It's best if you can just export your image not as a pseudocolor image but as the original grayscale image. That should be possible. If it's not, like you lifted this image off the web or somewhere, then you'll need to convert the colorbar into a colormap. You need to get the center column of the colorbar
theColorBar = rgbImage(100:300, 700, :); % Or whatever numbers locate the colorbar.
and for each color, interpolate its gray value, which will be between 0 and 0.4. Then call rgb2ind() to recover the missing grayscale information.
