Blokowy algorytm dopasowania obrazów multimodalnych w systemach monitorowania

Dopasowanie obrazów jest jednym z etapów fuzji obrazów. W artykule zaprezentowano blokowy algorytm dopasowania obrazów multimodalnych, bazujący na korelacji fazowej. Algorytm wykorzystuje podział obrazu na prostokątne bloki w celu lepszego dopasowania kilku planów obserwowanej sceny. Rozwiązanie zostało opracowane dla systemu monitorowania złożonego z kamer IR oraz TV, przy wynikających stąd założeniach upraszczających.

Sophisticated video surveillance systems use many cameras for watching over the same area. Image fusion allows combining two or more images into a single image containing the most relevant information. One of the most important phases of image fusion is image registration. In this article, we present a block based image registration algorithm for multi-modal images, using the example of TV and thermal (IR) camera images acquired by a monitoring head. For this type of head, the proposed algorithm searches only for translation parameters to align both images; scale and rotation parameters are assumed to be constant, and distortion is neglected. The rough translation parameters are calculated by the classic phase correlation method for image registration. Then, the same method is used to vertically align corresponding rectangular blocks of both images. Inaccurate alignment parameters are detected by the analysis of these parameters in some antecedent time probes and adequately corrected. Data integration by filling gaps between image blocks constitutes the last phase of the presented algorithm. This algorithm delivers good registration effects for images with several near and distant planes of images and preserves a low computation complexity enabling real-time hardware implementation.