This article describes how to convert C# Bitmap to Opencv Mat.
Convert C# Bitmap to Opencv Mat
If you already know how to create and configure CLI project in visual studio, simply use following function in CLI project to convert Opencv Mat to C# Bitmap.
System::Drawing::Bitmap^ MatToBitmap(Mat srcImg){
int stride = srcImg.size().width * srcImg.channels();//calc the srtide
int hDataCount = srcImg.size().height;
System::Drawing::Bitmap^ retImg;
System::IntPtr ptr(srcImg.data);
//create a pointer with Stride
if (stride % 4 != 0){//is not stride a multiple of 4?
//make it a multiple of 4 by fiiling an offset to the end of each row
//to hold processed data uchar *dataPro = new uchar[((srcImg.size().width * srcImg.channels() + 3) & -4) * hDataCount];
uchar *data = srcImg.ptr();
//current position on the data array
int curPosition = 0;
//current offset
int curOffset = 0;
int offsetCounter = 0;
//itterate through all the bytes on the structure
for (int r = 0; r < hDataCount; r++){
//fill the data
for (int c = 0; c < stride; c++){
curPosition = (r * stride) + c;
dataPro[curPosition + curOffset] = data[curPosition];
}
//reset offset counter
offsetCounter = stride;
//fill the offset
do{
curOffset += 1;
dataPro[curPosition + curOffset] = 0;
offsetCounter += 1;
} while (offsetCounter % 4 != 0);
}
ptr = (System::IntPtr)dataPro;//set the data pointer to new/modified data array
//calc the stride to nearest number which is a multiply of 4
stride = (srcImg.size().width * srcImg.channels() + 3) & -4;
retImg = gcnew System::Drawing::Bitmap(srcImg.size().width, srcImg.size().height,
stride,
System::Drawing::Imaging::PixelFormat::Format24bppRgb,
ptr);
}
else{
//no need to add a padding or recalculate the stride
retImg = gcnew System::Drawing::Bitmap(srcImg.size().width, srcImg.size().height,
stride,
System::Drawing::Imaging::PixelFormat::Format24bppRgb,
ptr);
}
array^ imageData;
System::Drawing::Bitmap^ output;
// Create the byte array.
{
System::IO::MemoryStream^ ms = gcnew System::IO::MemoryStream();
retImg->Save(ms, System::Drawing::Imaging::ImageFormat::Png);
imageData = ms->ToArray();
delete ms;
}
// Convert back to bitmap
{
System::IO::MemoryStream^ ms = gcnew System::IO::MemoryStream(imageData);
output = (System::Drawing::Bitmap^)System::Drawing::Bitmap::FromStream(ms);
}
return output;
}
