 	}
 }
 
+// compute the mean on the array's third dimension
+// this is used to compute the mean of all 28 filter responses at a given location/scale (used in the complex cell
+// normalization step)
 __global__ void dev_mean3(float *idata, float *odata, int nrXnrY, int nrZ) {
 	const int     tid = IMUL(blockDim.x, blockIdx.x) + threadIdx.x;
 	const int threadN = IMUL(blockDim.x, gridDim.x);

 	cutilCheckMsg("dev_split() execution failed\n");


	uint3 color_sizes = make_uint3(nrX,nrY,1);

	//d_center will contain center_red

	}
}

// reads in stimuli in RGB format and extracts R, G, B, and grayscale values (normalized to [0,1])
__global__ void dev_split(unsigned char *idata, float *red, float *green, float *blue, float *gray, int len) {
	const int     tid = IMUL(blockDim.x, blockIdx.x) + threadIdx.x;
	const int threadN = IMUL(blockDim.x, gridDim.x);
