How can I calculate the MSE between 2 images?

ref=imread("birdmiddle.png");

A=imread("birdmiddle2.png");

err = immse(A, ref);

fprintf('\n The mean-squared error is %0.4f\n', err);

** I am trying to find the MSE but the following error shows. Image 'A' is the original image 'ref' compressed using lossy jpeg compression, and then the compressed jpeg is converted back into a png. Why is there an error?**

Error using immse (line 34)

A and B must have the same class.

Answer 1

[KALYAN ACHARJYA]

ref=imread('birdmiddle.png');
A=imread('birdmiddle2.png');
err = immse(A, ref);
fprintf('\n The mean-squared error is %0.4f\n', err);

Still problem is not solved, please attached two images

[Tanish Mehta]

I think the problem earlier was that the original picture was uint16 but the second image was uint8. So i converted the second image to uint16 so both images would have the same class. The MSE calculation was successful however the number is very high. The MSE was '2041744502.9629'. Can this be correct?

Thanks a lot for the help!

[KALYAN ACHARJYA]

Can you attach the two original images? One suggestion, convert the both to uint8 and find the same, do share the result value (MSE)?

Tanish do calculate (samples) on notebook, you get the idea.