MATLAB: “Pixel Color”

Question

Hello everyone, basically I have a series of images like this one :

Which is an imagesc of a 256×256 matrix. Every values of the matrix that are "inside" the hexagon are greater than 0 while other values equal 0. What I would like to do is get every pixel coresponding to 0 to be white, not blue. I could use "paint" but I have a thousand of images that looks like this one … I've tried to modify the colormap using colormapeditor but the value difference between blue pixels inside the hexagon and yellow pixels is more 10^6, which gives me a result like this :

Any advice would be good, thanks in advance !

Answer 1

data = magic(30);
figure; h = imagesc( data );
h.AlphaData = data > 100;

You can do the same in your case, just keep the image handle and create a mask for the alpha data. This assumes your underlying axes are white though because it makes the data transparent, not white, but if your axes are white then it looks white.