// quantize into steps 
  float time=0;
  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);
          
          //float quant=floor(20*time);
          float quant=5;
          
            img  = floor(img*quant+0.9)/quant;
            
            return img;
  
  }