Two different colormaps overlaying

Hi

I've got an anatomical image 192*192 and a binary ROI with same size. I'd like to display them in one figure but with different colormaps, here's the code I use but it only shows ax2 and no idea why... any help much appreciated!

% read in image IM size 192*192
ax1 = axes;
A = imagesc(IM);
% read in mask m 192*192
ax2 = axes;
B = imagesc(m);
 
linkaxes([ax1,ax2]);
ax2.Visible = 'off';
ax2.XTick = [];
ax2.YTick = [];

colormap(ax1,'gray');
colormap(ax2,'hot');

Answer 1

[Walter Roberson]

You did not put the axes in different positions: axes() with no Position parameter puts the axes in the default position.

You also did not make the second axes background color 'none' so that objects below would show through.

You also did not make the second image transparent at all, so it will cover over all of the first image.

[Fiona Gong]

Thanks very much yes position adjusted now. Both my images are same size with background value 0, hence transparent won't work. Is there a way to make all 0s transparent in both ax?