diff --git a/.gitignore b/.gitignore
index 985f3a5..5a0e9ef 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,4 @@
################################################################################
/.vs/09_KNN/v16
+/09_KNN/x64/Debug
diff --git a/09_KNN.sln b/09_KNN.sln
new file mode 100644
index 0000000..0625610
--- /dev/null
+++ b/09_KNN.sln
@@ -0,0 +1,31 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.33423.256
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "09_KNN", "09_KNN\09_KNN.vcxproj", "{7B454EDC-9753-4C2F-B57E-8CC20B8A34C3}"
+EndProject
+Global
+ GlobalSection(SolutionConfigurationPlatforms) = preSolution
+ Debug|x64 = Debug|x64
+ Debug|x86 = Debug|x86
+ Release|x64 = Release|x64
+ Release|x86 = Release|x86
+ EndGlobalSection
+ GlobalSection(ProjectConfigurationPlatforms) = postSolution
+ {7B454EDC-9753-4C2F-B57E-8CC20B8A34C3}.Debug|x64.ActiveCfg = Debug|x64
+ {7B454EDC-9753-4C2F-B57E-8CC20B8A34C3}.Debug|x64.Build.0 = Debug|x64
+ {7B454EDC-9753-4C2F-B57E-8CC20B8A34C3}.Debug|x86.ActiveCfg = Debug|Win32
+ {7B454EDC-9753-4C2F-B57E-8CC20B8A34C3}.Debug|x86.Build.0 = Debug|Win32
+ {7B454EDC-9753-4C2F-B57E-8CC20B8A34C3}.Release|x64.ActiveCfg = Release|x64
+ {7B454EDC-9753-4C2F-B57E-8CC20B8A34C3}.Release|x64.Build.0 = Release|x64
+ {7B454EDC-9753-4C2F-B57E-8CC20B8A34C3}.Release|x86.ActiveCfg = Release|Win32
+ {7B454EDC-9753-4C2F-B57E-8CC20B8A34C3}.Release|x86.Build.0 = Release|Win32
+ EndGlobalSection
+ GlobalSection(SolutionProperties) = preSolution
+ HideSolutionNode = FALSE
+ EndGlobalSection
+ GlobalSection(ExtensibilityGlobals) = postSolution
+ SolutionGuid = {3012EDE3-A0E6-447E-9127-10B4B953AD2D}
+ EndGlobalSection
+EndGlobal
diff --git a/09_KNN/09_KNN.vcxproj b/09_KNN/09_KNN.vcxproj
new file mode 100644
index 0000000..6648f0d
--- /dev/null
+++ b/09_KNN/09_KNN.vcxproj
@@ -0,0 +1,150 @@
+
+
+
+
+ Debug
+ Win32
+
+
+ Release
+ Win32
+
+
+ Debug
+ x64
+
+
+ Release
+ x64
+
+
+
+ 16.0
+ Win32Proj
+ {7b454edc-9753-4c2f-b57e-8cc20b8a34c3}
+ My09KNN
+ 10.0
+
+
+
+ Application
+ true
+ v142
+ Unicode
+
+
+ Application
+ false
+ v142
+ true
+ Unicode
+
+
+ Application
+ true
+ v142
+ Unicode
+
+
+ Application
+ false
+ v142
+ true
+ Unicode
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ true
+
+
+ false
+
+
+ true
+
+
+ false
+
+
+
+ Level3
+ true
+ WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)
+ true
+
+
+ Console
+ true
+
+
+
+
+ Level3
+ true
+ true
+ true
+ WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)
+ true
+
+
+ Console
+ true
+ true
+ true
+
+
+
+
+ Level3
+ true
+ _DEBUG;_CONSOLE;%(PreprocessorDefinitions)
+ true
+ C:\opencv-4.6.0_X64\build\include
+
+
+ Console
+ true
+ C:\opencv-4.6.0_X64\build\x64\vc15\lib
+ opencv_world460d.lib;%(AdditionalDependencies)
+
+
+
+
+ Level3
+ true
+ true
+ true
+ NDEBUG;_CONSOLE;%(PreprocessorDefinitions)
+ true
+
+
+ Console
+ true
+ true
+ true
+
+
+
+
+
+
+
+
+
\ No newline at end of file
diff --git a/09_KNN/09_KNN.vcxproj.filters b/09_KNN/09_KNN.vcxproj.filters
new file mode 100644
index 0000000..1222a37
--- /dev/null
+++ b/09_KNN/09_KNN.vcxproj.filters
@@ -0,0 +1,22 @@
+
+
+
+
+ {4FC737F1-C7A5-4376-A066-2A32D752A2FF}
+ cpp;c;cc;cxx;c++;cppm;ixx;def;odl;idl;hpj;bat;asm;asmx
+
+
+ {93995380-89BD-4b04-88EB-625FBE52EBFB}
+ h;hh;hpp;hxx;h++;hm;inl;inc;ipp;xsd
+
+
+ {67DA6AB6-F800-4c08-8B7A-83BB121AAD01}
+ rc;ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe;resx;tiff;tif;png;wav;mfcribbon-ms
+
+
+
+
+ 소스 파일
+
+
+
\ No newline at end of file
diff --git a/09_KNN/09_KNN.vcxproj.user b/09_KNN/09_KNN.vcxproj.user
new file mode 100644
index 0000000..88a5509
--- /dev/null
+++ b/09_KNN/09_KNN.vcxproj.user
@@ -0,0 +1,4 @@
+
+
+
+
\ No newline at end of file
diff --git a/09_KNN/digits.png b/09_KNN/digits.png
new file mode 100644
index 0000000..01cdd29
Binary files /dev/null and b/09_KNN/digits.png differ
diff --git a/09_KNN/knn-result1.png b/09_KNN/knn-result1.png
new file mode 100644
index 0000000..ee6124c
Binary files /dev/null and b/09_KNN/knn-result1.png differ
diff --git a/09_KNN/knn-result2.png b/09_KNN/knn-result2.png
new file mode 100644
index 0000000..eb32984
Binary files /dev/null and b/09_KNN/knn-result2.png differ
diff --git a/09_KNN/knn-result3.png b/09_KNN/knn-result3.png
new file mode 100644
index 0000000..7aaf0ec
Binary files /dev/null and b/09_KNN/knn-result3.png differ
diff --git a/09_KNN/knn.cpp b/09_KNN/knn.cpp
new file mode 100644
index 0000000..1340b99
--- /dev/null
+++ b/09_KNN/knn.cpp
@@ -0,0 +1,201 @@
+#include
+#include
+#include
+#include
+//#include
+
+#include
+#include
+
+using namespace std;
+using namespace cv;
+using namespace cv::ml;
+void on_k_changed(int, void*);
+void addPoint(const Point& pt, int cls);
+void trainAndDisplay();
+
+Mat img;
+Mat train, label;
+Ptr knn;
+int k_value = 1;
+
+void kNN()
+{
+ img = Mat::zeros(Size(500, 500), CV_8UC3);
+ knn = KNearest::create();
+
+ namedWindow("knn");
+ //createTrackbar("k", "knn", &k_value, 5, on_k_changed);
+
+ const int NUM = 30;
+ Mat rn(NUM, 2, CV_32SC1);
+
+ randn(rn, 0, 50);
+ for (int i = 0; i < NUM; i++)
+ addPoint(Point(rn.at(i, 0) + 150, rn.at(i, 1) + 150), 0);
+
+ randn(rn, 0, 50);
+ for (int i = 0; i < NUM; i++)
+ addPoint(Point(rn.at(i, 0) + 350, rn.at(i, 1) + 150), 1);
+
+ randn(rn, 0, 70);
+ for (int i = 0; i < NUM; i++)
+ addPoint(Point(rn.at(i, 0) + 250, rn.at(i, 1) + 400), 2);
+
+ createTrackbar("k", "knn", &k_value, 5, on_k_changed);
+ trainAndDisplay();
+ waitKey();
+
+ return;
+}
+
+void on_k_changed(int, void*)
+{
+ if (k_value < 1) k_value = 1;
+ trainAndDisplay();
+}
+
+void addPoint(const Point& pt, int cls)
+{
+ Mat new_sample = (Mat_(1, 2) << pt.x, pt.y);
+ train.push_back(new_sample);
+
+ Mat new_label = (Mat_(1, 1) << cls);
+ label.push_back(new_label);
+}
+
+void trainAndDisplay()
+{
+ knn->train(train, ROW_SAMPLE, label);
+ for (int i = 0; i < img.rows; ++i) {
+ for (int j = 0; j < img.cols; ++j) {
+ Mat sample = (Mat_(1, 2) << j, i);
+ Mat res;
+ knn->findNearest(sample, k_value, res);
+ int response = cvRound(res.at(0, 0));
+ if (response == 0)
+ img.at(i, j) = Vec3b(128, 128, 255); // R
+ else if (response == 1)
+ img.at(i, j) = Vec3b(128, 255, 128); // G
+ else if (response == 2)
+ img.at(i, j) = Vec3b(255, 128, 128); // B
+ }
+ }
+
+ for (int i = 0; i < train.rows; i++)
+ {
+ int x = cvRound(train.at(i, 0));
+ int y = cvRound(train.at(i, 1));
+ int l = label.at(i, 0);
+
+ if (l == 0)
+ circle(img, Point(x, y), 5, Scalar(0, 0, 128), -1, LINE_AA);
+ else if (1 == 1)
+ circle(img, Point(x, y), 5, Scalar(0, 128, 0), -1, LINE_AA);
+ else if (1 == 2)
+ circle(img, Point(x, y), 5, Scalar(128, 0, 0), -1, LINE_AA);
+ }
+
+ imshow("knn", img);
+ imwrite("knn-result1.png", img);
+}
+
+
+///
+
+Ptr train_knn()
+{
+ Mat digits = imread("digits.png", IMREAD_GRAYSCALE);
+ if (digits.empty())
+ {
+ cerr << "Image load failed!" << endl;
+ return 0;
+ }
+
+ Mat train_images, train_labels;
+
+ for (int j = 0; j < 50; j++)
+ {
+ for (int i = 0; i < 100; i++)
+ {
+ Mat roi, roi_float, roi_flatten;
+ roi = digits(Rect(i * 20, j * 20, 20, 20));
+ roi.convertTo(roi_float, CV_32F);
+ roi_flatten = roi_float.reshape(1, 1);
+
+ train_images.push_back(roi_flatten);
+ train_labels.push_back(j / 5);
+ }
+ }
+
+ Ptr knn = KNearest::create();
+ knn->train(train_images, ROW_SAMPLE, train_labels);
+
+ return knn;
+}
+
+Point ptPrev(-1, -1);
+void on_mouse(int event, int x, int y, int flags, void* userdata)
+{
+ Mat img = *(Mat*)userdata;
+
+ if (event == EVENT_LBUTTONDOWN)
+ {
+ ptPrev = Point(x, y);
+ }
+ else if (event == EVENT_LBUTTONUP)
+ {
+ ptPrev = Point(-1, -1);
+ }
+ else if (event == EVENT_MOUSEMOVE && (flags & EVENT_FLAG_LBUTTON))
+ {
+ line(img, ptPrev, Point(x, y), Scalar::all(255), 40, LINE_AA, 0);
+ ptPrev = Point(x, y);
+ imshow("img", img);
+ }
+}
+
+int knn_digits()
+{
+ Ptr knn = train_knn();
+
+ if (knn.empty())
+ {
+ cerr << "Training failed!" << endl;
+ return -1;
+ }
+
+ Mat img = Mat::zeros(400, 400, CV_8U);
+ imshow("img", img);
+ setMouseCallback("img", on_mouse, (void*)&img);
+
+ while (true)
+ {
+ int c = waitKey(0);
+ if (c == 27)
+ break;
+ else if (c == ' ')
+ {
+ Mat img_resize, img_float, img_flatten, res;
+
+ resize(img, img_resize, Size(20, 20), 0, 0, INTER_AREA);
+ img_resize.convertTo(img_float, CV_32F);
+ img_flatten = img_float.reshape(1, 1);
+
+ knn->findNearest(img_flatten, 3, res);
+ cout << cvRound(res.at(0, 0)) << endl;
+
+ img.setTo(0);
+ imshow("img", img);
+ imwrite("knn-result2.png", img);
+ }
+ }
+
+ return 0;
+}
+
+int main()
+{
+ kNN();
+ knn_digits();
+}
\ No newline at end of file
diff --git a/x64/Debug/09_KNN.exe b/x64/Debug/09_KNN.exe
new file mode 100644
index 0000000..b5b6cfb
Binary files /dev/null and b/x64/Debug/09_KNN.exe differ
diff --git a/x64/Debug/09_KNN.pdb b/x64/Debug/09_KNN.pdb
new file mode 100644
index 0000000..2d9c59c
Binary files /dev/null and b/x64/Debug/09_KNN.pdb differ
diff --git a/x64/Debug/opencv_world460d.dll b/x64/Debug/opencv_world460d.dll
new file mode 100644
index 0000000..6921313
Binary files /dev/null and b/x64/Debug/opencv_world460d.dll differ