Abstract: A process for enhancing a frame of an image sequence, the process comprising dividing the frame into a number of blocks and matching the blocks with corresponding blocks in the directly preceding and directly succeeding frames of the sequence to compensate for object motion between frames. Damaged pixels are identified by comparing their actual intensity values with intensity values predicted by an autoregressive process conducted on the motion compensated data. Once identified, the intensity values of the damaged pixels are replaced by values interpolated by a further autoregressive process modified to ignore the effects of damaged pixels.

Abstract: A digital Wiener filtering method is proposed which applies motion compensation by successive approximations of increasing resolution to determine displacement vectors for two successive image frames, a vectors defining a real displacement only being applied to a block of one of the frames when the mean absolute error associated with that vector is not greater than a given fraction of the mean absolute error between that block and the corresponding block of the other frame. The current frame is then filtered block-by-block, with the blocks overlapping. In this filtering, each block is a 3D volume of pixels from the current frame and blocks selected from the preceding and succeeding frames so as to correspond according to the displacement vectors. In one embodiment, the filtering comprises applying a 3D FFT to convert to a power spectrum in the frequency domain, followed by attenuation according to a Wiener filter and conversion from the frequency domain by the inverse FFT.