JPH11313214A - Image processing method and image processing unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the image processing unit that processes correction of a magnification, chromatic aberration, and distortion based on an aberration characteristic of a lens at a low cost and a high speed by correcting the magnification, chromatic aberration and distortion through image processing so as to obtain an image with high image quality without color slurring and distortion even in the case of an image photographed on a film or the like with a lens having a large aberration characteristic and to provide the practical image processing method. SOLUTION: At least any image processing among correction processing of magnification and chromatic aberration, correction processing of distortion, and electronic magnification processing is applied to a photographed image in a 1st direction and a 2nd direction orthogonal to the 1st direction separately. In the case that a correction amount by image processing differs from the 1st and 2nd directions, the image processing is applied to the image in the direction whose correction amount is smaller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital photo printer or the like for obtaining a print (photograph) of an image photographed on a film photoelectrically and reproducing the image. The present invention belongs to the technical field of an image processing method and an image processing apparatus that corrects chromatic aberration of magnification, distortion, and the like generated in an image captured by a computer.

[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. This is performed by so-called direct exposure (analog exposure) that exposes a material surface.

On the other hand, in recent years, a printing apparatus using digital exposure, that is, an image recorded on a film is optically read, the read image is converted into a digital signal, and then various image processings are performed to perform recording. Image data,
A digital photo printer has been put to practical use, in which a photosensitive material is scanned and exposed by a recording light modulated in accordance with the image data to record an image (latent image) and perform (finished) printing.

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. (Sharpening) processing, correction of insufficient peripheral light amount, etc. are suitably performed, and a high-quality print that cannot be obtained by conventional direct exposure can be obtained. However, when the image quality of the image photographed and recorded on the film is deteriorated, the above correction may not be performed to improve the image quality of the print output image. As a cause of this image quality deterioration,
There are chromatic aberration of magnification and distortion caused by the performance of a lens mounted on a camera that has captured an image.

[0005] A color image is formed by three primary colors of red (R), green (G) and blue (B). Since the refractive index (imaging magnification) of a lens slightly differs depending on the wavelength, R, R
The imaging magnifications of the G and B lights are different, that is, lateral chromatic aberration occurs. As a result, when an image captured on a film is reproduced, a color shift occurs in the obtained image. Also,
In order to obtain a good captured 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 shifted in the optical axis direction. Displacement occurs, causing distortion (distortion) in the formed image. Therefore, when an image captured on film is reproduced, the obtained image is distorted.

A camera such as a single-lens reflex camera, which can afford a certain amount of cost, uses a high-precision lens and combines a plurality of lenses to correct various aberrations such as chromatic aberration of magnification and distortion. To shoot a proper image on film. However, a lens-equipped film, a compact camera, or the like cannot add cost to the lens, 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 distortion.

[0007] In order to solve the problem of image quality deterioration that cannot improve the image quality of a print output image, an image in which image aberration is corrected according to the aberration characteristic of a lens obtained through a certain information acquisition unit. Japanese Patent Application Laid-Open No. Hei 6-31425 and
It is disclosed in Japanese Patent Application Laid-Open No. 9-281613 (Japanese Patent Application No. 8-92804) filed by the present applicant. It is pointed out that these techniques can correct aberrations caused by the lens, prevent deterioration of image quality in the peripheral portion of the image, and always obtain a high-quality image.

[0008]

SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-Open No.
Japanese Patent Application Laid-Open No. 2816113 (Japanese Patent Application No. 8-92804) discloses a photographic processing apparatus and a photographic processing method, which include a process of correcting a decrease in peripheral light amount, and the light amount f at a pixel position (i, j) of an image. Correction is performed using the product f ′ (i, j) of (i, j) and the correction coefficient g (i, j) based on the characteristics of the lens as the corrected light amount at the pixel position (i, j). I have. In this case, a corrected image can be obtained by moving j while keeping i constant and then moving i, or moving i while keeping j constant and then moving j in order to correct the entire image. . However, in the correction of distortion and the correction of chromatic aberration of magnification, which change the object position of an image by correction, it is necessary to store information of all pixel positions before correction and to store information of all pixel positions after correction. Therefore, an enormous frame memory is required, and a circuit for performing the two processes relating to i and j in the above description needs to be provided. This not only increases the cost but also significantly increases the correction processing speed. There is a problem that it is difficult to use for practical use.

On the other hand, Japanese Patent Application Laid-Open No. 6-311425 discloses an image correction apparatus capable of performing high-speed image correction according to the aberration characteristics of a lens. , The hue and saturation of the color image are unclear,
As the amount of deterioration increases from the center of the image toward the periphery, as a correction emphasis coefficient for correcting them, the image region defined by concentric circles or squares from the center of the image to the periphery, from the center to the periphery Is used only for each lens characteristic, and the data of the predetermined pattern increased as the data goes to can be roughly corrected, but image correction deviating from a preset pattern cannot be performed. However, there is a problem that it is not possible to perform appropriate correction according to the characteristics of the taking lens. Furthermore, if an appropriate correction is performed by this technique, correction emphasis coefficients of all patterns predicted for the lens characteristics must be prepared in advance, which requires a large-capacity memory. However, if the prepared pattern is not a concentric circle or square centered on the center of a simple image, the amount of calculation of the matrix correction amount increases, and the overall image processing speed decreases.
Practical problems were also met in terms of cost and processing speed. In particular, this is a serious problem in a print service for reproducing a large number of images.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to quickly correct distortion and chromatic aberration of magnification even in an image taken by an inexpensive camera such as a film with a lens. It is another object of the present invention to provide an image processing method and an image processing apparatus which can obtain a high-quality image without distortion or color shift and which does not cost much.

[0011]

In order to achieve the above object, a first aspect of the present invention is to obtain input image data from an image optically photographed by using a photographing lens, and obtain a photographed image by photographing the image. After obtaining the lens characteristics of the lens, when performing image processing on the input image data using the obtained lens characteristics and the pixel position information of the captured image, the first direction of the captured image and For each of the second directions orthogonal to the first direction, separately, at least one image processing of magnification chromatic aberration correction processing, distortion aberration correction processing, and electronic scaling processing is performed on the input image data. The present invention provides an image processing method characterized by performing.

At this time, when performing at least one of the magnification chromatic aberration correction processing and the distortion aberration correction processing separately for each of the first direction and the second direction of the captured image, It is preferable that the order of the image processing for the first direction and the second direction can be selected, and for each of the first direction and the second direction, separately, magnification chromatic aberration correction processing, distortion Aberration correction processing, and when performing at least one image processing of the electronic magnification processing, it is preferable that at least one of the lateral chromatic aberration correction amount and the distortion aberration correction amount is different for the first direction and the second direction, Further, the magnification chromatic aberration correction processing and the distortion aberration correction processing may be performed before and after the first direction and the second direction, respectively. It is preferable to perform magnification chromatic aberration correction amount and the distortion correction amount small direction correction process first. When the input image data is obtained by photoelectrically reading a captured image by a line sensor having the first direction as a main scanning direction and the second direction as a sub-scanning direction, the second direction In the image processing described above, it is preferable to further perform a color misregistration correction process using the line sensor.

According to a second aspect of the present invention, input image data is obtained from an image optically photographed using a photographing lens, predetermined image processing is performed on the input image data, and the output image data is An image processing apparatus for obtaining, comprising: an obtaining unit configured to obtain information on a photographic lens that has captured the image; a storage unit configured to store lens characteristics of a photographic lens according to the information of the photographic lens; Using the lens characteristics of the corresponding photographic lens and the pixel position information of the input image obtained from the storage unit in accordance with the obtained photographic lens information, the input image data includes the first direction of the captured image and the First and second magnification chromatic aberration correction processing units that respectively perform magnification chromatic aberration correction processing in a second direction orthogonal to the first direction; and distortion correction in the first direction and the second direction. First and second distortion correction processing units that respectively perform correction processing, and first and second electronic magnification processing units that respectively perform the electronic magnification processing in the first direction and the second direction. An image processing apparatus comprising at least one image processing means.

At this time, the first and second magnification chromatic aberration correction processing units, the first and second distortion aberration correction processing units, and the first and second electronic variable power processing units of the processing means are arranged in the same manner. It is preferable that the order of the image processing for the first direction and the second direction can be selected, and the first and second magnification chromatic aberration correction processing units of the processing unit, the first and second Distortion correction processing unit,
And the first and second electronic magnification processing units perform at least one image processing among magnification chromatic aberration correction processing, distortion aberration correction processing, and electronic magnification processing in the first direction and the second direction. It is preferable to arrange so that the image processing of the smaller correction amount by the image processing is performed first, and further, the first and second magnification chromatic aberration correction processing units of the image processing means and the first and second chromatic aberration correction processing units It is preferable that the second distortion correction processing unit is arranged so that the first processing unit and the second processing unit perform processing with a smaller correction amount by the processing first. Further, the processing means obtains the input image data by photoelectrically reading the captured image by a line sensor having the first direction as a main scanning direction and the second direction as a sub-scanning direction. In this case, it is preferable that the image processing in the second direction further includes a color shift correction processing unit that performs a color shift correction process by the line sensor.

[0015]

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 shown in FIG. 1 basically includes a scanner (image reading device) 12 that photoelectrically reads an image captured on a film F, an image processing of read image data (image information), and a photo processing. An image processing apparatus 14 for performing operations and control of the entire printer 10 and an image exposure of a photosensitive material with a light beam modulated according to image data output from the image processing apparatus 14, and a developing process (finished) print And a printer 16 for outputting. Further, the image processing apparatus 14 includes an operation system 18 having a keyboard 18a and a mouse 18b for inputting (setting) various conditions, selecting and supporting processing, and inputting instructions such as color / density correction, and a scanner. A monitor 20 for displaying an image read at 12, various operation instructions, a setting / registration screen for various conditions, and the like is connected.

The scanner 12 is a device for photoelectrically reading an image photographed on the film F or the like. The light source 22, the variable aperture 24, and a diffusion device for making the reading light incident on the film F uniform in the surface direction of the film F. A box 28, an imaging lens unit 32, a CCD sensor 34 which is a photo sensor for reading one frame image of a film, and an amplifier (amplifier)
And a dedicated carrier 30 that can be attached to the main body of the scanner 12.

The carrier 30 has, for example, 13 pieces of 24 sheets.
Various dedicated carriers for long films, such as 5 size film, new photo system APS cartridges and film with lens, are available.
As shown schematically, while holding the film F at a predetermined reading position, the line CCD of the CCD sensor 34
A pair of transport rollers 3 that transports the film F in a sub-scanning direction that is orthogonal to the direction in which the sensor extends (main scanning direction), and that conveys the film F with the reading position interposed in the sub-scanning direction.
0a and 30b, and a mask 2 having slits 29a extending in the main scanning direction and located in correspondence with the reading position, for regulating projection light of the film F into a predetermined slit shape.
9, and a magnetic read / write device 31.

The CCD sensor 34 is schematically shown in FIG. 2B, and is a line CCD for reading an R image.
The sensor 34R has a line CCD sensor 34G for reading a G image and a line CCD sensor 34B for reading a B image. Each line sensor extends in the main scanning direction in the order of R, G, and B. I have. Film F
Are projected by the CCD sensor into R, G and B
And read photoelectrically.

The reading of the image by the CCD sensor 34 in the scanner 12 is performed by a pre-scan in which the image is read at a low resolution in order to determine image processing conditions and the like prior to image reading (main scan) for outputting the print P. Is performed, the image processing conditions are determined, and the operator confirms and adjusts the image on a monitor, and then performs a main scan for reading an image at a high resolution. In the pre-scan, the light is emitted from the light source 22 and
The reading light, the light amount of which has been adjusted by the variable aperture 24 and made uniform through the diffusion box 28, is incident on the film F held and conveyed at a predetermined reading position by the carrier 30 and transmitted therethrough, thereby being photographed on the film F. To obtain projection light carrying the image. The projection light of the film F is imaged 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 is subjected to image processing as image data. It is sent to the device 14.
This series of operations is not performed for each photographing frame, but one film at a time is continuously read at a constant speed.

When reading the film F continuously at a constant speed without discriminating the image frames, the film F of the new photographic system (APS) shown in FIG. 3, the conventional 135 film F or the film F of the brownie size is similarly used. The barcodes printed on the upper and lower areas S2 of the edge area S1 of the film F and the frames G1, G2, etc. are also at the same time.
Read by the CD sensor 34. In the case of a film with a lens photographed by a lens having a large aberration characteristic, the photographing lens is known in advance, and therefore, in a region S1 shown in FIG. As a part of
After the development, a bar code is displayed on the film F. Thereby, at the time of pre-scanning in which the image is read by the scanner 12, the barcode can be read together with the image, and the photographic lens type recognition code can be obtained.

A new photograph system (AP) shown in FIG.
In the film F of S), the upper and lower areas S of each of the tops G1, G2, etc. are provided on the back surface (non-emulsifier surface) side of the film F.
2 is provided with a magnetic recording layer, which can record photographing lens information and image photographing time as magnetic recording information at the time of photographing or printing.
The recorded magnetic information is read using the magnetic read / write device 31 shown in FIG. 2 and sent to the image processing device 14. As a result, it is possible to acquire various types of information such as the type of the photographed lens and the lens type recognition code. Also, the IC mounted on the film cartridge 33
Various types of information such as the type of the photographed lens and the lens type recognition code can be acquired from the memory.

In the main scan, similarly to the pre-scan, the reading light emitted from the light source 22, the light amount of which is adjusted by the variable aperture 24 and made uniform through the diffusion box 28 is held at a predetermined reading position by the carrier 30 and conveyed. When the light enters the transmitted film F and is transmitted therethrough, projection light carrying an image photographed on the film F is obtained. The projection light of the film F is imaged 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 the image signal is input as image data. It is sent to the processing device 14. This series of operations is performed for each photographing frame based on the center position information of each image frame obtained at the time of the prescan described later, unlike the prescan.

A block diagram of one embodiment of the image processing device 14 is shown in FIG. Image processing device 14 shown in FIG.
Is a unit that performs predetermined image processing on input image data digitized by the scanner 12 and outputs the processed image data to a printer. The data processing unit 38, the prescan memory 40, the main scan memory 42, the prescan image processing unit 44, and the main scan image Processing unit 46, condition setting unit 48, and correction coefficient setting unit 6
It consists of 0.

In the data processing section 38, each of the R, G and B output signals output from the scanner 12 is subjected to A / D (analog / digital) conversion, Log conversion, DC offset correction, dark correction, shading correction and the like. The pre-scan (image) data is stored in the pre-scan memory 40, and the main scan (image) data is stored (stored) in the main scan memory 42.
Is done.

The pre-scan memory 40 and the main scan memory 42 store the input image data processed by the data processing section 38, and perform a pre-scan image processing section to perform image processing and output as necessary. 44 or the main scan image processing unit 46.

The pre-scan image processing section 44 includes an image processing section 50 and an image data conversion section 52. The image processing section 50 includes an image data extraction section 49, an LUT / MTX operation section 62, an image correction section 51, and others. The image data extracting unit 49 further includes a lens type recognizing unit 49A (see FIG. 5) and a center position calculating unit 49B.
(See FIG. 5). Hereinafter, FIG. 5 will be described with reference to FIG.

The lens type recognizing section 49A (see FIG. 5) of the image data extracting section 49 extracts and recognizes the photographing lens type recognizing code in the lot code information from the data simultaneously captured together with the image in the prescan. Then, the photographic lens type recognition code is sent to the correction coefficient setting unit 60. The lot code is represented by an 8-digit decimal number, and the photographing lens type recognition code is a code number from 0 to 99 using the lower 3 and 4 digits therein. For example, if the shooting lens type recognition code is 01, the lens type 1
In the case of 02, it is recognized as lens type 2 or the like.
The center position calculation unit 49B (see FIG. 5) detects a captured image from the pre-scan image data for one film, cuts out the image, and calculates the center position of the image. The reason why the center position is calculated is that a correction equation for performing a correction process for chromatic aberration of magnification and distortion, which will be described later, is expressed as a function from the center position of the image. In addition, the calculated center position of the pre-scan image data is associated with the main scan image data with a certain degree of accuracy, and the center position of the image data of the main scan image data is determined by using the correspondence. Can be.

The LUT / MTX operation unit 62 performs color balance adjustment, contrast correction, and brightness correction image processing. The image correction unit 51 uses a correction formula based on the characteristics of the photographing lens determined by a correction coefficient setting unit 60, which will be described later, to correct the chromatic aberration of magnification, the correction process of the distortion, and the correction process of the color shift of the scanner. Are performed by a lens aberration correction unit 51A (see FIG. 5), and the enlargement / reduction unit 51B (see FIG. 5) performs enlargement / reduction of an image by electronic scaling processing. Further, for the first direction and the second direction orthogonal to the first direction in which the captured image is a feature of the image processing method of the present invention, magnification chromatic aberration correction processing is separately performed,
This is a part where a processing method for performing distortion aberration correction processing and electronic scaling processing is performed. The other image and other image processing unit 53 performs a process of correcting aberration of image data, a process of electronic scaling, and then performs a sharpness process, a dodging process, and the like in accordance with an instruction of an operator. 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 image processing section 54 and an image data conversion section 58. The image processing unit 54 is further subdivided into an LUT / MTX operation unit 64, an image correction unit 56, and another image processing unit 57. L
The UT / MTX operation unit 64 performs color balance adjustment, contrast correction (gradation processing), and brightness correction on the main scan image data under an image processing condition determined in the pre-scan image data by using an LUT (lookup table).
, And saturation correction is performed by a known method by MTX calculation (omitted in FIG. 5). The lens aberration correction unit 56A (see FIG. 5) in the image correction unit 56 uses the correction formula based on the characteristics of the photographing lens determined by the correction coefficient setting unit 60, which will be described later, to correct the chromatic aberration of magnification and the distortion. Is performed, and the color shift of the scanner is corrected as necessary. The enlargement / reduction unit 56B (see FIG. 5) enlarges / reduces the image by electronic scaling processing. The other image processing unit 57 performs a sharpness process, a dodging process, and the like according to an instruction from the operator. The image data conversion unit 58 converts the image data subjected to the image processing in the image processing unit 54 into image data to be printed out to the printer 16 by 3D (three-dimensional) -processing.
Conversion is performed using an LUT or the like.

The condition setting section 48 reads the pre-scan image data from the pre-scan memory 40, and is used to determine image processing conditions (not shown in FIG. 5). Specifically, from the pre-scanned image data, a density histogram is created, and image feature values such as average density, LATD (large area transmission density), highlight (lowest density), and shadow (highest density) are calculated. In addition, image processing conditions such as creation of a table (LUT) for gray balance adjustment and matrix calculation for performing saturation correction are determined in accordance with instructions from the operator performed as needed. The determined image processing conditions are further adjusted by the key correction unit 74, and the image processing conditions are reset. The output conditions such as the print size, the number of output pixels, and the electronic magnification for printing are set by the keyboard 18a and the mouse 18b.
Can be specified by

The correction coefficient setting section 60 includes a correction coefficient storage section 6
0A (see FIG. 5) and the correction parameter calculation unit 60B (see FIG. 5).
The correction coefficient storage unit 60A (see FIG. 5) stores correction coefficients for chromatic aberration of magnification and distortion for each photographing lens type recognition code, and a correction parameter calculation unit 60B (see FIG. 5). Can detect, analyze,
After recognizing and correcting the magnification chromatic aberration characteristic and the distortion characteristic of the lens corresponding to the recognition code, the correction coefficient storage unit 60A (FIG. 5).
), And calculates a pixel-by-pixel correction formula determined by the number of input pixels of the scanner 12, the print output size, the number of print output pixels, and the electronic scaling factor. Further, when the distortion correction processing is performed, a missing image without a captured image occurs in a peripheral area of a rectangular image, so that the image is enlarged at an electronic magnification that is larger than a preset electronic magnification, and the desired print size can be accommodated. For this reason, the electronic magnification is finely adjusted to the minimum electronic magnification which does not unnecessarily expand. However, the amount of image missing is calculated to calculate a fine adjustment coefficient for the fine adjustment.

The correction coefficient storage unit 60A (see FIG. 5)
Stores the correction coefficients of the correction formulas for the chromatic aberration of magnification and the distortion for each lens type recognition code. If necessary, a correction coefficient supply unit 60C (not shown) (see FIG. 5)
FD (floppy disk), MO (magneto-optical disk), and various storage media such as Zip can update the correction coefficient of the new lens type. In addition to the use of networks such as the Internet,
The correction factor may be updated using a telephone line. Further, the correction parameter calculating unit 60B (see FIG. 5) calculates a pixel-by-pixel correction coefficient determined by the input / output conditions from the called-up millimeter correction coefficient to obtain a correction formula. A correction coefficient determined by the number of output pixels, the document size, and each condition of the electronic scaling process may be obtained in advance and stored as a table, and the correction coefficient satisfying the condition may be directly called to obtain a correction formula.

FIG. 4 mainly shows parts related to image processing. The processing unit 14 includes a CPU for controlling and managing the entire photo printer 10 including the image processing unit 14, A memory for storing information necessary for the operation of the photo printer 10 and the like, a variable aperture 24 for the main scan
For example, means for determining the aperture value and the accumulation time of the CCD sensor 34 are arranged. The monitor 20 shown in FIG. 4 is used by an operator to check and verify whether image processing of prescanned image data is appropriate.
Is connected to the image processing apparatus 14 via the.

Next, the operation of the image processing apparatus 14 shown in FIG. 4 will be described with reference to the flowchart of an example of the image processing method of the present invention shown in FIG. The pre-scan image data stored in the pre-scan memory 40 is stored in an image condition setting unit 72.
And generates image density such as average density, LATD (large area transmission density), highlight (lowest density), shadow (highest density), etc. Table (LU) for gray balance adjustment, etc.
T) and image processing conditions such as creation of a matrix operation (MTX) for performing saturation correction are determined. The determined image processing conditions are further adjusted by the key correction unit 74, the image processing conditions are reset, all the conditions are integrated by the parameter integration unit 76, and sent to the image processing units 50 and 54.

On the other hand, the data of one film read by the scanner 12 is sent to the image data extracting section 49, and the photographic lens type recognition section 49A recognizes the photographic lens in the lot code code recorded in the area S1 of the film F. Recognize the code. In the case where the photographing lens type recognition code is not present or not recognized in the photographing lens type recognition unit 49A, or when the later-described aberration correction is not performed on the pre-scan image data for monitor display, the LUT / MTX calculation unit 62 (see FIG. ), Color balance adjustment, contrast correction (gradation processing), brightness correction, and the like are processed according to processing conditions instructed by the operator, and then correction of magnification chromatic aberration and distortion described below is not performed, and lens aberration correction is performed. The unit 51A passes through and performs an electronic scaling process in accordance with the output print size in the enlargement / reduction unit 51B. The other image processing unit 53 performs a sharpness process, a dodging process, and the like. The image is converted for display on a monitor and displayed on the monitor 20. When the photographing lens type recognition code is recognized, the recognized code is sent to the correction coefficient setting unit 60.

On the other hand, in the center position calculating section 49B in the image data extracting section 49, since the data called from the pre-scan memory 40 (see FIG. 4) is the data of one film, one frame of the image is obtained from the data. Is detected and sent to the LUT / MTX processing unit 62 (see FIG. 4), and the center position of the image data is calculated. The center position of the image data is calculated because the correction formula for correcting the chromatic aberration of magnification and distortion is expressed as a function from the center position of the image data. This is because the center position is associated with the main scan image data with a certain degree of accuracy, and by utilizing the correspondence, the center position of the image data of the main scan image data can be determined. Since the calculated center position is used in a correction formula for correcting lateral chromatic aberration and distortion, it is sent to the lens aberration correction unit 51A.

The correction parameter calculation section 60B in the correction coefficient setting section 60 loads, from the correction coefficient storage section 60A, correction coefficients for chromatic aberration of magnification and distortion according to the transmitted photographic lens type recognition code. The called correction coefficient corresponds to a coefficient of a function of a predetermined correction formula, and is a correction coefficient in units of millimeters. For this reason, the final coefficient of a pixel-by-pixel correction formula of an image determined from the number of input pixels of the scanner 12, the monitor display size and the print output size, the monitor display pixel number and the print output pixel number, and the electronic magnification is calculated. In addition, when the distortion aberration correction processing is performed, an image lacking in a peripheral area of a rectangular image without a captured image occurs, so that the image is enlarged at an electronic magnification larger than a preset electronic magnification, and a desired image display size and Fine adjustment is made to the minimum electronic scaling ratio that does not unnecessarily enlarge to accommodate the print output size, and the image missing amount is calculated to calculate a fine adjustment coefficient for the fine adjustment. The calculated final coefficients of the lateral chromatic aberration and distortion correction equations are sent to the lens aberration corrector 51A in the image corrector 51, while the calculated image missing amount is used by the operator to confirm and confirm the prescan image. Sent to monitor 20 for display. This is for displaying a rectangular image missing area frame determined from the image missing amount together with the prescan image. Further, it is sent to the scaling unit 51B for calculating the fine adjustment coefficient α of the electronic scaling factor K in the electronic scaling process. The product .alpha.K of the fine adjustment coefficient .alpha. And the electronic scaling factor K is a finely adjusted electronic scaling factor, which is used to perform electronic scaling processing at the time of printout.

In the present embodiment, correction processing of chromatic aberration of magnification and distortion is performed on pre-scan image data,
Although the image missing area of the rectangular frame is displayed, the prescanned image and the image missing area frame which have been subjected to the electronic scaling processing without performing the correction processing of the magnification chromatic aberration and the distortion for quick processing are displayed on the monitor 20. It may be displayed.

The pre-scan image data is LUT / MT
After predetermined processing is performed in the X processing unit 62 (see FIG. 4),
Using the correction formula having the final coefficient sent from the correction coefficient setting unit 60, the center position of the image data sent from the center position calculation unit 49B, and the pixel position information of the image to be corrected, the lens aberration correction unit 51A Performs the correction process of the chromatic aberration of magnification and the correction process of the distortion, and also performs the color shift correction process by the scanner 12 as necessary.

Next, electronic scaling processing is performed by the scaling section 51B in the image correction section 51. The electronic magnification change processing is performed after the correction processing of the chromatic aberration of magnification, the correction processing of the distortion aberration, and the correction processing of the color shift of the scanner, because it is necessary to enlarge or reduce the image using appropriate position information. The enlargement / reduction unit 51B calculates an electronic scaling factor K for enlarging or reducing the image data corrected by the lens aberration correction unit 51A in accordance with the display size or the number of pixels on the monitor, and uses the calculated electronic scaling factor K for electronic scaling. I do.

When the lens type recognition code is not present or is not recognized, the magnification correction and the distortion correction are not performed by the lens aberration corrector 51A, and the electronic scaling process is directly performed by the enlargement / reduction unit 51B. Done. In this case, the correction coefficients for the distortion and the chromatic aberration of magnification are set to zero. 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.

Now, the lens aberration correction unit 51A and the enlargement / reduction unit 51B are features of the image processing method and the image processing means of the image processing apparatus of the present invention, that is, the first direction of the photographed image and the first direction. This is a portion for separately performing the correction process of the chromatic aberration of magnification, the correction process of the distortion aberration, and the electronic scaling process in each of the second directions orthogonal to the directions. In the flowchart of one embodiment of the image processing method of the present invention shown in FIG. 5, the flow of the correction process of the chromatic aberration of magnification, the correction process of the distortion aberration, and the electronic scaling process is performed without distinction between the first direction and the second direction. Although briefly described, FIG. 6 illustrates an example of the flow of the image processing method which is a feature of the image processing method of the present invention, including a process of correcting chromatic aberration of magnification,
In the description, the distortion correction processing and the electronic scaling processing are distinguished from each other in the first direction and the second direction. That is, this is a case where an input image is obtained by photoelectrically reading with a line sensor having the first direction as the main scanning direction and the second direction as the sub-scanning direction, and the chromatic aberration of magnification in the main scanning direction which is the first direction. , Correction chromatic aberration and electronic scaling, and then chromatic aberration of magnification and distortion chromatic aberration in the sub-scanning direction, which is the second direction, color shift correction of the scanner, and electronic scaling. .

The reason why the image processing is separately performed in the first direction and the second direction will be described below. FIG.
When the image processing method of the present invention separately performs the first direction and the second direction image processing, how the position of one pixel on the image is moved by the image processing, shows a conceptual diagram thereof. ing. Conventionally, magnification chromatic aberration, distortion chromatic aberration correction processing and at least one image processing determined from electronic scaling processing, or image processing with the addition of scanner color shift correction processing that is added as needed The input data is converted at a time to obtain corrected output image data. That is, image processing is performed in which a point A0 of a certain subject in an image is set as a pixel position (x0, y0) before correction, and distortion correction processing, chromatic aberration of magnification correction processing, and enlargement / reduction processing of electronic magnification are collectively performed. If
The correction amount of the pixel position A0 by this image processing is Dx, Dy
Then, since the correction amount changes depending on the pixel position A0 (x0, y0), the correction amounts Dx and Dy are represented by x and y functions, respectively. That is, Dx is Dx (x0, y
0) and Dy are Dy (x0, y0). Then, the pixel position A0 (x0, y0) is A1 (x0 + D
The image moves to the position of x (x0, y0), y0 + Dy (x0, y0)). To perform this image processing, the correction amounts Dx and Dy are calculated using the pixel position A0 (x0, y0) before the image processing.
Therefore, in order to perform the processing of the entire image, it is necessary to store the position information of the entire image before the image processing in the memory and the memory for two screens for storing the position information after the image processing.

On the other hand, in the image processing method of the present invention, one point of a certain subject in the image is located at the pixel position A0 (x0,
y0), the main scanning direction which is the first direction is the y direction,
When the sub-scanning direction which is the second direction is the x direction, first, the movement in the x direction is fixed, and the movement in the y direction (main scanning direction) is considered, and the correction amount Dy (x0, y0) is obtained. Accordingly, the pixel position A0 (x0, y0) before the processing moves to A2 (x0, y0 + Dy (x0, y0)) after the processing.
Next, a correction amount Dx is obtained by considering movement in the x direction (sub-scanning direction) using the processed information. At this time, since the pixel position A2 (x0, y0 + Dy (x0, y0)) is processed, the correction amount Dx in the x direction (sub-scanning direction) is processed.
Is Dx (x0, y0 + Dy (x0, y0)), and finally the pixel position A0 (x0, y0) after image processing is A3
(X0 + Dx (x0, y0 + Dy (x0, y0)), y
0 + Dy (x0, y0)).

In this image processing method, pixel positions A1 (x0 + D) after accurate image processing obtained by the above-described conventional method are obtained.
For x (x0, y0), y0 + Dy (x0, y0)), A3 (x0 + Dx (x0, y0 + Dy (x0, y)
0)), y0 + Dy (x0, y0)), which do not completely match, but when output as an image, the difference is small and sufficiently acceptable. Furthermore, the movement in the x direction is fixed, and the movement in the y direction is considered.
Since one-dimensional processing is performed for obtaining y and then using the data after moving in the y-direction and considering the movement in the x-direction and calculating the movement amount Dx, the memory to be stored may be a one-dimensional line memory. The amount is smaller than that of the conventional method, and the correction processing time is shortened, leading to an increase in processing speed. Furthermore, since the correction amounts Dx and Dy are separately performed, only the correction coefficient, which is a parameter of the correction formula, needs to be changed, and the same circuit can be used in hardware, which leads to a reduction in hardware cost. Having.

The above is a feature of the image processing method and the processing means of the image processing apparatus of the present invention. In the above description, the processing in the main scanning direction is performed first, and then the processing in the sub scanning direction is performed. However, the processing in the sub scanning direction may be performed first, and then the processing in the main scanning direction may be performed. . Generally, the aberration characteristic of a lens is constant in a direction in a plane perpendicular to the optical axis, but in a direction perpendicular to the longitudinal direction of the film (main scanning direction), the film curves concavely as viewed from the taking lens. In this case, the distortion and chromatic aberration of magnification in that direction are smaller than in the longitudinal direction (sub-scanning direction). As a result, the correction amount of distortion and chromatic aberration of magnification in the main scanning direction of input image data is The correction amount in the main scanning direction is different from the correction amount in the sub-scanning direction. In this case, when the correction in the direction of the smaller correction amount is performed first, the distortion and the chromatic aberration of magnification are smaller than in the case where the correction in the direction of the larger correction amount is performed first, and the deterioration of the image quality is suppressed. Therefore, when the correction amount in the main scanning direction is different from the correction amount in the sub-scanning direction, it is preferable to perform the processing in the direction in which the correction amount is small (either the main scanning direction or the sub-scanning direction) first.

In the embodiment shown in FIG. 6, taking into account that the film with the lens is curved concavely when viewed from the taking lens in the direction (main scanning direction) perpendicular to the longitudinal direction of the film, Of the magnification chromatic aberration, the distortion aberration correction, and the electronic magnification change processing, and then the magnification chromatic aberration correction processing, the distortion aberration correction processing, and the electronic magnification change processing in the sub-scanning direction. ing.

In the processing in the sub-scanning direction, a color shift correction processing of the scanner is provided between the correction processing of the chromatic aberration of magnification and the correction processing of the distortion and the enlargement / reduction processing of the electronic magnification processing. This is because the line CCD sensor 34 that reads the R image when reading by the scanner 12
Line CCD sensor 34 for reading R and G images
Line CCD sensor 34B for reading G and B images
Read the R, G, and B images, respectively, but since the line sensors 34R, 34G, and 34B extending in the main scanning direction are arranged at regular intervals in the sub-scanning direction, each image is read by a preset reading method. There is a case where an image shift occurs between them. Therefore, before the enlargement process is performed in the electronic scaling process, the R, G, and B images are shifted, that is, the color shift of the scanner is corrected. As described above, although the processing contents are different in the main scanning direction and the sub-scanning direction, a processing circuit including all of the correction processing of the chromatic aberration of magnification, the correction processing of the distortion, the correction processing of the color shift of the scanner, and the electronic scaling processing is included. When the correction processing in the main scanning direction is performed, the color misregistration correction processing of the scanner is skipped by setting the parameter, and in the case of the correction processing in the sub-scanning direction, all the correction processing can be performed. . Thus, the processing can be performed by the same circuit regardless of the distinction of the direction to be processed. In addition, the image processing method of separately performing the correction processing in the first direction and the correction processing in the second direction not only corrects lateral chromatic aberration and distortion, but also corrects peripheral light reduction and out-of-focus caused by a lens. May be.

After the image correction section 51 performs the correction processing,
The image data is sent to the other image processing unit 53 to perform sharpness processing, dodging processing, and the like, and then sent to the image data conversion unit 52, where the image data is converted into monitor display image data.
Displayed as 0. The operator looks at the image displayed on the monitor 20 and checks whether or not the image processing is appropriate.
The operator looks at the image displayed on the monitor 20 and adjusts the processing conditions if inappropriate. When the operator adjusts the processing conditions for all pre-scanned images, the main scan starts.

The main scan is different from the prescan in that the scanner 12 reads the image at a high resolution, performs image processing under the image processing conditions defined by the prescan image, and obtains image data for printout. When the pre-scan is completed, the film F has been pulled out from the film cartridge 33 up to the last frame of the image. In the main scan, the frame of the image is read using the rewinding of the film F from that state. At this time, the center position of the frame on the film of each image is calculated from the image center position of the pre-scanned image data, so that the image is fully scanned for each frame using the center position information. R, G, and B output signals output from the scanner 12 are A / D (analog / analog).
Digital) conversion, Log conversion, DC offset correction, darkness correction, shading correction, and the like are performed to obtain digital input image data, and the main scan image data (fine scan image data) is stored (stored) in the main scan memory 42. You.

The main scan image data (fine scan data) stored in the main scan memory 42 is an LUT
Various kinds of data are sent to the MTX processing unit 64 by using a table (LUT) for gray balance adjustment and a matrix operation (MTX) for performing saturation correction based on image processing conditions adjusted and determined by the operator for the prescan image. Perform image processing. After being processed by the LUT / MTX processing unit 64, it is sent to the image correction unit 56. Similarly to the pre-scan image data, the image correction unit 56 uses the lens type information obtained at the time of the pre-scan to perform the correction process of the chromatic aberration of magnification and the correction process of the distortion by the lens aberration correction unit 56A, if necessary. Then, a color misregistration correction process of the scanner is performed, and an electronic scaling process is performed by the scaling unit 56B. In this case, since the main scan image data is output as a print output image, the correction coefficient is set according to the number of output pixels of the printer and the output conditions set at the time of prescan, such as the printer output size and the number of pixels of the input image data. Changes, and is different from the final correction coefficient determined by the prescan image data to be displayed on the monitor 20. The final correction coefficient used for the main scan image data is calculated at the time when the prescan image is confirmed and verified by the operator. In addition, the image missing amount generated by the distortion aberration correction processing is calculated, and the fine adjustment coefficient α of the electronic magnification K for preventing the image missing is also calculated.

The image data is corrected using the correction coefficient, the electronic scaling factor K, and the fine adjustment coefficient α. As in the case of the pre-scan image data, the main scan direction and the sub-scan direction of the image determined when the main scan image data is obtained. In the scanning direction, a chromatic aberration correction process, a distortion aberration correction process, and an electronic scaling process are separately performed. In particular,
Similarly to the pre-scan image data, as shown in FIG. 6, a process of correcting magnification chromatic aberration and distortion in the main scanning direction and an electronic scaling process are performed, and then a process of correcting magnification chromatic aberration and distortion in the sub-scanning direction. In addition, the electronic magnification change processing is performed, and the color misregistration correction processing of the scanner is performed after the magnification chromatic aberration and distortion aberration correction processing and before the electronic magnification change processing. The color misregistration correction processing of the scanner is for correcting the color misregistration in the sub-scanning direction of each of the R, G, and B images by the line sensors 34R, 34G, and 34B arranged at regular intervals in the sub-scanning direction of the scanner 12. The reason why the correction processing in the main scanning direction is performed first is that the film may be curved concavely when viewed from the photographing lens in a direction perpendicular to the elongate direction (main scanning direction) as in the case of pre-scanning. This is because the correction amount in the (main scanning direction) is small, and the deterioration of the image quality of the entire image is less when the correction process is performed first in the direction in which the correction amount is small. If there is no lens type recognition code, or if the lens type recognition code is not recognized, as in the case of the pre-scan image data, the magnification chromatic aberration correction processing and the distortion aberration correction processing are not performed, and the electronic variable power processing is performed.

The chromatic aberration of magnification is corrected by the image correction unit 56,
After performing distortion correction processing, scanner color shift correction processing, and electronic scaling processing as necessary, the image data is sent to the other image processing unit 57. The other image processing unit 57 performs a sharpness process, a dodging process, and the like as necessary,
Thereafter, the image data is sent to the image data conversion unit 58. The image is converted into data for printer output by the image data converter 58 and sent to the printer 16 as output image data. Also, an index print is performed based on the main scan image data.

The printer 16 exposes a photosensitive material (printing paper) in accordance with the supplied image data to record a latent image and prints a latent image on the photosensitive material. Processor (developing device) to output as print
It is composed of The recording device cuts the photosensitive material into a predetermined length corresponding to the print, and then outputs three types of beams, R exposure, G exposure, and B exposure, according to the spectral sensitivity characteristics of the photosensitive material. The light beam is modulated in accordance with the data and deflected in the main scanning direction, and the photosensitive material is conveyed in the sub-scanning direction orthogonal to the main scanning direction. And supply it to the processor. The processor that has received the photosensitive material performs a predetermined wet developing process such as color development, bleach-fixing, and washing with water, and then dries and sorts the prints into predetermined units such as one film to accumulate.

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.

[0057]

As described above in detail, according to the present invention, the distortion chromatic aberration correction processing, the magnification chromatic aberration correction processing, the electronic magnification change processing, and the color shift correction processing of the scanner as required are performed in the main scanning direction. In order to perform each in the sub scanning direction independently,
By changing only the correction coefficient, which is a parameter used in the correction formula, processing can be performed by the same circuit without distinction between the main scanning direction and the sub-scanning direction. As a result, the cost and the size of the image processing apparatus can be reduced. Further, the processing speed is improved, and even a high-quality image without distortion or color shift can be processed in a large amount in practical use, even if the image is captured by an inexpensive camera such as a film with a lens.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of an image reproducing apparatus including an image processing apparatus that performs an image processing method of the present invention.

FIG. 2A is a perspective view schematically showing a main part of an image reading apparatus used in the image processing apparatus shown in FIG. 1, and FIG. 2B is used in the image reading apparatus shown in FIG. FIG. 2 is a schematic diagram illustrating an arrangement of CCD line sensors.

FIG. 3 is a plan view of a film set in the image reading apparatus shown in FIG.

FIG. 4 is a block diagram showing an embodiment of the image processing apparatus of the present invention.

FIG. 5 is a flowchart of an embodiment of the image processing method of the present invention.

FIG. 6 is a flowchart showing one embodiment of a characteristic part of the image processing method of the present invention.

FIG. 7 is a conceptual diagram showing a difference between the image processing method of the present invention and a conventional image processing method.

[Explanation of symbols]

 10 (Digital) Photo Printer 12 Scanner 14 Image Processing Device 16 Printer 18 Operation System 18a Keyboard 18b Mouse 20 Monitor 22 Light Source 24 Variable Aperture 28 Diffusion Box 29 Mask 30 Carrier 31 Magnetic Read / Write Device 32 Imaging Lens Unit 33 Film Cartridge 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 49 Image data extraction unit 50, 54 (Image) processing unit 51, 56 Image correction unit 52, 58 Image data conversion unit 53, 57 Other image processing unit 60 Correction coefficient setting unit 62, 64 LUT / MTX calculation unit 72 (Image processing condition) setting unit 74 Key Tadashibu 76 parameter coordinating subsection

Claims (9)

[Claims] 1. An input image data is obtained from an image optically photographed using a photographing lens, and the lens characteristics of the photographing lens that photographed the image are obtained. Then, the obtained lens characteristics and the photographed image are obtained. When performing image processing on the input image data using the pixel position information and, for each of a first direction of the captured image and a second direction orthogonal to the first direction, respectively, An image processing method comprising: performing at least one of a chromatic aberration of magnification correction process, a distortion aberration correction process, and an electronic scaling process on the input image data. 2. An image of at least one of a magnification chromatic aberration correction process, a distortion aberration correction process, and an electronic scaling process, separately for each of the first direction and the second direction of the captured image. The image processing method according to claim 1, wherein when performing the processing, an order of the image processing in the first direction and the second direction can be selected. 3. At least one image processing of magnification chromatic aberration correction processing, distortion correction processing, and electronic magnification processing in each of the first direction and the second direction of the captured image. 3. The image processing method according to claim 1, wherein when performing, at least one of a chromatic aberration of magnification correction amount and a distortion aberration correction amount differs between the first direction and the second direction. 4. 4. The magnification chromatic aberration correction processing and the distortion aberration correction processing include a correction processing in a direction in which the magnification chromatic aberration correction amount and the distortion aberration correction amount are small in the first direction and the second direction, respectively. 4. The image processing method according to claim 3, wherein the method is performed first. 5. The method according to claim 1, wherein the captured image is photoelectrically read by a line sensor having the first direction as a main scanning direction and the second direction as a sub-scanning direction to obtain the input image data. 5. The image processing method according to claim 1, further comprising performing a color shift correction process using the line sensor in the image processing in the second direction. 6. 6. 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. Acquiring means for acquiring information on a photographing lens that has photographed the image; storage means for storing lens characteristics of the photographing lens in accordance with the information on the photographing lens; and a photographing lens information acquired by the acquiring means. Using the lens characteristics of the corresponding photographing lens and the pixel position information of the input image obtained from the storage means, the input image data is used to add a first direction of the photographed image and a second direction orthogonal to the first direction. First and second magnification chromatic aberration correction processing units that respectively perform the magnification chromatic aberration correction processing in the directions of the first and second directions, and the first and second magnification chromatic aberration correction processing that perform the distortion aberration correction processing in the first direction and the second direction, respectively. Image processing comprising at least one of a first and a second electronic magnification processing unit for performing electronic magnification processing in the first direction and the second direction, respectively. And an image processing apparatus. 7. The image processing means according to claim 1, wherein said first and second magnification chromatic aberration correction processing units, said first and second distortion aberration correction processing units, and said first and second electronic scaling processing units are provided. 7. The order of image processing in the first direction and the second direction can be selected.
An image processing apparatus according to claim 1. 8. The image processing means according to claim 1, wherein said first and second magnification chromatic aberration correction processing units and said first and second distortion aberration correction processing units are a first processing unit and a second processing unit. 8. The image processing apparatus according to claim 7, wherein the processing is performed such that the processing with the smaller correction amount by the processing is performed first. 9. The image processing means further comprising: photoelectrically reading the captured image with a line sensor having the first direction as a main scanning direction and the second direction as a sub-scanning direction; When obtaining image data, the image processing in the second direction further includes a color shift correction processing unit that performs a color shift correction process by the line sensor. The image processing apparatus according to any one of the preceding claims.