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Pb.cpp 2.93 KB
6dcc460e   Tianshu Cheng   cPb+tPb
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  #include <stim/image/image.h>
  //#include <cmath>
  #include <stim/visualization/colormap.h>
  #include <stim/image/image_contour_detection.h>
  
  void array_abs(float* img, unsigned int N);
  void array_multiply(float* lhs, float rhs, unsigned int N);
  void array_cos(float* ptr1, float* cpu_out, unsigned int N);
  void array_sin(float* ptr1, float* cpu_out, unsigned int N);
  void array_atan(float* ptr1, float* cpu_out, unsigned int N);
  void array_divide(float* ptr1, float* ptr2,float* cpu_quotient, unsigned int N);
  void array_multiply(float* ptr1, float* ptr2, float* product, unsigned int N);
  void array_add(float* ptr1, float* ptr2, float* sum, unsigned int N);
  
  /// This function uses odd-symmetric gaussian derivative filter to evaluate 
  /// the max probability of a contour on one scale, given an one-channel image 
  
  /// @param img is an 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
  
  stim::image<float> Pb(stim::image<float> image, int r, unsigned int sigma_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
  	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> theta(w, h);       // allocate space for theta matrix
  	stim::image<float> cos(w, h);       // allocate space for cos(theta)
  	stim::image<float> sin(w, h);       // allocate space for sin(theta)
  	stim::image<float> temp(w, h);       // allocate space for temp
  	stim::image<float> Ix(w, h);       // allocate space for Ix
  	stim::image<float> Iy(w, h);       // allocate space for Iy
  	stim::image<float> Pb(w, h);       // allocate space for Pb
  
  	I = Gd1(image, r, sigma_n);  // calculate the Ix, Iy
  	Ix = I.channel(0);
  	array_abs(Ix.data(), N);	  //get |Ix|;
  	//stim::cpu2image(Ix.data(), "data_output/Pb_Ix_0924.bmp", w, h, stim::cmBrewer); 
  	Iy = I.channel(1); 
  	array_abs(Iy.data(), N);	  //get |Iy|;
  	//stim::cpu2image(Iy.data(), "data_output/Pb_Iy_0924.bmp", w, h, stim::cmBrewer); 
  
  	array_divide(Iy.data(), Ix.data(), temp.data(), N);                //temp = Iy./Ix
  	array_atan(temp.data(), theta.data(), N);                   //theta = atan(temp)
  	array_cos(theta.data(), cos.data(), N);						//cos = cos(theta)
  	array_sin(theta.data(), sin.data(), N);						//sin = sin(theta)
  	array_multiply(Ix.data(), cos.data(), Ix.data(), N);		//Ix = Ix.*cos
  	array_multiply(Iy.data(), sin.data(), Iy.data(), N);		//Iy = Iy.*sin
  	array_add(Ix.data(), Iy.data(), Pb.data(), N);				//Pb = Ix + Iy;
  
  	float max = Pb.maxv();						// get the maximum of Pb used for normalization
  	array_multiply(Pb.data(), 1/max, N);		// normalize the Pb
  
  	//stim::cpu2image(Pb.data(), "data_output/Pb_0924.bmp", w, h, stim::cmBrewer); show the Pb(optional)
  
  	return Pb;
  
  }