Image encoding apparatus

Claim 2

An image encoding apparatus comprising: storing means (12) for storing, image data corresponding to an object having a specific portion for every frame; specific, image extracting means (15, 26) for detecting a difference between input image data and preceding image data, and extracting specific image data corresponding to the specific portion from the image data on the basis of the difference; and bit allocating means (17, 18, 19) for allocating more bits to the specific image data than those to the remaining image data.

Claim 3

An apparatus according to claim 1, characterized in that said specific image extracting means. comprisescsubtracting means (26) for calculating a difference between the image data read. out from said storing means in units of frames, and outputting differential data; means for comparing the differential data with a predetermined threshold value; means (31, 32) for detecting the pixels each having a level exceeding a predetermined threshold value; means (34, 38) for determining the specific portion from information corresponding to the amount of the pixels detected by said pixel detecting means and outputting the image data representing the specific portion to said bit allocating means.

Claim 4

An apparatus according to claim 1, characterized in that said specific image extracting means comprises subtracting means (26) for calculating a difference between the image data read out from said storing means (12) in units of frames, and outputting differential data; histogram forming means (31, 32) for forming at least X- and Y-axis histograms from the differential data; and coordinate data output means (34, 38) for determining coordinates corresponding to the specific portion from the X- and Y-axis histograms and outputting the coordinate data to said bit allocating means (19).

Claim 5

An apparatus according to claim 1, characterized in that said specific image extracting means comprises subtracting means (26) for calculating a difference between the image data read out from said storing means in units of frames, and outputting difference data; means for comparing the differential data with a predetermined threshold value; histogram forming means (31, 32) for forming at least X- and Y-axis histograms, by means of a comparison result obtained by said comparing means; and coordinate data output means (34, 38) for determining coordinates corresponding to the specific portion from the X- and Y-axis histograms and. outputting the coordinate data to said bit allocating means.

Claim 6

An apparatus according to claim 4, characterized in that the image data is formed by a predetermined block including a number of pixels, said histogram forming means comprises.counting means (42) for counting pixels corresponding to the-differential data and exceeding..a threshold value, and means (43, . 44) for forming the histograms by sequentially storing the count values of said counting meaas.

Claim 7

An apparatus according to claim 4, characterized in that said coordinate data output means comprises mean value means for (32, 36) calculating mean values of the Y- and X-axis histograms, and means (33, 37) for comparing the Y- and X-axis histograms on the basis of the mean values and detecting changes in histograms below the mean values.

Claim 8

An apparatus according to claim 1, characterized in that said bit allocating means comprises means (16) for dividing the image data read out from said storing means into a plurality of blocks and outputting a plurality of data blocks; means (25) for comparing the data block and data block of the preceding image data, detecting movement of the specific portion from both the data blocks, and outputting movement data; selecting means (24) for selecting data block corresponding to the movement data from the preceding image data; means (27) for calculating a difference between the data block selected by said selecting means (24) and the data block obtained by said dividing means (16) and outputting block differential data; and determining/encoding means (17, 18) for determining a movement region on the basis of the block differential data and the movement data and encoding the data block corresponding to the movement region by a predetermined number of bits.

Claim 9

An apparatus according to claim 7, characterized in that said determining/encoding means (17, 18) encodes the data block by different numbers of bits, to form a plurality of encoded data blocks, and which further comprises means (19) for selecting one of the encoded data blocks output from said determining/encoding means (17,18).

Claim 10

An apparatus according to claim 1, characterized in that said specific image extracting means comprises means (41) for limiting a processing range of 1-frame image data read out from said storing means to a predetermined region by the coordinate data, labeling means (45) for labeling the limited region, and means (46) for extracting the specific image data in accordance with data output from said labeling means (45).

Claim 11

An image encoding apparatus comprising: storing means (51) for storing image data corresponding to an object having a specific portion ; specific image extracting means (65) for outputting differential data corresponding to a difference between input image data and preceding image data, and extracting specific image data corresponding to the specific portion from the image data on the basis of the differential data; buffer means (62) for matching a generated data amount with an output data amount; encoding means (53) for encoding the differential data and outputting encoded data; parameter generating means (66) for generating a quantization parameter according to the specific image data extracted by said extracting means and a remaining amount of said buffer means; means (54) for quantizing the encoded data output from said encoding means in accordance with the quantization parameter so as to allocate more bits to the specific image data than those to the remaining image data, and outputting quantized data; and output means (67) for converting the quantized data to output data and outputting the output data to said buffer means.

Claim 12

An image encoding apparatus comprising: storing means (51) for storing image data corresponding to an object having a specific portion ; specific image extracting means (65) for outputting differential data corresponding to a difference between input image data and preceding image data, and extracting specific image data corresponding to the specific portion from the image data on the basis of the differential data; buffer means (62) for matching a generated data amount with an output data amount; encoding means (53) for encoding the differential data and outputting encoded data; parameter generating means (66) for generating a quantization parameter according to the specific image data extracted by said extracting means and a remaining amount of said buffer means; means (54) for quantizing the encoded data output from said encoding means in accordance with the quantization parameter so as to allocate more bits to the specific image data than those to the remaining image data, and outputting quantized data; and output means (67) for converting the quantized data to output data and outputting the output data to said buffer means.

Claim 13

An apparatus according to claim 10, characterized in that said parameter generating means comprises means (66) for outputting quantizing step size data corresponding to the buffer amount, means (72, 73) for multiplying the quantizing step size data with one and a predetermined value a (a > 1) and outputting one-and predetermined number-fold quantizing step size data, and means (74) for selecting the one- and predetermined number-fold quantizing step size data in accordance with the differential data and outputting the selected data to said quantizing means.

Claim 14

An apparatus according to claim 10, characterized in that said storing means (51) stores image data corresponding to a human body including a head portion and a background, and said specific image extracting means (65) comprises subtracting means for calculating a difference between the image data read out from said storing means for every frame and the preceding image data, and outputting difference data, means (31, 35) for forming at least X- and Y-axis histograms on the basis of the differential data, and coordinate data output means (34, 38) for determining coordinates corresponding to a vertex and side surfaces of the head portion and outputting coordinate data to said bit allocating means.

Claim 15

An apparatus according to claim 10, characterized in that said output means scan- converts the quantized data from said quantizing means in accordance with the specific image data and decreasing the number of bits allocated to a region other than the specific image region.

Claim 16

An image encoding apparatus comprising: generating means (91) for generating image data corresponding to an object having a specific portion for every frame; encoding means (92) for encoding the image data and outputting encoded image data; specific portion detecting means (95) for detecting a difference between input image data and preceding image data and outputting specific region data corresponding to the specific portion from the image data; determining means (96) for comparing the specific region data and predetermined data to determine validity of the specific region data, and outputting determination data; and means (99) for supplying the specific region data to said encoding means in response to the determination data from said determining means so that more bits are allocated to the image data corresponding to the specific portion than those to remaining image data to encode the image data.

Claim 17

An image encoding apparatus comprising: generating means (91) for generating image data corresponding to an object having a specific portion for every frame; encoding means (92) for encoding the image data and outputting encoded image data; specific portion detecting means (95) for detecting a difference between input image data and preceding image data and outputting specific region data corresponding to the specific portion from the image data; determining means (96) for comparing the specific region data and predetermined data to determine validity of the specific region data, and outputting determination data; and means (99) for supplying the specific region data to said encoding means in response to the determination data from said determining means so that more bits are allocated to the image data corresponding to the specific portion than those to remaining image data to encode the image data.

Claim 18

An apparatus according to claim 14, further comprising storing means (97) for storing preceding specific region data and means (98) for enlarging the specific region data stored in said storing means in accordance with a predetermined rule.

Claim 19

An image encoding apparatus comprising: storing means (101) for storing image data corresponding to an object having a specific portion for every frame; means (106) for dividing the image data into a plurality of blocks including M x N pixels; predictor output means (107) for predicting a pixel corresponding to each corner of each of said blocks with reference to already encoded pixels which are included in other adjacent blocks, and outputting a predictor; and quantizing/encoding means (104, 109) for detecting an error between the predictor and an actual value of the pixel, and quantizing and encoding differential data corresponding to the error in accordance with a relationship between the error and a predetermined value, wherein said predictor output means (107) predicts a pixel other than the corner pixel with reference to the corner pixel and pixels in other blocks adjacent to the corner pixel, and said quantizing/encoding means (104, 109) detects an error between the predictor and the actual value of the pixel, and quantizes and encodes differential data corresponding to the error in accordance with the relationship between the error and a predetermined value.

Claim 20

An image encoding apparatus comprising: storing means (101) for storing image data corresponding to an object having a specific portion for every frame; means (106) for dividing the image data into a plurality of blocks including M x N pixels; predictor output means (107) for predicting a pixel corresponding to each corner of each of said blocks with reference to already encoded pixels which are included in other adjacent blocks, and outputting a predictor; and quantizing/encoding means (104, 109) for detecting an error between the predictor and an actual value of the pixel, and quantizing and encoding differential data corresponding to the error in accordance with a relationship between the error and a predetermined value, wherein said predictor output means (107) predicts a pixel other than the corner pixel with reference to the corner pixel and pixels in other blocks adjacent to the corner pixel, and said quantizing/encoding means (104, 109) detects an error between the predictor and the actual value of the pixel, and quantizes and encodes differential data corresponding to the error in accordance with the relationship between the error and a predetermined value.

Claim 21

An apparatus according to claim 16, characterized in that said predictor output means comprises means (107) for obtaining a predictor on the basis of an already encoded pixel which is adjacent to a pixel to be predicted in view of a space and time.

Claim 22

An apparatus according to claim 16, characterized in that said quantizing/encoding means comprises means (137,143) for quantizing data indicating a value exceeding a predetermined threshold value or a threshold value corresponding to an ouptut buffer amount at equal intervals or unequal intervals.

Claim 23

An image transmission apparatus comprising: image data output means (202) for generating image data of a movement region of an input image; difference image output means (244) for outputting a difference image of images of two adjacent frames of the input image; detecting means (247) for detecting an outline of the movement region in the difference image output from the difference image output means; first storing means (250) for storing input image data outside the outline of the movement region detected by said detecting means as a background while updating the stored data; transmitting means (228) for transmitting the background image data stored in said first storing means and the movement region image data; receiving means (272) for receiving the movement region image data and the background image data transmitted from said transmitting means; means (273, 274) for reproducing the received movement region image data; second storing means (284) for storing the received background image data until new background data is received; synthesizing means (285) for synthesizing the background image data stored in said second storing means and the reproduced movement region image data; and means (286) for outputting the movement region image data and the background image data synthesized by said synthesizing means.

Claim 24

An image transmission apparatus comprising: image data output means (202) for generating image data of a movement region of an input image; difference image output means (244) for outputting a difference image of images of two adjacent frames of the input image; detecting means (247) for detecting an outline of the movement region in the difference image output from the difference image output means; first storing means (250) for storing input image data outside the outline of the movement region detected by said detecting means as a background while updating the stored data; transmitting means (228) for transmitting the background image data stored in said first storing means and the movement region image data; receiving means (272) for receiving the movement region image data and the background image data transmitted from said transmitting means; means (273, 274) for reproducing the received movement region image data; second storing means (284) for storing the received background image data until new background data is received; synthesizing means (285) for synthesizing the background image data stored in said second storing means and the reproduced movement region image data; and means (286) for outputting the movement region image data and the background image data synthesized by said synthesizing means.

Claim 25

An apparatus according to claim 19, characterized in that said image data output means divides the input image into a plurality of blocks, and performs motion compensated coding with reference to only pixels other than a background in each block.

Claim 26

An apparatus according to claim 19, characterized in that said image data output means divides the input image into a plurality of blocks, and performs transform coding while substituting a luminance value of a background in each block with a value determined by a predetermined rule.