JPH1083024A - Camera and printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the quality of a print by eliminating the unevenness of density and color balances caused by different cameras or different kinds of cameras. SOLUTION: A standard picture is taken and balance data of density and color is calculated based on the taken standard picture data. This balance data is previously stored in the ROM 19 of the camera 10. When photographing is executed by the camera 10 and then, the taken picture data is outputted, the above-mentioned balance data is outputted as well. In a digital printer 25, the picture data and the above-mentioned balance data are read by a picture data input part 26. In a table data preparing part 30, correction table data for correcting the taken picture data of the camera is prepared with the balance data. A correcting LUT 31 corrects the picture data from the camera by using the correction table data, to execute printing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera and a printer, and more particularly, to a camera and a printer which eliminate variations in density and color balance due to differences in camera models and machine differences.

[0002]

2. Description of the Related Art Images taken by a digital still camera are output by various printers such as a silver halide type, an ink jet type, and a thermal recording type. Before being output by a printer, the data is taken into a personal computer or the like, and is printed after being subjected to various image processing.

[0003]

Images taken with a digital still camera or the like have variations in density and color balance due to differences in models and machines, and when printed as it is, the print quality deteriorates due to these variations. There is a problem of doing. Further, geometric distortion and density unevenness may occur, and in this case, there is a problem that print quality is deteriorated. Furthermore, since the input characteristics of the digital camera and the output characteristics of the printer are different, there is a problem that color matching is difficult.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has been made to eliminate variations in density and color balance due to differences in camera models and differences, and to prevent print quality from deteriorating. It is an object to provide a camera and a printer.

[0005]

According to a first aspect of the present invention, there is provided a camera having a recording medium in which density or color balance data calculated based on standard image data of a standard image is recorded. And outputting the density or color balance data when outputting photographed image data.

A printer according to a second aspect of the present invention reads photographic image data from a camera and the density or color balance data, and corrects photographic image data from the camera based on the density or color balance data. The printing is performed using the captured image data.

[0007] Instead of obtaining the density or color balance data on the camera side, a standard image is simply photographed on the camera side, and the photographed standard image data and the identification data of the standard image are recorded on a recording medium in advance. When outputting captured image data, the standard image data and the identification data of the standard image may be output. In this case, the captured image data from the camera and the standard image data and the identification data of the standard image are read, and the density or the density for correcting the captured image data of the camera based on the standard image data and the identification data of the standard image is read. It is preferable to create a color correction table and print using the photographed image data corrected by the density or color correction table. In addition, instead of obtaining the density or color correction data based on the standard image data and the identification data of the standard image, a two-dimensional geometric distortion of the camera is detected to calculate a distortion correction amount, and photographing is performed using the distortion correction amount. The two-dimensional geometric distortion of the image data may be corrected, and printing may be performed using the corrected captured image data. Further, density unevenness of the camera is detected based on the standard image data and the identification data of the standard image, a shading correction amount for correcting the density unevenness is calculated, and the photographed image data is corrected using the shading correction amount. It is preferable to perform printing using the corrected photographed image data.

Further, the camera detects two-dimensional geometric distortion instead of obtaining density or color correction data based on the data obtained by photographing the standard image, records the distortion data in a recording medium in advance, When outputting the converted image data, the distortion data may also be output.
Furthermore, density unevenness may be detected instead of the distortion data, and the density unevenness data may be sent to the printer together with the photographed image data. Further, various data based on the captured standard image data is preferably obtained for each camera, and various data based on the captured standard image data may be obtained for each camera model or each production lot. Good.

[0009]

In an inspection process or the like, a standard image is photographed by a camera, and density or color balance data is calculated based on the standard image data. For this density or color balance data, for example, a standard image consisting of a uniform gray pattern is prepared in about 10 steps with different densities, and these are sequentially photographed to determine the relationship between the standard image density value and the camera photometric density value. It is determined for each of R, G, and B colors. In this way, a density or color balance table is obtained for each pixel, and this is recorded on a recording medium of the camera, for example, a ROM. After shooting with the camera, along with the captured image data,
The density or color balance data unique to the camera recorded in advance is output. The printer reads the captured image data from the camera and the density or color balance data. Then, based on the density or color balance data, correction is performed so that the image data captured by the camera has ideal characteristics. For example, a correction table indicating the relationship between the image data on the camera side and the corrected density value is created, and the image data on the camera side is corrected into corrected image data based on this table data. Then, printing is performed based on the corrected image data.

[0010]

FIG. 1 is a schematic view showing a camera according to the present invention. The digital still camera 10 includes an imaging unit 1
1, an image processing unit 12, a buffer memory 13, a system controller 14, and an image data writing unit 15. The imaging unit 11 includes a three-plate image area sensor and captures an image of a subject. Image processing unit 12
Performs A / D conversion after performing gamma conversion and known image processing, and stores this in the buffer memory 13. The buffer memory 13 includes two frame memories 13a and 13b. When one frame memory 13a performs a data compression process or the like, the other frame memory 13b stores image data from the image processing unit 12 in the other frame memory 13b. Can be written.

The image data writing section 15 reads digital image data for one frame from one of the buffer memories 13a and 13b and stores the image data in 1/10 to 1/2.
With a compression ratio of about 0, JPEG (Joint Photographic Expe
rts Group) Compress. The compressed image data is written to the IC memory card 16. Note that the data compression method is not limited to JPEG, and another well-known compression method may be used.

The system controller 14 comprises a well-known microcomputer, and includes an MPU 17, RA
M18, ROM 19 and the like are provided. In the ROM 19, in addition to a program for controlling the sequence of the entire camera, balance data is written. The balance data is obtained in an inspection process, and is written in a predetermined area of the ROM 19.

The balance data is calculated based on image data from each pixel of the CCD of the image pickup unit 11 obtained by photographing standard images SI1 to SI8 as shown in FIG. . Standard image SI
As examples 1 to SI8, for example, gray patterns G1 to G1 having a uniform density as shown in FIGS.
G8 is used. The gray patterns G1 to G8 are
For example, a density that is changed in steps of “0.2” is used. Gray patterns G1 to G1 of these densities
G8 is photographed, and based on the obtained image data, the amount of shift of each color of R, G, and B from the neutral gray density is obtained for each gray density, thereby obtaining balance data for each pixel.

FIG. 3 shows balance data for red, S1 shows an ideal state, and S2 shows an example of actual balance data. In addition, balance data is similarly obtained for green and blue. The obtained balance data is written into the ROM 19, and the ROM 19 in which the balance data has been written is replaced with the previously set ROM 19. Note that, instead of reloading the ROM 19 in which the camera-specific balance data is written, the inspection apparatus obtains the camera-specific balance data and writes it in the ROM 19, and then writes the RO
M19 may be loaded in the camera.

The balance data written in the ROM 19 is written in the balance data area of the memory card 16 when the IC memory card 16 is set in the camera 10 by the system controller 14. FIG. 4 is an example of a memory map showing recorded contents of the IC memory card 16.
Shows a balance data area BDA recorded in the ROM 19 and a photographed image data area IDA1 of each frame.
IDA2, IDA3,..., And in the photographed image data area IDA1,.

As shown in FIG. 1, the digital printer 25
Is composed of an image data input unit 26, an image processing unit 27, a printing unit 28, and a system controller 29. This digital printer 25 is installed in a developing laboratory. The camera user can use the IC memory card 16 after shooting.
To the laboratory. Based on the submitted IC memory card 16, the developing laboratory creates a print photograph.

The image data input section 26 includes a camera 1
The IC memory card 16 from 0 is inserted, and the balance data and the image data are read. The balance data is stored in the correction table data creation unit 3 of the image processing unit 27.
Sent to 0. The correction table data creation unit 30 calculates a correction amount based on the deviation of the density and color balance of the camera from the ideal characteristics based on the balance data, and based on the correction amount, calculates the corrected density value (correction) from the camera photometric density. Density table) is created.

FIG. 5 shows this correction table data. S3 shows an ideal state, and S4 shows an example of actual red correction table data. In addition, correction table data is similarly obtained for green and blue. This correction table data is written to the correction look-up table memory (LUT) 31. In the LUT 31, the image data from the camera 10 is converted into a corrected density value, whereby the density and color balance unique to each camera are eliminated. In addition, the image processing unit 27 performs well-known processing such as gamma correction, mattocris correction, character illustration synthesis, enlargement / reduction, and trimming.

The image data for one frame that has been subjected to the image processing is written in the print frame memory 33 of the print unit 28. The print unit 28 includes a print frame memory 33 and a printer 34. As shown in FIG. 6, the printer 34 includes a printing exposure unit 40 of a scanning exposure type using a laser beam. The printer 34
Image data is read from the frame memory 33 for printing, and a light beam is modulated based on the image data, and a silver halide photographic color photosensitive material (positive / positive color paper) 41
By scanning and exposing each of the yellow, magenta, and cyan photosensitive layers of the color paper in synchronism with the feed, the respective frames are printed and exposed. The color paper 41 which has been printed and exposed is developed by a paper processor 44, as is well known, and cut off for each frame based on a cut mark to form a hard copy 45. The above processing procedure is shown as a flowchart in FIG.

The printing exposure unit 40 may use a surface exposure method using a CRT or a liquid crystal display panel or a line exposure method in addition to a scanning exposure method using a laser beam. Instead of modulating the light beam, scanning exposure may be performed using a micromirror device. The micro mirror device is
A mirror (micromirror) having a very small size is arranged in a line or a matrix, and the tilt angle of each micromirror is controlled to deflect incident light. As is well known, when a negative / positive color paper is used, image data is subjected to positive / negative conversion. This positive / negative conversion may be performed by the print unit 28 instead of the image processing unit 27. The image data may be read out from the print frame memory 33 and simulated and displayed on a color monitor (not shown). In this case, the density and color correction may be further performed by observing the simulated image.

In the above embodiment, the balance data is created by detecting the density and the color balance for each pixel. In addition, standard images SI1 to SI8 consisting of the gray patterns G1 to G8 are photographed by a camera. The photographed image data and the identification numbers of the photographed standard images SI1 to SI8 are stored for each standard image, and when the image data is sent to the photo printer after photographing, the photographed data of the standard image and the standard data are stored. You may make it transmit the identification data of an image. In this case, the digital printer specifies the standard images SI1 to SI8 from the standard image identification numbers, and based on the standard images, creates correction table data as shown in FIG. The camera-side image data is corrected using the correction table data. Note that data of shooting condition information (illumination conditions, distance, exposure conditions on the camera side, etc. at the time of shooting the standard image) is added to the balance data or the standard image shooting data, and the conditions for the density / color balance data creation processing on the printer side It may be used for confirmation.

In the above embodiment, the balance data on the density and the color balance is obtained, and the image data from the camera is corrected by the correction table data based on the data. Alternatively, a standard image for detecting the image may be photographed, distortion correction data may be calculated from the photographed data, the distortion correction data may be stored in the ROM 19, and this may be output to the printer along with the image data.

As a standard image SI10 for correcting the two-dimensional geometric distortion, a graph paper pattern P1 displaying a line L1 divided into a square similar to the graph paper as shown in FIG. 8 is used. A distortion correction vector as a distortion amount of each pixel is obtained from the distortion state, and the distortion correction vector is recorded for each pixel. The distortion correction vector indicates the distance and direction between the position of each pixel in the ideal state without distortion and the position of each pixel in the distortion state. The pixels between the lines L1 divided into squares of the standard image SI10 are obtained by performing a complement process using the correction vectors of the pixels on the lines L1. Also, this complementing process may be performed on the digital printer side,
In this case, a correction vector may be provided only for a representative pixel on the line of the standard image SI10, and the other pixels may be obtained by a complement process on the digital printer side. In this case, it is not necessary to store the distortion correction data for all the pixels, so that the memory capacity of the camera is not overwhelmed by the distortion correction data. In addition,
In addition to the grid paper pattern P1, a concentric circle pattern not shown or a combination of a grid paper pattern and a concentric circle pattern may be used.

In the above embodiment, the density correction data is obtained for each of the R, G, and B colors to correct the density and the color balance. However, it is also possible to simply correct the density unevenness. Also in this case, a standard image composed of a uniform gray pattern is photographed to detect density unevenness of each pixel, and the density unevenness data is sent to the printer along with the image data. In this case, the printer performs shading correction based on the density unevenness. In addition to simply transmitting the density unevenness data to the printer, the camera may obtain shading correction data for eliminating the density unevenness based on the density unevenness data, and transmit the shading correction data to the printer together with the image data.

Further, as shown in FIG. 9, the photographing data of the standard image and its identification number may be simply transmitted to the printer together with the image data without obtaining the density unevenness or the like on the camera side. In this case, the printer creates correction table data for eliminating unevenness in the density and color balance of the camera based on the photographing data of the standard image and the identification number of the standard image, and the camera uses the correction table data to generate correction table data. Is corrected. Further, in addition to the density and color correction, two-dimensional geometric distortion correction and shading correction may be performed.

In the above embodiment, various data based on the photographed standard image data is obtained for each camera. Alternatively, various data may be obtained for each camera model or each production lot. In this case, it is not necessary to calculate balance data or the like for each camera based on the standard image data, and the configuration is simplified.

It should be noted that the resolution for creating the density or color balance data may be arbitrary. For example, one pixel unit data, one screen average data, or its intermediate resolution data (m × n pixels are grouped into one area to divide one screen into a plurality of areas and use, for example, an average value of each area) ) May be used. Further, the range in one screen when creating the density or color balance data may be limited to, for example, near the center of the screen. Create a correction table from the density or color balance data obtained in this way,
Applies to full screen correction. Further, one screen may be simply divided into a plurality of areas, density or color balance data may be obtained for each divided area in the same manner as described above, and the obtained data may be applied to correction of each pixel in each divided area.

In the above embodiment, the IC memory card 16
The image data and the balance data are output to the printer by using the digital printer 25. Alternatively, the image data is stored in the RAM in the camera, and the digital printer 25 is connected via a cable.
, The image data and the balance data may be output to the printer.

In the above embodiment, the present invention is applied to a digital camera. In addition, the above-described two-dimensional geometric distortion correction and shading correction may be applied to a camera using a photographic film. In this case, distortion correction data, shading correction data, or standard image photographing data and identification data for obtaining the data are recorded on an IC memory card or a transparent magnetic recording layer of a photographic film.

In the above embodiment, the present invention is applied to a silver halide printer for printing on color paper by scanning exposure.
In addition, the present invention may be applied to a thermal development transfer type color printer, a color inkjet printer, a color thermal printer, and a color laser printer.

[0031]

According to the first aspect of the present invention, a standard image is photographed in advance, and density or color balance data is calculated based on the photographed standard image data. It is recorded in advance on a recording medium, and when outputting photographed image data, since the density or color balance data is also output, by correcting the image data from the camera based on the density or color balance data on the printer side, Since unevenness in density or color balance due to differences in camera models or differences between cameras can be corrected, print quality can be improved.

According to the second aspect of the present invention, the photographed image data from the camera and the density or color balance data are read, and the photographed image data of the camera is corrected based on the density or color balance data. Since printing is performed using photographed image data, unevenness in density or color balance due to differences in camera models or differences can be corrected.

According to the third aspect of the present invention, when a standard image is photographed, the photographed standard image data and the identification data of the standard image are recorded in a recording medium in advance, and the photographed image data is output. In addition, since the standard image data and the identification data of the standard image are also output, it is possible to efficiently suppress unevenness in density or color balance caused by differences between cameras. Moreover, the camera only needs to record the image data, and the configuration of the camera can be simplified.

According to the fourth aspect of the present invention, the photographed image data from the camera and the standard image data and the identification data of the standard image are read, and the photographed image of the camera is read based on the standard image data and the standard image identification data. A density or color correction table for correcting data is created, and printing is performed using photographed image data corrected by the density or color correction table. The configuration on the camera side can be simplified.

Further, a standard image is photographed, two-dimensional geometric distortion is detected based on the photographed standard image data, and this distortion data is recorded in a recording medium in advance, and when outputting photographed image data, By outputting the distortion data, it becomes possible to correct the two-dimensional geometric distortion of the camera.

According to a seventh aspect of the present invention, two-dimensional geometric data of the camera is read based on the image data taken from the camera, the standard image data, and the identification data of the standard image. Since the amount of distortion is detected to calculate the amount of distortion correction, the two-dimensional geometric distortion of the captured image data is corrected using the amount of distortion correction, and printing is performed using the corrected captured image data. It is possible to eliminate two-dimensional distortion due to machine differences.

According to another aspect of the present invention, a standard image is photographed, density unevenness is detected based on the photographed standard image data, and the density unevenness data is recorded in a recording medium in advance, and the photographed image is obtained. By outputting the density unevenness data when outputting data, density unevenness can be suppressed, and print quality can be improved.

By obtaining various data based on the captured standard image data for each camera, it is possible to eliminate uneven density, uneven color, two-dimensional geometric distortion, and the like due to machine differences. Further, various data based on the captured standard image data may be obtained for each camera model or each production lot. In this case, although the correction accuracy is lower than that using individual correction data, Since it is not necessary to use each correction data for each camera, uneven density, uneven color, two-dimensional geometric distortion, and the like can be efficiently eliminated.

[Brief description of the drawings]

FIG. 1 is a functional block diagram illustrating a camera and a printer embodying the present invention.

FIG. 2 is an explanatory diagram showing an example of a standard image for obtaining density / color balance correction data.

FIG. 3 is a diagram illustrating an example of a balance table created based on shooting data of a standard image.

FIG. 4 is an example of a memory map showing recorded contents of an IC memory card of a camera.

FIG. 5 is a diagram showing an example of correction table data obtained on the digital printer side based on balance data.

FIG. 6 is a functional block diagram illustrating an example of a digital printer.

FIG. 7 is a flowchart illustrating a processing procedure in another embodiment in which a camera creates correction table data based on photographing data of a standard image.

FIG. 8 is a diagram illustrating an example of a reference image including a square pattern for correcting two-dimensional geometric distortion.

FIG. 9 is a flowchart illustrating a processing procedure in another embodiment in which a printer creates correction table data based on an identification number of a standard image and shooting data.

[Explanation of symbols]

 Reference Signs List 10 digital still camera 11 imaging unit 12 image processing unit 13 buffer memory 15 image data writing unit 16 IC memory card 25 digital printer 26 image data input unit 27 image processing unit 28 printing unit 30 correction table data creation unit 31 correction LUT SI1 SI8, SI10 Standard image G1 to G8 Gray pattern P1 Graph paper pattern

Claims (12)

[Claims] An image processing apparatus comprising: a recording medium in which density or color balance data calculated based on standard image data obtained by capturing a standard image is recorded in advance; and when outputting the captured image data, the density or color balance data is output from the recording medium. A camera that also outputs color balance data. 2. The photographed image data from the camera according to claim 1 and the density or color balance data are read, and the photographed image data from the camera is corrected based on the density or color balance data. A printer that performs printing using image data. 3. A recording medium in which density or color balance data calculated based on standard image data obtained by photographing a standard image is recorded in advance. When outputting the photographed image data, the standard image data and the standard image are output. A camera that also outputs the identification data of the camera. 4. A photographed image data from the camera according to claim 3, and the standard image data and the identification data of the standard image are read, and the photographed image data of the camera is corrected based on the standard image data and the standard image identification data. A density or color correction table for performing the printing, and printing is performed using the photographed image data corrected by the density or color correction table. 5. A recording medium in which density or color balance data calculated based on standard image data obtained by capturing a standard image is recorded in advance, and when outputting the captured image data, the distortion data is also output. A camera characterized by the following. 6. A photographed image data from the camera according to claim 5 and the distortion data are read, the photographed image data of the camera is corrected based on the distortion data, and a print is performed using the corrected photographed image data. A printer characterized by performing. 7. A two-dimensional geometric distortion of the camera based on the captured image data from the camera according to claim 3 and the standard image data and the identification data of the standard image. And calculating a distortion correction amount, correcting the two-dimensional geometric distortion of the photographed image data using the distortion correction amount, and performing printing using the corrected photographed image data. . 8. A recording medium in which density or color balance data calculated based on standard image data obtained by shooting a standard image is recorded in advance, and when outputting the shot image data, the density unevenness data is also output. A camera characterized in that: 9. Photographed image data from the camera according to claim 8 and the density unevenness data are read, shading correction is performed on the camera image data based on the density unevenness data, and the corrected photographed image data is used. A printer characterized by performing printing. 10. The image data from the camera according to claim 3, and the standard image data and the identification data of the standard image are read, and the density unevenness of the camera is detected based on the standard image data and the identification data of the standard image. A printer for calculating a shading correction amount for correcting the density unevenness, correcting photographed image data using the shading correction amount, and performing printing using the corrected photographed image data. 11. The camera according to claim 1, wherein various data based on the photographed standard image data are obtained for each individual camera. 12. The camera according to claim 1, wherein various data based on the photographed standard image data is obtained for each camera model or each production lot. camera.