gauss_deriv_odd.cpp
2.06 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
#include <stim/image/image.h>
#include <cmath>
#include <stim/visualization/colormap.h>
#include <stim/image/image_contour_detection.h>
#define PI 3.1415926
void array_multiply(float* lhs, float rhs, unsigned int N);
void array_add(float* ptr1, float* ptr2, float* sum, unsigned int N);
void array_abs(float* img, unsigned int N);
/// This function evaluates the theta-dependent odd symmetric gaussian derivative gradient of an one-channel image
/// @param img is the one-channel image
/// @param r is an array of radii for different scaled discs(filters)
/// @param sigma_n is the number of standard deviations used to define the sigma
/// @param theta is angle used for computing the gradient
stim::image<float> Gd_odd(stim::image<float> image, int r, unsigned int sigma_n, float theta){
float theta_r = (theta * PI)/180; //change angle unit from degree to rad
unsigned int w = image.width(); // get the width of picture
unsigned int h = image.height(); // get the height of picture
unsigned N = w * h; // get the number of pixels of picture
int winsize = 2 * r + 1; // set the winsdow size of disc(filter)
stim::image<float> I(w, h, 1, 2); // allocate space for return image of Gd1
stim::image<float> Ix(w, h); // allocate space for Ix
stim::image<float> Iy(w, h); // allocate space for Iy
stim::image<float> Gd_odd_theta(w, h); // allocate space for Pb
I = Gd1(image, r, sigma_n); // calculate the Ix, Iy
Ix = I.channel(0);
Iy = I.channel(1);
array_multiply(Ix.data(), cos(theta_r), N); //Ix = Ix*cos(theta_r)
array_multiply(Iy.data(), sin(theta_r), N); //Iy = Iy*sin(theta_r)
array_add(Ix.data(), Iy.data(), Gd_odd_theta.data(), N); //Gd_odd_theta = Ix + Iy;
array_abs(Gd_odd_theta.data(), N);
//stim::cpu2image(I.channel(0).data(), "data_output/Gd_odd_x_0919.bmp", w, h, stim::cmBrewer);
//stim::cpu2image(I.channel(1).data(), "data_output/Gd_odd_y_0919.bmp", w, h, stim::cmBrewer);
//stim::cpu2image(Gd_odd_theta.data(), "data_output/Gd_odd_theta_0919.bmp", w, h, stim::cmBrewer);
return Gd_odd_theta;
}