how to make a CUDA Histogram kernel?
- by kitw
Hi all,
I am writing a CUDA kernel for Histogram on a picture, but I had no idea how to return a array from the kernel, and the array will change when other thread read it. Any possible solution for it?
__global__ void Hist(
TColor *dst, //input image
int imageW,
int imageH,
int*data
){
const int ix = blockDim.x * blockIdx.x + threadIdx.x;
const int iy = blockDim.y * blockIdx.y + threadIdx.y;
if(ix < imageW && iy < imageH)
{
int pixel = get_red(dst[imageW * (iy) + (ix)]);
//this assign specific RED value of image to pixel
data[pixel] ++; // ?? problem statement ...
}
}
@para d_dst: input image TColor is equals to float4.
@para data: the array for histogram size [255]
extern "C" void
cuda_Hist(TColor *d_dst, int imageW, int imageH,int* data)
{
dim3 threads(BLOCKDIM_X, BLOCKDIM_Y);
dim3 grid(iDivUp(imageW, BLOCKDIM_X), iDivUp(imageH, BLOCKDIM_Y));
Hist<<<grid, threads>>>(d_dst, imageW, imageH, data);
}
