i am executing the code given in the matlab documentation and getting the error'Undefined function 'psnr' for input arguments of type 'double'.

is psnr is not inbuilt in matlab?

    ref = imread('lena256.bmp');
    ref=double(ref(:,:,1));
    A = imnoise(ref,'salt & pepper', 0.02);
    %Calculate the PSNR.

    [peaksnr, snr] = psnr(A, ref);

    fprintf('\n The Peak-SNR value is %0.4f', peaksnr);
    fprintf('\n The SNR value is %0.4f \n', snr);

Answer 1

[Meghana Dinesh]

As far as I know, only A should be of type double. Also, check if you have the necessary toolbox and the right version of MATLAB where psnr is included.

Regards,

Meghana.