Patent ID: 8200020
Filing Date: 2012-06-12
Classification: G06K

Abstract:
1. A method, comprising: a computing device selecting a source tile from a source image, wherein the source tile is represented by a source m×n rectangle that contains m×n pixels, and wherein each of the m×n pixels is represented by one or more pixel values; the computing device selecting a first rectangular feature and a second rectangular feature in the source tile, wherein both the first and second rectangular features are smaller than the source m×n rectangle in at least one dimension, and wherein at least one of the first and second rectangular features is 2×2 pixels or larger; the computing device calculating a source feature vector, wherein the source feature vector comprises (i) a first entry containing a first pixel value sum of the first rectangular feature in the source tile, and (ii) a second entry containing a second pixel value sum of the second rectangular feature in the source tile; the computing device selecting a search area of a target image, wherein the search area is represented by an m′×n′ rectangle that contains m′×n′ pixels, wherein each of the m′×n′ pixels is represented by one or more pixel values, and wherein the m′×n′ rectangle is larger than the source m×n rectangle in at least one dimension; the computing device selecting a target tile within the m′×n′ rectangle, wherein the target tile contains m×n pixels; the computing device selecting a first rectangular feature and a second rectangular feature in the target tile based on the first and second rectangular features in the source tile; the computing device calculating a target feature vector, wherein the target feature vector comprises (i) a first entry containing a first pixel value sum of the first rectangular feature in the target tile, and (ii) a second entry containing a second pixel value sum of the second rectangular feature in the target tile; the computing device determining that a difference between the source feature vector and the target feature vector is below an error threshold; based on the difference between the source feature vector and the target feature vector being below the error threshold, the computing device determining a mapping between the source image and the target image; and the computing device applying the mapping to the source image to produce a transformed source image.