Patent ID: 7965418

Claim:
An image processing apparatus for performing error diffusion processing on multivalued image data comprised of plural density data and outputting a result of the error diffusion processing, comprising: a first determination unit configured to, upon performing error diffusion processing on a first density data of the plural density data, determine a threshold value used for the error diffusion processing on the first density data, based on a second density data of the plural density data; a first error diffusion unit configured to perform the error diffusion processing on the first density data, based on the threshold value determined by said first determination unit; a first output unit configured to output a result of the error diffusion processing performed by said first error diffusion unit; a second determination unit configured to, upon performing error diffusion processing on the second density data, determine a threshold value used for the error diffusion processing on the second density data, based on a density value of the first density data; a second error diffusion unit configured to perform the error diffusion processing on the second density data, based on the threshold value determined by said second determination unit; and a second output unit configured to output a result of the error diffusion processing performed by said second error diffusion unit.