Reversible data hiding method based on pixel prediction and block adaptive coding

The invention discloses a reversible data hiding method based on pixel prediction and block adaptive coding, which comprises the following steps of: partitioning a grayscale image, setting a reference pixel point, calculating a pixel prediction value through MED, performing subtraction to obtain a prediction error, marking a prediction error sign bit, setting the highest bit surface of a prediction error image to be all zero, performing inter-block and in-block scrambling on the image, and hiding the pixel prediction value and the prediction error sign bit. The method comprises the following steps of: processing a gray level image, encrypting the gray level image by using a stream cipher function after the processing is completed, partitioning the encrypted image, analyzing high seven bit planes of pixels in blocks from high to low, obtaining different block types according to whether the bit planes are all zero and one or not, performing subdivision processing on an encrypted block of which the length t is l