diff --git a/src/convertcolor.cpp b/src/convertcolor.cpp
index 651cf46..41b7529 100644
--- a/src/convertcolor.cpp
+++ b/src/convertcolor.cpp
@@ -54,11 +54,14 @@ void ConvertColor_BGR2GRAY_BT709(const cv::Mat& src, cv::Mat& dst)
 
 void ConvertColor_BGR2GRAY_BT709_fpt(const cv::Mat& src, cv::Mat& dst)
 {
-    CV_Assert(CV_8UC3 == src.type());
+	CV_Assert(CV_8UC3 == src.type());
     cv::Size sz = src.size();
     dst.create(sz, CV_8UC1);
 
     const int bidx = 0;
+	unsigned int coef1 = 0.2126f*pow(2,16) + .5f;
+	unsigned int coef2 = 0.7152f*pow(2,16) + .5f;
+	unsigned int coef3 = 0.0722f*pow(2,16) + .5f;
 
     for (int y = 0; y < sz.height; y++)
     {
@@ -67,8 +70,8 @@ void ConvertColor_BGR2GRAY_BT709_fpt(const cv::Mat& src, cv::Mat& dst)
 
         for (int x = 0; x < sz.width; x++)
         {
-            float color = 0.2126 * psrc[x][2-bidx] + 0.7152 * psrc[x][1] + 0.0722 * psrc[x][bidx];
-            pdst[x] = (int)(color + 0.5);
+            unsigned int color = (coef1 * psrc[x][2-bidx] + coef2 * psrc[x][1] + coef3 * psrc[x][bidx]);
+			pdst[x] = (int)((float)color/pow(2,16) + .5f);
         }
     }
 }
diff --git a/test/test_skeleton.cpp b/test/test_skeleton.cpp
index 3e0a330..781f32e 100644
--- a/test/test_skeleton.cpp
+++ b/test/test_skeleton.cpp
@@ -60,3 +60,62 @@ TEST(skeleton, resize_matches_opencv)
     // std::cout << "Difference:\n" << reference - result << std::endl;
     EXPECT_LT(maxDifference(reference, result), 2);
 }
+
+TEST(skeleton, 2_plus_2_equals_4)
+{
+   EXPECT_EQ(4, 2 + 2);
+}
+
+TEST(skeleton, ConvertColorDoesNotChangeSize)
+{
+	Mat src(10, 20, CV_8UC3);
+	randu(src, Scalar::all(0), Scalar::all(255));
+	Mat dst;
+
+	ConvertColor_BGR2GRAY_BT709(src, dst);
+
+	EXPECT_EQ(src.size, dst.size);
+}
+
+TEST(skeleton, GuoHallThinningDoesNotChangeSize)
+{
+	Mat src(10, 20, CV_8UC1);
+	randu(src, Scalar(0), Scalar(255));
+	Mat dst;
+
+	GuoHallThinning(src, dst);
+
+	EXPECT_EQ(src.size, dst.size);
+}
+
+TEST(skeleton, ImageResizeSetsCorrectSize)
+{
+	Mat src(10, 20, CV_8UC1);
+	randu(src, Scalar(0), Scalar(255));
+	Mat dst;
+	int firstSize = 4;
+	int secondSize = 5;
+	Size sz(firstSize, secondSize);
+
+	ImageResize(src, dst, sz);
+
+	EXPECT_EQ(true, ((dst.cols == firstSize) && (dst.rows == secondSize)));
+}
+
+TEST(skeleton, ImageResizeSavesColor)
+{
+	Mat srcMtx(20, 16, CV_8UC1, Scalar(0));
+ 	Mat dstMtx;
+ 	Mat expectedMtx(4, 5, CV_8UC1, Scalar(0));
+ 	Size sz(4, 5);
+ 
+ 	ImageResize(srcMtx, dstMtx, sz);
+ 
+ 	double srcMin, srcMax;
+ 	minMaxLoc(srcMtx, &srcMin, &srcMax);
+ 	double dstMin, dstMax;
+ 	minMaxLoc(dstMtx, &dstMin, &dstMax);
+ 	EXPECT_EQ(dstMin, dstMax);
+ 	EXPECT_EQ(srcMin, dstMin);
+ 	EXPECT_EQ(srcMax, dstMax);
+}
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