Lossless Visible Watermark with Smooth Visual Appearance
兼顾视觉质量和载体图像无损重建的可见水印

To avoid poor appearance of lossless visible watermarks due to gray level flipping existence in some previous work,we propose two embedding methods capable of completely reconstructing the host image with satisfactory visual quality. The first calculates exclusive-OR between the image's MSB plane and the binary watermark. The other method uses a bit-shift strategy to push down high bits of the mark-covered pixels,and replaces the MSB with the mark data,making the watermark semi-transparent and other image areas completely transparent. The watermark can be embedded into any position of the carrier image with any size. Both methods can losslessly reconstruct the host image without knowing the watermark information.