Code for making a reddish image from an RGB image

If anyone knows the code for make a reddish image from an RGB image.Then plz share with me

Answer 1

[Walter Roberson]

grayimg = rgb2gray(RGBImage);
redimage = cat(3, grayimg, zeros(size(grayimg)), zeros(size(grayimg)));
image(redimage);

Answer 2

[Image Analyst]

Walter gave one way, which is to convert it to a grayscale image and then make that into a red image. Another alternative is to just extract the red channel from the RGB image,

redChannel = rgbImage(:,:,1);
redImage = cat(3, redChannel, zeros(size(redChannel), 'uint8'), zeros(size(redChannel), 'uint8'))

or zero out the green and blue channels

redImage = rgbImage; % Initialize
redImage(:,:,2:3) = 0; % Erase green and blue channels.

The above two ways will give you a different image than via Walter's method. Use whichever gives you the image you want (a monochrome/weighted image or the red channel-only image). If you don't know why they're different, or what I'm talking about, then ask.

[Image Analyst]

Yet another way is to not create an RGB image and just keep the gray scale image and apply a colormap

redColorMap=[(0:255)',zeros(256,2)]
imshow(grayImage); 
% grayImage is either rgbImage(:,:,1) or rgb2gray(rgbImage)
colormap(redColorMap);

[Image Analyst]

ANCY - Are you still there? What's going on?

Answer 3

[DGM]

I've answered a couple very similar-sounding questions recently:

How to make image "yellowish"? (explaining 'screen' blend, alternatives with imblend & MIMT tools)

How do I make image "reddish"? (basic non-MIMT blends, opacity comp, HSV colorize, Y+R)

This is also probably tangential to equally vague requests to colorize grayscale images:

https://www.mathworks.com/matlabcentral/answers/812105-grayscale-to-rgb-in-matlab