Localization of sampling points for interpolative VQ of images

A sampling point detection algorithm for interpolative vector quantization (IVQ) applied in image coding is developed and reported in this paper. The algorithm employs an optimal discontinuity detector to locate first order discontinuities which efficiently characterizes a scan line. Using the detected first order discontinuities as the initial guess, the final set of interpolating points is obtained using a modified split-and-merge algorithm. Experimental results show that, under the same bit-rate, an average of 0.5 dB improvement is achieved by our proposed method when compared with the results obtained by the traditional IVQ in terms of peak signal-to-noise ratio (PSNR)