From eb777abe16a13180fa6be2ef6273dadc3d51f490 Mon Sep 17 00:00:00 2001
From: Matt Hill <matthill@gmail.com>
Date: Sun, 28 Jun 2015 11:46:07 -0400
Subject: [PATCH] Ignore crops that are pure white or pure black with a little
 leniency

---
 src/openalpr/edges/platelines.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/openalpr/edges/platelines.cpp b/src/openalpr/edges/platelines.cpp
index ec7aa27..aba0a52 100644
--- a/src/openalpr/edges/platelines.cpp
+++ b/src/openalpr/edges/platelines.cpp
@@ -52,9 +52,9 @@ namespace alpr
 
     // Ignore input images that are pure white or pure black
     Scalar avgPixelIntensity = mean(inputImage);
-    if (avgPixelIntensity[0] == 255)
+    if (avgPixelIntensity[0] >= 252)
       return;
-    else if (avgPixelIntensity[0] == 0)
+    else if (avgPixelIntensity[0] <= 3)
       return;
 
     // Do a bilateral filter to clean the noise but keep edges sharp