JPH09321993A - Color image reproduction system and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily obtain a beautiful reproduced picture by acquiring the information having its reduced deterioration from each of compressed data stored in a storage medium and then acquiring the reproduced image data. SOLUTION: The read JPEG compressed data 20 are expanded by a JPEG decoding program 18, and the U and V components are extracted from the data in every pixel. At the same time, the read JBIG compressed data 21 are expanded by a JBIG decoder 17, and the data on every pixel are converted into the multivalued data from the binary data by a multivalued filtering program 19. The converted multivalued data show the luminance (Y component) of every pixel. Then the Y, U and V components of every pixel are acquired for reproduction from the extracted U and V components and the generated Y component of every pixel. These Y, U and V components are converted into the R, G and B value respectively. Then these converted R, G and B value of every pixel are displayed on a color CRT 13, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image reproducing system for generating a beautiful reproduced image from compressed data obtained by compressing an original image in which color photographs and color characters are mixed and outputting the reproduced image to a display device or a printing device. In particular, the present invention relates to a color image reproducing system and a color image reproducing method for suitably reproducing the same original image from compressed data having color information and compressed data obtained by binarizing the original image.

[0002]

2. Description of the Related Art A color image image in which a photograph and characters are mixed in a color image processing system is, for example, A4 size.
To represent a full-color image at a resolution of 200 dpi, a data capacity of about 12 MB is required, which is a very large data capacity. Therefore, when a color image is stored in a color image processing system, it is common to compress and store the data by a compression method such as a highly compressible and irreversible JPEG method. However, the JPEG method
A color change in the vicinity is gentle. Suitable compression is performed, so that a character part having a sharp color change is significantly deteriorated as compared with a photographic part where the color change is comparative.

In order to solve such a point, data obtained by compressing a color information image for reproducing a color image image and data obtained by compressing a character shape information image for reproducing a character shape are used. However, regarding the technology of expanding each of them and arranging and combining the color information of the color information image with the character shape information image, please refer to the IPSJ 51st (later 1995) National Convention, 1R-9 "Edge Information Hybrid coding method using ".

[0004]

However, even in such a conventional technique, when the color information image is compressed, the information indicating the luminance is significantly deteriorated as compared with the information indicating the saturation. By arranging the color information whose luminance is severely deteriorated, only the reproduced image whose severe deterioration is still obtained.

The present invention solves the problems in the prior art as described above, and it compresses binary data of compressed data including color information obtained from an original image in which color photographs and color characters are mixed and the original image. An object of the present invention is to provide a color image reproduction system and a color image reproduction method capable of easily obtaining a beautiful reproduced image from data.

[0006]

In order to solve the above-mentioned problems, a color image reproducing apparatus of the present invention includes a color image output apparatus, and color information compressed data including color information from a color original image, and arbitrary color information. A color image reproducing system for reproducing a color image from a storage medium stored in advance in association with binary image compressed data compressed after binarization by a binarization method, wherein the color image reproducing system is associated with the storage medium. Means for reading the color information compression data and the binary image compression data, first decompression means for decompressing the color information compression data read by the reading means, and the binary value read by the reading means Second decompression means for decompressing the image compressed data, multi-value conversion means for converting the binary data decompressed by the second decompression means into multi-valued data, and data decompressed by the first decompression means And means for synthesizing on the basis of the multi-valued data in serial multi-value means, characterized in that a means for sending the combined data to said color image output device.

In such a color image reproducing system, a saturation component having a comparatively mild deterioration is extracted from the compressed data containing color information, multivalued conversion is performed from the binary compressed data, and then the deterioration is caused. The RGB data to be reproduced by the color image output device can be generated from the saturation component and the luminance component by obtaining the gentle luminance component of No. 3, so that a beautiful reproduced image can be easily obtained.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a color image reproducing system according to the present embodiment, including a CPU 11 that controls the entire system, a memory 12 that stores programs and data for performing various controls by the CPU 11, A color CTR 13 for displaying a color image or the like generated by this system, a color printer 14 for printing the color image or the like generated by this system,
A keyboard 15 for inputting commands and data, a disk 16 for storing various data and programs,
And a JBIG decoder 17 for decompressing JBIG compressed data compressed by the JBIG method which is a general reversible compression method.

In the memory 12, the JPEG decoding program 1 which is a software program for expanding the JPEG compressed data further compressed by the JPEG compression method.
8 and a multi-valued filtering program 19 (which will be described in detail later) for converting binary data into multi-valued data are read from the disk 16 in advance and held therein.

Further, on the disk 16, for the same original image in which color photographs and color characters are mixed, the JPEG compressed data 20 compressed by the JPEG system and the color data are binarized for each pixel, and the binary data Are associated with the JBIG compressed data 21 compressed by the JBIG method, and a plurality of sets are stored in advance.

Next, the operation procedure of the system of this embodiment will be described with reference to the flowchart of FIG. First,
From a plurality of original images stored in advance on the disk 16,
When the image to be reproduced is selected with the keyboard 15, the JP corresponding to the original image selected from the disc 16 is selected.
The EG compressed data 20 and the JBIG compressed data 21 are read (S31).

The read JPEG compressed data 20 is
Decompression processing is performed by the JPEG decoding program 18 (S32). JPEG decoding program 18
The data expanded by is a Y component, U component, and V component for each pixel (Y component represents luminance, and U and V components represent saturation).
It is comprised including. From this, the U and V components for each pixel are extracted (S33).

Further, the read JBIG compressed data 2
For 1, the decompression processing is performed by the JBIG decoder 17 (S34). The data expanded in S34 is represented by binary data for each pixel. The decompressed data is converted from binary data to multivalued data of each pixel by the multivalued filtering program 19 (S35). The converted multi-valued data represents the brightness (Y component) of each pixel. Note that this process will be described in detail later.

The U component, V, for each pixel extracted in S33
From the component and the Y component for each pixel generated in S35,
The Y, U, and V components of each pixel for reproduction are obtained, but the color C of a normal computer system such as this system is obtained.
Since the RT 13, the color printer 14 cannot handle the Y, U, and V values as they are, they are converted into R, G, and B values that can be handled (S36). The converted R, G, and B values of each pixel are output (S37) and displayed on the color CRT 13 (S38), for example.

As described above, the irreversible compression method is used, however, the luminance component with severe deterioration is not extracted from the JPEG decompression data containing color information, and only the saturation component (U, V values) with mild deterioration is extracted. , A reversible compression method, it is possible to obtain data without deterioration after decompression by comparing with compressed data.
The G-decompressed data is subjected to multi-value filtering to obtain an excellent luminance component (Y value), and RGB data is obtained from the obtained Y, U, and V components, so that a reproduced image can be obtained easily and cleanly. It will be possible.

Next, step S3 of the flow chart shown in FIG.
An example of the processing of the multi-valued filtering program 19 of No. 5 will be described in detail with reference to FIGS. 3 and 4. JB
The data obtained by decompressing the JBIG compressed data 21 compressed by the IG system by the JBIG system is still binary data (1/0) in each pixel as it is.

First, each data is converted into 0 if 0 and 255 if 1 (S41). Note that the reason for setting 255 is that each RGB of the original image taken in at the time of creating the compressed data of the original image has 256 gradations.

Next, the data converted into 0 or 255 for each pixel is subjected to multi-valued filtering processing by the calculation method as shown in FIG. 4 (S42). FIG. 4 shows a method of deciding the data of p4. The p4 is affected by the data on the left, right, top and bottom by 1/8, and the effect of its own data is 1/2 (= 4/8). ), And by this calculation, p
4 true multi-valued data are determined. True multi-valued data is determined for all pixels by performing this multi-valued data determination method while performing calculations for each pixel. This value is a value representing so-called brightness, and the multilevel halftoning filtering process according to this example is set to 1 in the vertical and horizontal directions for convenience.
Although only pixels are referenced, it is possible to obtain a more accurate value by referring to several pixels vertically, horizontally, and diagonally.

The JB previously stored in the disk 16
The IG compressed data 21 is obtained by binarizing each RGB value of the original image captured at the time of creating the compressed data of the original image using the simple binarization method (binarization with a single threshold value) in JBIG.
Although it may be compressed, if JBIG compression is performed on binary data using the error diffusion binary method which is known as a binarization method considering brightness, brightness data with higher reproducibility is obtained. can get.

Next, FIG. 5 shows a method for obtaining R, G, and B values from the Y, U, and V values of each pixel obtained in S33 and S35. The R, G, and B values depend on the characteristics of each output device, but can generally be obtained by the formula shown in S51. The R, G, and B values are obtained from the respective expressions (S51), and the respective values are output as the R, G, and B values of each pixel (S52).

As described above, the conventional method for synthesizing the data obtained after obtaining RGB from YUV, which is the decompressed JPEG data, and the data for obtaining the shape (edge information) from the decompressed data represented by the binary value, and outputting it. The method of the present invention, which expands reversible data, filters it, and uses it as luminance information, can obtain luminance information with higher accuracy.
A beautiful reproduced image can be provided.

[0022]

As described in detail above, according to the present invention,
Color information compressed data of an original image in which color photographs and color characters are mixed and binarized compressed data obtained by binarizing and compressing the original image are associated with each other from a storage medium stored in advance and deteriorated from the respective compressed data. Is obtained and reproduced image data is obtained based on this information, so that a beautiful reproduced image can be obtained relatively easily.

[Brief description of drawings]

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

FIG. 2 is a color CRT 1 for reproducing a reproduced image according to the embodiment of the present invention.
The flowchart which showed the process until it is displayed on FIG.

FIG. 3 is a flowchart for explaining “multi-valued processing S 35” in FIG.

FIG. 4 is a conceptual diagram for explaining an example of “multi-valued filtering S42” in FIG.

[FIG. 5] “Conversion from YUV component to RGB S3 in FIG. 2”
6] is a flowchart for explaining an example of “6”.

[Explanation of symbols]

11 ... CPU, 12 ... Memory, 13 ... Color CRT 14 ... Color printer, 15 ... Keyboard, 1
6 ... Disk 17 ... JBIG decoder, 18 ... JPEG decoder program 19 ... Multi-valued filtering program 20 ... JPEG compressed data, 21 ... JBIG compressed data

Claims (4)

[Claims] 1. A color image output device is provided, and color information compressed data provided with color information from a color original image is associated with binary image compressed data compressed after binarization by an arbitrary binarization method. A color image reproduction system for reproducing a color image from a storage medium stored in advance, comprising: a unit for reading out the color information compressed data and the binary image compressed data associated with each other from the storage medium; First decompression means for decompressing the read color information compression data, second decompression means for decompressing the binary image compression data read from the reading means, and decompression by the second decompression means. Multi-value conversion means for converting the binary data into multi-value data, means for combining the data expanded by the first expansion means and the data multi-valued by the multi-value conversion means, And a means for sending the generated data to the color image output device. 2. The synthesizing means performs a predetermined calculation from the information indicating the saturation obtained by the first expanding means and the information indicating the luminance obtained by the multi-value quantization means, 2. A color image output data is converted.
The described color image reproduction system. 3. A color image output device is provided, and color information compressed data having color information from a color original image is associated with binary image compressed data compressed after binarization by an arbitrary binarization method. A color image reproducing method for reproducing a color image from a storage medium stored in advance, wherein the color information compressed data and the binary image compressed data associated with each other are read from the storage medium, and the color information compressed data is stored. The binary image compression data is decompressed by the first decompression method, the binary image compressed data is decompressed by the second decompression method, and then the multivalued processing is performed, and the data decompressed by the first decompression method and the multivalued processing are performed. A reproduced image data is generated based on the data and the image data is transmitted to the color image output device. 4. A color image output device is provided, and color information compressed data including color information from a color original image is associated with binary image compressed data compressed after binarization by an arbitrary binarization method. A color image reproduction / reproduction method for reproducing a color image from a storage medium stored in advance, wherein information of each dot to be output to a color output device is obtained by decompressing binary image compressed data and performing multi-value filtering processing. Then, obtain the brightness value of each dot, expand the color information compression data, extract the saturation value of each dot from the obtained brightness and saturation values of each dot, and obtain it. A method for reproducing a color image, wherein a value for outputting to a color output device is obtained by a predetermined calculation from the obtained luminance and saturation.