Image data compression apparatus and image data communication system

• US 5,787,192 A
• Filed: 09/08/1995
• Issued: 07/28/1998
• Est. Priority Date: 09/27/1994
• Status: Expired due to Fees

• Current Assignee: Kabushikikaisha Equos Research
• Original Assignee: Kabushikikaisha Equos Research
• Inventors: Nakagawa, Yoshihiro, Takaichi, Toshio
• Primary Examiner(s): Stoll, Thomas L.
• Application Number:
  US08/525,147
• Time in Patent Office: 1,054 Days
• Field of Search: 358/426-433, 358/539, 382/166, 382/232, 382/236
• US Class Current: 382/166
• CPC Class Codes: H04N 1/64 Systems for the transmission or the storage of the colour picture signal; Details therefor, e.g. coding or decoding means therefor H04N19/00 takes precedence
• CPC Class Codes: H04N 11/042 Codec means
• CPC Class Codes: H04N 19/186 the unit being a colour or a chrominance component
• CPC Class Codes: H04N 19/503 involving temporal prediction adaptive coding with adaptive selection between spatial and temporal predictive coding H04N19/107; adaptive coding with adaptive selection among a plurality of temporal predictive coding modes H04N19/109
• CPC Class Codes: H04N 19/593 involving spatial prediction techniques

Abstract

An image data compression apparatus and image data communication system is disclosed for compressing color image data in relatively simple software process, and compressing a still or moving picture of a color image to be transmitted and/or received thereby.

The image data compression apparatus generates image data having pixel data, each of which is constituted by a luminance signal and color difference signals, and generates n×m block data. Block components constituted by a plurality of luminance signals, color difference signals, and an n×m bit map representing a distribution of luminance signal components, all of which represent the generated blocks, are generated to compress the data.

Claims

1. An image data compression apparatus comprising:

image data generating means for generating image data of pixels, each of said data of pixels constituted by a luminance signal and color difference signals;

a block generator for generating data of blocks from the image data generated by said image data generating means, each of said blocks consisting of n×

m pixels;

block luminance generating means for generating two luminance signals ya and yb representing each of said blocks;

block color difference generating means for generating one pair of color difference signals u and v from said data of each of said blocks generated by said block generator, said color difference signals u and v representing said blocks;

bitmap generating means for generating n×

m bitmap bm for each of said blocks wherein the n×

m bitmap represents the distribution of the two luminance signals generated by said block luminance generating means; and

encoding means for generating block components from said to luminance signals ya and yb generated by said block luminance generating means, said one pair of color difference signals u and v generated by said block color difference generating means, and said n×

m bit map bm generated by said block generator.

2. An image data compression apparatus according to claim 1, further comprising:

similar block selecting means for selecting a similar block coincident with or similar to a block being encoded in regard to the block components generated by said encoding means; and

compressing means for encoding said block components of the block being encoded with code data and difference data, said code data representing the relative position of said similar block selected by said similar block selecting means in regard to said block being encoded, and said difference data representing differences between the block components of said similar block and the block components of said block being encoded by said encoding means.

3. An image communication system comprising:

said image data compression apparat image claim 1; and

an image elongation apparatus having receiving means for receiving a signal transmitted from said image data compression apparatus, and decoding means for generating a luminance signal and color difference signals of each pixel constituting an n×

m block in accordance with block components received by said receiving means.

4. An image communication system comprising:

said image data compression apparatus of claim 2; and

an image elongation apparatus having receiving means for receiving a signal transmitted from said image data compression apparatus, and decoding means for generating a luminance signal and color difference signals of each pixel constituting an n×

m block in accordance with block components received by said receiving means.

7. An apparatus according to claim 4, wherein said apparatus further comprises color reduction means for performing the color reduction process for the first and second color components of the block components generated by said encoding means in accordance with the CLUT generated by said CLUT generating means, thereby generating block components constituted by color-reduced first and second color components and an n×

m bit map, and

said transmitting means transmits the CLUT generated by said CLUT generating means and the color-reduced block components generated by said color reduction means.

10. An apparatus according to claim 7, wherein said apparatus further comprises compressing means for selecting a similar block whose block components coincide with or are most similar to the block components generated by said encoding means or the color-reduced block components generated by said color reduction means, and encoding the block components generated by said encoding means or color reduction means in accordance with code data representing the similar block and difference data between the block components of the similar block and the block components generated by said encoding means or said color reduction means, and said transmitting means transmits the CLUT generated by said CLUT generating means and the data encoded by said compressing means.

11. An image data compression apparatus according to claim 7, wherein said apparatus further comprises most frequent block detecting means for detecting a block having most frequent color-reduced block components upon the color reduction process using the CLUT generated by said CLUT generating means,

said image data generating means generates one-frame image data for a still image,

said encoding means selects a coincident or most similar block on the basis of block components including the block components of the most frequent block detected by said most frequent block detecting means, and

said transmitting means further transmits the block components of the most frequent block detected by said most frequent block detecting means.

5. An image data compression apparatus comprising:

image data generating means for generating one-frame image data for a still image, each data constituted by a luminance signal and color difference signals;

a block generator for generating block data representing blocks each consisting of n×

m pixels from the image data generated by said image data generating means;

a most frequent block detector for detecting a most frequent block component from all block components generated by said block generator;

encoding means for generating block components constituted by a plurality of luminance and color difference signals representing a block, and an n×

m bit map representing a luminance signal component distribution from the block data generated by said block generator;

said encoding means selecting a coincident or most similar block on the basis of block components including the block components of the most frequent block detected by said most frequent block detector; and

compressing means for encoding the block components generated by said encoding means in accordance with the block components, or in accordance with code data representing the selected coincident or most similar block from said encoding means and difference data between the block components of the selected block and the present block components generated by said encoding means.

6. An image data compression apparatus comprising:

image data generating means for generating image data having pixel data each constituted by a luminance signal and color difference signals;

block generating means for generating block data representing blocks each consisting of n×

m pixels from the image data generated by said image data generating means;

encoding means for generating block components constituted by first and second color components each representing a block and constituted by a luminance signal and color difference signals, and an n×

m bit map representing a distribution of the first and second color components in accordance with the block data generated by said block generating means;

CLUT generating means for generating a CLUT for performing a color reduction process for the first and second color components generated by said encoding means so as to obtain an arbitrary number of colors; and

transmitting means for transmitting the CLUT generated by said CLUT generating means and the block components generated by said encoding means.

8. An apparatus according to claim 6, wherein said apparatus further comprises compressing means for selecting a similar block whose block components coincide with or are most similar to the block components generated by said encoding means or the color-reduced block components generated by said color reduction means, and encoding the block components generated by said encoding means or color reduction means in accordance with code data representing the similar block and difference data between the block components of the similar block and the block components generated by said encoding means or said color reduction means, and said transmitting means transmits the CLUT generated by said CLUT generating means and the data encoded by said compressing means.

9. An image data compression apparatus according to claim 6, wherein said apparatus further comprises most frequent block detecting means for detecting a block having most frequent color-reduced block components upon the color reduction process using the GLUT generated by said GLUT generating means,

said image data generating means generates one-frame image data for a still image,

said encoding means selects a coincident or most similar block on the basis of block components including the block components of the most frequent block detected by said most frequent block detecting means, and

said transmitting means further transmits the block components of the most frequent block detected by said most frequent block detecting means.

12. An image data compression apparatus according to claim 8, wherein said apparatus further comprises most frequent block detecting means for detecting a block having most frequent color-reduced block components upon the color reduction process using the CLUT generated by said CLUT generating means,

said image data generating means generates one-frame image data for a still image,

said encoding means selects a coincident or most similar block on the basis of block components including the block components of the most frequent block detected by said most frequent block detecting means, and

said transmitting means further transmits the block components of the most frequent block detected by said most frequent block detecting means.