Added a must_match_pattern config option. When a text pattern is available, all non-matching values will be disregarded.

config/openalpr.conf.in

@@ -42,6 +42,10 @@ max_detection_input_height = 720
 ; morphcpu  - Experimental detector that detects white rectangles in an image.  Does not require training.
 detector = lbpcpu
 
+; If set to true, all results must match a postprocess text pattern if a pattern is available.  
+; If not, the result is disqualified. 
+must_match_pattern = 0
+
 ; Bypasses plate detection.  If this is set to 1, the library assumes that each region provided is a likely plate area.
 skip_detection = 0
 

src/openalpr/config.cpp

@@ -176,6 +176,8 @@ namespace alpr
     maxDetectionInputWidth = getInt(ini, "", "max_detection_input_width", 1280);
     maxDetectionInputHeight = getInt(ini, "", "max_detection_input_height", 768);
 
+    mustMatchPattern = getBoolean(ini, "", "must_match_pattern", false);
+    
     skipDetection = getBoolean(ini, "", "skip_detection", false);
     
     prewarp = getString(ini, "", "prewarp", "");

src/openalpr/config.h

@@ -104,6 +104,8 @@ namespace alpr
       std::string ocrLanguage;
       int ocrMinFontSize;
 
+      bool mustMatchPattern;
+      
       float postProcessMinConfidence;
       float postProcessConfidenceSkipLevel;
       unsigned int postProcessMinCharacters;

src/openalpr/postprocess/postprocess.cpp

@@ -381,9 +381,17 @@ namespace alpr
     if (allPossibilitiesLetters.end() != allPossibilitiesLetters.find(possibility.letters))
       return false;
 
-    allPossibilities.push_back(possibility);
-    allPossibilitiesLetters.insert(possibility.letters);
-    return true;
+    // If mustMatchPattern is toggled in the config and a template is provided, 
+    // only include this result if there is a pattern match
+    if (!config->mustMatchPattern || templateregion.size() == 0 || 
+        (config->mustMatchPattern && possibility.matchesTemplate))
+    {
+      allPossibilities.push_back(possibility);
+      allPossibilitiesLetters.insert(possibility.letters);
+      return true;
+    }
+    
+    return false;
   }
 
   std::vector<string> PostProcess::getPatterns() {