METHOD AND DEVICE FOR CODING AND DECODING

摘要

The invention relates to a method for video coding image sequences, wherein images of the image sequence are coded in a scaled manner such that the obtained video data contains information which represents the image in a plurality of different steps from a defined image resolution and/or image quality (e.g. according to the data rate), and the resolution is defined by the number of image pixels of each represented image. Coding takes place in a block-based manner such that, for a description of an approximate movement of parts of one of the images, contained in the image sequence, at least one block structure which describes the movement is produced, said structure being fitted in such a manner that it is divided from a block into partial blocks comprising, in parts, sub-blocks which divide in a fine manner the successive partial blocks. According to the invention, a first block structure is produced temporally for at least one first resolution level and a second block structure is produced for a second resolution level.The first resolution level has a lower image pixel number and/or image quality than the second resolution level. Also, the second block structure is compared to the first block structure such that differences in the block structure are determined, such that on the base of the properties of the structure differences, a modified second block structure is produced. The structure thereof represents one part of the second block structure. Subsequently, the modified block structure and the second block structure are compared based on at least one value which is proportional to the quality of the image and the block structure and the value thereof is directly proportional to an improved quality based on the coding of the bit sequence.