シンプルな二値化のサンプルを追加

[cuda.git] / binarize / binarize.cu

diff --git a/binarize/binarize.cu b/binarize/binarize.cu
new file mode 100644 (file)
index 0000000..4f5e447
--- /dev/null
+++ b/binarize/binarize.cu
@@ -0,0 +1,99 @@
+/*
+       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 <http://www.gnu.org/licenses/>.
+*/
+
+#include "stdafx.h"
+#include <cuda.h>
+
+#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<<<blocks_per_grid, threads_per_block>>>(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;
+}