From 61f37ba596949e87e29d4fc3b00f9bb5fca1ef65 Mon Sep 17 00:00:00 2001
From: Matt Hill <matthill@openalpr.com>
Date: Thu, 24 Sep 2015 22:12:31 -0400
Subject: [PATCH] Added a must_match_pattern config option.  When a text
 pattern is available, all non-matching values will be disregarded.

---
 config/openalpr.conf.in                  |  4 ++++
 src/openalpr/config.cpp                  |  2 ++
 src/openalpr/config.h                    |  2 ++
 src/openalpr/postprocess/postprocess.cpp | 14 +++++++++++---
 4 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/config/openalpr.conf.in b/config/openalpr.conf.in
index fd8a97e..3507682 100644
--- a/config/openalpr.conf.in
+++ b/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
 
diff --git a/src/openalpr/config.cpp b/src/openalpr/config.cpp
index f4794b0..4ce8fbb 100644
--- a/src/openalpr/config.cpp
+++ b/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", "");
diff --git a/src/openalpr/config.h b/src/openalpr/config.h
index 72deb78..47ef75e 100644
--- a/src/openalpr/config.h
+++ b/src/openalpr/config.h
@@ -104,6 +104,8 @@ namespace alpr
       std::string ocrLanguage;
       int ocrMinFontSize;
 
+      bool mustMatchPattern;
+      
       float postProcessMinConfidence;
       float postProcessConfidenceSkipLevel;
       unsigned int postProcessMinCharacters;
diff --git a/src/openalpr/postprocess/postprocess.cpp b/src/openalpr/postprocess/postprocess.cpp
index 6580d1d..1a66b33 100644
--- a/src/openalpr/postprocess/postprocess.cpp
+++ b/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() {