5 out vec3 flow_contribution;
7 uniform sampler2D image0_tex, image1_tex;
11 // Equation (3) from the paper. We're using additive blending, so the
12 // sum will happen automatically for us, and normalization happens on
15 // Note that equation (2) says 1 for the minimum error, but the code says 2.0.
16 // And it says L2 norm, but really, the code does absolute value even for
17 // L2 error norm (it uses a square root formula for L1 norm).
18 float diff = texture(image0_tex, image_pos).x - texture(image1_tex, image_pos + flow_du).x;
19 float weight = 1.0 / max(abs(diff), 2.0 / 255.0);
20 flow_contribution = vec3(flow_du.x * weight, flow_du.y * weight, weight);