#include <stim/image/image.h>
//#include <cmath>
#include <stim/visualization/colormap.h>
#include <stim/image/image_contour_detection.h>
#include <sstream>

/// This function convolve the grayscale image with a set of oriented Gaussian 
/// derivative filters, and return a texton image with (theta_n*2+1) channels

/// @param image is an one-channel grayscale image
/// @param theta_n is the number of angles used for computing the gradient

stim::image<float> textons(stim::image<float> image, unsigned int theta_n){

	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

	stim::image<float> textons(w, h, 1, theta_n*2+1);    // allocate space for textons
	stim::image<float> temp(w, h);						 // allocate space for temp

	unsigned int r_odd = 3;            // set disc radii for odd-symmetric filter
	unsigned int sigma_n_odd = 3;	   // set sigma_n for odd-symmetric filter
	unsigned int r_even = 3;		   // set disc radii for even-symmetric filter
	unsigned int sigma_n_even = 3;     // set sigma_n for even-symmetric filter
	unsigned int r_center = 3;		   // set disc radii for center-surround filter
	unsigned int sigma_n_center = 3;   // set sigma_n for center-surround filter

	//std::ostringstream ss1, ss2;                      // (optional) set the stream to designate the test result file

	for (unsigned int i = 0; i < theta_n; i++){

		//ss1 << "data_output/textons_channel_"<< i << ".bmp";  // set the name for test result file (optional)
		//std::string sss1 = ss1.str();
		//ss2 << "data_output/textons_channel_"<< i+theta_n << ".bmp";  // set the name for test result file (optional)
		//std::string sss2 = ss2.str();
	
		float theta = 180 * ((float)i/theta_n);              // calculate the even-splited angle for each oriented filter

		temp = Gd_odd(image, r_odd, sigma_n_odd, theta);     // return Gd_odd to temp
		//stim::cpu2image(temp.data(), sss1, w, h, stim::cmBrewer);  
		textons.set_channel(i, temp.data());                 // copy temp to ith channel of textons

		temp = Gd_even(image, r_even, sigma_n_even, theta);  // return Gd_even to temp
		//stim::cpu2image(temp.data(), sss2, w, h, stim::cmBrewer);  
		textons.set_channel(i + theta_n, temp.data());       // copy temp to (i+theta_n)th channel of textons

		//ss1.str("");   //(optional) clear the space for stream
		//ss2.str("");   //(optional) clear the space for stream

	}

	temp = Gd_center(image, r_center, sigma_n_center);  // return Gd_center to temp
	//stim::cpu2image(temp.data(), "data_output/textons_channel_16.bmp", w, h, stim::cmBrewer);  
	textons.set_channel(theta_n*2, temp.data());        // copy temp to (theta_n*2)th channel of textons

	return textons;

}