Methods and systems for image binarization using mean restrain are disclosed. A method includes: obtaining, by a computing device, a grayscale image; generating, by the computing device, a histogram from the grayscale image; determining, by the computing device, a foreground mean value and a background mean value for each pixel value in the histogram; determining, by the computing device, a binarization threshold using the foreground mean values and the background mean values; and generating, by the computing device, a binarized image using the grayscale image and the binarization threshold.