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Sample source for Halide - http://halide-lang.org
// Halide
#include "Halide.h"
// Include some support code for loading pngs.
#include "halide_image_io.h"
// for performance test
#include <sys/time.h>
double currentTime() {
timeval t;
gettimeofday(&t, NULL);
return t.tv_sec * 1000.0 + t.tv_usec / 1000.0f;
}
int main(int argc, char **argv) {
int count = 100;
Halide::Image<uint8_t> input = Halide::Tools::load_image("rgb.png");
Halide::Func blur, clamped, blur_x;
Halide::Var x, y, c;
// clampled image because output image is smaller than input image.
clamped(x,y,c) = input(clamp(x,1,input.width()-2),clamp(y,1,input.height()-2),c);
// Filtering
blur_x(x,y,c) = 0.2f * clamped(x-2, y, c) + 0.2f * clamped(x-1, y, c) + 0.2f * clamped(x, y, c) + 0.2f * clamped(x+1, y, c) + 0.2f * clamped(x+2, y, c);
Halide::Expr value = 0.2f * blur_x(x, y-2, c) + 0.2f * blur_x(x, y-1, c) + 0.2f * blur_x(x, y, c) + 0.2f * blur_x(x, y+1, c) + 0.2f * blur_x(x, y+2, c);
// Cast it back to an 8-bit unsigned integer.
value = Halide::cast<uint8_t>(value);
// Define the function.
blur(x, y, c) = value;
// do it
Halide::Image<uint8_t> output = blur.realize(input.width(), input.height(), input.channels());
// save image
Halide::Tools::save_image(output, "blured.png");
// performance test
{
Halide::Func temp = blur;
double t = currentTime();
for (int i = 0; i < count; i++) {
Halide::Image<uint8_t> output = blur.realize(input.width(), input.height(), input.channels());
}
printf("%f[msec] = Normal\n", (currentTime()- t)/count);
}
{
Halide::Var yi;
Halide::Func temp = blur;
temp.split(y, y, yi, 8).parallel(y).vectorize(x, 4);
double t = currentTime();
for (int i = 0; i < count; i++) {
Halide::Image<uint8_t> output = temp.realize(input.width(), input.height(), input.channels());
}
printf("%f[msec] = Compute oncurrently. \n", (currentTime()- t)/count);
}
return 0;
}
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