Tesseract  3.02
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Macros Groups Pages
intfeaturespace.cpp
Go to the documentation of this file.
1 // Copyright 2010 Google Inc. All Rights Reserved.
2 // Author: rays@google.com (Ray Smith)
4 // File: intfeaturespace.cpp
5 // Description: Indexed feature space based on INT_FEATURE_STRUCT.
6 // Created: Wed Mar 24 11:21:27 PDT 2010
7 //
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 //
19 
20 #include "intfeaturespace.h"
21 #include "intfx.h"
22 
23 namespace tesseract {
24 
26  : x_buckets_(0), y_buckets_(0), theta_buckets_(0) {
27 }
28 
29 void IntFeatureSpace::Init(uinT8 xbuckets, uinT8 ybuckets, uinT8 thetabuckets) {
30  x_buckets_ = xbuckets;
31  y_buckets_ = ybuckets;
32  theta_buckets_ = thetabuckets;
33 }
34 
35 // Serializes the feature space definition to the given file.
36 // Returns false on error.
37 bool IntFeatureSpace::Serialize(FILE* fp) const {
38  if (fwrite(&x_buckets_, sizeof(x_buckets_), 1, fp) != 1)
39  return false;
40  if (fwrite(&y_buckets_, sizeof(y_buckets_), 1, fp) != 1)
41  return false;
42  if (fwrite(&theta_buckets_, sizeof(theta_buckets_), 1, fp) != 1)
43  return false;
44  return true;
45 }
46 
47 // DeSerializes the feature space definition from the given file.
48 // If swap is true, the data is big/little-endian swapped.
49 // Returns false on error.
50 bool IntFeatureSpace::DeSerialize(bool swap, FILE* fp) {
51  if (fread(&x_buckets_, sizeof(x_buckets_), 1, fp) != 1)
52  return false;
53  if (fread(&y_buckets_, sizeof(y_buckets_), 1, fp) != 1)
54  return false;
55  if (fread(&theta_buckets_, sizeof(theta_buckets_), 1, fp) != 1)
56  return false;
57  return true;
58 }
59 
60 // Returns an INT_FEATURE_STRUCT corresponding to the given index.
61 // This is the inverse of the Index member.
64  index / theta_buckets_ % y_buckets_,
65  index % theta_buckets_);
66 }
67 
68 // Bulk calls to Index. Maps the given array of features to a vector of
69 // inT32 indices in the same order as the input.
71  int num_features,
72  GenericVector<int>* mapped_features) const {
73  mapped_features->truncate(0);
74  for (int f = 0; f < num_features; ++f)
75  mapped_features->push_back(Index(features[f]));
76 }
77 
78 // Bulk calls to Index. Maps the given array of features to a vector of
79 // sorted inT32 indices.
81  const INT_FEATURE_STRUCT* features, int num_features,
82  GenericVector<int>* sorted_features) const {
83  sorted_features->truncate(0);
84  for (int f = 0; f < num_features; ++f)
85  sorted_features->push_back(Index(features[f]));
86  sorted_features->sort();
87 }
88 
89 // Returns a feature space index for the given x,y position in a display
90 // window, or -1 if the feature is a miss.
91 int IntFeatureSpace::XYToFeatureIndex(int x, int y) const {
92  // Round the x,y position to a feature. Search for a valid theta.
93  INT_FEATURE_STRUCT feature = {static_cast<uinT8>(x), static_cast<uinT8>(y),
94  0, 0};
95  int index = -1;
96  for (int theta = 0; theta <= MAX_UINT8 && index < 0; ++theta) {
97  feature.Theta = theta;
98  index = Index(feature);
99  }
100  if (index < 0) {
101  tprintf("(%d,%d) does not exist in feature space!\n", x, y);
102  return -1;
103  }
104  feature = PositionFromIndex(index);
105  tprintf("Click at (%d, %d) ->(%d, %d), ->(%d, %d)\n",
106  x, y, feature.X, feature.Y, x - feature.X, y - feature.Y);
107  // Get the relative position of x,y from the rounded feature.
108  x -= feature.X;
109  y -= feature.Y;
110  if (x != 0 || y != 0) {
111  double angle = atan2(static_cast<double>(y), static_cast<double>(x)) + PI;
112  angle *= kIntFeatureExtent / (2.0 * PI);
113  feature.Theta = static_cast<uinT8>(angle + 0.5);
114  index = Index(feature);
115  if (index < 0) {
116  tprintf("Feature failed to map to a valid index:");
117  feature.print();
118  return -1;
119  }
120  feature = PositionFromIndex(index);
121  }
122  feature.print();
123  return index;
124 }
125 
126 // Returns an INT_FEATURE_STRUCT corresponding to the given bucket coords.
128  int y,
129  int theta) const {
130  INT_FEATURE_STRUCT pos = {
131  static_cast<uinT8>(ClipToRange(
133  0, MAX_UINT8)),
134  static_cast<uinT8>(ClipToRange(
136  0, MAX_UINT8)),
137  static_cast<uinT8>(ClipToRange(
139  0, MAX_UINT8))};
140  return pos;
141 }
142 
143 } // namespace tesseract.