Improved Spread Transform Dither Modulation using a Perceptual Model: Robustness to Amplitude Scaling and JPEG Compression

Spread transform dither modulation (STDM) is a form of quantization index modulation (QIM) that is more robust to re-quantization. However, the robustness of STDM to JPEG compression is still very poor and it remains very sensitive to amplitude scaling. Here, we show how a perceptual model that scales linearly with amplitude scaling can be used to (i) provide robustness to amplitude scaling, (ii) reduce the perceptual distortion at the embedder and (iii) significantly improve the robustness to re-quantization.