how to mesure PSNR in binary image???

hi everybody. I have an original binary image (A) and an binary image with Watermark (A+W). Please help me how to calculate PSNR of these binary images. thanks a lot. Best regards.

Answer 1

[Paras khandelwal]

PSNR is calculated according to the formula given in MathWorks - PSNR. The formula given on that page and also in the wikipedia is same Peak signa-to-noise ratio. It says that the formula is for monochrome/binary image. So the actual formula you have seen everywhere and in above links need not to be changed for binary/monochrome images. But to do calculation for color image, in MSE add the square of difference of each pixel in for every color space (e.g., difference of value of Red, Green and Blue), and then divide the MSE by three and the total number of pixels.

source : Peak signa-to-noise ratio. See the Application in color images