SAMPLE: QameraYUVMunge.qtzThis kernel distorts the color in the image using two source image "maps". Each image map is evaluated as a greyscale value. This results in an average brightness from 0.0 ... 1.0. Using 0.5 as the center, the source pixel is adjusted in the U and V color axes by the displacements from the maps. The effect is blended back into the source pixel according to amount_normal.

kernel vec4 msBlackColorDisplaceYUV(sampler image, sampler distort_u_map, sampler distort_v_map, float amount_normal)
{
float input_amount = clamp(amount_normal,0.0,1.0);
float inverse_amount = 1.0-input_amount;
const vec3 rgb_y = vec3(0.257, 0.504, 0.098);
const vec3 rgb_u = vec3(-0.148, -0.291, 0.439);
const vec3 rgb_v = vec3(0.439, -0.368, -0.071);
const vec3 yuv_r = vec3(1.0000, 0.0000, 1.4022 );
const vec3 yuv_g = vec3( 1.0000, -0.3457, -0.7145);
const vec3 yuv_b = vec3(1.0000, 1.7710, 0.0000);

vec4 pixel = sample(image, samplerCoord(image));
vec3 pel = pixel;
vec3 distort_u = sample(distort_u_map, samplerCoord(distort_u_map));
vec3 distort_v = sample(distort_v_map, samplerCoord(distort_v_map));

float delta_u = clamp((distort_u.x+distort_u.y+distort_u.z)/3.0,0.0,1.0)-0.5;
float delta_v = clamp((distort_v.x+distort_v.y+distort_v.z)/3.0,0.0,1.0)-0.5;
vec3 pixel_yuv;
pixel_yuv.x = dot(pel,rgb_y);
pixel_yuv.y = dot(pel,rgb_u);
pixel_yuv.z = dot(pel,rgb_v);

pixel_yuv.y = clamp(pixel_yuv.y + delta_u,0.0,1.0);
pixel_yuv.z = clamp(pixel_yuv.z + delta_v,0.0,1.0);

pel.r = dot(pixel_yuv,yuv_r);
pel.g = dot(pixel_yuv,yuv_g);
pel.b = dot(pixel_yuv,yuv_b);

vec3 result = (input_amount*pel) + inverse_amount*vec3(pixel);

return vec4(result.r, result.g, result.b,pixel.a);
}