tesseract  4.1.1
intfeaturespace.cpp
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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 //
7 // Licensed under the Apache License, Version 2.0 (the "License");
8 // you may not use this file except in compliance with the License.
9 // You may obtain a copy of the License at
10 // http://www.apache.org/licenses/LICENSE-2.0
11 // Unless required by applicable law or agreed to in writing, software
12 // distributed under the License is distributed on an "AS IS" BASIS,
13 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 // See the License for the specific language governing permissions and
15 // limitations under the License.
16 //
18 
19 #define _USE_MATH_DEFINES // for M_PI
20 #include "intfeaturespace.h"
21 #include <cmath> // for M_PI
22 #include "intfx.h"
23 
24 namespace tesseract {
25 
27  : x_buckets_(0), y_buckets_(0), theta_buckets_(0) {
28 }
29 
30 void IntFeatureSpace::Init(uint8_t xbuckets, uint8_t ybuckets, uint8_t thetabuckets) {
31  x_buckets_ = xbuckets;
32  y_buckets_ = ybuckets;
33  theta_buckets_ = thetabuckets;
34 }
35 
36 // Serializes the feature space definition to the given file.
37 // Returns false on error.
38 bool IntFeatureSpace::Serialize(FILE* fp) const {
39  if (fwrite(&x_buckets_, sizeof(x_buckets_), 1, fp) != 1)
40  return false;
41  if (fwrite(&y_buckets_, sizeof(y_buckets_), 1, fp) != 1)
42  return false;
43  if (fwrite(&theta_buckets_, sizeof(theta_buckets_), 1, fp) != 1)
44  return false;
45  return true;
46 }
47 
48 // Returns an INT_FEATURE_STRUCT corresponding to the given index.
49 // This is the inverse of the Index member.
52  index / theta_buckets_ % y_buckets_,
53  index % theta_buckets_);
54 }
55 
56 // Bulk calls to Index. Maps the given array of features to a vector of
57 // int32_t indices in the same order as the input.
59  int num_features,
60  GenericVector<int>* mapped_features) const {
61  mapped_features->truncate(0);
62  for (int f = 0; f < num_features; ++f)
63  mapped_features->push_back(Index(features[f]));
64 }
65 
66 // Bulk calls to Index. Maps the given array of features to a vector of
67 // sorted int32_t indices.
69  const INT_FEATURE_STRUCT* features, int num_features,
70  GenericVector<int>* sorted_features) const {
71  sorted_features->truncate(0);
72  for (int f = 0; f < num_features; ++f)
73  sorted_features->push_back(Index(features[f]));
74  sorted_features->sort();
75 }
76 
77 // Returns a feature space index for the given x,y position in a display
78 // window, or -1 if the feature is a miss.
79 int IntFeatureSpace::XYToFeatureIndex(int x, int y) const {
80  // Round the x,y position to a feature. Search for a valid theta.
81  INT_FEATURE_STRUCT feature(x, y, 0);
82  int index = -1;
83  for (int theta = 0; theta <= UINT8_MAX && index < 0; ++theta) {
84  feature.Theta = theta;
85  index = Index(feature);
86  }
87  if (index < 0) {
88  tprintf("(%d,%d) does not exist in feature space!\n", x, y);
89  return -1;
90  }
91  feature = PositionFromIndex(index);
92  tprintf("Click at (%d, %d) ->(%d, %d), ->(%d, %d)\n",
93  x, y, feature.X, feature.Y, x - feature.X, y - feature.Y);
94  // Get the relative position of x,y from the rounded feature.
95  x -= feature.X;
96  y -= feature.Y;
97  if (x != 0 || y != 0) {
98  double angle = atan2(static_cast<double>(y), static_cast<double>(x)) + M_PI;
99  angle *= kIntFeatureExtent / (2.0 * M_PI);
100  feature.Theta = static_cast<uint8_t>(angle + 0.5);
101  index = Index(feature);
102  if (index < 0) {
103  tprintf("Feature failed to map to a valid index:");
104  feature.print();
105  return -1;
106  }
107  feature = PositionFromIndex(index);
108  }
109  feature.print();
110  return index;
111 }
112 
113 // Returns an INT_FEATURE_STRUCT corresponding to the given bucket coords.
115  int y,
116  int theta) const {
117  INT_FEATURE_STRUCT pos(
121  return pos;
122 }
123 
124 } // namespace tesseract.
int DivRounded(int a, int b)
Definition: helpers.h:167
DLLSYM void tprintf(const char *format,...)
Definition: tprintf.cpp:35
const int kIntFeatureExtent
int push_back(T object)
void truncate(int size)
void Init(uint8_t xbuckets, uint8_t ybuckets, uint8_t thetabuckets)
void IndexFeatures(const INT_FEATURE_STRUCT *features, int num_features, GenericVector< int > *mapped_features) const
INT_FEATURE_STRUCT PositionFromIndex(int index) const
int Index(const INT_FEATURE_STRUCT &f) const
int XYToFeatureIndex(int x, int y) const
bool Serialize(FILE *fp) const
INT_FEATURE_STRUCT PositionFromBuckets(int x, int y, int theta) const
void IndexAndSortFeatures(const INT_FEATURE_STRUCT *features, int num_features, GenericVector< int > *sorted_features) const
void print() const
Definition: intproto.h:145