Patent ID: 8773718

Claim:
An image processing apparatus comprising: a printing unit configured to print an image with lines having a first line width and an image with lines having a second line width on a sheet, and output a printed product; a reading unit configured to acquire a read image by reading the printed product; a binarization unit configured to generate a binarization image by performing black pixelation on pixels corresponding to each of the lines in the read image by performing binarization processing on the read image using a predetermined threshold; an area setting unit configured to set an area with a size based on the line width of each of the lines for each of the lines in the binarization image; a counting unit configured to count a number of black pixels corresponding to each of the lines in the binarization image in the area set for each of the line widths; and a derivation unit configured to derive the line width of the lines on the printed product based on the number of black pixels counted by the counting unit, wherein in a case where the first line width is finer than the second line width, the size of the area set for the first line width by the area setting unit is larger than the size of the area set for the second line width by the area setting unit.