public static NDArray Im2Col(NDArray x, Tuple <uint, uint> kernalSize, int padding = 1, uint stride = 1, Tuple <uint, uint> dialation = null)
{
if (dialation == null)
{
dialation = Tuple.Create <uint, uint>(1, 1);
}
var(n, c, h, w) = x.GetConv2DShape();
var out_height = (h + 2 * padding - kernalSize.Item1) / stride + 1;
var out_width = (w + 2 * padding - kernalSize.Item2) / stride + 1;
NDArray cols = new NDArray(DeviceManager.Current, DType.Float32, (c * kernalSize.Item1 * kernalSize.Item2), (n * out_height * out_width));
if (DeviceManager.IsCuda)
{
Im2ColCuda im2ColKernels = new Im2ColCuda();
im2ColKernels.Im2Col(x, cols, (int)c, (int)h, (int)w, (int)kernalSize.Item1, (int)kernalSize.Item2,
padding, padding, (int)stride, (int)stride, (int)dialation.Item1, (int)dialation.Item2);
}
else
{
Im2ColCpu im2ColKernels = new Im2ColCpu();
im2ColKernels.Im2Cols(x, cols, (int)c, (int)h, (int)w, (int)kernalSize.Item1, (int)kernalSize.Item2,
padding, padding, (int)stride, (int)stride, (int)dialation.Item1, (int)dialation.Item2);
}
return(cols);
}