/// <summary>
/// Convert a 3 channel BGR Mat to a Tensor
/// </summary>
/// <param name="image">The input Emgu CV Mat</param>
/// <param name="inputHeight">The height of the image in the output tensor, if it is -1, the height will not be changed.</param>
/// <param name="inputWidth">The width of the image in the output tensor, if it is -1, the width will not be changed.</param>
/// <param name="inputMean">The mean, if it is not 0, the value will be substracted from the pixel values</param>
/// <param name="scale">The optional scale</param>
/// <param name="dataType">The type of the data in the tensor</param>
/// <param name="status">The tensorflow status</param>
/// <returns>The tensorflow tensor</returns>
public static Tensor ReadTensorFromMatBgr(Mat image, DataType dataType, int inputHeight = -1, int inputWidth = -1, float inputMean = 0.0f, float scale = 1.0f, Status status = null)
{
if (image.NumberOfChannels != 3)
{
throw new ArgumentException("Input must be 3 channel BGR image");
}
Emgu.CV.CvEnum.DepthType depth = image.Depth;
if (!(depth == Emgu.CV.CvEnum.DepthType.Cv8U || depth == Emgu.CV.CvEnum.DepthType.Cv32F))
{
throw new ArgumentException("Input image must be 8U or 32F");
}
//resize
int finalHeight = inputHeight == -1 ? image.Height : inputHeight;
int finalWidth = inputWidth == -1 ? image.Width : inputWidth;
Size finalSize = new Size(finalWidth, finalHeight);
if (image.Size != finalSize)
{
using (Mat tmp = new Mat())
{
CvInvoke.Resize(image, tmp, finalSize);
return(ReadTensorFromMatBgr(tmp, inputMean, scale, dataType));
}
}
else
{
return(ReadTensorFromMatBgr(image, inputMean, scale, dataType));
}
}
private static dynamic CreateElement(Emgu.CV.CvEnum.DepthType depthType)
{
if (depthType == Emgu.CV.CvEnum.DepthType.Cv8S)
{
return(new sbyte[1]);
}
if (depthType == Emgu.CV.CvEnum.DepthType.Cv8U)
{
return(new byte[1]);
}
if (depthType == Emgu.CV.CvEnum.DepthType.Cv16S)
{
return(new short[1]);
}
if (depthType == Emgu.CV.CvEnum.DepthType.Cv16U)
{
return(new ushort[1]);
}
if (depthType == Emgu.CV.CvEnum.DepthType.Cv32S)
{
return(new int[1]);
}
if (depthType == Emgu.CV.CvEnum.DepthType.Cv32F)
{
return(new float[1]);
}
if (depthType == Emgu.CV.CvEnum.DepthType.Cv64F)
{
return(new double[1]);
}
return(new float[1]);
}
private static dynamic CreateElement(Emgu.CV.CvEnum.DepthType depthType, dynamic value)
{
var element = CreateElement(depthType);
element[0] = value;
return(element);
}
/// <summary>
/// Public interface to convert a 3 channel BGR Mat to a Tensor.
/// BGR Mat are Emgu.CV.Mat objects. Tensor are Emgu.TF.Lite.Tensor objects.
/// NB: This function will resize the BGR mat to match the Tensor spatial dimensions if necessary.
///
/// Stolen from https://github.com/emgucv/emgutf/blob/master/Emgu.TF.Example/CVInterop/TensorConvert.cs
/// </summary>
/// <param name="image">The input Emgu CV Mat</param>
/// <param name="tensor">The pre-allocated output tensor. Dimension must match (1, inputHeight, inputWidth, 3)</param>
/// <param name="inputHeight">The height of the image in the output tensor, if it is -1, the height will not be changed.</param>
/// <param name="inputWidth">The width of the image in the output tensor, if it is -1, the width will not be changed.</param>
/// <param name="inputMean">The mean, if it is not 0, the value will be substracted from the pixel values</param>
/// <param name="scale">The optional scale</param>
/// <returns>The tensorflow tensor</returns>
public static void ReadTensorFromMatBgr(Mat image, Tensor tensor, int inputHeight = -1, int inputWidth = -1, float inputMean = 0.0f, float scale = 1.0f)
{
if (image.NumberOfChannels != 3)
{
throw new ArgumentException("Input must be 3 channel BGR image");
}
Emgu.CV.CvEnum.DepthType depth = image.Depth;
if (!(depth == Emgu.CV.CvEnum.DepthType.Cv8U || depth == Emgu.CV.CvEnum.DepthType.Cv32F))
{
throw new ArgumentException("Input image must be 8U or 32F");
}
//resize
int finalHeight = inputHeight == -1 ? image.Height : inputHeight;
int finalWidth = inputWidth == -1 ? image.Width : inputWidth;
Size finalSize = new Size(finalWidth, finalHeight);
int[] dim = tensor.Dims;
if (dim[0] != 1)
{
throw new ArgumentException("First dimension of the tensor must be 1 (batch size)");
}
if (dim[1] != finalHeight)
{
throw new ArgumentException("Second dimension of the tensor must match the input height");
}
if (dim[2] != finalWidth)
{
throw new ArgumentException("Third dimension of the tensor must match the input width");
}
if (dim[3] != 3)
{
throw new ArgumentException("Fourth dimension of the tensor must be 3 (BGR has 3 channels)");
}
if (image.Size != finalSize)
{
using (Mat tmp = new Mat())
{
CvInvoke.Resize(image, tmp, finalSize);
ReadTensorFromMatBgr(tmp, inputMean, scale, tensor);
tmp.Dispose();
}
}
else
{
ReadTensorFromMatBgr(image, inputMean, scale, tensor);
}
}
