Linked-list image feature extraction

摘要

The present invention is a technique for use in image processing for extracting feature information from an array of pixels. Each pixel within the array of pixels has a pixel value selected from among a plurality of possible pixel values. As the pixels are recalled from the array of pixels in a raster scan fashion a pixel address memory is incremented to contain a current pixel address indicative of the location of the current pixel. If the current pixel is the first occurrence of its pixel value, the current pixel address is stored in a first occurrence pointer memory at a memory location corresponding to the current pixel value. The current pixel address is stored within a last occurrence pointer memory at the memory location corresponding to the current pixel value. The current pixel address is stored in a memory location within a linked-list memory corresponding to a pixel address stored within the last occurrence pointer memory at a memory location corresponding to the current pixel address. This process builds within the linked-list memory a plurality of linked chains from the first occurrence of a particular pixel value, through successive occurrences of the pixel value for the entire array of pixels.