How to create sepia image in gui?

global im
is=im;
inputRed = im(:,:,1); %// Extract each colour plane
inputGreen = im(:,:,2);
inputBlue = im(:,:,3);
%// Create sepia tones for each channel
outputRed = (inputRed * .393) + (inputGreen *.769) + (inputBlue * .189);
outputGreen = (inputRed * .349) + (inputGreen *.686) + (inputBlue * .168);
outputBlue = (inputRed * .272) + (inputGreen *.534) + (inputBlue * .131);
%// Create output image by putting all of these back into a 3D matrix
%// and convert back to uint8
out = uint8(cat(3, outputRed, outputGreen, outputBlue));
axes(handles.axes2);
imshow(is);

That's my code, but Sepia is suposed to be more.. yellow

Answer 1

[Geoff Hayes]

Rossana - look at your last line of code

 imshow(is);

You are displaying the original image is when you want to display the modified one out as

 imshow(out);

As an aside you may want to rename your sepia image variable to something more meaningful like sepiaImg.

[Rossana Parada]

I know, but if i write out, there is a black image... So, I just changed my code for copper filter... :) thanks.

[Geoff Hayes]

I was able to use your above code to generate a sepia image from my original, so perhaps there was something incorrect about your image (?).

[Image Analyst]

The copper look up table (colormap) only applies to a monochrome (grayscale) image. Not sure which monochrome image you applied

colormap(copper(256));

to. Like maybe one of the color channels??? But you can't apply it to a floating point, or uint8, RGB color image - it will be ignored since a colormap only applies to, and makes sense for, grayscale or indexed images.

Regarding the black image, in your unshown code where you call imwrite() to write "out" out (to disk), you need to convert to uint8, otherwise you might get all black (like you did) or possibly all white or gibberish (not sure since that's not the right thing to do, so I never do it to check on it).