X-Git-Url: http://git.rot13.org/?p=zxing.git;a=blobdiff_plain;f=cpp%2Fcore%2Fsrc%2Fcommon%2FBlackPointEstimator.cpp;h=9b4e1e1f5091abba85c5f1781813e0612ae2fae3;hp=976ed228fcefc564ae8e943c387288d34c9b5b17;hb=d5d1e96fd3936324b31fe645acc4ce65956ec2e1;hpb=ca9d7b07d124cc454c38b984677c511476fd8d9b

diff --git a/cpp/core/src/common/BlackPointEstimator.cpp b/cpp/core/src/common/BlackPointEstimator.cpp
index 976ed228..9b4e1e1f 100644
--- a/cpp/core/src/common/BlackPointEstimator.cpp
+++ b/cpp/core/src/common/BlackPointEstimator.cpp
@@ -28,6 +28,7 @@ namespace common {
   size_t BlackPointEstimator::estimate(valarray<int> &histogram) {
     
     size_t numBuckets = histogram.size();
+    int maxBucketCount = 0;
     
     // Find tallest peak in histogram
     size_t firstPeak = 0;
@@ -37,6 +38,9 @@ namespace common {
         firstPeak = i;
         firstPeakSize = histogram[i];
       }
+      if (histogram[i] > maxBucketCount) {
+        maxBucketCount = histogram[i];
+      }
     }
     
     // Find second-tallest peak -- well, another peak that is tall and not
@@ -65,7 +69,7 @@ namespace common {
     // Decoding the image/line is either pointless, or may in some cases lead to a false positive
     // for 1D formats, which are relatively lenient.
     // We arbitrarily say "close" is "<= 1/16 of the total histogram buckets apart"
-    if (secondPeak - firstPeak <= histogram.size() >> 4) {
+    if (secondPeak - firstPeak <= numBuckets >> 4) {
       throw new IllegalArgumentException
         ("Too little dynamic range in luminance");
     }
@@ -77,7 +81,7 @@ namespace common {
       int fromFirst = i - firstPeak;
       // Favor a "valley" that is not too close to either peak -- especially not the black peak --
       // and that has a low value of course
-      int score = fromFirst * fromFirst * (secondPeak - i) * (256 - histogram[i]);
+      int score = fromFirst * fromFirst * (secondPeak - i) * (maxBucketCount - histogram[i]);
       if (score > bestValleyScore) {
         bestValley = i;
         bestValleyScore = score;