Add LDA SubspaceProject and SubspaceReconstruct functions

binding.gyp

@@ -19,7 +19,8 @@
         "src/Constants.cc",
         "src/Calib3D.cc",
         "src/ImgProc.cc",
-        "src/Stereo.cc"
+        "src/Stereo.cc",
+        "src/LDAWrap.cc"
       ],
 
       "libraries": [

src/LDAWrap.cc

@@ -0,0 +1,94 @@
+#include "LDAWrap.h"
+#include "OpenCV.h"
+
+#if ((CV_MAJOR_VERSION >= 2) && (CV_MINOR_VERSION >=4) && (CV_SUBMINOR_VERSION>=4))
+
+#include "Matrix.h"
+#include <nan.h>
+
+Nan::Persistent<FunctionTemplate> LDAWrap::constructor;
+
+void LDAWrap::Init(Local<Object> target) {
+  Nan::HandleScope scope;
+
+  // Constructor
+  Local<FunctionTemplate> ctor = Nan::New<FunctionTemplate>(LDAWrap::New);
+  constructor.Reset(ctor);
+  ctor->InstanceTemplate()->SetInternalFieldCount(1);
+  ctor->SetClassName(Nan::New("LDA").ToLocalChecked());
+
+  Nan::SetPrototypeMethod(ctor, "subspaceProject", SubspaceProject);
+  Nan::SetPrototypeMethod(ctor, "subspaceReconstruct", SubspaceReconstruct);
+
+  target->Set(Nan::New("LDA").ToLocalChecked(), ctor->GetFunction());
+};
+
+NAN_METHOD(LDAWrap::New) {
+  Nan::HandleScope scope;
+
+  if (info.This()->InternalFieldCount() == 0) {
+    JSTHROW_TYPE("Cannot Instantiate without new")
+  }
+
+  LDAWrap *pt = new LDAWrap();
+
+  pt->Wrap(info.This());
+  info.GetReturnValue().Set(info.This());
+}
+
+LDAWrap::LDAWrap() {
+}
+
+/**
+ * http://docs.opencv.org/master/db/d59/classcv_1_1LDA.html#a69c7019a344edc5c55799c16a9fc9ada
+ */
+NAN_METHOD(LDAWrap::SubspaceProject) {
+  if (info.Length() != 3) {
+    JSTHROW("SubspaceProject function requires 3 arguments")
+  }
+
+  // param 0 - eigenvectors
+  Matrix *w = Nan::ObjectWrap::Unwrap<Matrix>(info[0]->ToObject());
+
+  // param 1 - mean
+  Matrix *mean = Nan::ObjectWrap::Unwrap<Matrix>(info[1]->ToObject());
+
+  // param 2 - src
+  Matrix *src = Nan::ObjectWrap::Unwrap<Matrix>(info[2]->ToObject());
+
+  cv::Mat m = cv::subspaceProject(w->mat, mean->mat, src->mat);
+
+  Local<Object> im = Nan::New(Matrix::constructor)->GetFunction()->NewInstance();
+  Matrix *img = Nan::ObjectWrap::Unwrap<Matrix>(im);
+  img->mat = m;
+
+  info.GetReturnValue().Set(im);
+}
+
+/**
+ * http://docs.opencv.org/master/db/d59/classcv_1_1LDA.html#acbf9949e7567e23af5f71c29fcef76d4
+ */
+NAN_METHOD(LDAWrap::SubspaceReconstruct) {
+  if (info.Length() != 3) {
+    JSTHROW("SubspaceReconstruct function requires 3 arguments")
+  }
+
+  // param 0 - eigenvectors
+  Matrix *w = Nan::ObjectWrap::Unwrap<Matrix>(info[0]->ToObject());
+
+  // param 1 - mean
+  Matrix *mean = Nan::ObjectWrap::Unwrap<Matrix>(info[1]->ToObject());
+
+  // param 2 - src
+  Matrix *src = Nan::ObjectWrap::Unwrap<Matrix>(info[2]->ToObject());
+
+  cv::Mat m = cv::subspaceReconstruct(w->mat, mean->mat, src->mat);
+
+  Local<Object> im = Nan::New(Matrix::constructor)->GetFunction()->NewInstance();
+  Matrix *img = Nan::ObjectWrap::Unwrap<Matrix>(im);
+  img->mat = m;
+
+  info.GetReturnValue().Set(im);
+}
+
+#endif // End version > 2.4

src/LDAWrap.h

@@ -0,0 +1,19 @@
+#include "OpenCV.h"
+
+#if ((CV_MAJOR_VERSION >= 2) && (CV_MINOR_VERSION >=4))
+
+#include "opencv2/contrib/contrib.hpp"
+
+class LDAWrap: public Nan::ObjectWrap {
+public:
+  static Nan::Persistent<FunctionTemplate> constructor;
+  static void Init(Local<Object> target);
+  static NAN_METHOD(New);
+
+  LDAWrap();
+
+  JSFUNC(SubspaceProject)
+  JSFUNC(SubspaceReconstruct)
+};
+
+#endif

src/init.cc

@@ -14,6 +14,7 @@
 #include "ImgProc.h"
 #include "Stereo.h"
 #include "BackgroundSubtractor.h"
+#include "LDAWrap.h"
 
 extern "C" void init(Local<Object> target) {
   Nan::HandleScope scope;
@@ -37,6 +38,7 @@ extern "C" void init(Local<Object> target) {
   BackgroundSubtractorWrap::Init(target);
   Features::Init(target);
   FaceRecognizerWrap::Init(target);
+  LDAWrap::Init(target);
 #endif
 };