Integral P-channels for fast and robust region matching

We present a new method for matching a region between an input and a query image, based on the P-channel representa-tion of pixel-based image features such as grayscale and color information, local gradient orientation and local spatial co-ordinates. We introduce the concept of integral P-channels, which conciliates the concepts of P-channel and integral im-ages. Using integral images, the P-channel representation of a given region is extracted with a few arithmetic operations. This enables a fast nearest-neighbor search in all possible tar-get regions. We present extensive experimental results and show that our approach compares favorably to existing meth-ods for region matching such as histograms or region covari-ance. Index Terms — Region matching, integral images 1