The filter makes an image look like an old brown photo. The main idea of the algorithm:
1) RGB -> YIQ: Y = 0.299 * R + 0.587 * G + 0.114 * B I = 0.596 * R - 0.274 * G - 0.322 * B Q = 0.212 * R - 0.523 * G + 0.311 * B
2) update: I = 51 Q = 0
3) YIQ -> RGB: R = 1.0 * Y + 0.956 * I + 0.621 * Q G = 1.0 * Y - 0.272 * I - 0.647 * Q B = 1.0 * Y - 1.105 * I + 1.702 * Q
The filter accepts 24/32 bpp color images for processing.
Sample usage:
// create filter Sepia filter = new Sepia( ); // apply the filter filter.ApplyInPlace( image );
Initial image:
Result image: