Efficient way to set specific range of pixels to zero.

Question

Ivan Shorokhov 2015-4-23

评论： Ivan Shorokhov 2015-4-24

Hello everybody,

I have gray image with pixels from 0 to 255. And I would like to set pixel from 90 to 100 to zero.

I've wrote following code:

new_gray=gray;  
new_gray(gray>90&gray<100) = 255;figure;imshow(new_gray);

And it seems to be working fine, but I'm wondering, if there are any other ways of doing it?

Thanks in advance.

Answer 1

Image Analyst 2015-4-23

You could use intlut(). Something like

lut = gray(256);
% Make gray levels 91 through 99 be 0
lut(92:100) ;
new_gray = intlut(grayImage, lut);

DON'T name your image gray. That is the name of a built-in function that creates a colormap.

Ivan Shorokhov 2015-4-24

Ok, thank you!