How to implement filters ?

asked 2014-03-20 10:27:41 -0600

FLY
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updated 2016-01-17 18:59:14 -0600

6772 ●3 ●48 ●79 https://github.com/stu...

I am trying to make filters like sepia filter in my app like other photo editing applications , till now I don't have any idea about it , Can any one help me out for it about its algorithms and how to do it ? and Can I implement in opencv using native c++ or we have any of its build in functions ?

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answered 2014-03-21 13:30:01 -0600

berak
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updated 2014-03-21 13:56:16 -0600

i can give you a c++ answer only, but looking at this it should be quite easy:

Mat img = imread("lena.jpg");
Mat_<float> sepia(3,3); 
//sepia << .393,.769,.189  // rgb
//        ,.349,.686,.168
//        ,.272,.534,.131;
sepia << .131,.534,.272    // bgr (rows as well as cols swapped)
        ,.168,.686,.349
        ,.189,.769,.393;
Mat out;
cv::transform(img,out,sepia);
imshow("i",out);
waitKey();

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