1 /******************************************************************************
2 *
3 * File: blkocc.h (Formerly blockocc.h)
4 * Description: Block Occupancy routines
5 * Author: Chris Newton
6 *
7 * (c) Copyright 1991, Hewlett-Packard Company.
8 ** Licensed under the Apache License, Version 2.0 (the "License");
9 ** you may not use this file except in compliance with the License.
10 ** You may obtain a copy of the License at
11 ** http://www.apache.org/licenses/LICENSE-2.0
12 ** Unless required by applicable law or agreed to in writing, software
13 ** distributed under the License is distributed on an "AS IS" BASIS,
14 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 ** See the License for the specific language governing permissions and
16 ** limitations under the License.
17 *
18 ******************************************************************************/
19
20 #ifndef BLKOCC_H
21 #define BLKOCC_H
22
23 #include "elst.h"
24 #include "params.h"
25
26 namespace tesseract {
27
28 class C_BLOB;
29
30 /***************************************************************************
31 CLASS REGION_OCC
32
33 The class REGION_OCC defines a section of outline which exists entirely
34 within a single region. The only data held is the min and max x limits of
35 the outline within the region.
36
37 REGION_OCCs are held on lists, one list for each region. The lists are
38 built in sorted order of min x. Overlapping REGION_OCCs are not permitted on
39 a single list. An overlapping region to be added causes the existing region
40 to be extended. This extension may result in the following REGION_OCC on the
41 list overlapping the amended one. In this case the amended REGION_OCC is
42 further extended to include the range of the following one, so that the
43 following one can be deleted.
44
45 ****************************************************************************/
46
47 class REGION_OCC : public ELIST_LINK {
48 public:
49 float min_x; // Lowest x in region
50 float max_x; // Highest x in region
51 int16_t region_type; // Type of crossing
52
53 REGION_OCC() = default; // constructor used
54 // only in COPIER etc
REGION_OCC(float min,float max,int16_t region)55 REGION_OCC( // constructor
56 float min, float max, int16_t region) {
57 min_x = min;
58 max_x = max;
59 region_type = region;
60 }
61 };
62
ELISTIZEH(REGION_OCC)63 ELISTIZEH(REGION_OCC)
64 #define RANGE_IN_BAND(band_max, band_min, range_max, range_min) \
65 (((range_min) >= (band_min)) && ((range_max) < (band_max)))
66 /************************************************************************
67 Adapted from the following procedure so that it can be used in the bands
68 class in an include file...
69
70 bool range_in_band[
71 range within band?
72 int16_t band_max,
73 int16_t band_min,
74 int16_t range_max,
75 int16_t range_min]
76 {
77 if ((range_min >= band_min) && (range_max < band_max))
78 return true;
79 else
80 return false;
81 }
82 ***********************************************************************/
83 #define RANGE_OVERLAPS_BAND(band_max, band_min, range_max, range_min) \
84 (((range_max) >= (band_min)) && ((range_min) < (band_max)))
85 /************************************************************************
86 Adapted from the following procedure so that it can be used in the bands
87 class in an include file...
88
89 bool range_overlaps_band[
90 range crosses band?
91 int16_t band_max,
92 int16_t band_min,
93 int16_t range_max,
94 int16_t range_min]
95 {
96 if ((range_max >= band_min) && (range_min < band_max))
97 return true;
98 else
99 return false;
100 }
101 ***********************************************************************/
102 /**********************************************************************
103 Bands
104 -----
105
106 BAND 4
107 --------------------------------
108 BAND 3
109 --------------------------------
110
111 BAND 2
112
113 --------------------------------
114
115 BAND 1
116
117 Band 0 is the dot band
118
119 Each band has an error margin above and below. An outline is not considered to
120 have significantly changed bands until it has moved out of the error margin.
121 *************************************************************************/
122 class BAND {
123 public:
124 int16_t max_max; // upper max
125 int16_t max; // nominal max
126 int16_t min_max; // lower max
127 int16_t max_min; // upper min
128 int16_t min; // nominal min
129 int16_t min_min; // lower min
130
131 BAND() = default; // constructor
132
133 void set( // initialise a band
134 int16_t new_max_max, // upper max
135 int16_t new_max, // new nominal max
136 int16_t new_min_max, // new lower max
137 int16_t new_max_min, // new upper min
138 int16_t new_min, // new nominal min
139 int16_t new_min_min) { // new lower min
140 max_max = new_max_max;
141 max = new_max;
142 min_max = new_min_max;
143 max_min = new_max_min;
144 min = new_min;
145 min_min = new_min_min;
146 }
147
148 bool in_minimal( // in minimal limits?
149 float y) { // y value
150 return (y >= max_min) && (y < min_max);
151 }
152
153 bool in_nominal( // in nominal limits?
154 float y) { // y value
155 return (y >= min) && (y < max);
156 }
157
158 bool in_maximal( // in maximal limits?
159 float y) { // y value
160 return (y >= min_min) && (y < max_max);
161 }
162
163 // overlaps min limits?
164 bool range_overlaps_minimal(float y1, // one range limit
165 float y2) { // other range limit
166 if (y1 > y2) {
167 return RANGE_OVERLAPS_BAND(min_max, max_min, y1, y2);
168 } else {
169 return RANGE_OVERLAPS_BAND(min_max, max_min, y2, y1);
170 }
171 }
172
173 // overlaps nom limits?
174 bool range_overlaps_nominal(float y1, // one range limit
175 float y2) { // other range limit
176 if (y1 > y2) {
177 return RANGE_OVERLAPS_BAND(max, min, y1, y2);
178 } else {
179 return RANGE_OVERLAPS_BAND(max, min, y2, y1);
180 }
181 }
182
183 // overlaps max limits?
184 bool range_overlaps_maximal(float y1, // one range limit
185 float y2) { // other range limit
186 if (y1 > y2) {
187 return RANGE_OVERLAPS_BAND(max_max, min_min, y1, y2);
188 } else {
189 return RANGE_OVERLAPS_BAND(max_max, min_min, y2, y1);
190 }
191 }
192
193 bool range_in_minimal( // within min limits?
194 float y1, // one range limit
195 float y2) { // other range limit
196 if (y1 > y2) {
197 return RANGE_IN_BAND(min_max, max_min, y1, y2);
198 } else {
199 return RANGE_IN_BAND(min_max, max_min, y2, y1);
200 }
201 }
202
203 bool range_in_nominal( // within nom limits?
204 float y1, // one range limit
205 float y2) { // other range limit
206 if (y1 > y2) {
207 return RANGE_IN_BAND(max, min, y1, y2);
208 } else {
209 return RANGE_IN_BAND(max, min, y2, y1);
210 }
211 }
212
213 bool range_in_maximal( // within max limits?
214 float y1, // one range limit
215 float y2) { // other range limit
216 if (y1 > y2) {
217 return RANGE_IN_BAND(max_max, min_min, y1, y2);
218 } else {
219 return RANGE_IN_BAND(max_max, min_min, y2, y1);
220 }
221 }
222 };
223
224 /* Standard positions */
225
226 #define MAX_NUM_BANDS 5
227 #define UNDEFINED_BAND 99
228 #define NO_LOWER_LIMIT -9999
229 #define NO_UPPER_LIMIT 9999
230
231 #define DOT_BAND 0
232
233 /* Special occupancy code emitted for the 0 region at the end of a word */
234
235 #define END_OF_WERD_CODE 255
236
237 extern double_VAR_H(textord_underline_threshold);
238
239 bool test_underline( // look for underlines
240 bool testing_on, // drawing blob
241 C_BLOB *blob, // blob to test
242 int16_t baseline, // coords of baseline
243 int16_t xheight // height of line
244 );
245
246 } // namespace tesseract
247
248 #endif
249