| 摘要 |
A method of obtaining access to a two-dimensional (2-D) portion of a digital picture signal, the signal comprising a plurality of digital words representing respective pixels (P) when, when arranged in a 2-D array, make up the picture, comprises the following steps. The words are allocated into groups such that the pixels (P) represented by the words of each group make up a 2-D area (T0, T1, etc.) of the picture having a shape and size which is the same for all of the groups, the shape being such that the areas tessellate with one another to constitute at least part of the picture. Each word is stored in one of a plurality of memories (M0 to M15), the number of memories being equal to the number of pixels (P) in the 2-D area (T0, T1, etc.), such that, for each pixel position in the area, the words from all of the groups representing the pixels having that pixel position in the area are stored in a respective one of the memories. Then, a set of the stored words which represent a set of pixels are read in parallel. The pixels of the set are so positioned relative to one another as to constitute at least some of the pixels (P0 to P15) of a 2-D portion of the picture which is of the same size and shape as the above-mentioned 2-D area (T0, T1, etc.) whereby, even if the pixels of the set are located in different ones of the 2-D areas, the words representing the pixels (P0 to P15) of the set are each stored in a respective different one of the memories (M0 to M15) so that they can be read in parallel. |
