JPH07107505A - Image pickup device - Google Patents

Abstract

(57) [Summary] [Object] To provide an imaging device capable of maintaining various functions provided in the device main body in good condition. The electric signal photoelectrically converted by the image sensor 2 is converted into a video signal by a video signal processing circuit 3, and the video signal is output as a video and stored in a frame memory 4. Then, the in-plane position input circuit 5 specifies the position coordinates on the screen, and then the specified position hue calculation circuit 6 obtains the hue at the specified position. Further, the hue calculation circuit 7 obtains the hue of the peripheral portion of the designated position, and then the image area extraction circuit 8 extracts the specific image area based on the hue of the designated position and the hue of the peripheral portion, and the image control circuit 9 Thus, desired image control is executed for the specific image area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus, and more particularly, to an image pickup apparatus for extracting a subject in a television or a video camera and performing image processing using the extracted image.

[0002]

2. Description of the Related Art Conventionally, functions such as automatic focusing (AF), automatic exposure (AE), automatic white balance (AWF), and automatic image stabilization (AS) in an image pickup device such as a video camera are preset in the camera. Processing was performed using the positional information on the screen.

[0003]

Therefore, in the conventional image pickup apparatus, when the main subject does not exist at the position within the screen set in advance in the camera, for example, when the main subject is set at the edge of the screen, etc. There is a problem in that the above-mentioned functions may not be fully exhibited.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an imaging device capable of maintaining various functions of the device in a good state.

[0005]

In order to achieve the above object, the present invention provides an image pickup apparatus which extracts a subject through a photoelectric conversion element and performs image processing on the extracted subject image. An in-plane position input section for designating position coordinates on the screen to be projected, a designated position color signal computing section for computing a color signal at an in-plane position designated by the in-plane position input section, and the in-plane location in the image A color signal calculation unit that calculates a color signal in a predetermined range wider than the position; and an image region extraction unit that extracts a specific region in the screen based on the calculation results of the color signal calculation unit and the designated position color signal calculation unit. And an image control unit for performing image control on the image region extracted by the image region extraction unit.

[0006] Specifically, the in-plane position input unit has an in-plane position setting means that allows a photographer to set the in-plane position during or before photographing.

Further, the designated position color signal calculating section is characterized in that it has conversion means for converting the color signal at the in-plane position into another color signal or color system data.

Further, the color signal calculation section has a conversion means for converting a color signal of the peripheral predetermined portion of the in-plane position or the entire screen into another color signal or color system data. There is.

The image area extracting section extracts information which is the same as the color signal calculated based on the designated position color signal calculating section and the color signal calculating section or information which satisfies a specific condition. It is characterized by having.

Further, it is characterized in that it has a storage section for storing the image area information extracted by the image area extracting section.

[0011]

According to the above construction, the specific image area arbitrarily set in the image obtained by picking up the image, that is, the main subject is detected and the control is performed based on that, so that it is set in advance in the camera. Unlike the case where the control is performed using the information in the position on the screen, it is possible to exert the functions such as automatic focusing, automatic exposure, automatic white balance, and automatic image stabilization in a stable state. .

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a block diagram of a video camera as an embodiment of an image pickup apparatus according to the present invention.

In the figure, reference numeral 1 denotes a zoom lens as an image pickup lens. An optical image of a subject transmitted through the zoom lens 1 is converted into an electric signal by an image sensor 2 (end plate type) as a photoelectric conversion element. Video signal processing circuit 3
Entered in. Then, in the video signal processing circuit 3, the electric signal from the image sensor 2 is converted into, for example, NTSC, E
It is converted into a video signal such as IA, CCIR, PAL and the like, and at the same time, processing such as gamma correction and edge enhancement is performed. Then, the video signal from the video signal processing circuit 3 is output as it is to the video signal and stored in the frame memory 4.

Next, the video signal stored in the frame memory 4 is input to the in-plane position input circuit 5, and the photographer inputs the main subject to be controlled on the screen while looking at the viewfinder and monitor. That is, for example, as shown in FIG. 2A, a square frame 10 indicated by hatching is displayed on the monitor, the main subject 11 intended by the photographer and the frame 10 are aligned, and a button is pressed when they match. Then, the main subject 11 to be controlled is input. Note that the display on the monitor is not limited to the rectangular frame 10 as shown in FIG. 2A, and the crossing points of the cross lines 12 as shown in FIG. 2B may be used. Alternatively, it is possible to use a line-of-sight detection sensor (not shown).

Next, the output signals of the in-plane position input circuit 5 and the frame memory 4 are input to the designated position hue calculation circuit 6. Then, the designated position hue calculation circuit 6 calculates the hue at the coordinate position (designated position) from the image information of the frame memory 4 corresponding to the coordinate position of the control target input from the in-plane position input circuit 5. In the present embodiment, the hue calculation is performed by converting from NTSC-RGB to Munsell color system. The conversion to the Munsell color system is, for example, from NTSC-RGB to CIE-XY.
When converting to the Z color system, there are a method of converting to the Munsell color system, a method of converting to the Munsell color system using a lookup table, and the like. The NTSC-RGB signal, which is the converted signal for performing the hue calculation, is a rectangular frame designated by the in-plane position input circuit 5, one point such as a cross line, or each of R, G, and B of peripheral pixel signals. Any of the average value and the value obtained by calculation using the peripheral pixel signal may be used, but in the present embodiment, the average value of each of R, G and B of the peripheral pixel signal is used.

Next, the hue signal at the designated position calculated by the designated position hue calculation circuit 6 is input to the hue calculation circuit 7 and converted into an image based on the hue signal and the image information of the frame memory 4. Calculate the hue of the range.
That is, for example, using the Munsell color system, the range of the peripheral pixels of the portion designated by the in-plane position input circuit 5 such as the portion 13 surrounded by the dotted line in FIG. Is calculated. The conversion range may be the entire image.

Then, the image area extraction processing circuit 8 is based on the signal calculated by the specified position hue calculation circuit 6 and the information obtained by the hue calculation circuit 7 in the vicinity of the input coordinates designated by the in-plane position input circuit 5. Area having the same hue is extracted. For example, the designated position hue calculation circuit 6
Let H, V, C be the values obtained in step 1, and let Hi, Vi, Ci (i is the pixel number) be the data obtained by the hue calculation circuit 7,
The specific region is extracted using the value ΔH obtained by the mathematical expression (1).

ΔH = | Hi−H | (i = 0,1,2,3 ... n) (1) FIG. 4 shows an example in which the specific region is extracted using the mathematical expression (1). ing. The hue is used for the region extraction in order to make it less likely to be affected by the brightness and spatial frequency of the subject.

The extracted image area, that is, the main subject portion can be distinguished from other portions by the brightness in the case of a monochrome monitor, and in the case of a color monitor, as shown in FIG. It is possible to distinguish from other parts by color conversion, emphasis expression, and the like.

Finally, in the image control circuit 9, the AE (automatic exposure control), AWF (automatic white balance control), AF ( Automatic focus control), A
Various video cameras such as S (automatic image stabilization control) are controlled and fed back to the zoom lens 1 and the video signal processing circuit 3.

FIG. 6 is a block diagram showing a second embodiment of the present invention. In the second embodiment, the designated position color signal arithmetic circuit 14 receives other signals such as NTSC-RGB signals to be converted. Converted to color signals. Similar to the first embodiment, the converted signal is a rectangular frame designated by the in-plane position input circuit 5, one point such as a cross line, or R, G, and
It may be obtained by using the average value of each B or the peripheral pixel signal.

The color signal obtained by conversion here is YCrC.
g, CIE-L * a * b * color system, CIE-L * u *
New color signals can be created using colorimetric data such as v * colorimetric system, CIE-XYZ colorimetric system, CIE-xyY colorimetric system, and the like. For example, CI
When the E-L * a * b * color system is used, the color signals DH,
DV and DC are displayed as in equations (2) to (4).

[0024]

[Equation 1] Here, A, B, C are coefficients, L *, a *, b * are CIE
-L * a * b * The respective values of the color system are shown.

Further, in the second embodiment, the color signal arithmetic circuit 15 uses the same conversion method as that used in the conversion of the designated position color signal arithmetic circuit 14 to convert the set range of the image to be converted. Perform signal conversion.

In the next image area extraction processing circuit 16, the image area specified by the operation of the color signal obtained by the designated position color signal operation circuit 14 and the color signal in the range obtained by the color signal operation circuit 15 is set. Extract. For the calculation for extracting, for example, the value obtained by the designated position color signal calculation circuit 14 is DH,
DV, DC, data obtained by the color signal calculation circuit 15
If Hi, DVi, and DCi (i is a pixel number), the specific area is extracted using the value W obtained by the mathematical expression (5).

W = A · | DHi-DH | + B · | DVi-DV | + C · | DCi-DC | (i = 0,1,2,3 ... n) (5) where A and B , C are coefficients. The above equation (5)
Shows an example of an arithmetic expression used for extracting a specific area, and it is also possible to use another color signal. In addition, any method other than using the above equation (5) can be used as long as the specific area can be extracted.

FIG. 7 is a block diagram showing a third embodiment of the present invention. As shown in FIG. 8, the in-plane position input circuit 17 allows a photographer to view a finder or a monitor before photographing. However, the position is set in advance. In this setting method, as in the first embodiment, a rectangular frame shown by hatching can be displayed on the monitor and input can be made with buttons or the like, and the display on the monitor is not a rectangular frame but a crosshair. It is also possible to use intersecting points such as, or it is also possible to perform by visual line detection input.

Similar to the first and second embodiments, the signal to be converted is a rectangular frame designated by the in-plane position input circuit 17, one point such as a cross line, or R, G, B of peripheral pixel signals. Any of the average and those obtained by calculation using peripheral pixel signals may be used.

FIG. 9 is a block diagram showing the fourth embodiment of the present invention. The color signal arithmetic circuit 18 is the same as the color signal arithmetic circuit 15 shown in the second embodiment, but the conversion range is changed. Shows the case of the entire image. A color information input circuit 19 presets color information to be controlled. For example, color information perceived as a skin color is set.

In the fourth embodiment, the image area extraction processing circuit 20 uses the color signal of the entire screen obtained by the color information input circuit 19 and the color signal set by the color signal calculation circuit 18 to specify the color signal. Extract a region. When similar color signals are present in several blocks in the image, the specific region is discriminated based on a certain set condition, such as the area. still,
In the fourth embodiment, the color information input to the color information input circuit 19 is set to the skin color, but it goes without saying that any color can be used as the set color.

FIG. 10 is a block diagram showing the fifth embodiment of the present invention. In the color signal arithmetic circuit 21, a peripheral image at a position designated by the in-plane position input circuit 22 is cut out and its color is cut out. The signals are color signal converted as in the second embodiment. Next, in the image area extraction processing circuit 23, the color signal obtained by the color signal calculation circuit 21 and the color information input circuit 19 are inputted.
The specific area, that is, the main subject is extracted by calculating the color signal input in step S3.

As a result, as shown in FIG. 11, it is possible to detect the main subject and set the main subject as the control target.

FIG. 12 is a block diagram showing a sixth embodiment of the present invention. The photographer matches the image extracted by the image region extraction processing circuit 16 with the main subject or the region to be controlled. In this case, the specific image area position and the specific image area color signal are stored in the extracted image storage circuit 24 by inputting with a button or the like. Next, in the image comparison processing circuit 25, the captured image color signal is compared with the data stored in the extracted image storage circuit 24, and the same color signal as the color signal stored in the extracted image storage circuit 24, or It is detected whether or not a similar image area shape exists. When a color signal similar to the captured image color signal or a similar image area shape is detected, the image control circuit 26 performs desired control such as recording start or zoom-up processing of that portion. . That is, in the sixth embodiment, the control is performed by using the data stored in the extracted image storage circuit 24 as the trigger signal.

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. For example, it goes without saying that a specific image area may be detected and the image area portion may be set as a control target by a combination of the individual devices shown in the first to sixth embodiments. Further, although the zoom lens is used as the image pickup lens in the above-mentioned embodiments, a fixed focus lens or a varifocal lens may be used. Further, although the end plate type image sensor is used as the photoelectric conversion element, the two plate type or three plate type image sensor may be used.

[0036]

As described above in detail, according to the present invention, the photographer detects the main subject by setting the main subject area in the image obtained by the image pickup, and controls based on the main subject. Autofocus, autoexposure, even when the main subject is not in the preset control area of the camera.
Functions such as automatic white balance and automatic image stabilization can be exhibited in a stable state.

[Brief description of drawings]

FIG. 1 is a block configuration diagram showing an embodiment of an image pickup apparatus according to the present invention.

FIG. 2 is a diagram showing an example of an in-plane position input method.

FIG. 3 is a diagram showing a region for color system conversion in a color signal arithmetic circuit.

FIG. 4 is a diagram showing an area obtained by extracting a specific image area.

FIG. 5 is a diagram showing a region extracted by an image extraction process.

FIG. 6 is a block diagram showing a second embodiment of the present invention.

FIG. 7 is a block diagram showing a third embodiment of the present invention.

FIG. 8 is a diagram showing setting of a control target position in the third embodiment.

FIG. 9 is a block diagram showing a fourth embodiment of the present invention.

FIG. 10 is a block diagram showing a fifth embodiment of the present invention.

FIG. 11 is a diagram showing an example in which main subject detection is performed.

FIG. 12 is a block diagram showing a sixth embodiment of the present invention.

[Explanation of symbols]

 1 zoom lens 2 image sensor (photoelectric conversion element) 5 in-plane position input circuit (in-plane position input section) 6 designated position hue calculation circuit (designated position hue calculation section) 7 hue calculation circuit (hue calculation section) 8 image area extraction Processing circuit (image area extraction unit) 9 Image control circuit (image control unit) 24 Extracted image storage circuit (storage unit)

Claims (6)

[Claims] 1. An in-plane position input unit that specifies a position coordinate in a screen where the object is projected, in an imaging device that extracts the object through a photoelectric conversion element and performs image processing of the extracted object image. And a designated position color signal calculation unit that calculates a color signal at the in-plane position designated by the in-plane position input unit,
A color signal calculation unit that calculates a color signal in a predetermined range wider than the in-plane position in the image, and a specific region in the screen is extracted based on the calculation results of the color signal calculation unit and the designated position color signal calculation unit. An image pickup apparatus, comprising: an image area extracting unit for controlling the image area; and an image control unit for performing image control on the image area extracted by the image area extracting unit. 2. The in-plane position input unit has an in-plane position setting unit that allows a photographer to set the in-plane position during or before photographing. Imaging device. 3. The specified position color signal calculation section has a conversion means for converting the color signal at the in-plane position into another color signal or color system data. The image pickup apparatus according to claim 2. 4. The color signal calculation section has a conversion means for converting a color signal of the peripheral predetermined portion of the in-plane position or the entire screen into another color signal or color system data. The imaging device according to claim 1, wherein 5. The information extraction means for extracting the same information as the color signal calculated on the basis of the designated position color signal calculation section and the color signal calculation section or information satisfying a specific condition. The imaging device according to any one of claims 1 to 4, further comprising: 6. The image pickup apparatus according to claim 1, further comprising a storage unit that stores the image area information extracted by the image area extraction unit.