Semi-fragile watermarking-based color image authentication with recovery capability

A watermarking method for color image content authentication with localization and recovery capability of the tampered areas is proposed, in which a halftone image is used as approximate version for the luminance information and the coefficients of the Discrete Cosine Transform (DCT) of the two chrominance channels are encoded and used as approximate version of color information. The luminance and color information are embedded into the lower sub-bands of the Integer Wavelet Transform (IWT) of the host image using the Quantization Index Modulation-Dither Modulation (QIM-DM). The luminance information is embedded into the LL sub-band, while the color information is embedded redundantly into the LH and HL sub-bands in order to increase the robustness against JPEG compression. Moreover, a Multilayer Perceptron (MLP) Neural Network is employed as inverse halftoning process to improve the recovered image quality. The experimental results demonstrate the effectiveness of the proposed method compared with previously proposed methods.