Adds two more examples of croped word recognition, and show how to set the beam…

Adds two more examples of croped word recognition, and show how to set the beam size parameter for small lexicon.

modules/text/samples/cropped_word_recognition.cpp

@@ -39,12 +39,13 @@ int main(int argc, char* argv[])
     string vocabulary = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; // must have the same order as the clasifier output classes
     vector<string> lexicon;  // a list of words expected to be found on the input image
     lexicon.push_back(string("abb"));
-    lexicon.push_back(string("patata"));
+    lexicon.push_back(string("riser"));
     lexicon.push_back(string("CHINA"));
     lexicon.push_back(string("HERE"));
     lexicon.push_back(string("President"));
     lexicon.push_back(string("smash"));
     lexicon.push_back(string("KUALA"));
+    lexicon.push_back(string("Produkt"));
     lexicon.push_back(string("NINTENDO"));
 
     // Create tailored language model a small given lexicon
@@ -54,16 +55,18 @@ int main(int argc, char* argv[])
     // An alternative would be to load the default generic language model
     //    (created from ispell 42869 english words list)
     /*Mat transition_p;
-    string filename = "OCRHMM_transitions_table.xml"; // TODO use same order for voc
+    string filename = "OCRHMM_transitions_table.xml";
     FileStorage fs(filename, FileStorage::READ);
     fs["transition_probabilities"] >> transition_p;
     fs.release();*/
 
     Mat emission_p = Mat::eye(62,62,CV_64FC1);
 
+    // Notice we set here a beam size of 50. This is much faster than using the default value (500).
+    // 50 works well with our tiny lexicon example, but may not with larger dictionaries.
     Ptr<OCRBeamSearchDecoder> ocr = OCRBeamSearchDecoder::create(
                 loadOCRBeamSearchClassifierCNN("OCRBeamSearch_CNN_model_data.xml.gz"),
-                vocabulary, transition_p, emission_p);
+                vocabulary, transition_p, emission_p, OCR_DECODER_VITERBI, 50);
 
     double t_r = (double)getTickCount();
     string output;