private static void RandomlyCropImage(Matrix <RgbPixel> inputImage, Matrix <ushort> labelImage, TrainingSample crop, Rand rnd)
{
var rect = MakeRandomCroppingRectResNet(inputImage, rnd);
using (var chipDims = new ChipDims(227, 227))
using (var chipDetails = new ChipDetails(rect, chipDims))
{
// Crop the input image.
crop.InputImage = Dlib.ExtractImageChip <RgbPixel>(inputImage, chipDetails, InterpolationTypes.Bilinear);
// Crop the labels correspondingly. However, note that here bilinear
// interpolation would make absolutely no sense - you wouldn't say that
// a bicycle is half-way between an aeroplane and a bird, would you?
crop.LabelImage = Dlib.ExtractImageChip <ushort>(labelImage, chipDetails, InterpolationTypes.NearestNeighbor);
// Also randomly flip the input image and the labels.
if (rnd.GetRandomDouble() > 0.5)
{
var tmpInput = Dlib.FlipLR(crop.InputImage);
var tmpLabel = Dlib.FlipLR(crop.LabelImage);
crop.InputImage?.Dispose();
crop.LabelImage?.Dispose();
crop.InputImage = tmpInput;
crop.LabelImage = tmpLabel;
}
// And then randomly adjust the colors.
Dlib.ApplyRandomColorOffset(crop.InputImage, rnd);
}
}