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A near-lossless image compression system with data hiding capability

This paper proposes a near-lossless compression method for images where the method can conceals data to an image before compression, i.e., a data hiding-then-compression system. The proposed method first preprocesses an image near-losslessly, i.e., the difference between a pixel of the original image and that of the preprocessed image is not more than the user given maximum allowed error. This method, then, embeds data to the preprocessed image and reversibly post-processes the image conveying data to improve the compression efficiency. Finally, the method losslessly compresses the post-processed image. The framework of the proposed system accepts any arbitrary lossless compression technique, whereas ordinary joint compression-and-data hiding and compression-then-data hiding systems do not have such flexibility. In addition, the near-lossless condition is satisfied between the preprocessed image and that with hidden data and between the original image and the preprocessed image with hidden data. For low bitrate compression, the proposed method serves better decompressed image than lossy compression of the original image in terms of the image quality. Experimental results show the effectiveness of the proposed method.