A fast algorithm for registration of individual frames and information recovery in fluorescein angiography video image analysis

A fast algorithm, based on power cepstrum and crosscorrelation, techniques, for registration of image frames in a video is presented. Since compensation for unwanted rotations between image frames is needed, the shift invariance property of Fourier spectrum is used to find this rotation. The registration and information recovery approaches involve three image processing steps: a feature extraction step using the difference of Gaussian filtered images combined with median filtering for removal of noise, to enhance significant fluorescent blood vessels combined with median filtering for removal of noise; compensation for rotational and translational shifts in the Fourier domain using the spectral properties, crosscorrelation, and power cepstrum; lastly, information in each frame is maximized in comparison to the subsequent frames. Such analysis allows better interpretation of the video content for diagnostic evaluation of retinopathies