Image processing apparatus, method of controlling image processing apparatus, and storage medium

A method of controlling an image processing apparatus, comprising:

• calculating a density value histogram based on an acquired scanned image;
• setting a necessary area density that has a predetermined value range around a most frequently appearing density value having a highest appearance frequency in the density value histogram, and setting a threshold value for binarization based on the necessary area density;
• and
• controlling execution of binarization processing for correcting an area of the scanned image, in which density values are equal to or higher than the threshold value, to black, and correcting an area of the scanned image, in which density values are lower than the threshold value, to white,
• wherein the scanned image is an image generated by reading an answer sheet, and
• wherein the method includes
• controlling whether or not to execute the binarization processing based on information indicating an answer format of the answer sheet, and
• controlling whether or not to execute the binarization processing, on an answer field-by-an answer field basis, for the answer sheet.

A non-transitory computer-readable storage medium storing a program for causing a computer to execute a method of controlling an image processing apparatus,

• wherein the method comprises:
• calculating a density value histogram based on an acquired scanned image;
• setting a necessary area density that has a predetermined value range around a frequently appearing density value having a highest appearance frequency in the density value histogram, and setting a threshold value for binarization based on the necessary area density;
• and
• controlling execution of binarization processing for correcting an area of the scanned image, in which density values are equal to or higher than the threshold value, to black, and correcting an area of the scanned image, in which density values are lower than the threshold value, to white,
• wherein the scanned image is an image generated by reading an answer sheet, and
• wherein the method includes
• controlling whether or not to execute the binarization processing based on information indicating an answer format of the answer sheet, and
• controlling whether or not to execute the binarization processing, on an answer field-by-an answer field basis, for the answer sheet.