#ifndef pz_image_H
#define pz_image_H

/* Tools for image processing */
/* Last edited on 2017-06-20 21:04:28 by stolfilocal */

#include <pz_types.h>
#include <jspnm.h>
#include <uint16_image.h>

typedef enum { pz_side_inner, pz_side_interpolated, pz_side_outer } pz_side_t;

typedef uint16_image_t pz_image_t;

pz_image_t *pz_image_read_pgm (char *fName);
  /* 
    Reads a PGM file {fName} and returns the image */

void pz_image_write_pgm (char *fName, pz_image_t *img);
  /*
    Writes the image {img} as file {fName}, in PGM format. */

r3_vec_t pz_image_extract_boundary
  ( pz_image_t *img,
    uint16_t maxbg,
    pz_side_t side
  );
  /*
    Given a PGM image {img} of an object, returns a polygon with {Z=0}
    that approximates the object's outline, in the counterclockwise
    direction..
    
    For this procedure, a pixel {(x,y)} is `inside the object' if
    {img[y,x] > maxbg}, and `outside' if  {img[y,x] <= maxbg}.
  
    The {side} parameter selects between the inner, outer, and
    interpolated outlines. The first two have integer points {(x,y)}
    where {img[y,x] > maxbg} or {img[y,x] <= maxbg}, respectively. The
    interpolated outline lies between the two; it traces the level
    curve {img[x,y] == maxbg + 0.5} with subpixel accurancy. The procedure
    assumes that the pixels along the four edges of {img} are outside
    the object. */

/*
  Copyright © 2001 Universidade Estadual de Campinas (UNICAMP).
  Authors: Helena C. G. Leitão and Jorge Stolfi.
  
  This file can be freely distributed, used, and modified, provided
  that this copyright and authorship notice is preserved, and that any
  modified versions are clearly marked as such.
  
  This software has NO WARRANTY of correctness or applicability for
  any purpose. Neither the authors nor their employers chall be held
  responsible for any losses or damages that may result from its use.
*/
#endif