How to color a binary image?

Suppose a binary image is considered, which consists of two colors. Is it possible to assign red color to the white portions in the image?

[Jan]

Yes.

A binary image consiste of two colors, 0 and 1. Which of them do you call "red" and where does the color information come from?

[Sabarinathan Vadivelu]

Pixels with 1 should be coloured as red. Is it possible?

Answer 1

[Jan]

bin = rand(320, 200) > 0.5;  % Binary test image
R   = 1;  % Value in range [0, 1]
G   = 1;
B   = 1;
RGB = cat(3, bin * R, bin * G, bin * B);

Now the pixels which have the value 1 in the bin image have the value [R,G,B] in the RGB image, while the other pixels are black.

Alternatively:

CMap = [0.5, 0.2, 0.9;  0.1, 0.8, 0.3];
RGB  = ind2rgb(bin + 1, CMap)

[Sabarinathan Vadivelu]

Pixels with 1 should be coloured as red. Is it possible?

[Sabarinathan Vadivelu]

figure,set(gca,'Color','r'),imshow(outImage);

Where outImage is a binary Image. Is this true?

[Jan]

To get red for pixels of color 1 (you still do not specify what the 0 pixels should look like...):

• Either set B=0 and G=0 in my 1st example
• Or use the colormap CMap=[0,0,0; 1,0,0] in the 2nd example.