root/lib/gocr/gocr.h

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/*
This is a Optical-Character-Recognition program
Copyright (C) 2000-2006 Joerg Schulenburg

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
of the License, 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

 see README for EMAIL-address

  sometimes I have written comments in german language, sorry for that

 - look for ??? for preliminary code
*/
 
/* General headerfile with gocr-definitions */

#ifndef __GOCR_H__
#define __GOCR_H__

#include "pnm.h"
#include "unicode.h"
#include "list.h"
#include <stddef.h>
#ifdef HAVE_GETTIMEOFDAY
#include <sys/time.h>
#endif

/*
 *  wchar_t should always exist (ANSI), but WCHAR.H is sometimes missing
 *  USE_UNICODE should be removed or replaced by HAVE_WCHAR_H in future
 */
#ifdef HAVE_WCHAR_H
#define USE_UNICODE 1
#endif

/* extern "C"{ */
/* ------------------------ feature extraction ----------------- */
#define AT 7    /* mark */
#define M1 1    /* mark */
enum direction {
  UP=1, DO, RI, LE
};
typedef enum direction DIRECTION;
#define ST 7    /* stop */
/* ------------------------------------------------------------- */
/* detect maximas in of line overlapps (return in %) and line koord */
#define HOR 1    /* horizontal */
#define VER 2    /* vertikal   */
#define RIS 3    /* rising=steigend */
#define FAL 4    /* falling=fallend */

#define MAXlines 1024

/* ToDo: if we have a tree instead of a list, a line could be a node object */
struct tlines {
    int num;
    int dx, dy;         /* direction of text lines (straight/skew) */
    int m1[MAXlines],   /* start of line = upper bound of 'A' */
        m2[MAXlines],   /* upper bound of 'e' */
        m3[MAXlines],   /* lower bound of 'e' = baseline */
        m4[MAXlines];   /* stop of line = lower bound of 'q' */
    int x0[MAXlines],
        x1[MAXlines];   /* left and right border */
    int wt[MAXlines];   /* weight, how sure thats correct in percent, v0.41 */
    int pitch[MAXlines]; /* word pitch (later per box?), v0.41 */
    int mono[MAXlines];  /* spacing type, 0=proportional, 1=monospaced */
};

#define NumAlt 10 /* maximal number of alternative chars (table length) */
#define MaxNumFrames 8       /* maximum number of frames per char/box */
#define MaxFrameVectors 128  /* maximum vectors per frame (*8=1KB/box) */
/* ToDo: use only malloc_box(),free_box(),copybox() for creation, destroy etc.
 *       adding reference_counter to avoid pointer pointing to freed box
 */
struct box { /* this structure should contain all pixel infos of a letter */
    int x0,x1,y0,y1,x,y,dots; /* xmin,xmax,ymin,ymax,reference-pixel,i-dots */
    int num_boxes, /* 1 "abc", 2 "!i?", 3 "&auml;" (composed objects) 0.41 */
        num_subboxes;   /* 1 for "abdegopqADOPQR", 2 for "B"  (holes) 0.41 */
    wchar_t c;          /* detected char (same as tac[0], obsolete?) */
    wchar_t modifier;   /* default=0, see compose() in unicode.c */
    int num;            /* same number = same char */
    int line;           /* line number (points to struct tlines lines) */
    int m1,m2,m3,m4;    /* m2 = upper boundary, m3 = baseline */
    /* planed: sizeof hole_1, hole_2, certainty (run1=100%,run2=90%,etc.) */
    pix *p;             /* pointer to pixmap (v0.2.5) */
    /* tac, wac is used together with setac() to manage very similar chars */
    int num_ac;         /* length of table (alternative chars), default=0 */
    wchar_t tac[NumAlt]; /* alternative chars, only used by setac(),getac() */
    int     wac[NumAlt]; /* weight of alternative chars */
    char   *tas[NumAlt]; /* alternative UTF8-strings or XML codes if tac[]=0 */
                         /*   replacing old obj */
                         /* ToDo: (*obj)[NumAlt] + olen[NumAlt] ??? */
                         /* ToDo: bitmap for possible Picture|Object|Char ??? */
/*  char    *obj; */     /* pointer to text-object ... -> replaced by tas[] */
                         /*  ... (melted chars, barcode, picture coords, ...) */
                         /*  must be freed before box is freed! */
                         /*  do _not_ copy only the pointer to object */
    /* --------------------------------------------------------
     *  extension since v0.41 js05, Store frame vectors,
     *  which is a table of vectors sourrounding the char and its
     *  inner white holes. The advantage is the independence from
     *  resolution, handling of holes, overlap and rotation.
     * --------------------------------------------------------- */
    int num_frames;      /* number of frames: 1 for cfhklmnrstuvwxyz */
                         /*                   2 for abdegijopq */
    int frame_vol[MaxNumFrames]; /* volume inside frame +/- (black/white) */
    int frame_per[MaxNumFrames]; /* periphery, summed length of vectors */
    int num_frame_vectors[MaxNumFrames]; /* index to next frame */
                /* biggest frame should be stored first (outer frame) */
                /* biggest has the maximum pair distance */
                /* num vector loops */
    int frame_vector[MaxFrameVectors][2]; /* may be 16*int=fixpoint_number */
    
};
typedef struct box Box;

/* true if the coordination pair (a,b) is outside the image p */
#define outbounds(p, a, b)  (a < 0 || b < 0 || a >= (p)->x || b >= (p)->y)

/* ToDo: this structure seems to be obsolete, remove it */
typedef struct path {
  int start;    /* color at the beginning of the path, (0=white, 1=black) */
  int *x;       /* x coordinates of transitions */
  int *y;       /* y coordinates of transitions */
  int num;      /* current number of entries in x or y */
  int max;      /* maximum number of entries in x or y */
  /* (if more values need to be stored, the arrays are enlarged) */
} path_t;

/* job_t contains all information needed for an OCR task */
typedef struct job_s {
  struct {       /* source data */
    char *fname; /* input filename; default value: "-" */
    pix p;       /* source pixel data, pixelmap 8bit gray */
  } src;
  struct { /* temporary stuff, e.g. buffers */
#ifdef HAVE_GETTIMEOFDAY
    struct timeval init_time; /* starting time of this job */
#endif
    pix ppo; /* pixmap for visual debugging output, obsolete */

    /* sometimes recognition function is called again and again, if result was 0
       n_run tells the pixel function to return alternative results */
    int n_run;   /* num of run, if run_2 critical pattern get other results */
                 /* used for 2nd try, pixel uses slower filter function etc. */
    List dblist; /* list of boxes loaded from the character database */
  } tmp;
  struct {         /* results */
    List boxlist;  /* store every object in a box, which contains */
                   /* the characteristics of the object (see struct box) */
    List linelist; /* recognized text lines after recognition */
    
    struct tlines lines; /* used to access to line-data (statistics) */
                         /* here the positions (frames) of lines are */
                         /* stored for further use */
    int avX,avY;         /* average X,Y (avX=sumX/numC) */
    int sumX,sumY,numC;  /* sum of all X,Y; num chars */
  } res;
  struct {    /* configuration */
    int cs;   /* critical grey value (pixel<cs => black pixel) */
              /* range: 0..255,  0 means autodetection */
    int spc;  /* spacewidth/dots (0 = autodetect); default value: 0 */
    int mode; /* operation modes; default value: 0 */
              /* operation mode (see --help) */
    int dust_size;    /* dust size; default value: 10 */
    int only_numbers; /* numbers only; default value: 0 */
    int verbose; /* verbose mode; default value: 0 */ 
                 /* verbose option (see --help) */
    FORMAT out_format; /* output format; default value: ISO8859_1*/
    char *lc; /* debuglist of chars (_ = not recognized chars) */
              /* default value: "_" */
    char *db_path; /* pathname for database; default value: NULL */
    char *cfilter; /* char filter; default value: NULL, ex: "A-Za-z" */
        /* limit of certainty where chars are accepted as identified */
    int  certainty; /* in units of 100 (percent); 0..100; default 95 */
  } cfg;
} job_t;

/* initialze job structure */
void job_init(job_t *job);

/* free job structure */
void job_free(job_t *job);

/*FIXME jb: remove JOB; */
extern job_t *JOB;

/* calculate the overlapp of the line (0-1) with black points 
 * by rekursiv bisection 
 * (evl. Fehlertoleranz mit pixel in Umgebung dx,dy suchen) (umschaltbar) ???
 * MidPoint Line Algorithm (Bresenham) Foley: ComputerGraphics better?
 * will be replaced by vector functions
 */

/* gerade y=dy/dx*x+b, implizit d=F(x,y)=dy*x-dx*y+b*dx=0 
 * incrementell y(i+1)=m*(x(i)+1)+b, F(x+1,y+1)=f(F(x,y))  */
int get_line(int x0, int y0, int x1, int y1, pix *p, int cs, int ret);
int get_line2(int x0, int y0, int x1, int y1, pix *p, int cs, int ret);

/* look for white 0x02 or black 0x01 dots (0x03 = white+black) */
char get_bw(int x0, int x1, int y0, int y1,
             pix *p, int cs,int mask);

/* look for black crossing a line x0,y0,x1,y1
 * follow line and count crossings ([white]-black-transitions)
 */
int num_cross(int x0, int x1, int y0, int y1,
               pix *p,  int cs);

/* memory allocation with error checking */
void *xrealloc(void *ptr, size_t size);

/* follow a line x0,y0,x1,y1 recording locations of transitions,
 * return count of transitions 
 */
int follow_path(int x0, int x1, int y0, int y1, pix *p,  int cs, path_t *path);

/* -------------------------------------------------------------
 * mark edge-points
 *  - first move forward until b/w-edge
 *  - more than 2 pixel?
 *  - loop around
 *    - if forward    pixel : go up, rotate right
 *    - if forward no pixel : rotate left
 *  - stop if found first 2 pixel in same order
 * mit an rechter-Wand-entlang-gehen strategie
 * --------------------------------------------------------------
 * turmite game: inp: start-x,y, regel r_black=UP,r_white=RIght until border
 *               out: last-position
 * Zaehle dabei, Schritte,Sackgassen,xmax,ymax,ro-,ru-,lo-,lu-Ecken
 * +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 *
 * is this the right place for declaration?
 */
void turmite(pix *p, int *x, int *y, 
             int x0, int x1, int y0, int y1, int cs, int rw, int rb);

/* test if points are connected via t-pixel (rekursiv!) */
int joined(pix *p, int x0, int y0, int x1, int y1, int cs);

/* move from x,y to direction r until pixel or l steps
 * return number of steps
 */
int loop(pix *p, int x, int y, int l, int cs, int col, DIRECTION r);

#define MAX_HOLES 3
typedef struct list_holes { 
  int num;    /* numbers of holes, initialize with 0 */ 
  struct hole_s {
    int size,x,y,x0,y0,x1,y1; /*  size, start point, outer rectangle */
  } hole[MAX_HOLES];
} holes_t;
          
/* look for white holes surrounded by black points
 * at moment white point with black in all four directions
 */
int num_hole(int x0, int x1, int y0, int y1, pix *p, int cs, holes_t *holes);

/* count for black nonconnected objects --- used for i,auml,ouml,etc. */
int num_obj(int x0, int x1, int y0, int y1, pix  *p, int cs);

int distance(   pix *p1, struct box *box1,      /* box-frame */
                pix *p2, struct box *box2, int cs);

/* call the OCR engine ;) */
/* char whatletter(struct box *box1,int cs); */

/* declared in pixel.c */
/* getpixel() was pixel() but it may collide with netpnm pixel declaration */
int getpixel(pix *p, int x, int y);
int marked(pix *p, int  x, int  y);
void put(pix * p, int x, int y, int ia, int io);

/* } */ /* extern C */
#endif /* __GOCR_H__ */

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