Patent ID: 6750983
Filing Date: 2004-06-15
Classification: H04N

Abstract:
An image processing apparatus for multiplexing additional information onto image information, comprising:quantization means for quantizing a pixel of interest of the image information by a pseudo halftone process based on error diffusion; and control means for controlling a quantization value of the pixel of interest with quantization values of a plurality of pixels, including the pixel of interest, forming a specific pattern indicating the additional information, wherein said control means comprises: additional information quantization means for setting the quantization value of the pixel of interest on the basis of surrounding pixels, which have already been quantized by said quantization means, the additional information, and pixel values around the pixel of interest before quantization by said quantization means; and determination means for determining the quantization value of the pixel of interest on the basis of quantization results of said quantization means and said additional information quantization means.