I assume your image is grayscale, right?
If I understand you correctly:
min_val=min(example_img(:));
max_val=max(example_img(:));
figure(1);
imshow(example_img, [min_val, max_val]);
set(gca, 'colormap', parula);
colorColumn = uint8(linspace(double(min_val), double(max_val), size(example_img, 1))');
colorBarIm = repmat(colorColumn, 1, size(example_img, 2));
figure(2);
imshow(colorBarIm);
view(180, 90);
set(gca, 'colormap', parula);
axis on;
xticks([]);
Best Answer