This program is able to convert real document photo to a scanned copy with scanner texture.
This program extracts the RGB channels and pixel values in the file image, and sets the color thresholds of red, green, blue and gray according to the conversion relationship between gray and RGB in the sRGB color gamut. By adjusting the RGB assignment, the red, green, and blue domains are saturated and the areas exceeding the grayscale threshold are replaced with white. The saturation of the color part is preserved and the white background effect of the document can be realized.

The picture wiht 1 RGB primary color can be smoothly converted by saturizing the color and wiping out the region with intermediate gray value. The fold of paper can also be relieved of eliminated since it is classified as an intermediate gray value.

The picture mainly composed of black and RGB primary colors can be smoothly converted by saturizing the color.

The conversion of photo part with mixed color is a limitation.

The document with black and white and the RGB primary colors blue and red can be smoothly converted by saturizing the color, but the conversion of photo part with mixed color is not that perfect since the mixed color is stratified to RGB primary colors. The blurred areas performed by Gaussian blur can be replaced by white color if the blur radius is relatively larger (greater than approximately 40 pixels).