An apparatus includes an input unit configured to read a document and input image data, a division unit configured to divide the image data into a margin area and a print information area, an acquisition unit configured to count a number of pixels having a gradation value greater than a first threshold value in each divided area, and acquire the number of counted pixels per unit area, and a determination unit configured to determine that the document is white paper if a difference of two acquired pixel numbers per unit area is smaller than a second threshold value.