How to implement filters ?

1

asked Mar 20 '14

FLY
853 ●3 ●11 ●31

updated Jan 18 '16

sturkmen

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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3

answered Mar 21 '14

berak
32993 ●7 ●81 ●312

updated Mar 21 '14

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();