Device for encoding one contour side of segmented images, and decoder therefor

Claim 1

A device for coding still images, comprising means for segmenting said images into homogeneous regions, and means for coding contents and contours of said regions, characterized in that said contour coding means comprises a sub-assembly for coding contour information, and said sub-assembly comprises: (a) means for detecting contours in the image to be coded; (b) means for detecting, on the contour of each region successively considered, the real direction of orientation on a type of contour edge to be retained for transmission after coding; (c) means for detecting, for each pair of successive image points of each contour segment of said region, the instantaneous direction of orientation between two successive image points of each pair; (d) means for comparing the instantaneous direction of orientation for each said pair with said real direction of orientation for said region, in order to test whether or not these real and instantaneous directions are identical; (e) means for selecting and coding exclusively the contour segments traversed in said real direction of orientation; and (f) means for controlling the effective execution of said coding of said contours, utilizing the means specified in subparagraphs (a), (b), (c), (d) and (e) for each of the regions resulting from the segmentation.

Claim 2

A device for coding still images, comprising means for segmenting said images into homogeneous regions, and means for coding contents and contours of said regions, characterized in that said contour coding means comprises a sub-assembly for coding contour information, and said sub-assembly comprises: (a) means for detecting contours in the image to be coded; (b) means for detecting, on the contour of each region successively considered, the real direction of orientation on a type of contour edge to be retained for transmission after coding; (c) means for detecting, for each pair of successive image points of each contour segment of said region, the instantaneous direction of orientation between two successive image points of each pair; (d) means for comparing the instantaneous direction of orientation for each said pair with said real direction of orientation for said region, in order to test whether or not these real and instantaneous directions are identical; (e) means for selecting and coding exclusively the contour segments traversed in said real direction of orientation; and (f) means for controlling the effective execution of said coding of said contours, utilizing the means specified in subparagraphs (a), (b), (c), (d) and (e) for each of the regions resulting from the segmentation.

Claim 4

A device for decoding signals, which correspond to still images previously coded by a coding device comprising means for segmenting said images into homogeneous regions each associated with a respective label, and means for coding contents and contours of said regions, wherein said decoding device comprises means for decoding said signals and means for reconstructing decoded images corresponding to the original still images, characterized in that said means for decoding comprises a sub-assembly for decoding coded information relating to the contours of said regions, and said sub-assembly comprises: (a) means for decoding the first point of each contour segment transmitted, and other points of said segment, (b) means for writing said first and other points of each transmitted contour segment into an image memory, for identifying each segment by the label of the corresponding region, and for scanning and filling said image memory with the current label corresponding to each said segment; and (c) sequencing means for controlling the effective execution of said decoding said signals utilizing the means specified in subparagraphs (a) and (b).

Claim 5

A device for decoding signals, which correspond to still images previously coded by a coding device comprising means for segmenting said images into homogeneous regions each associated with a respective label, and means for coding contents and contours of said regions, wherein said decoding device comprises means for decoding said signals and means for reconstructing decoded images corresponding to the original still images, characterized in that said means for decoding comprises a sub-assembly for decoding coded information relating to the contours of said regions, and said sub-assembly comprises: (a) means for decoding the first point of each contour segment transmitted, and other points of said segment, (b) means for writing said first and other points of each transmitted contour segment into an image memory, for identifying each segment by the label of the corresponding region, and for scanning and filling said image memory with the current label corresponding to each said segment; and (c) sequencing means for controlling the effective execution of said decoding said signals utilizing the means specified in subparagraphs (a) and (b).