Tesseract  3.02
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blkocc.cpp
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1 /*****************************************************************************
2  *
3  * File: blkocc.cpp (Formerly blockocc.c)
4  * Description: Block Occupancy routines
5  * Author: Chris Newton
6  * Created: Fri Nov 8
7  * Modified:
8  * Language: C++
9  * Package: N/A
10  * Status: Experimental (Do Not Distribute)
11  *
12  * (c) Copyright 1991, Hewlett-Packard Company.
13  ** Licensed under the Apache License, Version 2.0 (the "License");
14  ** you may not use this file except in compliance with the License.
15  ** You may obtain a copy of the License at
16  ** http://www.apache.org/licenses/LICENSE-2.0
17  ** Unless required by applicable law or agreed to in writing, software
18  ** distributed under the License is distributed on an "AS IS" BASIS,
19  ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
20  ** See the License for the specific language governing permissions and
21  ** limitations under the License.
22  *
23  ******************************************************************************/
24 
25 /*
26 ----------------------------------------------------------------------
27  I n c l u d e s
28 ----------------------------------------------------------------------
29 */
30 
31 #include "mfcpch.h"
32 #include <ctype.h>
33 #include <math.h>
34 #include "errcode.h"
35 #include "drawtord.h"
36 #include "blkocc.h"
37 #include "helpers.h"
38 #include "notdll.h"
39 
40 double_VAR(textord_underline_threshold, 0.5, "Fraction of width occupied");
41 
42 // Forward declarations of static functions
43 static void horizontal_cblob_projection(C_BLOB *blob, // blob to project
44  STATS *stats); // output
45 static void horizontal_coutline_projection(C_OUTLINE *outline,
46  STATS *stats); // output
47 
55 BOOL8 test_underline( //look for underlines
56  BOOL8 testing_on, //< drawing blob
57  C_BLOB *blob, //< blob to test
58  inT16 baseline, //< coords of baseline
59  inT16 xheight //< height of line
60  ) {
61  inT16 occ;
62  inT16 blob_width; //width of blob
63  TBOX blob_box; //bounding box
64  inT32 desc_occ;
65  inT32 x_occ;
66  inT32 asc_occ;
67  STATS projection;
68 
69  blob_box = blob->bounding_box ();
70  blob_width = blob->bounding_box ().width ();
71  projection.set_range (blob_box.bottom (), blob_box.top () + 1);
72  if (testing_on) {
73  // blob->plot(to_win,GOLDENROD,GOLDENROD);
74  // line_color_index(to_win,GOLDENROD);
75  // move2d(to_win,blob_box.left(),baseline);
76  // draw2d(to_win,blob_box.right(),baseline);
77  // move2d(to_win,blob_box.left(),baseline+xheight);
78  // draw2d(to_win,blob_box.right(),baseline+xheight);
79  tprintf
80  ("Testing underline on blob at (%d,%d)->(%d,%d), base=%d\nOccs:",
81  blob->bounding_box ().left (), blob->bounding_box ().bottom (),
82  blob->bounding_box ().right (), blob->bounding_box ().top (),
83  baseline);
84  }
85  horizontal_cblob_projection(blob, &projection);
86  desc_occ = 0;
87  for (occ = blob_box.bottom (); occ < baseline; occ++)
88  if (occ <= blob_box.top () && projection.pile_count (occ) > desc_occ)
89  //max in region
90  desc_occ = projection.pile_count (occ);
91  x_occ = 0;
92  for (occ = baseline; occ <= baseline + xheight; occ++)
93  if (occ >= blob_box.bottom () && occ <= blob_box.top ()
94  && projection.pile_count (occ) > x_occ)
95  //max in region
96  x_occ = projection.pile_count (occ);
97  asc_occ = 0;
98  for (occ = baseline + xheight + 1; occ <= blob_box.top (); occ++)
99  if (occ >= blob_box.bottom () && projection.pile_count (occ) > asc_occ)
100  asc_occ = projection.pile_count (occ);
101  if (testing_on) {
102  tprintf ("%d %d %d\n", desc_occ, x_occ, asc_occ);
103  }
104  if (desc_occ == 0 && x_occ == 0 && asc_occ == 0) {
105  tprintf ("Bottom=%d, top=%d, base=%d, x=%d\n",
106  blob_box.bottom (), blob_box.top (), baseline, xheight);
107  projection.print();
108  }
109  if (desc_occ > x_occ + x_occ
110  && desc_occ > blob_width * textord_underline_threshold)
111  return TRUE; //real underline
112  if (asc_occ > x_occ + x_occ
113  && asc_occ > blob_width * textord_underline_threshold)
114  return TRUE; //overline
115  return FALSE; //neither
116 }
117 
118 
126 static void horizontal_cblob_projection( //project outlines
127  C_BLOB *blob, //< blob to project
128  STATS *stats //< output
129  ) {
130  //outlines of blob
131  C_OUTLINE_IT out_it = blob->out_list ();
132 
133  for (out_it.mark_cycle_pt (); !out_it.cycled_list (); out_it.forward ()) {
134  horizontal_coutline_projection (out_it.data (), stats);
135  }
136 }
137 
138 
146 static void horizontal_coutline_projection( //project outlines
147  C_OUTLINE *outline, //< outline to project
148  STATS *stats //< output
149  ) {
150  ICOORD pos; //current point
151  ICOORD step; //edge step
152  inT32 length; //of outline
153  inT16 stepindex; //current step
154  C_OUTLINE_IT out_it = outline->child ();
155 
156  pos = outline->start_pos ();
157  length = outline->pathlength ();
158  for (stepindex = 0; stepindex < length; stepindex++) {
159  step = outline->step (stepindex);
160  if (step.y () > 0) {
161  stats->add (pos.y (), pos.x ());
162  }
163  else if (step.y () < 0) {
164  stats->add (pos.y () - 1, -pos.x ());
165  }
166  pos += step;
167  }
168 
169  for (out_it.mark_cycle_pt (); !out_it.cycled_list (); out_it.forward ()) {
170  horizontal_coutline_projection (out_it.data (), stats);
171  }
172 }