Patent ID: 8515178

Claim:
A method for performing imaging feature extraction, comprising: extracting a cutout image that includes an object from an original image; filling borders of the cutout image with a single color as a background to generate a minimum square image; resizing the minimum square image into a resized square image having a first predetermined size; dividing the resized square image into sub-image blocks having a second predetermined size; computing luminosity derivatives of neighboring pixels in horizontal, vertical, positive 45°, and negative 45° directions for each of the sub-image blocks; obtaining a quintuplet characteristic vector for each of the sub-image blocks; and forming an image characteristic vector of the original image using the quintuplet characteristic vectors of all the sub-image blocks, wherein the quintuplet characteristic vector includes a first dimension representing a number of times where a border of the object in the resized image lies on a border of the sub-image block, a second dimension representing a number of edges of the object in the sub-image block with an extremum of the luminosity derivative in the horizontal direction, a third dimension representing a number of edges of the object in the sub-image block with an extremum of the luminosity derivative in the sub-image block in the vertical direction, a fourth dimension representing a number of edges of the object in the sub-image block with an extremum of the luminosity derivative in the positive 45° direction, and a fifth dimension representing a number of edges of the object in the sub-image block with an extremum of the luminosity derivative in the negative 45° direction.