openCV/OpenCV/OpenCVClass.cs

using OpenCvSharp;
using System;

namespace OpenCV
{
    class OpenCVClass : IDisposable
    {
        IplImage gray;

        public IplImage GrayScale(IplImage src)
        {
            gray = new IplImage(src.Size, BitDepth.U8, 1);
            Cv.CvtColor(src, gray, ColorConversion.BgrToGray);
            return gray;
        }

        public void Dispose()
        {
            if (gray != null)
                Cv.ReleaseImage(gray);
        }
    }
}