My Project
computer_vision/fast.cpp
/*******************************************************
* Copyright (c) 2015, ArrayFire
* All rights reserved.
*
* This file is distributed under 3-clause BSD license.
* The complete license agreement can be obtained at:
* http://arrayfire.com/licenses/BSD-3-Clause
********************************************************/
#include <cstdio>
#include <arrayfire.h>
#include <cstdlib>
using namespace af;
static void fast_demo(bool console)
{
// Load image
array img_color;
if (console)
img_color = loadImage(ASSETS_DIR "/examples/images/square.png", true);
else
img_color = loadImage(ASSETS_DIR "/examples/images/man.jpg", true);
// Convert the image from RGB to gray-scale
array img = colorSpace(img_color, AF_GRAY, AF_RGB);
// For visualization in ArrayFire, color images must be in the [0.0f-1.0f] interval
img_color /= 255.f;
features feat = fast(img, 20.0f, 9, true, 0.05);
float* h_x = feat.getX().host<float>();
float* h_y = feat.getY().host<float>();
// Draw draw_len x draw_len crosshairs where the corners are
const int draw_len = 3;
for (size_t f = 0; f < feat.getNumFeatures(); f++) {
int x = h_x[f];
int y = h_y[f];
img_color(y, seq(x-draw_len, x+draw_len), 0) = 0.f;
img_color(y, seq(x-draw_len, x+draw_len), 1) = 1.f;
img_color(y, seq(x-draw_len, x+draw_len), 2) = 0.f;
// Draw vertical line of (draw_len * 2 + 1) pixels centered on the corner
// Set only the first channel to 1 (green lines)
img_color(seq(y-draw_len, y+draw_len), x, 0) = 0.f;
img_color(seq(y-draw_len, y+draw_len), x, 1) = 1.f;
img_color(seq(y-draw_len, y+draw_len), x, 2) = 0.f;
}
printf("Features found: %lu\n", feat.getNumFeatures());
if (!console) {
af::Window wnd("FAST Feature Detector");
// Previews color image with green crosshairs
while(!wnd.close())
wnd.image(img_color);
} else {
af_print(feat.getX());
af_print(feat.getY());
}
}
int main(int argc, char** argv)
{
int device = argc > 1 ? atoi(argv[1]) : 0;
bool console = argc > 2 ? argv[2][0] == '-' : false;
try {
af::setDevice(device);
std::cout << "** ArrayFire FAST Feature Detector Demo **" << std::endl << std::endl;
fast_demo(console);
} catch (af::exception& ae) {
std::cerr << ae.what() << std::endl;
throw;
}
return 0;
}
Window object to render af::arrays.
Definition graphics.h:37
A multi dimensional data container.
Definition array.h:27
Definition exception.h:20
virtual const char * what() const
Definition exception.h:34
Definition features.h:20
array getY() const
size_t getNumFeatures() const
array getX() const
seq is used to create seq for indexing af::array
Definition seq.h:46
@ AF_GRAY
Grayscale.
Definition defines.h:296
@ AF_RGB
3-channel RGB
Definition defines.h:297
AFAPI void info()
AFAPI void setDevice(const int device)
Sets the current device.
void image(const array &in, const char *title=NULL)
Renders the input array as an image to the window.
bool close()
Check if window is marked for close.
T * host() const
Copy array data to host and return host pointer.
Definition algorithm.h:15
#define af_print(...)
Definition util.h:141