lines.c

/*  detect-lines, extract lines and their width from images.
    Copyright (C) 1996-1998 Carsten Steger

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2, or (at your option)
    any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 
    
*/

/* 

   http://www.lsc-group.phys.uwm.edu/~ballen/grasp-distribution/GRASP/src/timefreq/lines.c
   http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.42.2266&rep=rep1&type=pdf
   http://katpyxa.info/feedbacks/?p=154
   Changes Made by R. Balasubramanian for incorporating the the detect lines code to incorporate
   within GRASP (May 10th 1999) 

   The type of the pointer image has been changed to float from unsigned char in function 
   get_lines();

   new function added by Warren Anderson  get_line_lens()
   
   
   
   
   10.12 Function: get line lens()
int get line lens(double sigma, double high, double low, int rows, int cols,
float **pic, char *file)
This function detects one dimensional structures in the TF map. The arguments are:
double sigma: Input. The width of the line to be detected in pixels.
double high: Input. The upper threshhold on the second directional derivative.
double low: Input. The lower threshhold on the second directional derivative.
int rows: Input. The number of rows in the TF map.
int cols: Input. The number of columns. in the TF map.
float **pic: Input. The pointer to the TF map.
char *file: Input. The name of the file to which the output is to be written. The file is written to disk
only if at least one line is detected in the map. The first entry in the file is the number of lines detected.
Then for each line detected the number of pixels in the line and the sum of the TF map pixel values
along the line is recorded. A typical output file looks as shown below:
3
57 44.564186
24 10.698793
20 9.513889
Author: Warren G. Anderson, warren@ricci.phys.uwm.edu This routine is an interface to the routines by
Carsten Steger to detect one dimensional structures in two dimensional images, [34, 35].
10.13 Function: get lines()
int get lines(double sigma, double high, double low, int rows, int cols,
float **pic, float **out img)
This function is almost identical with the function get line lens() defined in the previous subsection.
The only difference being the last argument of the function. The routine returns a map (out img)
whose pixels have the value of either unity if the pixel corresponds to a line point and zero otherwise.
Author: Warren G. Anderson, warren@ricci.phys.uwm.edu This routine is an interface to the routines by
Carsten Steger to detect one dimensional structures in two dimensional images, [34, 35]
   
   
   
   */


#include "lines.h"



/* Type declarations */

/* Command line options for the program */
typedef struct {
  double sigma;
  double low;
  double high;
  long   mode;
  bool   correct;
  bool   width;
  bool   extend;
  bool   postscript;
  bool   encapsulated;
  bool   image;
} options;

/* Local function prototypes */

static void check_sigma __P((double sigma, long width, long height));

/* Check whether sigma is in the allowed range for the current image size. */
static void check_sigma(sigma, width, height)
  double sigma;
  long width;
  long height;
{
  long min_dim;

  min_dim = width < height ? width : height;
  if (sigma < 0.4)
    print_error(ERR_SOR,"< 0.4");
  if (MASK_SIZE(MAX_SIZE_MASK_2,sigma) >= min_dim)
    print_error(ERR_SOR,"too large for image size");
}



/* The main program */
int get_lines(double sigma, double high, double low, int rows,
		int cols, float  **in_img, float **out_img){
  
  float    *image;
  contour **contours, *cont;
  long    i, num_cont;
  static options opts = {
    -1.0, -1.0, -1.0, MODE_LIGHT, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE
  };
  int retvalue;
  

  opts.sigma=sigma;
  opts.high=high;
  opts.low=low;

  check_sigma(opts.sigma,cols,rows);
  {
      int i,j;
      image = (float *) malloc(rows*cols*sizeof(float));
      for (i=0;i<rows;i++)
          for(j=0;j<cols;j++)
              *(image + i*cols + j) = *(in_img[i] + j);
  }
  
  detect_lines(image,cols,rows,&contours,&num_cont,opts.sigma,opts.low,
               opts.high,opts.mode,opts.width,opts.correct,opts.extend);
  retvalue = num_cont;
  
  show_lines(rows,cols,contours,num_cont,out_img);

  for (i=0; i<num_cont; i++) {
    cont = contours[i];
    if (cont->width_r != NULL)
      free(cont->width_r);
    if (cont->width_l != NULL)
      free(cont->width_l);
    if (cont->angle != NULL)
      free(cont->angle);
    if (cont->col != NULL)
      free(cont->col);
    if (cont->row != NULL)
      free(cont->row);
    free(cont);
  }
  free(contours);
  free(image);
  return retvalue;
}


int get_line_lens(double sigma, double high, double low, int rows,
		int cols, float **in_img, char *outfilename){
    float *image;
  contour **contours, *cont;
  long    i, num_cont;
  static options opts = {
    -1.0, -1.0, -1.0, MODE_LIGHT, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE
  };
  int retvalue;


  opts.sigma=sigma;
  opts.high=high;
  opts.low=low;

  check_sigma(opts.sigma,cols,rows);
  {
      int i,j;
      image = (float *) malloc(rows*cols*sizeof(float));
      for (i=0;i<rows;i++)
          for(j=0;j<cols;j++)
              *(image + i*cols + j) =  *(in_img[i] + j);
  }
    

  detect_lines(image,cols,rows,&contours,&num_cont,opts.sigma,opts.low,
               opts.high,opts.mode,opts.width,opts.correct,opts.extend);
  {
      FILE *fout;
      int j,num_points,intx,inty;
      float strength;
      
      if(num_cont!= 0){
          fout=fopen(outfilename,"w");
          fprintf(fout,"%ld\n",num_cont);
          for(i=0;i<num_cont;i++){
              cont = contours[i];
              num_points = cont->num;
              strength = 0.0;
              for(j=0;j<num_points;j++){
                  intx = (int) (cont->row[j] +0.5);
                  inty = (int) (cont->col[j] +0.5);
                  strength += *(in_img[intx] + inty);
              }
              fprintf(fout,"%d %f \n",num_points,strength);
          }
          fclose(fout);
      }
      
  }
  retvalue = num_cont;
  
  for (i=0; i<num_cont; i++) {
    cont = contours[i];
    if (cont->width_r != NULL)
      free(cont->width_r);
    if (cont->width_l != NULL)
      free(cont->width_l);
    if (cont->angle != NULL)
      free(cont->angle);
    if (cont->col != NULL)
      free(cont->col);
    if (cont->row != NULL)
      free(cont->row);
    free(cont);
  }
  free(contours);
  free(image);
  return retvalue;
}

extern void show_lines(int rows, int cols, contour **contours, long num_cont, 
                       float **out_img)
{
    int i,j,points;
    contour *cont;
    
    
    for(i=0;i<num_cont;i++){
		cont=contours[i];
        points=cont->num;
        for(j=0;j<points;j++){
            out_img[(int)(cont->row[j]+0.5)][(int)(cont->col[j]+0.5)]=1.0;
        }
    }
}