Efficient VQ-based image coding scheme using inverse function and lossless index coding

•In this paper, a lossy image coding scheme based on VQ is proposed.•The encoding of the inverse image block is cooperated with the VQ scheme.•The lossless index coding process is employed in the scheme.•It improves the image qualities while keeping bit rates.

A novel image coding scheme based on vector quantization (VQ) is proposed in this paper. The goal of the proposed scheme is to provide better image qualities of the compressed grayscale images while keeping low bit rates. To achieve the goal, the encoding of the inverse image block is cooperated with the VQ scheme. In addition, the lossless index coding process is employed in the proposed scheme to cut down the required bit rates. From the results, it is shown that the proposed scheme achieves better image qualities than VQ while keeping low bit rates.