JPH11261832A - Image processing method and image processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processing method and an image processor capable of detecting aberration characteristics even in the case that the aberration characteristics can not be obtained from photographing lens information and photographing film information for images photographed by the inexpensive camera of a film with a lens or the like and the images photographed by an inexpensive digital camera, correcting aberration by an image processing utilizing the aberration characteristics and reproducing the images of high image quality without color slippage or distortion as print images as desired by a user. SOLUTION: For image data obtained from the optically photographed images, this image processing method for detecting the aberration characteristics from the image data without using lens information or the like and correcting the aberration based on the detected aberration characteristics is used. Also, the aberration characteristics considered as best are selected from the detected aberration characteristics and the plural aberration characteristics for which the aberration characteristics are slightly changed while confirming aberration corrected images on a monitor 20, etc., the images for which the aberration is corrected based on the selected aberration characteristics are outputted to a printer 16 and thus, the problem is solved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for photoelectrically reading an image captured on a film or directly obtaining digital image data by capturing an image of a subject, and reproducing an image based on the digital image data. The present invention belongs to the technical field of an image processing method and an image processing apparatus for correcting chromatic aberration of magnification and distortion occurring in an image photographed by a film with a lens or the like in a digital photo printer for obtaining a printed image (photograph).

[0002]

2. Description of the Related Art At present, an image photographed on a photographic film (hereinafter referred to as a film) such as a negative film or a reversal film is printed on a photosensitive material (photographic paper) by projecting an image of the film onto the photosensitive material. Surface-exposing the photosensitive material,
This is performed by so-called direct exposure (analog exposure).

On the other hand, in recent years, a printing apparatus using digital exposure, that is, an image recorded on a film is photoelectrically read, and the read image is converted into a digital signal, and then subjected to various image processing. 2. Description of the Related Art Digital photo printers have been put to practical use in which image data for recording is printed, and a photosensitive material is scanned and exposed with recording light modulated according to the image data to record an image (latent image) and print (finished). .

In a digital photo printer, exposure conditions at the time of printing can be determined by image data processing using an image as digital image data, so that image skipping and blurring caused by backlight, strobe photography, and the like can be corrected, and sharpness can be reduced. Properly perform (sharpening) processing, correction of color feria and density feria, correction of underexposure and overexposure, correction of insufficient peripheral light quantity, etc. to obtain high-quality prints that could not be obtained by conventional direct exposure Can be. In addition, synthesis of a plurality of images, image division, and synthesis of characters can be performed by image data processing, and prints that have been freely edited / processed according to the intended use can be output.
In addition, according to digital photo printing, not only can images be output as prints (photographs), but also image data can be supplied to a computer or the like or stored on a recording medium such as a floppy disk. Can be used for various purposes other than photography.

[0005] Such a digital photo printer basically includes a scanner (image reading device) for photoelectrically detecting an image recorded on a film, image processing of the read image, and image data for recording (exposure conditions). ) And a printer (image recording device) that scans and exposes the photosensitive material in accordance with the image data, performs development processing, and prints.

In a scanner, reading light emitted from a light source is incident on a film to obtain projection light for holding an image photographed on the film, and the projection light is transmitted to an image sensor such as a CCD sensor by an imaging lens. The image is read by subjecting the image to photoelectric conversion and subjected to various types of image processing as necessary, and then sent to an image processing apparatus as image data (image data signal) of the film. The image processing apparatus sets image processing conditions from image data read by a scanner, performs image processing according to the set conditions on the image data, and sends the image data to a printer as output image data (exposure conditions) for image recording. . In the printer, for example, if the device uses light beam scanning exposure, the light beam is modulated according to the image data sent from the image processing device,
The photosensitive material is two-dimensionally scanned and exposed (printed) to form a latent image, and then subjected to a predetermined developing process and the like, so that an image photographed on the film is reproduced (printed).

[0007]

By the way, as causes of image quality deterioration of an image reproduced in a print, there are chromatic aberration of magnification and distortion caused by the performance of a lens mounted on a camera which has taken the image. A color image is formed by three primary colors of red (R), green (G), and blue (B), but since the bending ratio (imaging magnification) of the lens slightly varies depending on the wavelength, R, G, and B are used. Are different in imaging magnification, that is, chromatic aberration of magnification occurs. As a result, when an image captured on a film is reproduced, a color shift occurs in the obtained image. Further, in order to obtain a good photographed image, a plane perpendicular to the optical axis needs to be imaged correspondingly on the image plane, but with a normal lens, the image position is the optical axis. A deviation occurs in the direction, and distortion (distortion), that is, distortion occurs in the formed image. Therefore, when an image captured on film is reproduced, the obtained image is distorted.

For a camera such as a single-lens reflex camera that can afford a certain amount of cost, use a high-precision lens,
Further, by combining a plurality of lenses, it is possible to correct lateral chromatic aberration and distortion, and to photograph an appropriate image on a film. However, in the case of a film with a lens or an inexpensive compact camera, the cost of the lens cannot be increased, so that chromatic aberration of magnification and distortion occur in an image photographed on the film. As a result, an image reproduced as a print has color shift and distortion.

In a conventional image processing apparatus, if information on a photographing lens that has photographed a subject and lens characteristics of the photographing lens are known, chromatic aberration of magnification, distortion, and the like are determined according to the lens characteristics of the photographing lens. It is conceivable to correct, but it is difficult to correct these aberrations if the information of the taking lens and the lens characteristics of the taking lens are not known, and it is extremely difficult to obtain an image in the best corrected state. There was a problem.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to photograph an image photographed optically by an inexpensive camera such as a film with a lens or an image photographed by an inexpensive digital camera. Even when the aberration characteristic cannot be obtained from the lens information or the film information, the aberration characteristic can be detected based on the captured image data, for example, based on an image displayed on an image display device using the image data. It is possible to correct magnification chromatic aberration and distortion by image processing using the aberration characteristics, and to reproduce a high quality image without color shift and distortion in the best aberration correction state as a print image. An object of the present invention is to provide a processing method and an image processing device.

[0011]

In order to achieve the above object, the present invention obtains input image data from an image optically photographed using a photographing lens, and performs predetermined image processing on the input image data. An image processing method for obtaining output image data, based on the input image data,
Detecting at least one of a magnification chromatic aberration characteristic and a distortion characteristic of the taking lens, and correcting at least one of the magnification chromatic aberration and the distortion based on the detected aberration characteristic and position information of the image; An image processing method is provided.

At this time, the aberration characteristic is detected by displaying the image on an image display device based on the input image data, and identifying at least two aberration correction target objects selected from the display image of the image display device. The position information of a point is obtained, the object between the at least two points is extracted based on the input image data, and the position information of the object before the aberration correction is obtained, and the position information is predicted in advance between the at least two points. The position information after the aberration correction of the subject is acquired, and the aberration correction formula is calculated from the position information before the aberration correction and the position information after the aberration correction. Preferably, the at least one aberration is performed over the entire image based on the position information, and the at least one aberration is extracted from the input image data. That the position information after the aberration before correction of the position information and the aberration correction of the subject is preferably a is position information of the object edges.

According to the present invention, there is provided an image processing apparatus for obtaining input image data from an image optically captured using a photographic lens, performing predetermined image processing on the input image data, and obtaining output image data. An image display device that displays the image based on the input image data, and an aberration correction target object selected from the image displayed on the image display device, and a magnification caused by the photographing lens. Detecting means for detecting at least one of the chromatic aberration characteristic and the distortion characteristic; and at least one of a magnification chromatic aberration characteristic and a distortion of the photographed image from the aberration characteristic and the position information of the image detected by the detecting means. It is an object of the present invention to provide an image processing apparatus having a correction means for correcting aberration.

At this time, the detecting means obtains position information of at least two points for specifying the subject to be corrected for aberration selected from the display image of the image display device.
The subject between points is extracted based on the input image data, and the position information of the subject before aberration correction is obtained, and the position information of the subject after the aberration correction is predicted in advance between at least two points. It is desirable to calculate the aberration correction formula from the position information before the aberration correction and the position information after the aberration correction, and the position information of the aberration correction target object is an edge of the aberration correction target object. Desirably, it is location information.

Further, the present invention provides an image processing method for obtaining input image data from an image optically captured using a photographic lens, performing predetermined image processing on the input image data, and obtaining output image data. An image display device that displays the image based on the input image data; an acquisition unit configured to acquire at least one of a magnification chromatic aberration characteristic and a distortion aberration characteristic of the photographing lens; and the acquisition unit. A correction unit that corrects at least one of chromatic aberration of magnification and distortion of the captured image from the acquired at least one aberration characteristic and position information of the image, and a correction unit that corrects the at least one aberration characteristic by the correction unit. Adjusting means for adjusting the correction intensity or the aberration pattern; and Displaying an image in which one aberration is corrected, a plurality of correction intensities or aberration patterns different by the adjustment unit are adjusted, and a plurality of displays corrected by the correction unit by the adjusted correction intensity or aberration pattern. Determine the best correction state from the image,
Another object of the present invention is to provide an image processing apparatus which outputs aberration-corrected image data in the best correction state as the output image data.

At this time, the image display device displays at least one aberration-corrected image by the correction means, and corrects the aberration corrected by the correction means every time the correction intensity or the aberration pattern is adjusted by the adjustment means. It is desirable that the image processing apparatus is characterized in that displaying an image on the image display device is repeated for a plurality of the correction intensities and the aberration patterns, and the best correction state is determined. An image processing apparatus for simultaneously displaying a plurality of aberration-corrected images corrected by the correction means for each adjustment of the correction intensity or the aberration pattern, and determining the best correction state from the displayed plurality of aberration-corrected images. It is desirable.

Further, the acquisition unit specifies the subject to be corrected for aberration selected from the image displayed on the image display device, and obtains at least one of a chromatic aberration of magnification and a distortion caused by the photographing lens. Preferably, the detecting means is a detecting means for detecting the characteristic, and the detecting means obtains at least two pieces of positional information for specifying the aberration correction target object selected from the display image of the image display device. The subject between the points is extracted based on the input image data, and the position information before the aberration correction of the subject is obtained, and the position information after the aberration correction of the subject predicted in advance between the at least two points is obtained. An image processing apparatus that calculates an aberration correction equation from the position information before the aberration correction and the position information after the aberration correction is desirable. Properly, It is further desirable the aberration correction target object is a positional information of the edge. Further, the acquisition unit may select one from a plurality of aberration characteristics having a predetermined aberration pattern and aberration correction intensity prepared in advance.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an image processing method and an image processing apparatus according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

FIG. 1 is a block diagram showing an example of a digital photo printer using an image processing apparatus of the present invention for implementing the image processing method of the present invention. A digital photo printer 10 (hereinafter, referred to as a photo printer 10) shown in FIG. 1 basically includes a scanner (image reading device) 12 that photoelectrically reads an image photographed on a film F, and a read image data. An image processing device 14 that performs image processing of (image information), operation and control of the entire photo printer 10, and the like, and imagewise exposes a photosensitive material with a light beam modulated according to image data output from the image processing device 14, Printer 1 that develops and outputs as a (finished) print
6. The image processing apparatus 14 has a keyboard 1 for inputting (setting) various conditions, selecting and supporting processing, and inputting instructions such as color / density correction.
An operation system 18 having an 8a and a mouse 18b, and a monitor 20 for displaying images read by the scanner 12, various operation instructions, setting / registration screens for various conditions, and the like are included.

The scanner 12 is a device for photoelectrically reading an image photographed on a film F or the like one frame at a time.
, A variable aperture 24, and three color filters of R, G, and B for separating the image into three primary colors of R (red), G (green), and B (blue). A color filter plate 26 acting on the optical path of a color filter, a diffusion box 28 for making the reading light incident on the film F uniform in the surface direction of the film F, an imaging lens unit 32,
A CCD sensor 34 as an area sensor for reading an image of a frame and an amplifier (amplifier) 36 are provided.

In the illustrated photo printer 10, a new photo system (Advanced Photo System)
A dedicated carrier that can be attached to the main body of the scanner 12 according to the type and size of a film such as a negative (or reversal) film of 35 size, the form of the film such as strips and slides, and the type of processing such as trimming. It is prepared and can handle various films and processes by exchanging the carrier. An image (frame) photographed on a film and provided for print production is conveyed and held at a predetermined reading position by this carrier.

In such a scanner 12, the reading light emitted from the light source 22, the light amount is adjusted by the variable aperture 24, the color is adjusted by passing through the color filter 26, and diffused by the diffusion box 28 is transmitted by the carrier to a predetermined amount. Is incident on one frame of the film F held at the reading position and transmitted therethrough, thereby obtaining projection light carrying an image of this frame photographed on the film F. The projection light of the film F is formed into an image on the light receiving surface of the CCD sensor 34 by the imaging lens unit 32, is read photoelectrically by the CCD sensor 34, and its output signal is amplified by the amplifier 36 and transmitted to the image processing device 14. Sent. CCD sensor 34
Is, for example, an area CCD sensor having 1380 × 920 pixels.

In the scanner 12, such image reading is performed three times by sequentially inserting the respective color filters of the color filter plate 26, so that one frame of image is read by R, G and B.
And read out. Here, in the photo printer 10, a pre-scan for reading an image at a low resolution is performed in order to determine image processing conditions and the like, before reading an image for printing a print (main scan). Therefore, a total of six image readings are performed in one frame.

The scanner 12 uses an area CCD sensor and separates projection light into three primary colors by a color filter plate 26 to read an image. The scanner used in the present invention includes R, G, and B scanners. The image reading may be performed by slit scanning for reading an image while scanning and transporting the film F using a carrier by using three line CCD sensors corresponding to reading of each of the three primary colors.

The illustrated photo printer 10 uses a scanner 12 that photoelectrically reads an image photographed on a film such as a negative film or a reversal film as an image data supply source of the image processing device 14. As an image data supply source for supplying the image data, other than the scanner 12, an image reading device for reading an image of a reflection original, a digital camera, a digital video camera, a LAN (Local Area N
communication means such as a network and a computer communication network, various image reading means and photographing means such as a memory card and a medium (recording medium) such as an MO (magneto-optical recording medium) and various storage means for image data can be used. It is.

As described above, the output signal (image data) from the scanner 12 is output to the image processing device 14.
FIG. 2 shows an image processing apparatus 14 (hereinafter, referred to as an embodiment) of the present invention.
FIG. 2 is a block diagram of a processing device 14). Processing device 1
4 includes a data processing unit 38, a pre-scan (frame) memory 40, a main scan (frame) memory 42, a pre-scan image processing unit 44, a main scan image processing unit 46, a condition setting unit 48, and an image display unit 20. It is composed.

In the data processing section 38, the R, G and B output signals output from the scanner 12 are converted into A / D (analog / digital), Log, DC offset, dark, shading, etc. And the obtained prescan (image) data is stored in the prescan memory 4
0, the main scan (image) data is stored in the main scan memory 4
2 are stored (stored). Scanner 1
2 are basically the same data except that the resolution (pixel density) and the signal level are different.

The pre-scan memory 40 and the main scan memory 42 store digitized data processed by the data processing section 38, and perform pre-scan image processing in order to perform image processing and output as necessary. Part 44,
Alternatively, it is called by the main scan image processing unit 46.

The pre-scan image processing unit 44 detects aberration characteristics of chromatic aberration of magnification and distortion, which will be described later, and adjusts the correction intensity to correct the aberration.
7, an aberration characteristic adjustment unit 49 and an aberration correction unit 51, image processing blocks 50 A and 50 B, and an image data conversion unit 52. The aberration characteristic detection unit 47, the aberration characteristic adjustment unit 49, and the aberration correction unit 51 are units that implement an aberration characteristic detection unit, an aberration characteristic adjustment unit, and an aberration correction unit that characterize the image processing apparatus of the present invention. , The aberration characteristic detecting section 47 and the aberration correcting section 51 perform the image processing method of the present invention.

In the image processing block 50A, color balance adjustment, contrast correction (gradation processing), and brightness correction are performed by an LUT (look-up table) (not shown).
The saturation correction is performed by a known method by an MTX operation (not shown). In the image processing unit block 50B, sharpness processing, dodging processing, and the like are performed according to instructions from an operator, image data, and the like. The image data conversion unit 52 converts the image data subjected to the image processing by the image processing unit 50 into an image data corresponding to the display on the monitor 20 using a 3D (three-dimensional) -LUT or the like.

The main scan image processing section 46 includes an aberration correction section 56 for correcting aberration of the main scan data, a characteristic data supply section 60, image processing blocks 54A and 54B, and an image data conversion section 58. Image processing block 5
In 4A, similar to the image processing block 50A, the main scan data is subjected to color balance adjustment, contrast correction (gradation processing), and brightness correction by processing using an LUT (look-up table) (not shown), and saturation correction is performed. This is performed by a known method by an MTX operation (not shown). In the image processing unit block 54B, sharpness processing, dodging processing, and the like are performed according to instructions from an operator, image data, and the like. The image data conversion unit 58 converts the image data subjected to the image processing by the image processing unit 54 into image data to be printed out to the printer 16 using a 3D (three-dimensional) -LUT or the like.

The characteristic data supply unit 60 stores the correction strength of the detected aberration characteristic adjusted by the aberration characteristic adjustment unit 49, and is used when the aberration correction unit 56 corrects the aberration of the main scan data. Supply data. The aberration corrector 56 corrects the aberration by using the aberration characteristic of the correction intensity supplied from the characteristic data supply unit 60, and furthermore, performs an electronic scaling process according to the size of the printed image. Done in

The condition setting section 48 includes an (image processing condition) setting section 72, a key correction section 74, and a parameter integration section 76.
Consists of In the setting unit 72, the pre-scan data is read from the pre-scan memory 40 and is used to determine image processing conditions. Specifically, the setting unit 72
Performs density histogram creation from prescan data, calculation of image feature amounts such as average density, LATD (large area transmission density), highlight (lowest density), shadow (highest density), and the like. An image processing condition such as creation of a table (LUT) for the above-described gray balance adjustment and creation of a matrix operation for performing saturation correction is determined in accordance with an instruction from the operator performed as necessary. The determined image processing conditions are sent to the parameter integration unit 76. In addition,
When correcting distortion, the magnification of the electronic magnification processing is different from the usual, so various image processing conditions,
For example, the coefficients of the sharpness processing, the coefficients applied to various filters, the various correction coefficients, and the like may be changed.

The key correction section 74 is provided for controlling image processing conditions in accordance with keys set on the keyboard 18a for adjusting brightness, color, contrast, sharpness, saturation, etc., and various instructions input with the mouse 18b. Adjustment amount (for example, L
The correction amount of the UT is calculated and supplied to the parameter integration unit 76. The parameter integrating unit 76 includes a setting unit 7
2 receives the set image processing conditions, and sets the supplied image processing conditions in the processing unit 50 of the pre-scan image processing unit 44 and the processing unit 54 of the main scan image processing unit 46;
Further, according to the adjustment amount calculated by the key correction unit 74,
Correct (adjust) the image processing conditions set for each part, or reset the image processing conditions.

FIG. 2 mainly shows parts related to image processing. The processing device 14 includes a CPU for controlling and managing the entire photo printer 10 including the processing device 14, A memory for storing information necessary for the operation of the photo printer 10 and the like, means for determining the aperture value of the variable aperture 24 and the accumulation time of the CCD sensor 34 at the time of the main scan, and the like are arranged.

As will be described later, the monitor 20 displays the image before the correction processing on the monitor 20, specifies the subject of the image while watching the image, detects the aberration characteristic based on the image data, and monitors the image. Is used to adjust the correction strength of the aberration characteristic while looking at the image displayed in.

The pre-scan data stored in the pre-scan memory 40 is subjected to color balance adjustment, brightness correction, contrast correction, and saturation correction in the image processing block 50A. Without passing through the characteristic adjustment unit 49 and the aberration correction unit 51,
The image data is sent to the image data conversion unit 52, and the 3D (3D) -LU
After being processed into image data corresponding to the display on the monitor 20 using T or the like, the image data is displayed on the monitor 20. As shown in FIG. 3A, the user pays attention to a subject 70 (for example, a pillar) that is originally considered to be a straight line from the image displayed on the monitor 20, and focuses on the focused subject from the original straight line. It is determined whether distortion, which is distortion, is allowed. If it is determined that the distortion needs to be corrected, the target object 70 on the display image is marked at two or more places with the keyboard 18a or the mouse 18b. For example, in FIG. 3A, two landmarks 70a and 70b
Has been indicated. The mark on the subject 70 is preferably provided at the edge and the end of the subject. The reason is,
This is because image data of the subject can be accurately extracted.
Straight line 70c connecting two or more attached marks with a straight line
Is considered to be the original subject.

When taking out the coordinates on the image data of the object 70 of interest, the operator may directly trace the object 70 with the mouse 18b or the like, or specify a certain area including the object 70, and The coordinates on the image data of the subject 70 may be automatically extracted using the density change of the image. Then, a correction formula for correcting the coordinate values of the image data of the extracted subject 70 to the coordinate values of the image data of the straight line 70c, which should be, is calculated. The correction formula is calculated by determining each order coefficient of a cubic function using the position information as a parameter from the position information of the image data (for example, the coordinate position x-y from the center of the image), so that the distortion characteristic can be calculated. Can be detected. In general, the distortion characteristic of a lens is approximated to some extent by a cubic function having a parameter (for example, indicated by xy) from the optical axis of the lens, that is, the center of an image captured on the film F. It is based on what can be done. Note that the distortion characteristics detected above are usually three of R, G and B.
This is performed based on the image data of the color G serving as the reference of the primary color.

The detection of the magnification chromatic aberration characteristic is performed by calculating a magnification chromatic aberration correction formula for adjusting the R and B images to the G image for the color shift due to the magnification chromatic aberration. This is performed using the deviation. The correction formula determines each coefficient of a cubic function using the position information as a parameter from the position information of the image data (for example, the coordinate position xy from the center of the image) in the same manner as the method of detecting the distortion characteristic. Thus, the chromatic aberration of magnification characteristic is detected. This is because, similarly to the distortion aberration characteristic, the magnification chromatic aberration characteristic of the lens generally uses the distance (indicated by xy) from the optical axis of the lens, that is, the center of the image captured on the film F, as a parameter. The fact that it can be approximated to some extent by a cubic function is used.

Using the detected aberration characteristics, the image magnifications of R and B are converted with reference to the three primary colors of R, G and B, usually G, to convert the R and B images. The chromatic aberration of magnification is corrected by adjusting to the G image, and then the distortion is corrected. Thus, by calculating an appropriate position of each pixel and using the calculated position to interpolate the image data of each pixel, it is possible to obtain image data in which the chromatic aberration and distortion of the image photographed on the film are corrected. it can. In the above embodiment, the detection of the aberration characteristic and the correction of the aberration are for the distortion and the chromatic aberration of magnification. However, only the distortion or the chromatic aberration of magnification may be performed.

The aberration characteristic adjusting section 49 adjusts the correction strength of the aberration characteristic detected based on the image displayed on the monitor 20 by the user. The detected aberration characteristic is adjusted, and an image including the subject 70 whose aberration has been corrected is displayed on the monitor 20. However, since the correction of the aberration characteristic detected based on the subject 70 is too strong or too weak, the detection is performed. Means are provided for displaying an image including the subject whose aberration has been corrected by changing the correction strength of the aberration characteristic in three to five steps and selecting the aberration characteristic that the user considers to be optimal. While looking at the screen, the user can select from among the correction strength, strong, medium, and weak by inputting with the keyboard 18a, the mouse 18b, and the correction key (not shown), and select +2, +1, N, -1, -2. It is possible to select one from which the correction strength is determined to be optimum.

Although not shown, the chromatic aberration of magnification is also checked by the monitor 20 for the color misregistration of the subject 70, and while the user sees it, the correction intensity, strong, medium, and weak are input by the keyboard 18a. From within, again +
It is possible to select a correction intensity determined to be optimum from 2, +1, N, -1, and -2. In the present invention, the steps of the correction intensity are not limited to three to five steps.

FIG. 3B shows an example displayed on the monitor 20 in the aberration characteristic adjusting section 49 as the aberration characteristic adjusting means. Although the subject 70 is corrected to 70c by the aberration characteristic detected by the aberration characteristic detection unit 47, the correction side is strengthened around the detected aberration characteristic (N) where the subject 70 becomes a straight line due to the correction. (+
(1, +2) and a plurality of images in which the aberration is corrected by changing the level to the minus side (−1, −2) where the correction strength is weakened, and an image that the user determines to be the best can be selected.
FIG. 3C shows an image (−1) in which the aberration is corrected by weakening the correction intensity. The selection is +2 at the bottom of the screen of the monitor 20 of the image corrected for each correction intensity,
It is selected from among +1, N, -1, and -2 by input from the keyboard 18a. It should be noted that, depending on the characteristics of the photographing lens, the aberration characteristics may show a barrel-shaped characteristic in addition to a pincushion-type characteristic. Therefore, it is preferable that the user can select either of them according to the image. Further, the present invention is not limited to the case where an image corrected by the aberration characteristic detected by the aberration characteristic detection unit 47 and an image corrected by changing the correction intensity are selected, but a representative aberration characteristic is set in advance. You may make it select from the corrected image.

Here, the user adjusts the aberration characteristics by looking at the image whose aberration has been corrected.
The image whose aberration has been corrected by the aberration correction unit 51 is displayed. The aberration is corrected by converting the image magnification of R and B with respect to the three primary colors of R, G and B, usually G, and matching the R and B images with the G image. The chromatic aberration is corrected, and then the distortion is corrected. Thus, by calculating an appropriate position of each pixel and using the calculated position to interpolate the image data of each pixel, it is possible to obtain image data in which the chromatic aberration and distortion of the image photographed on the film are corrected. it can. The prescanned image data whose aberration has been corrected is further subjected to sharpness processing, dodging processing, and the like in a block 50A according to a user instruction, image data, and the like. Is done.

In the aberration characteristic adjusting section 49, as shown in FIG. 3D, the image after the correction based on the detected aberration characteristic and the correction intensity of the correction characteristic are changed in advance into three to five stages. The monitor 20 may be divided into a plurality of images whose aberration has been corrected and the plurality of images may be displayed simultaneously.

As described above, the user confirms by looking at the monitor 20 that a rectangular image corrected for distortion has no image in the peripheral portion of the image due to distortion correction, that is, a so-called vignetting is generated. Because there is. It is not desirable to print out an image with vignetting, so in order to output a rectangular image without vignetting to the specified output print size, slightly enlarge the image and cut off the peripheral area of the image. It is necessary to create a rectangular image having a specified output print size without vignetting. However, in the above-described operation of cutting off the image peripheral area, there is a possibility that the cut-out image peripheral area includes a subject that should not be originally cut off. In particular, since the area around the image to be cut out to fit a rectangular image that does not cause vignetting to the specified output print size changes depending on the correction strength of distortion aberration correction, the user checks whether or not any objects that should not be cut off are included. There is a need to.

For example, in FIG. 3D, the displayed images (a) to (d) correspond to the correction intensities set in advance based on the aberration characteristics detected by the aberration characteristic detection unit 47. This is an image in which aberration has been corrected. Further, it is possible to set a print output frame 71 to be printed out and to check whether or not a subject considered to be important is included outside the range. The user determines the image to be output by comprehensively judging the cutout of the subject and the color shift and distortion of the image while looking at the display screen.

When the user adjusts the aberration characteristics with the aberration characteristic adjustment unit 49, the aberration characteristics are sent to the characteristic data supply unit 60 and stored in the memory. The main scan data stored in the main scan memory 42 is transmitted to the main scan image processing unit 46.
In, the process is started. Image processing in the main scan data processing unit 54 includes color balance adjustment, contrast correction (gradation processing), brightness correction, dodging processing (compression / expansion of density dynamic range), saturation correction, and sharpness (sharpening). ) Processing is exemplified. These are performed by a well-known method that appropriately combines arithmetic, processing by an LUT (look-up table), matrix (MTX) arithmetic, processing by a filter, and the like. Color balance adjustment, brightness correction and contrast correction, The saturation correction is performed in the image processing block 54A. In addition, other sharpness processing, dodging processing, and the like may be performed according to an instruction from an operator, image data, or the like.
This is performed in the image processing block 54B. After each processing is performed in the image processing block 54A, it is sent to the aberration correction unit 56.

The aberration corrector 56 corrects distortion and chromatic aberration of magnification, and performs electronic scaling. Further, the aberration correction unit 56 is connected to a characteristic data supply unit 60 that stores the characteristics of the detected aberration characteristics adjusted by the user in the aberration characteristic adjustment unit 49, and supplies the data of the characteristics to the aberration correction unit 56. Is done. In the processing device 14 shown in FIG. 2, the aberration correction unit 56 uses the aberration characteristics and the pixel position of the image data (the distance from the center (that is, the optical axis) of the image) on the film F by image processing. The correction of the distortion chromatic aberration and the magnification chromatic aberration of the captured image is performed in the same manner as the correction of the magnification chromatic aberration and the distortion of the pre-scan data described above. As a result, it is possible to stably output a print in which a high-quality image without distortion or color shift is reproduced.

Here, if the correction of the chromatic aberration of magnification and the distortion using the selected aberration characteristic and the position information of the image (hereinafter, referred to as pixel position) are separately performed, it takes a long time for the calculation and the interpolation Since the calculation also needs to be performed a plurality of times, there is a problem that the image quality is deteriorated. Therefore, it is preferable that the reference colors of the three primary colors of R, G and B, usually G
, The R and B image magnifications are converted, the chromatic aberration of magnification is corrected by matching the R and B images with the G image, and then the distortion is corrected. Thus, by calculating an appropriate position of each pixel and using the calculated position to interpolate the image data of each pixel, it is possible to obtain image data in which the chromatic aberration and distortion of the image photographed on the film are corrected. it can. Accordingly, since only the operation on the G image needs to be performed for the distortion, it is possible to perform more appropriate correction of the chromatic aberration of magnification and the distortion by reducing the amount of operation and the interpolation operation.

In the image processing apparatus, usually, the image is enlarged or reduced by image data processing, that is, the image is electronically resized, and the image (image data) is output in a size corresponding to the output image. This electronic scaling process is usually performed by performing an interpolation operation on image data. However, since the interpolation calculation is performed even in the correction of the chromatic aberration of magnification and the distortion, the result is that the interpolation is performed twice, which may deteriorate the image quality.

Therefore, in the present invention, it is more preferable to use the aberration characteristic and the pixel position of the image data to calculate the shift amount of the R and B pixel positions with respect to the reference color (G) caused by the chromatic aberration of magnification. An appropriate position for each pixel is calculated from the shift amount of the pixel position of the reference color due to the distortion, and image information is interpolated by using the calculated information on the appropriate position of each pixel to interpolate the image data. Perform double processing. In other words, by calculating the amount of displacement of the pixel position due to chromatic aberration of magnification and distortion, it is possible to know where each pixel should be originally located, and perform interpolation calculation of image data according to the appropriate position. To perform electronic scaling. Thereby, the correction of the distortion and the chromatic aberration of magnification and the electronic scaling process can be performed by one interpolation calculation. There is no particular limitation on the method of the electronic scaling process, and various known methods can be used. Examples thereof include a method using bilinear interpolation and a method using spline interpolation.

After being processed by the image processing section 54, sharpness processing, dodging processing, and the like are performed in a block 54B according to an instruction from an operator, image data, and the like. And output to the printer 16.

Here, the image data processed by the processing device 14 is sent to the printer 16. Printer 16
Is to expose a photosensitive material (photographic paper) in accordance with image data to record a latent image, perform development processing in accordance with the photosensitive material, and output as a (finished) print. For example, after the photosensitive material is cut into a predetermined length corresponding to the print, recording of the back print, red (R) exposure, green (G) exposure, and blue (B) according to the spectral sensitivity characteristics of the photosensitive material (photographic paper). )
Recording of latent images by modulating three types of light beams for exposure in accordance with image data (recorded image), deflecting in the main scanning direction, and transporting the photosensitive material in a sub-scanning direction orthogonal to the main scanning direction. The photosensitive material on which the latent image has been recorded is subjected to a predetermined wet developing process such as color development, bleach-fixing, washing with water, dried and printed, then sorted and accumulated.

In the image processing device 14 shown in FIG.
The image data processed by the aberration characteristic detection unit 47 and the aberration characteristic adjustment unit 49 uses prescan image data obtained by performing a prescan by the scanner 12. However, the present invention is not limited to this.
As shown in (1), the aberration characteristics may be detected and adjusted using only the main scan image data (fine scan image data), and then the aberration may be corrected. In this case, when an image is displayed on the monitor 20, since the main scan image data is high-resolution data, the corrected image data is thinned out to match the output pixel density of the monitor 20, and the image size is reduced. It may be displayed.

An image processing apparatus 15 shown in FIG. 5 shows another embodiment of the present invention for detecting and adjusting the aberration characteristics from the above-mentioned main scan image data, and is different from the image processing apparatus 14 shown in FIG. Does not include the image processing block 50A in the prescan memory 40 and the image processing unit 50 of the prescan image processing unit 44. On the other hand, in order to thin out and reduce the aberration-corrected main scan image data, Since they are the same except that they are also connected to the monitor image data conversion unit 52 via the unit 59, the same components are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the image processing device 15 shown in FIG.
As in the image processing apparatus 14 shown in FIG.
The high-resolution fine scan image data (main scan image data) read in 2 is subjected to various data processing in the data processing unit 38 and then to the fine scan memory 4.
2 is stored. Next, the setting unit 72 of the condition setting unit 48
The image data is read out from the frame memory 42, the image processing conditions are set, and the parameter integration unit 76 includes instructions and information by key input from the operation unit 18.
Sent to Further, the image data is sent from the parameter integration unit 76 to the image processing unit 54 of the main scan processing unit 46. Next, the image data stored in the frame memory 42 is read out, sent to the processing unit 54, and subjected to predetermined image processing according to the image processing conditions sent from the parameter integration unit 76. It is sent to the detection unit 47.

Here, as described in the image processing apparatus 14 of FIG. 2, the aberration characteristic is detected by the aberration characteristic detecting section 47, and the aberration characteristic is adjusted by the aberration characteristic adjusting section 49 while watching the monitor 20. At the time of display on the monitor 20, since the main scan image data is high-resolution image data, the main scan image data is sent to the decimation / reduction processing unit 59 before being converted into monitor image data by the image data conversion unit 52. After thinning or reduction processing is performed, the image data is converted into low-resolution image data having an image size and pixel density suitable for monitor display, and then output to the image data conversion unit 52. The image data converter 52 converts the aberration-corrected low-resolution image data into image data for monitor display, and outputs the image data to the monitor 20. The aberration characteristic detection unit 47 and the aberration characteristic adjustment unit 4 of the image processing device 15 shown in FIG.
9. The aberration correction unit 51 has the operation described in the image processing device 14 of FIG.

When the user adjusts the aberration characteristic detected by the aberration characteristic adjustment section 49, the adjusted aberration characteristic is sent to the characteristic data supply section 60 and stored in the memory. On the other hand, processing of the main scan data stored in the main scan memory 42 is started in the main scan image processing unit 46, and color balance adjustment, contrast correction (gradation processing), and brightness correction are performed as image processing in the processing unit 54. , Dodging processing (compression / expansion of density dynamic range), saturation correction, sharpness (sharpening) processing, etc. are started. These are performed by a well-known method that appropriately combines calculation, processing by an LUT (look-up table), matrix (MTX) calculation, processing by a filter, and the like. Color balance adjustment, brightness correction and contrast correction, Further, saturation correction is performed in the image processing block 54A. In addition, other sharpness processing, dodging processing, and the like may be performed according to an instruction from an operator, image data, or the like.
This is performed in the image processing block 54B. After the image processing is performed in the image processing block 54A, the image is sent to the aberration correction unit 56.

The aberration corrector 56 corrects distortion and chromatic aberration of magnification, and performs electronic scaling. The aberration correction unit 56 is connected to a characteristic data supply unit 60 storing aberration characteristics adjusted by the user. The data of the adjusted aberration characteristics is supplied to the aberration correction unit 56. In the processing device 15 shown in FIG.
In the above, using the adjusted aberration characteristics and the pixel position of the image data (the distance from the center (that is, the optical axis) of the image), the distortion chromatic aberration and the chromatic aberration of magnification of the image photographed on the film F by the image processing are described above. The same correction as the chromatic aberration of magnification and distortion correction of the pre-scan data is performed. As a result, it is possible to stably output a print in which a high-quality image without distortion or color shift is reproduced. The main scan image data corrected by the aberration correction unit 56 is subjected to sharpness processing, dodging processing, and the like in accordance with an instruction from an operator, image data, and the like.
The image data is converted into image data of the printer 16 by the image data conversion unit 58 and output to the printer 16. As a result, it is possible to print out an image in which the aberration is corrected by the aberration characteristic adjusted by the aberration characteristic adjusting unit 49.

Although the image processing method and the image processing apparatus of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be made without departing from the gist of the present invention. Of course you can do it. For example, at least one of the chromatic aberration of magnification and the distortion may be corrected not only by the image processing method and the image processing apparatus according to the present invention, but also at the same time to correct a decrease in peripheral light amount and out-of-focus caused by the lens.

[0062]

As described above, according to the present invention, an image photographed by a film with a lens, an inexpensive compact camera, or the like can be used even if there is no photographed lens or photographed film information and the aberration characteristics are not known. The distortion can be corrected based on the distortion characteristic and the chromatic aberration characteristic of the photographed image determined by the user to be optimal.
The user can output a high-quality print to a printer while viewing a high-quality image without color shift on the image displayed by the user on the image display device.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of a digital photo printer using an image processing apparatus that performs an image processing method of the present invention.

FIG. 2 is a block diagram of an embodiment of an image processing apparatus according to the present invention.

FIGS. 3A, 3B, and 3C are monitor display screens each showing an example of an aberration-corrected subject image according to an embodiment of the image processing method of the present invention, and FIG. 11 is an example of a monitor display screen of an aberration-corrected image according to another embodiment of the image processing method of FIG.

FIG. 4 is a block diagram illustrating an example of a flow of an image processing method according to the present invention.

FIG. 5 is a block diagram of another embodiment of the image processing apparatus of the digital photo printer shown in FIG.

[Explanation of symbols]

 Reference Signs List 10 (Digital) photo printer 12 Scanner 14, 15 (Image) processing device 16 Printer 18 Operation system 18a Keyboard 18b Mouse 20 Monitor 22 Light source 24 Variable aperture 26 Color filter plate 28 Diffusion box 32 Imaging lens unit 34 CCD sensor 36 Amplifier 38 Data processing unit 40 Prescan (frame) memory 42 Main scan (frame) memory 44 Prescan image processing unit 46 Main scan image processing unit 48 Condition setting unit 47 Aberration characteristic detection unit 49 Aberration characteristic adjustment unit 50, 54 (Image) processing Units 51, 56 Aberration correction unit 52, 58 Image data conversion unit 59 Thinning / reduction data processing unit 60 Characteristic data supply unit 72 (Image processing condition) setting unit 74 Key correction unit 76 Parameter integration unit

Claims (13)

[Claims] An image processing method for obtaining input image data from an image optically photographed using a photographing lens, performing predetermined image processing on the input image data, and obtaining output image data. Detecting at least one of a chromatic aberration of magnification and a distortion of the photographing lens based on the input image data, and detecting the chromatic aberration of magnification and a position of the image based on the detected aberration and the position information of the image. An image processing method, wherein at least one aberration of distortion is corrected. 2. The method according to claim 1, wherein the aberration characteristic is detected by displaying the image on an image display device based on the input image data, and identifying at least two aberration correction target objects selected from the display image on the image display device. The position information of the subject is extracted between the at least two points based on the input image data, and the position information of the subject before the aberration correction is obtained. Obtain the position information of the subject after the aberration correction, and perform the aberration correction formula from the position information before the aberration correction and the position information after the aberration correction, and correct the aberration according to the aberration correction formula. 2. The image processing method according to claim 1, wherein the at least one aberration is performed over the entire image based on the position information. 3. The image processing method according to claim 2, wherein the position information before and after the aberration correction of the subject extracted from the input image data is the position information of the edge of the subject. 4. An image processing apparatus for obtaining input image data from an image optically photographed using a photographing lens, performing predetermined image processing on the input image data, and obtaining output image data. An image display device that displays the image based on the input image data; and an aberration correction target object selected from the image displayed on the image display device, and magnification chromatic aberration characteristics and distortion caused by the photographing lens. Detecting means for detecting at least one of the aberration characteristics; and correcting at least one of chromatic aberration of magnification and distortion of the captured image from the aberration characteristics and the position information of the image detected by the detecting means. An image processing apparatus comprising: a correction unit. 5. The apparatus according to claim 1, wherein said detecting means obtains position information of at least two points that specify an object to be corrected for aberration selected from a display image of said image display device, and stores said object between said at least two points in said input image data. To obtain the position information of the subject before the aberration correction, and obtain the position information of the subject after the aberration correction predicted in advance between the at least two points, and obtain the position information before the aberration correction. The image processing apparatus according to claim 4, wherein an aberration correction equation is calculated from the position information after the aberration correction. 6. The image processing apparatus according to claim 5, wherein the position information of the aberration correction target object is edge position information of the aberration correction target object. 7. An image processing apparatus for obtaining input image data from an image optically captured using a photographic lens, performing predetermined image processing on the input image data, and obtaining output image data. An image display device that displays the image based on the input image data; an acquisition unit that acquires at least one aberration characteristic of a chromatic aberration of magnification and a distortion aberration of the imaging lens; Correction means for correcting at least one of chromatic aberration of magnification and distortion of the captured image from at least one aberration characteristic and position information of the image; and a correction intensity of the at least one aberration characteristic used in the correction means. Or adjusting means for adjusting the aberration pattern. Displaying an image in which the aberrations are corrected, and adjusting the plurality of correction intensities or aberration patterns different by the adjustment unit, and adjusting the corrected intensity or aberration pattern by the adjusted correction unit in the plurality of display images. An image processing apparatus, wherein a best correction state is determined from among them, and aberration-corrected image data in the best correction state is output as the output image data. 8. The image display device displays at least one aberration-corrected image by the correction unit, and corrects the aberration-corrected image corrected by the correction unit every time the correction intensity or the aberration pattern is adjusted by the adjustment unit. The image processing apparatus according to claim 7, wherein displaying on the image display device is repeated for a plurality of the correction intensities and the aberration patterns to determine the best correction state. 9. The image display device displays simultaneously a plurality of aberration-corrected images corrected by the correction means each time the correction intensity or the aberration pattern is adjusted by the adjustment means, and displays the displayed plurality of aberration-corrected images. The image processing apparatus according to claim 7, wherein the best correction state is determined from the following. 10. The apparatus according to claim 7, wherein said acquisition means selects one of a plurality of aberration characteristics having a predetermined aberration pattern and aberration correction intensity prepared in advance. Image processing device. 11. An image processing apparatus according to claim 1, wherein said acquisition unit specifies the aberration correction target object selected from the image displayed on the image display device, and at least one of a chromatic aberration of magnification and a distortion caused by the photographing lens. The image processing device according to claim 7, wherein the image processing device is a detection unit that detects a characteristic. 12. The detection means obtains at least two pieces of positional information for specifying a subject to be corrected for aberration selected from a display image of the image display device, and converts the subject between at least two points into the input image data. To obtain the position information of the subject before the aberration correction, and obtain the position information of the subject after the aberration correction predicted in advance between the at least two points, and obtain the position information before the aberration correction. The image processing apparatus according to claim 11, wherein an aberration correction formula is calculated from the position information after the correction of the aberration. 13. The position information of the subject to be corrected for aberration includes:
The image processing apparatus according to claim 12, wherein the information is position information of an edge of the aberration correction target subject.