Notes for Anu

https://stackoverflow.com/questions/45305957/modifying-a-function-in-opencv-and-emgucv-by-adding-extra-parameter


Original OpenCV filter2D signature:

CV_EXPORTS_W void filter2D(InputArray src
    , OutputArray dst
    , int ddepth
    , InputArray kernel
    , Point anchor = Point(-1,-1)
    , double delta = 0
    , int borderType = BORDER_DEFAULT);

Modified OpenCV filter2D signature (according to your comment, an extra integer parameter):

CV_EXPORTS_W void filter2D(InputArray src
    , OutputArray dst
    , int ddepth
    , InputArray kernel
    , Point anchor = Point(-1,-1)
    , double delta = 0
    , int borderType = BORDER_DEFAULT
    , int extra = 0);




Let's begin with https://github.com/emgucv/emgucv/blob/master/Emgu.CV.Extern/imgproc/imgproc_c.cpp#L24

void cveFilter2D( cv::_InputArray* src, cv::_OutputArray* dst, cv::_InputArray* kernel, CvPoint* anchor, double delta, int borderType )
{
    CV_Assert( src->size() == dst->size() && src->channels() == dst->channels() );
    cv::filter2D( *src, *dst, dst->depth(), *kernel, *anchor, delta, borderType );
}

becomes

void cveFilter2D( cv::_InputArray* src, cv::_OutputArray* dst, cv::_InputArray* kernel, CvPoint* anchor, double delta, int borderType, int extra )
{
    CV_Assert( src->size() == dst->size() && src->channels() == dst->channels() );
    cv::filter2D( *src, *dst, dst->depth(), *kernel, *anchor, delta, borderType, extra );
}



We also need to change the associated header: https://github.com/emgucv/emgucv/blob/master/Emgu.CV.Extern/imgproc/imgproc_c.h#L21

CVAPI(void) cveFilter2D(cv::_InputArray* src, cv::_OutputArray* dst, cv::_InputArray* kernel, CvPoint* anchor, double delta, int borderType );

becomes

CVAPI(void) cveFilter2D(cv::_InputArray* src, cv::_OutputArray* dst, cv::_InputArray* kernel, CvPoint* anchor, double delta, int borderType, int extra );



Next, https://github.com/emgucv/emgucv/blob/master/Emgu.CV/PInvoke/CvInvokeCvextern.cs

First, let's fix the dll import https://github.com/emgucv/emgucv/blob/master/Emgu.CV/PInvoke/CvInvokeCvextern.cs#L244

    [DllImport(ExternLibrary, CallingConvention = CvInvoke.CvCallingConvention)]
    private static extern void cveFilter2D(IntPtr src, IntPtr dst, IntPtr kernel, ref Point anchor, double delta, Emgu.CV.CvEnum.BorderType borderType);

becomes

    [DllImport(ExternLibrary, CallingConvention = CvInvoke.CvCallingConvention)]
    private static extern void cveFilter2D(IntPtr src, IntPtr dst, IntPtr kernel, ref Point anchor, double delta, Emgu.CV.CvEnum.BorderType borderType, int extra);



Now the wrapper function: https://github.com/emgucv/emgucv/blob/master/Emgu.CV/PInvoke/CvInvokeCvextern.cs#L226

public static void Filter2D(IInputArray src, IOutputArray dst, IInputArray kernel, Point anchor, double delta = 0,
Emgu.CV.CvEnum.BorderType borderType = CvEnum.BorderType.Default)
{
    using (InputArray iaSrc = src.GetInputArray())
    using (OutputArray oaDst = dst.GetOutputArray())
    using (InputArray iaKernel = kernel.GetInputArray())
    cveFilter2D(iaSrc, oaDst, iaKernel, ref anchor, delta, borderType);
}

becomes (you can fix the documentation comments yourself)


public static void Filter2D(IInputArray src, IOutputArray dst, IInputArray kernel, Point anchor, double delta = 0,
Emgu.CV.CvEnum.BorderType borderType = CvEnum.BorderType.Default, int extra = 0)
{
    using (InputArray iaSrc = src.GetInputArray())
    using (OutputArray oaDst = dst.GetOutputArray())
    using (InputArray iaKernel = kernel.GetInputArray())
    cveFilter2D(iaSrc, oaDst, iaKernel, ref anchor, delta, borderType, extra);
}



Finally, Image:  https://github.com/emgucv/emgucv/blob/master/Emgu.CV/Image.cs#L3653


public Image<TColor, Single> Convolution(ConvolutionKernelF kernel)
{
    Image<TColor, Single> floatImage =
       (typeof(TDepth) == typeof(Single)) ?
       this as Image<TColor, Single>
       : Convert<TColor, Single>();

    Image<TColor, Single> res = new Image<TColor, Single>(Size);
    ForEachDuplicateChannel(
       delegate (IImage srcFloat, IImage dest, int channel)
       {

           //perform the convolution operation
           CvInvoke.Filter2D(
               srcFloat,
               dest,
               kernel,
               kernel.Center,
               0);

       },
       res);

    if (!object.ReferenceEquals(floatImage, this))
        floatImage.Dispose();

    return res;
}



becomes something like this perhaps:


public Image<TColor, Single> Convolution(ConvolutionKernelF kernel, int extra = 0)
{
    Image<TColor, Single> floatImage =
       (typeof(TDepth) == typeof(Single)) ?
       this as Image<TColor, Single>
       : Convert<TColor, Single>();

    Image<TColor, Single> res = new Image<TColor, Single>(Size);
    ForEachDuplicateChannel(
       delegate (IImage srcFloat, IImage dest, int channel)
       {

           //perform the convolution operation
           CvInvoke.Filter2D(
               srcFloat,
               dest,
               kernel,
               kernel.Center,
               0,
               CvEnum.BorderType.Default,
               extra);

       },
       res);

    if (!object.ReferenceEquals(floatImage, this))
        floatImage.Dispose();

    return res;
}