JPH11331602A - Image processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the image processor that can simply apply edge emphasis processing to image data including block coded data without causing deterioration in image quality. SOLUTION: The image processor receives compressed image data through coding. A BTC expansion means 3 and a VQ expansion means 4 expand the received image data. An edge discrimination generating means 6 sets a window consisting of 3×3 pixels to the received coded data to detect an edge part and to generate edge data. An edge emphasis means 11 applies edge emphasis processing to the expanded image data based on the edge data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image processing apparatus that receives compressed data of a multi-tone image as input.

[0002]

2. Description of the Related Art In recent years, the amount of image data has been remarkably increased due to colorization and multi-gradation. Along with this, in order to reduce the data amount of an image, data compression techniques such as encoding have been applied to various devices.
An output device such as a printer must receive such compressed data and perform printing. At the time of printing, the compressed data is decompressed and processing such as edge sharpening is performed to generate print image data.

Conventionally, in order to perform enhancement processing such as edge sharpening, the compressed data is expanded once, and then edge detection and edge enhancement processing are performed.

A description will now be given of edge enhancement processing of an image processing apparatus to which conventional compressed data is input.

FIG. 16 is a block diagram of a conventional image processing apparatus. This image processing device 49 performs an edge enhancement process. First, the compressed encoded image data is decompressed by the decompression means 50, and the original image is restored. Next, the pixel data composed of the luminance and the hue in the restored image is converted into a different color space by the color conversion means 10. FIG. 6 is a block diagram of the color conversion means. As shown in FIG. 6, the color conversion means 10 is divided into two stages, and the first color conversion means 21 converts pixel data in the YUV color space composed of luminance and hue into RG
Convert to data in B space. The second color converter 22 converts the data in the RGB space output from the first color converter 21 into the data in the CMYK space.

Next, a window is formed by the window means 51 shown in FIG. FIG. 17 is a schematic diagram of a window. In this window 53, T is a pixel to be processed. The window means 51 calculates the value b0 of the surrounding pixels.
It is determined whether or not | b0−b3 | or | b1−b2 | exceeds a certain threshold value by using 〜b3. If so, “1” indicating that T is an edge pixel is output. If not exceeded, edge data to be set to "0" is generated.

Further, the edge emphasizing means 52 performs an edge emphasizing process using the decompressed image data and the edge data generated by the window means 51. FIG. 18 is a block diagram of a conventional edge enhancing means. As shown in FIG. 18, the edge emphasizing means 52 includes a dither matrix 5
The data generated from step 4 is compared with the CMYK data to perform binarization. Here, the dither matrix 54 is C
It has data for four pixels of the bit width of the MYK data element.

FIG. 9 is a block diagram of the binarizing comparison means. In the binarization comparing unit 28, the CMYK multivalued data converted by the color converting unit 10 and the dither data supplied from the dither selecting unit (not shown) are divided into dither data 1 and dither data 2 for each pixel. , Dither data 3 and dither data 4 are compared by the comparator 30, respectively, and the CMYK data is converted to the dither data x (x = 1, x = 1).
If the value is larger than (2, 3, 4), “1” is set. If the value is equal or smaller, “0” is set.
It is output as value data 3 and binary data 4. In the binary data 31 of one pixel when edge enhancement is not performed, 32 is a position where the binary data 1 is arranged, 33 is a position where the binary data 2 is arranged, and 34 is an arrangement of the binary data 3 Is the position where the binary data 4 is arranged. FIG. 9 is a diagram for one element (one of C, M, Y, and K), and the above-described binary data is output for each element.

In FIG. 18, if the edge data generated by the window means 51 is "1", the data selecting means 55 converts the binary data 1, binary data 2, binary data 3, binary data 4 All are replaced with "1" and output.
If the edge data is “0”, the binary comparison means 28
Output the value data as it is. Edge-enhanced image data is obtained as described above.

[0010]

However, in general, when the resolution is improved, the size of the window is changed from 3 × 3 pixels of the window 53 shown in FIG.
It grows like a x5 pixel or a 7x7 pixel, which leads to an increase in memory and complexity of processing. Further, when used with a small window size, the edge detection is performed excessively or too little, which may cause deterioration of the image quality.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image processing apparatus capable of easily performing edge enhancement processing on image data including block coded data without deteriorating image quality.

[0012]

SUMMARY OF THE INVENTION An image processing apparatus according to the present invention is an image processing apparatus that expands input data of an original image compressed by encoding to enhance an edge portion. Decompressing means for decompressing input data generated to generate decompressed data, edge data generating means for generating edge data indicating an edge portion in the encoded input data, and edge data generated by the edge data generating means. And an edge emphasizing means for emphasizing an edge portion of the decompressed data generated by the decompressing means.

[0013] In the image processing apparatus according to the present invention, the edge portion is detected using the encoded input data.
The edge emphasizing means performs an edge emphasizing process on the detected edge. For this reason, even when the resolution of the image is improved, edge detection can be performed using the smallest inspection window, and it is possible to prevent the edge detection processing from increasing and becoming complicated.

Further, an image processing apparatus according to the present invention is an image processing apparatus for expanding input data of an original image compressed by encoding to enhance an edge portion, wherein the input data is Block coded data in which image data is divided into a plurality of blocks, pixel data is coded for each block using binary data and a representative value, and non-block coding coded by a process different from block coding Data, and decompression means for decompressing the encoded input data, edge candidate generation means for generating edge candidate data indicating that the input data is an edge candidate when the input data is block coded data, A window forming means for forming a window, and a window forming means based on the edge candidate data generated by the edge candidate generating means. And determining the edge determination means whether the edge at each pixel location in the window formed Ri,
And an edge emphasizing means for emphasizing an edge portion of the decompressed data based on the judgment result of the edge judging means.

In the image processing apparatus according to the present invention,
Edge enhancement processing by edge detection with the minimum window size can be performed on block encoded data having binarized data.

[0016]

An image processing apparatus according to the first aspect of the present invention is an image processing apparatus that expands input data of an original image compressed by encoding to enhance an edge portion. Expanding means for expanding expanded input data to generate expanded data, edge data generating means for generating edge data indicating an edge portion in the encoded input data, and edge data generated by the edge data generating means Edge emphasizing means for emphasizing the edge portion of the decompressed data generated by the decompressing means based on. Accordingly, the number of edge detection target data is reduced, and edge detection and edge enhancement processing can be easily performed.

According to a second aspect of the present invention, in the image processing apparatus according to the first aspect of the present invention, the encoded input data divides the image data of the original image into a plurality of blocks, The block data includes block coded data obtained by coding pixel data for each block, and non-block coded data coded by a process different from block coding. It generates edge data indicating a part. Thus, edge enhancement can be performed only on specific encoded data.

According to a third aspect of the present invention, in the image processing apparatus according to the second aspect of the present invention, the block coded data includes binary coded data and a plurality of representative values for each block. The edge data generating unit includes the encoded first block encoded data and the second block encoded data encoded only with a plurality of representative values for each block, and the edge data generating unit outputs the second block encoded data of the first block encoded data. It includes a first generation unit that generates edge data including position information of an edge portion based on the quantified data. Thereby, the position of the edge can be easily detected based on the binarized data.

An image processing apparatus according to a fourth aspect of the present invention is the image processing apparatus according to the third aspect, wherein
The generation means generates edge data further including edge direction information based on the binarized data of the first block encoded data. As a result, not only the edge position but also the direction can be detected, and highly accurate edge enhancement can be performed.

According to a fifth aspect of the present invention, in the image processing apparatus according to the third or fourth aspect of the present invention, the image processing apparatus is configured based on a plurality of representative values of the first and second block encoded data. And edge data determining means for determining whether the edge data generated by the edge data generating means is valid. The edge emphasizing means includes an edge of the expanded data based on the edge data determined to be valid by the edge data determining means. The emphasis processing is performed on the set. This makes it possible to control the degree of edge enhancement using the representative value of the block coded data.

According to a sixth aspect of the present invention, in the image processing apparatus according to any one of the third to fifth aspects, the edge data generating means is configured to determine whether the input data is a second block coded image. If the data is data, the data processing apparatus further includes second generation means for generating edge data in which data indicating an edge candidate is arranged at the outermost position of each block of the second block encoded data. Window forming means for forming an edge data window using the edge data generated by the means and the edge data generated by the second generating means, and correction for correcting data in the edge data window formed by the window forming means And edge enhancement means,
The emphasis processing of the edge portion of the decompressed data is performed based on the edge data corrected by the correction means. As a result, it is possible to smoothly form the emphasized portion of the edge.

An image processing apparatus according to a seventh aspect of the present invention is the image processing apparatus according to any one of the third to sixth aspects, wherein the edge processing is performed based on a plurality of representative values of the block coded data. Edge strength generating means for generating data indicating the strength of the edge portion, wherein the edge emphasis means performs edge processing according to the data indicating the strength of the edge portion generated by the edge strength generating means.
This makes it possible to control the degree of edge enhancement using the representative value of the block coded data.

An image processing apparatus according to an eighth aspect of the present invention is an image processing apparatus for expanding input data of an original image compressed by encoding to enhance an edge portion, wherein the input data is an original image. Image data is divided into a plurality of blocks, and pixel data for each block is coded with binary data and a representative value, and non-block codes coded by a process different from block coding. Expansion means for expanding the encoded input data, the edge data generating means generating edge candidate data indicating that the input data is an edge candidate when the input data is block-coded data, Window forming means for forming a window with respect to the image data, and the window forming means based on the edge candidate data generated by the edge candidate generating means. And determining the edge determination means whether the edge at each pixel location in the window formed Ri,
And an edge emphasizing means for emphasizing an edge portion of the decompressed data based on the judgment result of the edge judging means. Thus, edge detection can be performed with the minimum window size to perform edge enhancement.

(Embodiment 1) Hereinafter, Embodiment 1 of the present invention will be described with reference to FIGS.

FIG. 1 is a block diagram of an image processing apparatus for performing edge enhancement according to the first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an image processing apparatus according to the first embodiment of the present invention.

The BTC decompression means 3 converts the input coded image data into binary data of pixels and luminance
Block coded data (hereinafter referred to as BT) consisting of only four representative values of representative values and hues, or only three representative values of luminance and hues
C data).

The VQ decompression means 4 decompresses input data (hereinafter referred to as VQ data) obtained by encoding image data composed of luminance and hue by vector quantization. The VQ data encoded by vector quantization contains 2 pixels
No coded data exists.

The edge strength generating means 2 generates an edge strength using the difference between the two representative values of the brightness of the BTC data. Two preset thresholds TH1 and TH2 (where T
H2> TH1), and the difference between the two representative values of the luminance is the threshold value TH.
When the value is less than or equal to 1, "0" is generated as the edge intensity data, and the difference between the two representative values of the luminance is larger than the threshold value TH1.
When the difference is equal to or less than H2, "1" is output as the edge intensity data, and when the difference between the two representative values of the luminance is larger than the threshold value TH2, "2" is output as the edge intensity data.

If the input encoded image data is not BTC data having binarized data, the edge judgment generating means 6 outputs "0" as edge data, and outputs the encoded image data as binary data. In the case of BTC data having digitized data, edge data is output as follows.

FIGS. 2 and 3 are diagrams for explaining the generation of edge data. In this embodiment, the BTC data is 4 ×
Input data obtained by encoding a 4-pixel block is used. Reference numeral 12 denotes binarized data of the encoded image data, and reference numeral 13 denotes edge data generated from the data 12. When the edge data 13 is “1”, the binarized data in the encoded pixel data is “0”, and the adjacent pixel is “0”.
1 ". FIG. 2 shows the state of edge data 13 when edge position data is generated.

Further, the edge determination generation means 6 can generate not only edge position data but also edge direction data. In FIG. 3, reference numerals 14, 16, and 17 indicate binarized data of the encoded image data, and reference numeral 15 indicates edge data including edge direction information. When generating edge data for a pixel inside a thick frame in the data 16 and 17, when the binarized data in the encoded pixel data is
In the state shown in FIG. 7, "1" is generated as edge data, and in the state shown in data 17, "2" is generated as edge data. However, the binarized data of the pixel of interest is “0”, and the binarized data of the left and right pixels are both “0”.
In the case of "1", "3" is generated as edge data.

In any state other than the above, if the binarized data of the target pixel is "0" and the binarized data "1" exists in an adjacent pixel, "3" is generated as edge data. I do. Thus, edge data 15 is generated from the binarized data 14 in the encoded pixel data.

The flat part edge determination generation means 7 generates edge data 18 as shown in FIG. 4 when the input coded image data has only a plurality of representative values without binary data. I do. The edge data 18 is edge data when the block coding is 4 × 4 pixels, and generates “4” indicating that there is a possibility that peripheral pixels may become edges.

The edge output control means 5 determines whether the coded image data corresponding to each pixel position of the edge data output from the edge window forming means 8 is BTC data including binary data of pixels. The difference between the two representative values of the luminance is compared with the threshold. If the difference between the two representative values of the luminance is larger than the threshold, "1" indicating that the edge data is valid.
Otherwise, "0" indicating that the edge data is invalid is output.

FIG. 5 is a schematic diagram showing the state of the edge window. The edge data 19 is stored in the edge determination generation unit 6.
Edge data from the flat portion edge determination generation means 7 is input, and is formed by the edge window forming means 8. The upper left, upper right, and lower left blocks are edge data generated from BTC data having binary data, and the lower right block is edge data generated from BTC data including a plurality of representative values having no binary data. It is. The size of the window 20 formed by the edge window forming means 8 as in the thick frame is 3 × 3 pixels.

In the edge data correcting means 9, the window 2
The correction is performed on the pixel formed at the center of 0 as inside the thick frame. In the correction process, the value of the central pixel is "
In the case of “0”, “1”, “2”, “3”, the output is performed as it is, and (1) the value of the central pixel is “4” (2) the value of the edge data is “0” (3) Pixels whose edge data values are not "0" and "4" are not continuous in the horizontal and vertical directions. (4) (3) If the above conditions are satisfied, the edge data value of the center pixel is changed to the same value as the edge data values other than “0” and “4” of the surrounding pixels. Otherwise, the edge data value of the central pixel is changed to "0".

Further, when the edge output control means 5 determines that the edge data is invalid, the edge data of the central pixel is changed to "0".

For example, if the edge data at the center pixel position in the thick frame of the edge window 19 is valid, if this is corrected, there are two pixels of edge data value "1" other than "0" and "4". Further, since the data is not continuous in the horizontal and vertical directions, the value of the edge data at the center of the window is changed from “4” to “1” as shown in the window 20.

The color conversion means 10 converts the pixel data composed of the luminance and the hue expanded by the BTC expansion means 3 and the VQ expansion means 4 into different color spaces. As shown in FIG. 6, the color conversion unit 10 is divided into two-stage conversion units, and the first color conversion unit 21 converts pixel data in the YUV color space including luminance and hue into data in the RGB space. . The second color conversion unit 22 converts the data in the RGB space output from the first color conversion unit 21 into the data in the CMYK space.

The edge emphasis means 11 includes the edge intensity data generated by the edge intensity generation means 2 and the color conversion means 10.
Based on the CMYK data output from the CPU and the edge data output from the edge data correcting means 9, edge-enhanced image data with edge enhancement is generated. FIG. 7 is a block diagram of the edge enhancement means. In FIG. 7, the edge emphasis means 11 includes 23 dithers 1 and 24 dithers 2 and 2.
It is composed of three dither matrices of five dithers 3 and gradation processing means 26. 23 is a dither matrix used when the edge intensity data is "0", 24 is a dither matrix used when the edge intensity data is "1", and 25 is a dither matrix used when the edge intensity data is "1".
This is a dither matrix used at 2 ″.

FIG. 8 is a block diagram of the gradation processing means.
As shown in FIG. 8, the gradation processing unit 26 selects the dither data output from the dither matrices 23 to 25 in FIG. 7 based on the edge intensity data output from the edge intensity generation unit 2. 23 when the edge strength data is "0"
The dither data output from the dither 1 is selected. When the edge intensity data is "1", the dither data output from the dither 2 is selected, and the edge intensity data is "2".
In this case, the dither data output from the 25 dithers 3 are selected and supplied to the binarization comparing means 28. Here, the dither data is 4 times the bit width of the CMYK data element.
It has pixel data.

As shown in FIG. 9, the binarizing / comparing means 28 converts the input CMYK multivalued data and the dither data supplied from the dither selecting means 27 into dither data 1 obtained by dividing the dither data by one pixel. Dither data 2, dither data 3,
The dither data 4 is compared with the dither data 4 by the comparator 30, respectively.
The CMYK data is dither data x (x = 1, 2, 3,
4) "1" is output as binary data 1, binary data 2, binary data 3, binary data 4 if the value is smaller than dither data x. In the output 31 of the binary data of one pixel when the edge enhancement is not performed, 3
2 is a position where the binary data 1 is arranged, 33 is a position where the binary data 2 is arranged, 34 is a position where the binary data 3 is arranged, and 35 is a position where the binary data 4 is arranged. FIG. 9 is a diagram of one of the elements C, M, Y, and K, and binarized data as shown in FIG. 9 is output for each element.

The rearrangement means 29 of FIG. 8 outputs the binary data 31 of FIG. 9 when the edge data is "0", but otherwise outputs the binary data 1 (3) of FIG.
2) binary data 2 (33), binary data 3 (34),
The binary data of FIG. 10 is output using the sum of the binary data 4 (35). FIG. 10 is a diagram of sorting binary data by edge data. 36 indicates binary data output when the edge data is "1", 37 indicates binary data output when the edge data is "2", and 38 indicates binary data output when the edge data is "3". Binary data x (x = 1, 2, 3,
If the sum of 4) is equal to or larger than the numerical value, binary data "1" is output at that position, and otherwise, binary data "0" is output. Edge-enhanced image data is generated by the above binary data.

In the first embodiment, the BTC decompression means 3 and the VQ decompression means 4 correspond to the decompression means of the present invention, the edge judgment generation means 6 corresponds to the edge data generation means and the first generation means, and the flat portion The edge determination generation means 7 corresponds to the edge data generation means and the second generation means, the edge output control means 5 corresponds to the edge data determination means, and the edge data correction means 3 corresponds to the correction means.

(Embodiment 2) Hereinafter, Embodiment 2 of the present invention will be described with reference to FIGS.

FIG. 11 is a block diagram of an image processing apparatus for performing edge enhancement according to the second embodiment of the present invention. FIG.
1, reference numeral 39 denotes the entire image processing apparatus according to the second embodiment of the present invention.

The BTC decompression means 3 converts the input coded image data into pixel binarized data and luminance 2 bits.
Data expansion of block coded data (BTC data) consisting of only four representative values of the representative value and the hue or three representative values of the luminance and the hue is performed.

The VQ decompression means 4 decompresses input data (VQ data) obtained by encoding image data composed of luminance and hue by vector quantization. VQ data encoded by vector quantization does not include binarized code data of pixels.

The edge candidate generation means 40 generates edge candidate data "1" indicating an edge candidate when the input coded image data is BTC data, and generates an edge candidate data indicating a non-edge candidate when the input coded image data is VQ data. Data "0" is generated. FIG. 12 is a schematic diagram of the edge candidate data.
The edge data 44 of C data and the edge data 45 of VQ data are shown.

FIG. 13 is a block diagram of the color conversion means. The color conversion unit 41 converts pixel data composed of luminance and hue expanded by the BTC expansion unit 3 and the VQ expansion unit 4 into different color spaces. As shown in FIG. 6, the color conversion means 41 is divided into two-stage conversion means.
The color conversion means 21 converts pixel data in the YUV color space composed of luminance and hue into data in the RGB space. The second color conversion unit 22 converts the data in the RGB space output from the first color conversion unit 21 into the data in the CMYK space. In addition, Y, which is a luminance component of input data, is output without color conversion.

FIG. 14 is a block diagram of the window forming means. The window forming means 42 includes a luminance window forming means 46 for forming a 3 × 3 pixel window for Y data which is luminance, and data for delaying CMYK data and edge candidate data to a central pixel position of the 3 × 3 pixel window. And a delay means 47.

FIG. 15 is an explanatory diagram of a window. The edge determining unit 43 performs an edge determination on the window 48 formed by the window forming unit 42. A0 to a4 in FIG. 15 indicate luminance values at respective pixel positions. If the position of the center pixel is not an edge candidate position, “0” is output as edge intensity data and “0” is output as edge data. If the position of the central pixel is an edge candidate position, the luminance value a2 of the central pixel and the luminance values a0, a1, a3,
A difference a2-ax (x = 0, 1, 3, 4) from a4 is calculated.

Next, the largest value (DI
FFMAX) and two preset thresholds TH
Comparison with D1 and THD2 (where THD2> THD1) is performed. If DIFFMAX <THD1, "0" is output as edge intensity data and "0" is output as edge data. When DIFFMAX ≧ THD1 (a2-a1)
Is the maximum value, "2" is output as the edge data, and when (a2-a3) is the maximum value, "1" is output as the edge data. Also, THD2> DIFFMA
In the case of X ≧ THD1, “
If "1" and DIFFMAX≥THD2, "2" is output as edge strength data.

The edge emphasizing means 11 includes an edge judging means 43
Edge-enhanced image data that is edge-enhanced based on the edge intensity data, CMYK data, and edge data generated from. As shown in FIG. 7, the edge emphasizing means 11 includes 23 dithers 1, 24 dithers 2, 25
Dither matrix 3 and gradation processing means 2
6 is comprised. 23 is a dither matrix used when edge strength data indicating a non-edge portion is "0", and 24 dither 2 is a dither matrix having edge strength data of "1".
Is the dither matrix used in the case of
Is a dither matrix used when the edge strength data is "2".

As shown in FIG. 8, the gradation processing means 26 selects the dither data output from the dither matrices 23 to 25 in FIG.

When the edge strength data is "0", the dither data output from dither 1 is selected. When the edge strength data is "1", the dither data output from dither 2 is selected. When the edge strength data is "2", the dither data output from the 25 dithers 3 is selected and supplied to the binarization comparing means 28. Here, the dither data has data of four pixels of the bit width of each element of the CMYK data.

In the binarization comparing means 28, the CMYK multi-value data inputted as shown in FIG.
7, the dither data 1, dither data 2, dither data 3, and dither data 4 obtained by dividing the dither data supplied from the pixel 7 for each pixel are compared by the comparator 30.
When the YK data is larger than the dither data x (x = 1, 2, 3, 4), “1” is set, and in the following cases, “0” is set to binary data 1, binary data 2, binary data 3, binary Output as data 4. 2 of one pixel when edge enhancement is not performed
In the value data 31, 32 is a position where the binary data 1 is arranged, 33 is a position where the binary data 2 is arranged, 34 is a position where the binary data 3 is arranged, and 35 is a position where the binary data 4 is arranged. Position. FIG. 9 is a diagram for one of the elements C, M, Y, and K, and binary data is output for each element as shown in FIG.

The rearrangement means 29 of FIG. 8 outputs the binary data 31 of FIG. 9 when the edge data is "0", but otherwise outputs the binary data 1 and the binary data 2 of FIG. The binary data of FIG. 10 is output using the sum of the binary data 3 and the binary data 4. When the edge data of the data 36 is “1”, the edge data of the data 37 is “2”.
, The data 38 indicates binary data output when the edge data is “3”, and the numerical value (1 to 4) is the sum of the binary data x (x = 1, 2, 3, 4) Is greater than the value, binary data "1" is output at that position,
Otherwise, it indicates that binary data “0” is output. Edge-enhanced image data is generated from the above binary data.

[0059]

As described above, according to the present invention, it is possible to directly generate edge data from encoded data having binary data, and it is possible to easily perform edge detection. Furthermore, by generating edge candidates that make use of the characteristics of the block coded data and performing edge detection with a minimum window size, it is possible to perform edge enhancement processing while suppressing an increase in the amount of edge detection processing.

[Brief description of the drawings]

FIG. 1 is a block diagram of an image processing apparatus that performs edge enhancement according to a first embodiment of the present invention;

FIG. 2 is an explanatory diagram of edge data generation.

FIG. 3 is an explanatory diagram of edge data generation.

FIG. 4 is an explanatory diagram of edge data.

FIG. 5 is a schematic diagram showing a state of an edge window.

FIG. 6 is a block diagram of a color conversion unit.

FIG. 7 is a block diagram of an edge enhancement unit.

FIG. 8 is a block diagram of a gradation processing unit.

FIG. 9 is a block diagram of a binarization comparison unit.

FIG. 10 is a diagram of sorting binary data by edge data.

FIG. 11 is a block diagram of an image processing apparatus that performs edge enhancement according to the second embodiment of the present invention.

FIG. 12 is a schematic diagram of edge candidate data.

FIG. 13 is a block diagram of a color conversion unit.

FIG. 14 is a block diagram of a window forming unit.

FIG. 15 is an explanatory diagram of a window.

FIG. 16 is a block diagram of a conventional image processing apparatus.

FIG. 17 is a schematic view of a window.

FIG. 18 is a block diagram of a conventional edge enhancement unit.

[Explanation of symbols]

 Reference Signs List 1, 39 Image processing device 2 Edge strength generation means 3 BTC decompression means 4 VQ decompression means 5 Edge output control means 6 Edge judgment generation means 7 Flat part edge judgment generation means 8 Edge window formation means 9 Edge data correction means 10, 41 colors Conversion means 11 Edge enhancement means 21 First color conversion means 22 Second color conversion means 26 Gradation processing means 27 Dither selection means 28 Binarization comparison means 29 Rearrangement means 30 Comparator 40 Edge candidate generation means 42 Window formation means 43 Edge determining means 46 Luminance window forming means 47 Data delay means

Claims (8)

[Claims] An image processing apparatus for expanding input data of an original image compressed by encoding to enhance an edge portion, and generates expanded data by expanding the encoded input data. Decompression means, edge data generation means for generating edge data indicating an edge portion in the encoded input data, and edge data generated by the decompression means based on the edge data generated by the edge data generation means. An image processing apparatus comprising: edge enhancement means for performing an enhancement process on an edge portion of the decompressed data. 2. The encoded input data is obtained by dividing image data of an original image into a plurality of blocks, encoding pixel data for each block, and processing different from the block encoding. 2. The image processing apparatus according to claim 1, wherein the edge data generation unit generates edge data indicating an edge portion with respect to the block encoded data. apparatus. 3. The block coded data includes first block coded data coded with binary data and a plurality of representative values for each block, and only a plurality of representative values for each block. Wherein the edge data generating means generates edge data including position information of an edge portion based on the binarized data of the first block encoded data. 3. The image processing apparatus according to claim 2, further comprising a generation unit. 4. The apparatus according to claim 3, wherein said first generating means generates edge data further including direction information of an edge portion based on said binarized data of said first block coded data. Image processing device. 5. An edge data determining means for determining whether or not the edge data generated by the edge data generating means is valid based on the plurality of representative values of the first and second block encoded data. 5. The image processing apparatus according to claim 3, wherein the edge emphasis unit performs an emphasis process on an edge portion of the decompressed data based on edge data determined to be valid by the edge data judgment unit. . 6. When the input data is the second block coded data, the edge data generating means indicates that an edge candidate is located at the outermost position of each block of the second block coded data. The apparatus further includes second generation means for generating edge data in which data is arranged, and using the edge data generated by the first generation means and the edge data generated by the second generation means. Further comprising: a window forming means for forming a data window; and a correcting means for correcting data in the edge data window formed by the window forming means, wherein the edge emphasizing means comprises the edge corrected by the correcting means. 6. An emphasis process for an edge portion of the decompressed data based on the data. The image processing apparatus according to any Re. 7. An apparatus according to claim 1, further comprising an edge strength generating means for generating data indicating the strength of an edge portion based on said plurality of representative values of said block coded data, wherein said edge emphasis means is generated by said edge strength generating means. The image processing apparatus according to claim 3, wherein an edge processing is performed in accordance with the data indicating the strength of the edge. 8. An image processing apparatus for expanding input data of an original image compressed by encoding to enhance an edge portion, wherein the input data divides the image data of the original image into a plurality of blocks. And the pixel data for each block is 2
Decompression means for decompressing the encoded input data, including block-encoded data encoded by the coded data and the representative value, and non-block-encoded data encoded by a process different from the block encoding. An edge candidate generating means for generating edge candidate data indicating that the input data is an edge candidate when the input data is block-coded data; a window forming means for forming a window for the decompressed data; Edge determining means for determining the presence or absence of an edge at each pixel position in the window formed by the window forming means based on the edge candidate data generated by the generating means; and the expanded data based on the determination result of the edge determining means. Image processing apparatus, comprising: an edge emphasizing means for emphasizing an edge portion of the image.