diff --git a/CMakeLists.txt b/CMakeLists.txt
index e247d8d..44349bf 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -43,6 +43,7 @@ add_library(${PROJECT_NAME} SHARED
   "src/${PROJECT_NAME}/node/ninshiki_cpp_node.cpp"
   "src/${PROJECT_NAME}/utils/color.cpp"
   "src/${PROJECT_NAME}/utils/contours.cpp"
+  "src/${PROJECT_NAME}/utils/circles.cpp"
   "src/${PROJECT_NAME}/utils/utils.cpp"
 )
 
@@ -52,6 +53,7 @@ add_library(${PROJECT_NAME}_exported SHARED
   "src/${PROJECT_NAME}/detector/lbp_detector.cpp"
   "src/${PROJECT_NAME}/utils/color.cpp"
   "src/${PROJECT_NAME}/utils/contours.cpp"
+  "src/${PROJECT_NAME}/utils/circles.cpp"
   "src/${PROJECT_NAME}/utils/utils.cpp"
 )
 
diff --git a/include/ninshiki_cpp/node/ninshiki_cpp_node.hpp b/include/ninshiki_cpp/node/ninshiki_cpp_node.hpp
index d4470f7..d944a9e 100644
--- a/include/ninshiki_cpp/node/ninshiki_cpp_node.hpp
+++ b/include/ninshiki_cpp/node/ninshiki_cpp_node.hpp
@@ -63,7 +63,7 @@ class NinshikiCppNode
   rclcpp::TimerBase::SharedPtr node_timer;
 
   rclcpp::Publisher<DetectedObjects>::SharedPtr detected_object_publisher;
-  rclcpp::Publisher<Contours>::SharedPtr field_segmentation_publisher;
+  rclcpp::Publisher<Contours>::SharedPtr color_segmentation_publisher;
   rclcpp::Subscription<Image>::SharedPtr image_subscriber;
 
   ConfigGrpc config_grpc;
diff --git a/include/ninshiki_cpp/utils/circles.hpp b/include/ninshiki_cpp/utils/circles.hpp
new file mode 100644
index 0000000..8b40205
--- /dev/null
+++ b/include/ninshiki_cpp/utils/circles.hpp
@@ -0,0 +1,56 @@
+// Copyright (c) 2021 ICHIRO ITS
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+#ifndef NINSHIKI_CPP__UTILS__CIRCLES_HPP_
+#define NINSHIKI_CPP__UTILS__CIRCLES_HPP_
+
+#include <opencv2/opencv.hpp>
+#include <vector>
+
+namespace ninshiki_cpp::utils
+{
+
+class Circles
+{
+private:
+
+    std::vector<cv::Point> centers;
+    std::vector<float> radiuses;
+
+public:
+
+    Circles();
+    Circles(std::vector<std::vector<cv::Point>> contours) { find(contours); }
+    
+    cv::Mat get_binary_mat(cv::Size mat_size) { return get_binary_mat_line(mat_size, cv::FILLED); }
+    cv::Mat get_binary_mat_line(cv::Size mat_size, int line_size);
+
+    std::vector<cv::Point> get_centers() { return centers; }
+    std::vector<float> get_radiuses() { return radiuses; }
+
+    cv::Point get_first_center();
+    float get_first_radiuses();
+
+    void find(std::vector<std::vector<cv::Point>> contours);
+};
+
+}  // namespace ninshiki_cpp::utils
+
+#endif // NINSHIKI_CPP__UTILS__CIRCLES_HPP_
\ No newline at end of file
diff --git a/src/ninshiki_cpp/node/ninshiki_cpp_node.cpp b/src/ninshiki_cpp/node/ninshiki_cpp_node.cpp
index d3bf4e6..849646f 100644
--- a/src/ninshiki_cpp/node/ninshiki_cpp_node.cpp
+++ b/src/ninshiki_cpp/node/ninshiki_cpp_node.cpp
@@ -37,7 +37,7 @@ NinshikiCppNode::NinshikiCppNode(
 {
   detected_object_publisher = node->create_publisher<DetectedObjects>(
     get_node_prefix() + "/dnn_detection", 10);
-  field_segmentation_publisher = node->create_publisher<Contours>(
+  color_segmentation_publisher = node->create_publisher<Contours>(
     get_node_prefix() + "/color_detection", 10);
 
   image_subscriber =
@@ -67,7 +67,7 @@ void NinshikiCppNode::publish()
   detected_object_publisher->publish(dnn_detection->detection_result);
 
   color_detection->detection(hsv_frame);
-  field_segmentation_publisher->publish(color_detection->detection_result);
+  color_segmentation_publisher->publish(color_detection->detection_result);
 
   lbp_detection->detection(received_frame);
   detected_object_publisher->publish(lbp_detection->detection_result);
diff --git a/src/ninshiki_cpp/utils/circles.cpp b/src/ninshiki_cpp/utils/circles.cpp
new file mode 100644
index 0000000..7b4bb6a
--- /dev/null
+++ b/src/ninshiki_cpp/utils/circles.cpp
@@ -0,0 +1,79 @@
+// Copyright (c) 2021 ICHIRO ITS
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+#include "ninshiki_cpp/utils/circles.hpp"
+
+namespace ninshiki_cpp::utils
+{
+
+Circles::Circles()
+{
+    centers.clear();
+    radiuses.clear();
+}
+
+cv::Mat Circles::get_binary_mat_line(cv::Size mat_size, int line_size)
+{
+    cv::Mat binary_mat(mat_size, CV_8UC1);
+    binary_mat = cv::Scalar(0);
+
+    if (centers.size() > 0 && radiuses.size() > 0)
+    {
+        for (unsigned int i = 0; i < centers.size() && i < radiuses.size(); i++)
+        {
+		    cv::circle(binary_mat, centers[i], radiuses[i], 255, line_size);
+        }
+    }
+
+    return binary_mat;
+}
+
+cv::Point Circles::get_first_center()
+{
+    if (centers.size() <= 0)
+        return cv::Point(-1, -1);
+
+    return centers[0];
+}
+
+float Circles::get_first_radiuses()
+{
+    if (radiuses.size() <= 0)
+        return 0;
+    
+    return radiuses[0];
+}
+
+void Circles::find(std::vector<std::vector<cv::Point>> contours)
+{
+    centers.clear();
+    radiuses.clear();
+
+    for (std::vector<cv::Point> &contour : contours)
+    {
+        cv::Point2f center;
+        float radius;
+        cv::minEnclosingCircle(cv::Mat(contour), center, radius);
+        
+        centers.push_back(center);
+        radiuses.push_back(radius);
+    }
+}
+} // namespace ninshiki_cpp::utils
\ No newline at end of file