source: downloads/Samples/Media/materials/programs/GrayScale.cg @ 3

sampler RT : register(s0);

float4 GrayScale_ps(float2 iTexCoord : TEXCOORD0) : COLOR
{
    float3 greyscale = dot(tex2D(RT, iTexCoord).rgb, float3(0.3, 0.59, 0.11));
        return float4(greyscale, 1.0);
}

float4 Embossed_ps(float2 iTexCoord : TEXCOORD0) : COLOR
{
    float4 Color;
    Color.a = 1.0f;
    Color.rgb = 0.5f;
    Color -= tex2D( RT, iTexCoord - 0.001)*2.0f;
    Color += tex2D( RT, iTexCoord + 0.001)*2.0f;
    Color.rgb = (Color.r+Color.g+Color.b)/3.0f;
    return Color;
}