Shadertoy-Shaders/Optimized-Bilateral-Filter/Image.glsl

72 lines
1.5 KiB
GLSL

float tentKernel(in vec2 xy, in float r)
{
return (1.0 - abs(xy.x/r)) * (1.0 - abs(xy.y/r)) / (r*r);
}
float gaussianWeight(in float delta, in float sigma)
{
return exp(-delta*delta/(2.0 * sigma * sigma)) * 2.5 * sigma;
}
float luminance(in vec3 col)
{
return dot(col, vec3(0.2126, 0.7152, 0.0722));
}
vec3 fasterBilateralFilter(in vec2 uv, in sampler2D tex, in int r, in int steping, in float omegaColor)
{
vec2 scale = 1.0 / vec2(textureSize(tex, 0));
vec3 sum = vec3(0);
vec3 original = texture(tex, uv).rgb;
float wp = 0.0;
for (int x = -r; x <= r; x+=steping)
for (int y = -r; y <= r; y+=steping)
{
vec2 off = vec2(x, y) * scale;
vec3 col = texture(tex, uv + off).rgb;
float di = luminance(original) - luminance(col);
float space = tentKernel(vec2(x, y), float(r));
float range = gaussianWeight(di, omegaColor);
float w = space * range;
wp += w;
sum += col * w;
}
return sum / wp;
}
void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
vec2 uv = fragCoord/iResolution.xy;
vec3 col;
if (uv.x < 0.33333)
{
col = texture(iChannel0, uv).rgb;
}
else if (uv.x > 0.33333 && uv.x < 0.66666)
{
col = fasterBilateralFilter(uv, iChannel0, 12, 3, 0.1);
}
else
{
col = texture(iChannel1, uv).rgb;
}
const float PI = 3.141592653589793;
float border = step(0.02, abs(sin(uv.x*PI*3.0)));
col *= border;
fragColor = vec4(col,1.0);
}