public void TestGreyscaleTransformImages()
{
IHostEnvironment env = new MLContext();
var imageHeight = 150;
var imageWidth = 100;
var dataFile = GetDataPath("images/images.tsv");
var imageFolder = Path.GetDirectoryName(dataFile);
var data = TextLoader.Create(env, new TextLoader.Arguments()
{
Columns = new[]
{
new TextLoader.Column("ImagePath", DataKind.TX, 0),
new TextLoader.Column("Name", DataKind.TX, 1),
}
}, new MultiFileSource(dataFile));
var images = new ImageLoaderTransformer(env, imageFolder, ("ImageReal", "ImagePath")).Transform(data);
var cropped = new ImageResizerTransformer(env, "ImageCropped", imageWidth, imageHeight, "ImageReal").Transform(images);
IDataView grey = new ImageGrayscaleTransformer(env, ("ImageGrey", "ImageCropped")).Transform(cropped);
var fname = nameof(TestGreyscaleTransformImages) + "_model.zip";
var fh = env.CreateOutputFile(fname);
using (var ch = env.Start("save"))
TrainUtils.SaveModel(env, ch, fh, null, new RoleMappedData(grey));
grey = ModelFileUtils.LoadPipeline(env, fh.OpenReadStream(), new MultiFileSource(dataFile));
DeleteOutputPath(fname);
grey.Schema.TryGetColumnIndex("ImageGrey", out int greyColumn);
using (var cursor = grey.GetRowCursorForAllColumns())
{
var bitmapGetter = cursor.GetGetter <Bitmap>(greyColumn);
Bitmap bitmap = default;
while (cursor.MoveNext())
{
bitmapGetter(ref bitmap);
Assert.NotNull(bitmap);
for (int x = 0; x < imageWidth; x++)
{
for (int y = 0; y < imageHeight; y++)
{
var pixel = bitmap.GetPixel(x, y);
// greyscale image has same values for R,G and B
Assert.True(pixel.R == pixel.G && pixel.G == pixel.B);
}
}
}
}
Done();
}
public static CommonOutputs.TransformOutput ImageGrayscale(IHostEnvironment env, ImageGrayscaleTransformer.Arguments input)
{
var h = EntryPointUtils.CheckArgsAndCreateHost(env, "ImageGrayscaleTransform", input);
var xf = ImageGrayscaleTransformer.Create(h, input, input.Data);
return(new CommonOutputs.TransformOutput()
{
Model = new TransformModelImpl(h, xf, input.Data),
OutputData = xf
});
}
public Mapper(ImageGrayscaleTransformer parent, Schema inputSchema)
: base(parent.Host.Register(nameof(Mapper)), parent, inputSchema)
{
_parent = parent;
}
