Patent ID: 6559897
Filing Date: 2003-05-06
Classification: H04N

Abstract:
A method for random access to picture blocks in a video picture composed of lines composed of pixels, including reading the picture blocks from a picture memory at least partially storing the video picture and storing the picture blocks in an access memory, which comprises the steps of:storing a first excerpt of a sub-picture of the video picture in a first area of the access memory, the first excerpt being dimensioned such that it encompasses a main picture block having x pixels in a horizontal direction of the sub-picture and also at least one adjacent picture block adjoining it in the horizontal direction and having equivalent dimensions; reading out at least some of the pixels of the main picture block and the at least one adjacent picture block from the first area (AB) of the access memory in order to access the pixels read out; storing a portion of the sub-picture which adjoins the first excerpt horizontally in a second area (PB) of the access memory while the pixels of the main picture block and the at least one adjacent picture block are being read out from the first area (AB) of the access memory, the portion being chosen such that it contains x pixels in the horizontal direction and, in a vertical direction, as many of the pixels as the first excerpt has in the vertical direction; and overwriting the data stored in the first area of the access memory with data from the picture memory and the data of the second area of the access memory as a second excerpt of the sub-picture having equivalent dimensions to the first excerpt, causing the second excerpt to represent a horizontally shifted version of the first excerpt in combination with the complete portion of the sub-picture stored in the second area of the access memory.