http://blog.csdn.net/popy007/article/details/1797121

float3 res = 0;
float2 invSize = GetPostProcessInputSize(0).zw;
int TexIndex = 14;
float weights[] =
{
0.01, 0.02, 0.04, 0.02, 0.01,
0.02, 0.04, 0.08, 0.04, 0.02,
0.04, 0.08, 0.16, 0.08, 0.04,
0.02, 0.04, 0.08, 0.04, 0.02,
0.01, 0.02, 0.04, 0.02, 0.01
};
float offsets[] = { -2, -1, 0, 1, 2 };
uv *= 0.5;
for (int i = 0; i < 5; ++i)
{
float v = uv.y + offsets[i] * invSize.y;
int temp = i * 5;
for (int j = 0; j < 5; ++j)
{
float u = uv.x + offsets[j] * invSize.x;
float2 uvShifted = uv + float2(u, v);
float weight = weights[temp + j];
float3 tex = SceneTextureLookup(uvShifted, TexIndex, false);
res += tex * weight;
}
}
return float4(res, 1);

float3 res = 0;
float2 invSize = GetPostProcessInputSize(0).zw;
int TexIndex = 14;
float weights[] =
{
5,20,5,
20,-100,20,
5,20,5
};
float offsets[] = { -1, 0, 1 };
uv *= 0.5;
for (int i = 0; i < 3; ++i)
{
float v = uv.y + offsets[i] * invSize.y;
int temp = i * 3;
for (int j = 0; j < 3; ++j)
{
float u = uv.x + offsets[j] * invSize.x;
float2 uvShifted = uv + float2(u, v);
float weight = weights[temp + j];
float3 tex = SceneTextureLookup(uvShifted, TexIndex, false);
res += tex * weight;
}
}
float grey=res.x*0.299 + res.y*0.587 + res.z*0.114;
if(grey>0.5){
grey=0;
}
else{
grey=1;
}
return float4(grey,grey,grey,1);

http://www.manew.com/thread-141286-1-1.html