled.

[0138]

As described above, according to the present invention,
A plurality of image quality sample images are created by performing image processing with a plurality of different characteristic values based on the photographed image, and the image quality sample images are displayed on a table so that a photographer can select a desired image quality sample image. At the same time, when the image quality sample image is selected, the photographed image is subjected to image processing with the same characteristic values as the image quality sample image, so that a photographed image of the image quality imaged by the photographer can be obtained.

Further, a predetermined photographing mode can be selectively set. When the photographing mode is set, a plurality of image quality sample images are created from the photographed images, and the image quality sample images are displayed. Can select a desired image quality sample image. For example, a shooting mode in which suitable image processing is performed according to a shooting target or a shooting purpose such as a landscape photograph, a portrait photograph, or a sunset photograph can be selected. In this case, the image quality image of the photographer can be reflected in the characteristic image processing (for example, processing such as contrast and saturation enhancement) of the shooting mode, and a shot image with more favorable image quality in the shooting mode can be obtained. be able to.

In particular, the sunset mode can be set, and when photographing is performed in this photographing mode, the image quality sample image can be monitored to set a desired white balance adjustment value. Sunset images can be easily obtained.

[Brief description of the drawings]

FIG. 1 is a front view of a digital camera according to the present invention.

FIG. 2 is a rear view of the digital camera according to the present invention.

FIG. 3 is a top view of the digital camera according to the present invention.

FIG. 4 is a bottom view of the digital camera according to the present invention.

FIG. 5 is a diagram showing a schematic structure in an imaging unit.

FIG. 6 is a front view showing a state in which a lid of a power battery and a memory card are opened.

FIG. 7 is a block diagram of a digital camera according to the present invention.

FIG. 8 is a block diagram illustrating a circuit configuration of a frequency processing unit.

FIG. 9 is a diagram illustrating characteristics of a level conversion table.

FIG. 10 is a diagram illustrating γ characteristics of a γ correction table.

FIG. 11 is a diagram showing a storage position of each pixel data in an image memory.

FIG. 12 is a diagram illustrating an embodiment of a digital low-pass filter.

FIG. 13 is a diagram illustrating an embodiment of a digital high-pass filter.

FIG. 14 is a diagram showing level conversion characteristics in coring processing.

FIG. 15 is a diagram showing one embodiment of a plurality of thumbnail images displayed in a matrix on the LCD display unit.

FIG. 16 is a flowchart illustrating shooting control in a recording mode.

FIG. 17 is a flowchart illustrating shooting control in a recording mode.

FIG. 18 is a flowchart illustrating shooting control unique to the sunset mode.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Digital camera 2 Camera main body 201 Main body control part (display control means) 202 Reference clock generation circuit 203 Timing control circuit 204 RTC 205 A / D converter 206 Black level correction circuit 207 WB circuit 208 γ correction circuit 209 Image memory (No. 1 storage means) 210 VRAM 211 switch group 212 card I / F 213 communication I / F 214 FL control circuit 215 brightness determination unit 216 shutter speed setting unit 217 frequency processing unit 218 saturation processing unit 219 thumbnail image creation unit (sample) Image creating means, image processing means) 220 preview image creating section 221 recorded image generating section 222 reproduced image generating section 3 imaging section 301 macro zoom lens 302 imaging circuit 303 CCD area sensor (imaging means) 304 dimming circuit 305 dimming sensor 308 Signal processing circuit 309 Timing generator 310 Switch group 4 Grip unit 5 Flash 6 UP switch (image selection unit) 7 DOWN switch (image selection unit) 8 Erase switch 9 Shutter button 10 LCD display unit (display unit) 11 FL mode setting switch 12 compression ratio setting switch 13 connection terminal 14 recording / playback mode setting switch 15 lid 16 shooting mode setting switch 17 main switch 18 memory card (second storage means)

Claims (3)

[Claims] An imaging unit that photoelectrically converts a subject light image into an image signal and captures the image signal; a display unit that displays an image; a first storage unit that temporarily stores the image signal captured by the imaging unit; Sample image reading means for reading the image signal from the first storage means, performing image processing with each of a plurality of preset characteristic values, and creating a plurality of image quality sample images having different image qualities; Display control means for displaying the plurality of image quality sample images created by the creating means on the display means, and selecting one of the image quality sample images from the plurality of image quality sample images displayed on the display means Image selection means, image processing means for reading the image signal from the first storage means, and performing image processing with the same characteristic values as the image quality sample image selected by the image selection means; A second storage unit for storing an image signal subjected to image processing. 2. A digital camera according to claim 1, wherein a predetermined photographing mode set in advance can be set, and when the photographing mode is set, the sample image forming means, the display control means, and the image processing means can be set. A digital camera that enables processing by each means. 3. The digital camera according to claim 2, wherein the shooting mode is a sunset mode for shooting a sunset scene, and the image processing performed by the sample image creating means is a white balance adjustment process. Digital camera.