to measure the similarity between watermark image and recovered watermark image

in image watermarking the effectiveness/ perceptibility of the watermarking is checked by the comparing the watermark image and the extracted watermarking image. and for comparing the two images usually used Normalized Correlation Coefficient (NC) function.

please help me to code the NC function in matlab . . .

the value of NC should the 1 for two exactly similar images and 0 for two dissimilar images . . .

[Kazi Shakib]

You can use normxcorr2.