/*
Copyright (C) 2012 fmaj7b5.info
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see .
*/
#include "stdafx.h"
#include
#include "binarize.cuh"
using namespace FM7b5;
void
FM7b5::binarize_gpu(ImageGray& out, const ImageGray& in, const uint8_t thres)
{
if (in.width() != out.width() || in.height() != out.height()) {
throw std::runtime_error("sizes of input and output images are diferent.");
}
const size_t width(in.width()), height(in.height()), bpp(in.bpp());
uint8_t* d_in(nullptr);
uint8_t* d_out(nullptr);
size_t in_pitch(0), out_pitch(0);
const size_t threads_per_dim(32);
dim3 threads_per_block(threads_per_dim, threads_per_dim);
dim3 blocks_per_grid((width + threads_per_block.x - 1)/ threads_per_block.x,
(height + threads_per_block.y - 1)/ threads_per_block.y);
cudaError_t status;
// allocate input/output memories
status = cudaMallocPitch(&d_in, &in_pitch, width * bpp, height);
if (status != cudaSuccess) {
goto on_error_in;
}
status = cudaMallocPitch(&d_out, &out_pitch, width * bpp, height);
if (status != cudaSuccess) {
goto on_error_out;
}
// copy an input image to device memory
status = cudaMemcpy2D(d_in, in_pitch, in.data(), in.stride(), bpp * width, height, cudaMemcpyHostToDevice);
if (status != cudaSuccess) {
goto on_error_proc;
}
// launch kernel
binarize<<>>(d_out, out_pitch, d_in, in_pitch, width, height, thres);
// copy the result back to host memory
status = cudaMemcpy2D(out.data(), out.stride(), d_out, out_pitch, bpp * width, height, cudaMemcpyDeviceToHost);
if (status != cudaSuccess) {
goto on_error_proc;
}
// free device memories
cudaFree(d_out);
cudaFree(d_in);
return;
// error handling
on_error_proc:
cudaFree(d_out);
on_error_out:
cudaFree(d_in);
on_error_in:
throw std::runtime_error(cudaGetErrorString(status));
}
__global__
void
FM7b5::binarize(uint8_t* out, const size_t out_pitch, const uint8_t* in, const size_t in_pitch, const size_t width, const size_t height, const uint8_t thres)
{
const size_t w(blockDim.x * blockIdx.x + threadIdx.x);
const size_t h(blockDim.y * blockIdx.y + threadIdx.y);
if (w >= width || h >= height) {
return;
}
out[out_pitch * h + w] = (in[in_pitch * h + w] < thres) ? 0 : 255;
}