Gray image to rgb image

I converted a color image to gray using rgb2gray and denoised the image. Now i wanted to convert the denoised gray image to a color image... Is it possible.... Please can someone help me.... Please do reply....

Answer 1

[Image Analyst]

You can use ind2rgb() but you have to supply a colormap. It won't look like the original colors though - you lost those when you went to gray. Why don't you just denoise each channel one at a time? Or convert to hsv and denoise just the v channel. Either of those methods will not lose the color information like your method does.

I posted a demo here: Salt and pepper noise removal in a color image

[Image Analyst]

MATLAB has a rgb2ycbcr function and ycbcr2rgb function - try that. ALso, why are your arrays 4D arrays? Inside the custom-written functinos they're 3D arrays but I don't even know why they're that. Why aren't they 2D arrays like normal?

[kailas jobu]

i have this code that filters image,but when i use it with a colored image it turns grayscale. could you help me?

I = imread('phonebox2_noisy.bmp');
Im = rgb2gray(I);

noisy = imnoise(Im, 'salt & pepper',0.1);

[m,n] = size(noisy);


output = zeros(m,n);
output = uint8(output);

for i = 1:m
    for j = 1:n  
        xmin = max(1,i-1); 
        xmax = min(m,i+1);
        ymin = max(1,j-1);
        ymax = min(n,j+1);
        
        temp = noisy(xmin:xmax, ymin:ymax);
        
        output(i,j) = median(temp(:));

    end
end
figure(1);
set(gcf, 'Position', get(0,'ScreenSize'));
subplot(131),imshow(I),title('Original Image');
subplot(133),imshow(output),title('filtered image');

[Image Analyst]

@kailas jobu, after you read this

TUTORIAL: How to ask a question (on Answers) and get a fast answer

attach 'phonebox2_noisy.bmp' in your own, new question.

Also attach the "noisy()" function. And you might want to consider medfilt2() instead of median.

Answer 2

[Donghui Sun]

ind2rgb() or ind2rgb8().