A Quasi-Lossless Data Embedding Technique for Color Palletized Images

Recently data embedding over images have drawn tremendous interest, using either lossy or lossless techniques. Although lossy techniques can allow large hiding capacity, host image cannot be recovered with high fidelity. The aim of this work is to increase the embedding capacity while maintaining the visual quality of the stego image. The new technique is named "quasi-lossless" because the image histogram has been changed with the condition of satisfying high PSNR value (> 35 dB). The quasi-lossless technique is based on the image histogram where least repeated colors are treated as unused colors to increase the embedding capacity. The proposed technique reported an embedding capacity that reached up to 60%.