diff --git a/src/core/chars_segment.cpp b/src/core/chars_segment.cpp
index f3289dd..202c64d 100644
--- a/src/core/chars_segment.cpp
+++ b/src/core/chars_segment.cpp
@@ -90,7 +90,7 @@ Mat CCharsSegment::histeq(Mat in)
 //getPlateType
 //判断车牌的类型，1为蓝牌，2为黄牌，0为未知，默认蓝牌
 //通过像素中蓝色所占比例的多少来判断，大于0.3为蓝牌，否则为黄牌
-int CCharsSegment::getPlateType(Mat input)
+PlateColor CCharsSegment::getPlateType(Mat input)
 {
 	Mat img;
 	input.copyTo(img);
@@ -121,11 +121,11 @@ int CCharsSegment::getPlateType(Mat input)
 	double percentWhite = countWhite/nums;
 
 	if (percentBlue - m_BluePercent > 0 && percentWhite - m_WhitePercent > 0)
-		return 1;
+        return PlateColor::Blue;
 	else
-		return 2;
+        return PlateColor::Yellow;
 
-	return 0;
+    return PlateColor::Unknown;
 }
 
 //clearLiuDing
@@ -162,12 +162,12 @@ int CCharsSegment::charsSegment(Mat input, vector<Mat>& resultVec)
 	{ return -3; }
 
 	//判断车牌颜色以此确认threshold方法
-	int plateType = getPlateType(input);
+	PlateColor plateType = getPlateType(input);
 	cvtColor(input, input, CV_RGB2GRAY);
 
 	//Threshold input image
 	Mat img_threshold;
-	if (1 == plateType)
+    if (PlateColor::Blue == plateType)
 		threshold(input, img_threshold, 10, 255, CV_THRESH_OTSU+CV_THRESH_BINARY);
 	else 
 		threshold(input, img_threshold, 10, 255, CV_THRESH_OTSU+CV_THRESH_BINARY_INV);
diff --git a/src/include/chars_recognise.h b/src/include/chars_recognise.h
index ea17452..6443d93 100644
--- a/src/include/chars_recognise.h
+++ b/src/include/chars_recognise.h
@@ -45,9 +45,9 @@ public:
 	{
 		string color = "未知";
 		int result = m_charsSegment->getPlateType(input);
-		if (1 == result)
+        if (PlateColor::Blue == result)
 			color = "蓝牌";
-		if (2 == result)
+        if (PlateColor::Yellow == result)
 			color = "黄牌";
 		return color;
 	}
diff --git a/src/include/chars_segment.h b/src/include/chars_segment.h
index c6dc289..4fd896f 100644
--- a/src/include/chars_segment.h
+++ b/src/include/chars_segment.h
@@ -19,6 +19,12 @@
 */
 namespace easypr {
 
+    enum PlateColor {
+        Blue,
+        Yellow,
+        Unknown
+    };
+    
 class CCharsSegment 
 {
 public:
@@ -43,7 +49,7 @@ public:
 	Mat histeq(Mat in);
 
 	//! 获得车牌颜色
-	int getPlateType(Mat input);
+	PlateColor getPlateType(Mat input);
 
 	//! 去除影响字符识别的柳钉
 	void clearLiuDing(Mat &img);