Changing red colour to yellow colour

Hi,

I am a newbie to matlab and I am having problem with changing my picture which I named red_dragon.jpg file. The dragon is red so i want to change the skin to yellow. So far, I have learned to change the red,blue,green colour but i have searched for more information to change the picture to yellow color

Here is my trial. I am pretty sure that there is point that I am doing wrong and I can't figure it out. Can someone help me? I know there is various way to change the colour but i really want to follow this script.

Thanks you

clc
red_dragon=imread('red_dragon.jpg');
yellow_dragon=red_dragon;
dims=size(red_dragon);
    for a=1:dims(1);
        for b=1:dims(2);
            if red_dragon(a,b,1)>1.2*mean(red_dragon(a,b,:))
                yellow_dragon(:,:,0)=red_dragon(a,b,1);
                yellow_dragon(a,b,1:3)=0;
                 image(yellow_dragon)
            end
        end
    end       

Answer 1

[Image Analyst]

Convert to HSV color space with rgb2hsv(), then alter the H channel somehow, then convert back with hsv2rgb(). For example

hsvImage = rgb2hsv(rgbImage);
hsvImage(:, :, 1) = hsvImage(:, :, 1) + 0.5;
rgbImage = hsv2rgb(hsvImage);

Attached are some full demos.

Change red into green:

Change red into blue:

[David]

hi, thanks for your idea. it really helpful but i want to make it by my code . Thanks you so much