JP2000232618A - Photo-finishing method, system therefor and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate a print with high image quality by using photographing data obtained by an image pickup means such as a digital camera. SOLUTION: A recording medium 2 records raw image pickup data S0 resulting from applying minimum processing such as exposure control processing and calibration processing to data Sorg obtained by an image pickup means 4 of a digital camera 1. A printer 3 reads the raw image pickup data S0 recorded on the recording medium 2, an image processing means 12 applies required processing such as interpolation processing, sharpness emphasis processing and color conversion processing required for printing to obtain processed data S1. Then a print means 13 reproduces the processed data S1 as a print 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method of disposing a plurality of types of photoelectric conversion elements having different spectral sensitivities on a single surface.
A photofinishing method and system for applying image processing to image data obtained by an imaging means such as a digital camera having an imaging device such as a so-called single-chip CCD so as to be suitable for printing and performing printing, and processing in the photofinishing method. The present invention relates to a computer-readable recording medium on which a program to be executed by a computer is recorded.

[0002]

2. Description of the Related Art In a digital camera, received light is converted into digital image pickup data using an image pickup device such as a CCD and recorded on a recording medium. In such a digital camera, interpolation processing, gamma conversion, sharpness enhancement processing, and color reproduction characteristics of the monitor are performed in the digital camera so that the image data recorded on the recording medium can be immediately displayed on a monitor such as a CRT. Image processing such as color conversion processing according to the image processing, and the processed image data is recorded on a recording medium.

On the other hand, CCDs used in digital cameras
For example, a so-called single-chip CCD in which a plurality of types of photoelectric conversion elements having different spectral sensitivities are alternately arranged on the same plane is used as an imaging device. here,
In the case of a single-chip CCD in which photoelectric conversion elements having spectral sensitivity in each of R, G, and B, that is, photoelectric conversion elements of R, G, and B channels are alternately arranged, continuous R, G, and
A set of three B-channel photoelectric conversion elements constitutes one pixel. However, such a veneer C
In a CD, since the R, G, and B values of each pixel cannot be obtained at the same pixel position, a color shift or a false color may occur. Further, since the number of photoelectric conversion elements in each channel is smaller than the total number of elements constituting the single CCD, a high-resolution image cannot be obtained. For example, in a single-plate CCD in which photoelectric conversion elements of R, G, and B channels are alternately arranged, the number of photoelectric conversion elements in each channel is only 1/3 of the total number of elements. In comparison, the resolution is reduced to 1/3.

For this reason, attention is paid to the fact that human visual characteristics are more sensitive to luminance than to color, and a high-frequency luminance signal representing the luminance of each pixel is interpolated from image data obtained by a single-chip CCD. A method has been proposed in which a low-frequency chromaticity signal is generated by processing and smoothing processing, and an imaging data signal is reconstructed using a luminance signal and a chromaticity signal (Japanese Patent Laid-Open No. 10-200906, 9-6507
No. 5, etc.). According to this method, more information is given to a luminance component having high sensitivity in human visual characteristics, so that it is possible to obtain imaging data capable of reproducing an image having an apparently high resolution. As described above, in the digital camera, various image processing is performed on the raw image data obtained by imaging, and the raw image data is recorded on the recording medium.

On the other hand, when recording image data obtained by a digital camera on a recording medium, the gamma characteristics of the camera, the focal length of the lens, the F value of the lens, the contents of the AE processing performed in the camera, and the like are taken. A method of recording conditions on a recording medium has been proposed (Japanese Patent Laid-Open No. 10-1).
No. 91246). According to this method, when printing the imaging data, it is possible to perform processing for improving the image quality of the imaging data with reference to the imaging information recorded on the recording medium, thereby obtaining a print with a good finish. Can be.

[0006]

However, since the image data obtained by the digital camera is originally processed on the assumption that it is reproduced on a monitor, various kinds of data are reproduced when the image data is reproduced as a print. Problems arise. That is, since the color gamut of the monitor differs from that of the printer, the color gamut that can be reproduced only by the printer is removed from the raw imaging data obtained by the imaging device of the digital camera. For this reason, it is necessary to reproduce the removed color range when printing, and since the originally existing color range has been removed, a part of the raw image data is wasted. Further, the image data acquired by the digital camera is obtained by performing an interpolation process on the raw image data so as to have a predetermined size that can be reproduced on a monitor. However, the print size and the pixel density differ from printer to printer, and it is necessary to further interpolate the image data obtained by the interpolation processing in order to obtain the desired size. It will be degraded. Furthermore, digital cameras cannot perform very sophisticated processing because of savings in cost and calculation time. For example, the sharpness enhancement processing is performed only in one direction, not in all directions of the image. For this reason, a high-quality print cannot be obtained based on only the imaging data, and it is necessary to perform the image processing again at the time of printing despite the image processing performed by the digital camera. Therefore, the processing becomes useless.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a computer with a photofinishing method and system capable of producing high-quality prints without waste using image data obtained by a digital camera. It is an object of the present invention to provide a computer-readable recording medium on which a program to be executed is recorded.

[0008]

A photofinishing method according to the present invention records raw imaging data obtained by an imaging means having an imaging device in which a plurality of types of photoelectric conversion elements having different spectral sensitivities are arranged on a single surface. Recording on the medium, reading the raw imaging data recorded on the recording medium, performing image processing required for printing on the raw imaging data to obtain processed data, and printing the processed data. It is a feature.

Here, "an imaging device in which a plurality of types of photoelectric conversion elements having different spectral sensitivities are arranged on a single surface"
Means an imaging device such as the above-mentioned single-plate CCD. Note that each photoelectric conversion element is represented by R
(Red), G (green), B (blue), C (cyan), M (magenta), Y (yellow), and CM
CMYG obtained by adding G (green) to Y may have spectral sensitivity, and the arrangement of these photoelectric conversion elements is not limited to a specific one.

[0010] "Raw image data" refers to data obtained by the above-mentioned image pickup device and lacking pixel information at each pixel position. In other words, it means data that has not been subjected to image processing on the assumption that it will be reproduced on a monitor and that has been obtained from an imaging device. Note that the raw imaging data may be data that has been subjected to minimum necessary processing such as exposure control processing based on exposure conditions at the time of shooting, or calibration processing for correcting differences between models, differences between bodies, and differences over time. Alternatively, it may be one that has been subjected to compression processing such as run-length encoding and DCT encoding.

[0011] The recording conditions may be recorded on the recording medium together with the raw photographing data. Here, the photographing conditions include information such as a gamma characteristic, a focus distance, and an exposure value of the imaging unit. In addition to the raw shooting data, print size,
Order information such as the number of prints may be recorded on a recording medium.

Further, examples of the “recording medium” for recording raw image data include compact flash, smart media, and memory stick.

The "image processing required for printing" means a process of reconstructing image data from raw image data as in the method described in Japanese Patent Application Laid-Open No. Hei 10-191246, where raw image data is desired. Expanded to print size,
Interpolation processing for reduction, sharpness enhancement processing according to print size, color conversion processing to correct the spectral sensitivity of the imaging device, color conversion processing to convert the color of raw imaging data to a color suitable for printing, white And a balance process. These processes may be performed in any order, and the two color conversion processes may be performed at once using one table.

[0014] A photofinishing system according to the present invention comprises: an imaging unit having an imaging device in which a plurality of types of photoelectric conversion elements having different spectral sensitivities are arranged on a single surface; and a recording medium for storing raw imaging data obtained by the imaging unit. Recording means for recording the raw image data recorded on the recording medium, performing image processing necessary for printing on the raw image data to obtain processed data, and image processing means Printing means for printing the processed data obtained by the means.

Further, a digital camera according to the present invention has an image pickup device having an image pickup device in which a plurality of types of photoelectric conversion elements having different spectral sensitivities are arranged on a single surface, and records raw image pickup data obtained by the image pickup device. Recording means for recording on a medium.

Further, the printer according to the present invention reads out the raw image data recorded on the recording medium in the digital camera according to the present invention, performs image processing required for printing on the raw image data, and processes the raw image data. And a printing means for printing the processed data obtained by the image processing means.

Further, the image processing apparatus according to the present invention reads out the raw image data recorded on the recording medium in the digital camera according to the present invention, and performs image processing necessary for printing on the raw image data to process the raw image data. Image processing means for obtaining completed data.

Note that the program executed by the digital camera, the printer, and the image processing apparatus according to the present invention may be recorded on a computer-readable recording medium and provided as a program.

[0019]

According to the present invention, the raw imaging data obtained by the imaging means is recorded on a recording medium, and the raw imaging data recorded on the recording medium is subjected to image processing necessary for printing. , Will be printed. Here, since the raw image data has not been subjected to the processing premised on being reproduced on the monitor, the color range that can be reproduced only by the printer has not been removed, and image processing such as color conversion processing and sharpness enhancement processing has been performed. No processing and no interpolation processing has been performed. Therefore, in the processed data obtained by performing image processing necessary for printing on the raw image data, the color reproduction area is insufficient as in the print as in the case of the conventional image data, and the resolution due to the repetition of the interpolation processing is reduced. This eliminates the need for repetition of the same image processing, so that high-quality prints can be obtained without waste. Further, since the processing is performed in the image processing means provided separately from the imaging means, there is no restriction on the processing content as in a conventional digital camera, and more advanced image processing can be performed.
As a result, a print with higher image quality can be created.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic block diagram showing a configuration of a photofinishing system according to an embodiment of the present invention. As shown in FIG. 1, the photofinishing system according to the embodiment of the present invention records raw imaging data S0 acquired by a digital camera 1 on a recording medium 2 and reads out the raw imaging data S0 from the recording medium 2 by a printer 3. To create a print.

The digital camera 1 has an image pickup means 4 having an image pickup device 4a composed of a single CCD, an exposure control means 5 for controlling the exposure of the image pickup device 4a, and a calibration for data Sorg obtained by the image pickup means 4. Calibration means 6 for performing calibration processing, and data Sorg 'processed by the calibration means 6
Data compression means 7 for obtaining compressed data S0 'by compressing
And file format means 8 for recording the compressed data S0 'on the recording medium 2 as raw image data S0 in a predetermined format.

FIG. 2 is a view showing an arrangement of photoelectric conversion elements of a single CCD used as the image pickup device 4a. FIG.
FIG. 2A is a diagram in which R, G, and B channel photoelectric conversion elements having spectral sensitivity are alternately arranged in R, G, and B, and FIG. The R and B channels are alternately arranged between every other row. FIG. 2C shows an arrangement in which C, M, and Y-channel photoelectric conversion elements having spectral sensitivities in C, M, and Y are alternately arranged. FIG. 2D shows C, M, and Y photoelectric conversion elements.
The photoelectric conversion elements in which the G channel is further added to the channels are arranged alternately. Where RGB and CMY
Since the chromaticity of each primary color is defined, they can be mutually converted. Therefore, the imaging device 4a may be a single CCD having any arrangement, but in the present embodiment, the single CCD having the arrangement of the photoelectric conversion elements shown in FIG. 2A will be described. The imaging means 4 is a single-chip CCD
In addition to the imaging device 4a composed of
It has an autofocus function.

The exposure control means 5 controls the exposure of the imaging device 4a, and inputs the result of the exposure control to the calibration means 6. Here, as the exposure control result, for example, an EV value representing the brightness of the subject itself or an exposure setting value at the time of shooting is used. The result of the exposure control is stored in the file format means 8 as raw image data S.
It may be recorded on the recording medium 2 together with 0.

The calibration means 6 performs a calibration process on the data Sorg for compensating for differences between models of the digital camera 1, differences between machines, and differences over time. Further, the calibration unit 6 may perform an exposure control process on the data Sorg based on the exposure control result input from the exposure control unit 5.

The data compression means 7 performs compression processing such as run-length encoding and DCT encoding on the data Sorg 'that has been
0 'is obtained. Note that the imaging device 4a is shown in FIG.
Since the R, G, and B channels are arranged as shown in (a), the respective channels are arranged, for example, as shown in FIG. 3 for the R channel, and the R signal is placed at the pixel position indicated by X in FIG. It does not exist. For this reason,
Pixels other than the pixel having only the R, G, and B signal values are
R, G, and B data representing an image of 1/3 size in the horizontal direction are obtained by thinning out in the horizontal direction in FIG. 3, and each data is subjected to a compression process by run-length encoding or DCT encoding to be compressed. The data S0 'may be used. Further, assuming that the R, G, and B signal values that are continuously arranged are obtained at the same pixel position, the horizontal direction is 1/3 of the horizontal direction in FIG.
Data representing an image of a size may be obtained, and this data may be converted into a YCC luminance / color difference space and subjected to JPEG compression processing. When performing JPEG compression processing, lossless compression is preferable in order not to degrade image quality, but irreversible compression may be used as long as image quality is not degraded in order to reduce the number of data.

The file format means 8 obtains raw image data of a predetermined file format from the compressed data S0 'obtained by the data compression means 7, the exposure control result obtained by the exposure control means 5, and the shooting conditions at the time of shooting. S0 is generated and recorded on the recording medium 2. Here, the shooting conditions include, in addition to the exposure control result, camera-specific information such as the gamma characteristics of the digital camera 1, the lens focal length, the lens F value, and the shooting distance such as the focus distance, the type of illumination, and whether or not a strobe is used. Information about the environment. In addition,
As the recording medium 2, various media such as a compact flash, a smart media, and a memory stick can be used. It should be noted that the recording medium 2 also records information on the compression method used by the data compression means 7.

The printer 3 includes a reading means 10 for reading the raw image data S0 recorded on the recording medium 2, a data expanding means 11 for expanding the raw image data S0 to obtain expanded data S2, An image processing unit 12 that performs image processing to obtain processed data S1 and a printing unit 13 that prints the processed data S1 to create a print 14 are provided.

The data decompression means 11 generates the raw image data S based on the information about the compression method recorded on the recording medium 2.
0 is expanded to obtain expanded data S2. The decompressed data S2 is the same as the data Sorg 'processed by the calibration means 6. That is, R, G, B for each position of each channel of the imaging device 4a.
It has G and B signal values.

The image processing means 12 performs image processing as follows. First, a chromaticity signal representing low-frequency color information at each pixel position is obtained by interpolation using the method described in JP-A-10-200906 on the expanded data S2, and the luminance of each pixel is calculated. A high-frequency luminance signal to be represented is obtained, and three-channel data having R, G, and B signal values at the same pixel position is created from the low-frequency chromaticity signal and the luminance signal. Further, an interpolation operation is performed on the three channel data based on the print size to obtain interpolation data representing an image of the print size. At this time, the interpolation calculation for the three-channel data and the interpolation calculation for the print size may be performed simultaneously. That is, the R signals in the decompressed data S2 are arranged as shown in FIG.
In the case where the size is 1.5 times the size represented by all the pixels of the data Sorg obtained in the above, interpolation using the R, G, and B signal values at each pixel position is performed by 4.5 times in the horizontal direction. A calculation (for example, a higher-order interpolation calculation such as a B-spline interpolation calculation) may be performed, and then an interpolation calculation that enlarges 1.5 times in the vertical direction may be performed. In this case, different interpolation calculations may be performed according to the print size. For example, when the print size is a reduced size of the image represented by all the pixels of the imaging device 4a,
Since the resolution doesn't have to be that high,
The interpolation operation may be performed without obtaining the high-frequency luminance information in the method described in JP-A-10-200906.

Further, in the image processing means 12, sharpness enhancement processing corresponding to the print size, color conversion processing for correcting the spectral sensitivity of the imaging device 4a, expansion data S
Color conversion processing for converting 2 into the color space of the printing means 13;
Processing such as white balance processing is performed, and further, various image processing is performed based on the photographing information recorded on the recording medium 2 to obtain processed data S1. Note that these processes may be performed in any order, and the two color conversion processes may be performed at once using one table.

Next, the operation of this embodiment will be described. FIG. 4 is a flowchart showing the operation of the present embodiment. First, photographing is performed by the digital camera 1 (step S1), and data Sorg representing a subject image is acquired by the imaging unit 4 (step S2). Next, the exposure control unit 5 acquires the exposure control result of the imaging device 4a and inputs the result to the calibration unit 6 (Step S3). Then, the calibration means 6 performs a calibration process on the data Sorg to obtain data Sorg '(step S4), and the data Sorg' is compressed by the data compression means 7 to obtain compressed data S0 '. (Step S5). The compressed data S0 'is recorded on the recording medium 2 as raw image data S0 by the file format means 8 together with information on the photographing conditions and the compression method (step S6). The above is the processing performed in the digital camera 1.

In the printer 3, the reading means 10 first reads the raw image data S0 recorded on the recording medium 2 (step S7). The raw image data S0 is expanded by the data expansion unit 11 to obtain expanded data S2 (step S8). Then, the image processing unit 12 performs image processing on the decompressed data S2 to obtain processed data S1 (step S9). Then, the processed data S1 is reproduced by the printing means 13 as a print 14 (step S10), and the process is terminated.

As described above, in the present embodiment, since the raw image data S0 obtained by the digital camera 1 is not subjected to the processing on the assumption that it is reproduced on the monitor, the color gamut that can be reproduced only by the printer 3 Are not removed, and image processing such as color conversion processing and sharpness enhancement processing, and interpolation processing are not performed.
Therefore, the raw image data S0
In the processed data S1 obtained by performing image processing required for printing, the shortage of the color gamut as a print and the deterioration of the resolution due to the repetition of the interpolation processing are eliminated unlike the conventional imaging data. Further, since it is not necessary to repeat the same image processing, a high-quality print 14 can be obtained without waste. Further, since the processing is performed in the image processing means 12 in the printer 3 provided separately from the digital camera 1, the processing content is not limited as in the conventional digital camera, and more advanced image processing can be performed. As a result, a print 14 with higher image quality can be created.

In the above embodiment, the present invention has been described as a photofinishing system.
The digital camera 1 and the printer 3 may be provided separately. Further, the image processing means 12 may be provided as a single image processing device.

In the digital camera 1 according to the above embodiment, the raw image data S0 not subjected to image processing is processed.
Is obtained and recorded on the recording medium 2. The raw image data S0 is subjected to the above-described processing of recording the raw image data S0 on the recording medium 2 and image processing on the assumption that the image data is reproduced on a conventional monitor. Alternatively, a process of obtaining processed data and recording the processed data on the recording medium 2 may be selectable. In this case, by providing the obtained data with identification information indicating whether the data is raw imaging data or processed data, the data can be used for monitor reproduction or for printing. This is more preferable because it can be identified.

Further, in the above embodiment, when the raw image data S0 is recorded on the recording medium 2, order information such as the print size and the number of prints may be simultaneously recorded. Thereby, the processing in the printer 3 can be easily performed.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing a configuration of an image processing system according to an embodiment of the present invention.

FIG. 2 is a diagram showing an arrangement of photoelectric conversion elements.

FIG. 3 is a diagram showing a pixel position of an R signal.

FIG. 4 is a flowchart showing the operation of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Digital camera 2 Recording medium 3 Printer 4 Imaging means 4a Imaging device 5 Exposure control means 6 Calibration means 7 Data compression means 8 File formatting means 10 Reading means 11 Data decompression means 12 Image processing means 13 Printing means 14 Printing

Claims (7)

[Claims] 1. Raw image data obtained by an imaging means having an imaging device in which a plurality of types of photoelectric conversion elements having different spectral sensitivities are arranged on a single surface is recorded on a recording medium, and the raw image data is recorded on the recording medium. A photofinishing method comprising: reading out the raw imaging data, performing image processing required for printing on the raw imaging data to obtain processed data, and printing the processed data. 2. Imaging means having an imaging device in which a plurality of types of photoelectric conversion elements having different spectral sensitivities are arranged on a single surface, and recording means for recording raw imaging data obtained by the imaging means on a recording medium. Image processing means for reading the raw image data recorded on the recording medium, performing image processing required for printing on the raw image data to obtain processed data, and processing obtained by the image processing means And a printing means for printing completed data. 3. Imaging means having an imaging device in which a plurality of types of photoelectric conversion elements having different spectral sensitivities are arranged on a single surface, and recording means for recording raw imaging data obtained by the imaging means on a recording medium. A digital camera comprising: 4. The digital camera according to claim 3, wherein the raw imaging data recorded on the recording medium is read out,
Image processing means for performing image processing necessary for printing on the raw imaging data to obtain processed data; and printing means for printing the processed data obtained by the image processing means. Printer. 5. The digital camera according to claim 3, wherein the raw imaging data recorded on the recording medium is read out,
An image processing apparatus comprising: an image processing unit that performs image processing required for printing on the raw imaging data to obtain processed data. 6. The digital camera according to claim 3, wherein said raw image data recorded on said recording medium is read out, and said raw image data is subjected to image processing required for printing, and said processed data is processed. A computer-readable recording medium on which a program for causing a computer to execute a procedure for obtaining and a step for printing the processed data is recorded. 7. The digital camera according to claim 3, wherein said raw image data recorded on said recording medium is read out, and said raw image data is subjected to image processing necessary for printing, and said processed data is processed. A computer-readable recording medium that records a program for causing a computer to execute the obtaining procedure.