// identity 
  float time=0.5;
  float sampleDist = 1.0f/512.0f;  // distance one pixel in u/v
  
  sampler2D image : register(s0);
  
  float4 main(
          float4 Pos : POSITION,
          float2 texCoord: TEXCOORD0) : COLOR 
  {
          float4 img = tex2D(image, texCoord);
  
          return img;
          //return lerp(sum,float4(1,1,1,1)-sum,time);          //-sum
  }