how to extract the orange color from the image? how to convert the red band to orange band?

i want to change the red band of the image to the orange band others remaining unaffected.

[Thorsten]

Please add the image.

Answer 1

[Image Analyst]

Three different color segmentation methods are given in my File Exchange. http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862 You might try the HSV one first.

The basic concept is to find the range of hues that represents orange. Let's say orange ranges from 0.2 to 0.3 in the hue component. Then just set all of those to 0.2 (the shade of red closest to the orange boundary).

hsv = rgb2hsv(rgbImage);
h = hsv(:,:,1);
imshow(h, []); % Display the hue channel 
axis on;
s = hsv(:,:,2);
v = hsv(:,:,3);
% Get mask for orange pixels.
orangePixels = h > 0.2 & h < 0.3;
% Set those pixels to a hue of red - the red that is closest to orange
h(orangePixels) = 0.2;
% Now convert back to RGB
hsv = cat(3, h, s, v);
rgbImage = hsv2rgb(hsv);