Patent ID: 6707946
Filing Date: 2004-03-16
Classification: G06T

Abstract:
A method of decoding coded signals corresponding to successive segmented pictures, or partitions, divided into homogeneous regions to which specific labels are respectively associated, said partitions having been coded by means of a coding method comprising, for each partition to be coded, the steps of:translating the picture of labels into a description in terms of a contour elements chain in which the elements are defined by means of their movements through successive basic cells, between an input point and an output point of said cells; tracking inside each successive cell each contour from its initial contour point, previously extracted, to its end by storing chain symbols corresponding both to input, internal and output elements of said cell and to priorities between possible multiple outputs elements; repeating these steps up to the end of each contour of the partition and coding the information corresponding in each cell both to the initial point of each contour segment and to the associated chain of movements between that initial point and the initial one of the following cell; said decoding method being characterized in that it comprises: (A) a forward decoding step, provided for decoding within said chain symbols all contour points that are sure in the decoded partition and detecting local inconsistencies; (B) a backward decoding step, provided for tracking in a backwards manner the decoded contours and solving said inconsistencies on the basis of marks introduced during the detection of these inconsistencies; without storing an original coded bitstream, which is not used during the backward decoding step.