초록 ▼

This invention relates to an image processing method of quantizing a multivalued image to perform image processing. The luminance frequency of the multivalued image is calculated, a quantization threshold for quantization is specified on the basis of the calculated luminance frequency, a representat

This invention relates to an image processing method of quantizing a multivalued image to perform image processing. The luminance frequency of the multivalued image is calculated, a quantization threshold for quantization is specified on the basis of the calculated luminance frequency, a representative value used for quantization of the multivalued image is calculated on the basis of the specified quantization threshold and the luminance frequency, and the multivalued image is quantized using the calculated representative value. The quantization threshold is an average luminance value obtained when the histogram distribution converges to make the skew of the histogram distribution of the luminance frequency fall within a predetermined range. The representative value is an average luminance value in each distribution region of the histogram distribution of the luminance frequency that is divided by the quantization threshold.

대표청구항 ▼

[ What is claimed is:] [1.]1. An image processing apparatus for quantizing a multivalued image to perform image processing, comprising:forming means for calculating a luminance frequency of the multivalued image to form a histogram;specifying means for specifying a quantization threshold for quantiz

[ What is claimed is:] [1.]1. An image processing apparatus for quantizing a multivalued image to perform image processing, comprising:forming means for calculating a luminance frequency of the multivalued image to form a histogram;specifying means for specifying a quantization threshold for quantization on the basis of the formed histogram;representative value determination means for determining a first representative value from a region having a value smaller than the specified quantization threshold and a second representative value from a region having a value larger than the quantization threshold specified by said specifying means in the histogram;quantization means for quantizing the multivalued image;means for performing image region separation for the image quantized by said quantization means, and outputting region data including an attribute of a region obtained by the image region separation; anddiscriminating means for discriminating the attribute of each region of the separated image by using the quantized multivalued image data, wherein the first representative value is used as information representing character data, and the second representative value is used as information representing background data of the character in the discrimination,wherein said quantization means generates binary data on the basis of the specified quantization threshold, and obtains the binary data and header information of the first and second representative values as quantization results.