Abstract-This paper presents a new direct Fourier-based algorithm for performing image-to-image registration to subpixel accuracy, where the image differences are restricted to translations and uniform changes of illumination. The algorithm detects the Fourier components that have become unreliable estimators of shift due to aliasing, and removes them from the shift-estimate computation. In the presence of aliasing, the average precision of the registration is a few hundredths of a pixel.Experimental data presented here show that the new algorithm yields superior registration precision in the presence of aliasing when compared to several earlier methods and has comparable precision to the iterative method of Thévenaz et al. [21].

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Abstract-This paper describes a hybrid motion-compensated wavelet transform coder designed for encoding video at very low bit rates. The coder and its components have been submitted to MPEG-4 to support the functionalities of compression efficiency and scalability. Novel features of this coder are the use of overlapping block motion compensation in combination with a discrete wavelet transform followed by adaptive quantization and zerotree entropy coding, plus rate control. The coder outperforms the VM of MPEG-4 for coding of I-frames and matches the performance of the VM for P-frames while providing a path to spatial scalability, object scalability, and bitstream scalability.

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