From 49d5cbbb6832dfaf1110d70f7a35097039dc9c27 Mon Sep 17 00:00:00 2001
From: Salman <salman@tunacode.com>
Date: Sun, 7 Sep 2014 13:41:26 +0500
Subject: [PATCH] added check for number of channels in fetching pixel value.
 Addresses issue #147

---
 examples/convert_image.js |  2 ++
 src/Matrix.cc             | 32 ++++++++++++++++++++++----------
 2 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/examples/convert_image.js b/examples/convert_image.js
index eeb88da..0f130ae 100755
--- a/examples/convert_image.js
+++ b/examples/convert_image.js
@@ -9,6 +9,8 @@ cv.readImage("./mona.png", function(err, im) {
 				img_hsv.convertHSVscale();
 				img_gray.convertGrayscale();
 
+				console.log(img_gray.pixel(100,100));
+
 				im.save("/tmp/nor.png");
 				img_hsv.save("/tmp/hsv.png");
 				img_gray.save("/tmp/gray.png");
diff --git a/src/Matrix.cc b/src/Matrix.cc
index c94064f..6dc9ea6 100755
--- a/src/Matrix.cc
+++ b/src/Matrix.cc
@@ -212,19 +212,32 @@ Matrix::Pixel(const Arguments& args){
 
 		Local<Object> objColor = args[2]->ToObject();
 
-		self->mat.at<cv::Vec3b>(y, x)[0] =  (uchar) objColor->Get(0)->IntegerValue();
-		self->mat.at<cv::Vec3b>(y, x)[1] =  (uchar) objColor->Get(1)->IntegerValue();
-		self->mat.at<cv::Vec3b>(y, x)[2] =  (uchar) objColor->Get(2)->IntegerValue();
+		if(self->mat.channels() == 3){
+			self->mat.at<cv::Vec3b>(y, x)[0] =  (uchar) objColor->Get(0)->IntegerValue();
+			self->mat.at<cv::Vec3b>(y, x)[1] =  (uchar) objColor->Get(1)->IntegerValue();
+			self->mat.at<cv::Vec3b>(y, x)[2] =  (uchar) objColor->Get(2)->IntegerValue();
+		}
+		else if(self->mat.channels() == 1)
+			self->mat.at<uchar>(y,x) = (uchar) objColor->Get(0)->IntegerValue();
+
 		return scope.Close(args[2]->ToObject());
 	}else{
-		cv::Vec3b intensity = self->mat.at<cv::Vec3b>(y, x);
 
-		v8::Local<v8::Array> arr = v8::Array::New(3);
-		arr->Set(0, Number::New( intensity[0] ));
-		arr->Set(1, Number::New( intensity[1] ));
-		arr->Set(2, Number::New( intensity[2] ));
-		return scope.Close(arr);
+		if(self->mat.channels() == 3){
+			cv::Vec3b intensity = self->mat.at<cv::Vec3b>(y, x);
 
+			v8::Local<v8::Array> arr = v8::Array::New(3);
+			arr->Set(0, Number::New( intensity[0] ));
+			arr->Set(1, Number::New( intensity[1] ));
+			arr->Set(2, Number::New( intensity[2] ));
+			return scope.Close(arr);
+		}
+		else if(self->mat.channels() == 1){
+
+			uchar intensity = self->mat.at<uchar>(y, x);
+			return scope.Close(Number::New(intensity));
+
+		}
 	}
 
 	return scope.Close(Undefined());
@@ -305,7 +318,6 @@ Matrix::Clone(const Arguments& args){
   return scope.Close(im_h);
 }
 
-
 Handle<Value>
 Matrix::Row(const Arguments& args){
 	SETUP_FUNCTION(Matrix)