negative values in matrix to show in white

hello,

I have a matrix, where I changed certain values (row 23-30, columns 25-30) to -10.Now I have to display these negative values in white. How should I approach that? thanks

Kay

Answer 1

[Image Analyst]

Here's one way:

matrixForDisplay = originalMatrix; % Initialize a copy.
negativeIndexes = originalMatrix < 0;
matrixForDisplay(negativeIndexes) = max(originalMatrix);
imshow(matrixForDisplay, []);

That's one way, which will work even for floating point images. it will scale the max of your array to 255 and negative values will also be set to the max and so will also show up as 255. The lowest value after the negative values have been changed to the max (say, perhaps it's 3 or 5 or something) will display as 0 (black).

[Walter Roberson]

I would suggest max(originalMatrix(:))

Note that the behavior of the above code will depend upon the colormap that is in effect.

[Kay]

It worked! thank you both!