Use this more robust code:
while true;
[baseFileName, folder] = uigetfile({'*.jpg;*.gif;*.png;*.tif;*.bmp','All Image Files'},' Select image')
if baseFileName == 0;
% They canceled out.
return;
end
fullFileName = fullfile(folder, baseFileName)
[originalImage, storedColorMap] = imread(fullFileName);
[rows, columns, numberOfColorChannels] = size(originalImage)
if numberOfColorChannels == 3 % Will be 3 for color.
% It's a color image.
uiwait(warndlg('Please select a grayscale image, not a color image.')); % Will Loop again
else
% It's an indexed or gray image.
if ~isempty(storedColorMap)
% It's an indexed, not grayscale, image.
uiwait(warndlg('Please select a grayscale image, not an indexed image.')); % Will Loop again
else
break; % It's color so continue on.
end
end
end
imshow(originalImage);
