Problem in OpenCV

[hatem faheem]

Hi,
I'm Hatem Faheem
An Egyptian student in Computer Engineering, Cairo university

I have a small problem in implementing a code that sharpen an image
here is the code

void Sharpen(const cv::Mat& myImage,cv::Mat& Result)
{
	Result.create(myImage.size(),myImage.type());

	for(int j=1;j<myImage.rows-1;j++)
	{
		const uchar* previous = myImage.ptr<uchar>(j-1);
		const uchar* current  = myImage.ptr<uchar>(j);
		const uchar* next     = myImage.ptr<uchar>(j+1);
		uchar* output = Result.ptr<uchar>(j);

		for(int i=1;i<myImage.cols-1;i++)
		{
			*output++ = cv::saturate_cast<uchar>(5*current[i]-current[i-1]-previous[i]-next[i]);
		}

		Result.row(0).setTo(cv::Scalar(0));
		Result.row(Result.rows-1).setTo(cv::Scalar(0));
		Result.col(0).setTo(cv::Scalar(0));
		Result.col(Result.cols-1).setTo(cv::Scalar(0));
	}
}

when I apply this function to a gray-level image just abput 20% of it appears on the left the rest of the image is disappeared

here's an image shows the original image and the output image
http://www.imageupload.org/?d=1A0AC61F1

Thank You,