It's showing Unrecognized function or variable 'paddedsize'. Error in Untitled (line 7) PQ = paddedsize​(size(foot​Ball)); error

footBall=imread('football.jpg');
%Convert to grayscale
footBall=rgb2gray(footBall); 
imshow(footBall)

%Determine good padding for Fourier transform
PQ = paddedsize(size(footBall));

%Create a Gaussian Lowpass filter 5% the width of the Fourier transform
D0 = 0.05*PQ(1);
H = lpfilter('gaussian', PQ(1), PQ(2), D0);

% Calculate the discrete Fourier transform of the image
F=fft2(double(footBall),size(H,1),size(H,2));

% Apply the highpass filter to the Fourier spectrum of the image
LPFS_football = H.*F;

% convert the result to the spacial domain.
LPF_football=real(ifft2(LPFS_football)); 

% Crop the image to undo padding
LPF_football=LPF_football(1:size(footBall,1), 1:size(footBall,2));

%Display the blurred image
figure, imshow(LPF_football, [])

% Display the Fourier Spectrum 
% Move the origin of the transform to the center of the frequency rectangle.
Fc=fftshift(F);
Fcf=fftshift(LPFS_football);
% use abs to compute the magnitude and use log to brighten display
S1=log(1+abs(Fc)); 
S2=log(1+abs(Fcf));
figure, imshow(S1,[])
figure, imshow(S2,[])

Answer 1

[Adam Danz]

paddedsize is not a Matlab function.

A quick google search resulted in these two leads that may be helpful to identify that function:

• https://www.mathworks.com/matlabcentral/answers/44112-is-paddedsize-the-matlab-command#answer_97424
• https://www.mathworks.com/matlabcentral/mlc-downloads/downloads/submissions/32384/versions/1/previews/MIDAS_2010/paddedsize.m/index.html
• https://www.cs.uregina.ca/Links/class-info/425-nova/Lab5/

I think the 3rd link refers to your code. There's a link within that link that points to the paddedsize function.