Patent ID: 8170336

Claim:
An image processing apparatus that determines, based on data of an image including a plurality of pixels, whether data of the image is of a blank page image, the apparatus comprising: an average value calculating section that calculates, for respective color components, an average value of pixel values within a first pixel block composed of a plurality of pixels including a pixel of interest, to define the calculated average values as a pixel value of the pixel of interest; a histogram generating section that obtains, for respective pixels of interest, a maximum value of the average values among the color components and a maximum difference in the average values among the color components, based on the average values for the respective color components which are calculated by the average value calculating section, and generates histograms respectively for the maximum value and the maximum difference in which histograms a number of pixels for a density bin is considered as a frequency-of-occurrence value; a determination section that obtains numbers of density bins that correspond to a frequency-of-occurrence value greater than or equal to a predetermined frequency-of-occurrence value in the histogram for the maximum value and the histogram for the maximum difference which are generated by the histogram generating section, respectively, and determines that the data of image is of a blank page image when both of the numbers of density bins are less than or equal to a bin threshold; and a pixel determining section that calculates, for respective color components, density information about density in a second pixel block composed of a plurality of pixels including a pixel of interest, compares the calculated density information with a predetermined density threshold to determine whether the pixel of interest is an edge pixel, and counts a number of pixels determined to be edge pixels, wherein the determination section determines that the data of image is of a blank page image when both of the numbers of density bins are less than or equal to the bin threshold and the number of pixels determined to be edge pixels is less than or equal to a number-of-pixel threshold.