A Block Matching Technique Using Unit Gradient Vectors.
Toshiaki Kondo, Waree Kongprawechnon · 2009
Irregular lighting causes temporal variations of image intensities, which makes most existing block matching techniques ineffective. For this, we propose a novel matching technique based on gradient orientation that is known to be insensitive to variations of intensities. We show that gradient orientation information can be effectively utilized by means of two intensity patterns that are obtained as the x and y components of unit gradient vectors. Simulation results show the proposed technique is remarkably robust to both spatially uniform and non-uniform changes of image intensities. 1.