How can I paint a list of pixels in a matlab image?

I'm working with a lot of images here and I have to find all the pixels above a scalar value and paint all them into any color.

I've all the indexes of this pixels but I don't know how can I paint them now...

Thx for the help again.

[Jan]

In which format are the "images" represented? Printed on paper, as JPEGs on the harddisk or as arrays in Matlab? What does "paint all of them in any color" exactly mean?

Answer 1

[Image Analyst]

Here's the way to do it without using slow loops:

grayImage = imread('coins.png');
subplot(2,2,1);
imshow(grayImage);
binaryImage = uint8(255 * ~(grayImage > 150));
subplot(2,2,2);
imshow(binaryImage, []);
uniformImage = uint8(255 * ones(size(grayImage)));
zeroImage = uint8(255 * zeros(size(grayImage)));
rgbImage = cat(3, uniformImage, binaryImage, zeroImage);
subplot(2,2,3);
imshow(rgbImage);

Answer 2

[Wanderson]

LoL, sorry I'll try to explain it better now.

I have one image 320x256 as arrays in matlab. I use the function "find" to find all the pixels between 0 and 0.5 and I have to paint this set of pixel from "yellow" for example and them I'll do the same thing to find another set of pixel between 0.5 and 1.0 and paint this new set to "red".

better now?

Answer 3

[Wanderson]

Thank you both for the help.