Patent ID: 7899255
Filing Date: 2011-03-01
Classification: G06F,G06K,G06T

Abstract:
1. A method of recognizing and indexing a digital image, comprising: converting the digital image to an image; comparing each pixel of the digital image with each pixel's local neighborhood of the digital image; identifying a first pixel value of a first pixel, a second pixel value of a second pixel, and a third pixel value of a third pixel; determining i) a first difference value between the first pixel value and the second pixel value and ii) a second difference value between the second pixel value and the third pixel value; comparing the first difference value with the second difference value; determining a number of occurrences of each pixel difference value; identifying a threshold difference corresponding to a dynamic threshold value of the number of occurrences, wherein the dynamic threshold value of the number of occurrences of each pixel pair difference is selected as a first local minimum occurring in a histogram graph of number of occurrences for each difference value; and determining that each difference being greater than the threshold difference is an edge pixel.