public void TestBackAndForthConversionWithAlphaNoInterleaveNoOffset() { IHostEnvironment env = new MLContext(); const int imageHeight = 100; var imageWidth = 130; var dataFile = GetDataPath("images/images.tsv"); var imageFolder = Path.GetDirectoryName(dataFile); var data = TextLoader.Create(env, new TextLoader.Arguments() { Column = new[] { new TextLoader.Column("ImagePath", DataKind.TX, 0), new TextLoader.Column("Name", DataKind.TX, 1), } }, new MultiFileSource(dataFile)); var images = ImageLoaderTransform.Create(env, new ImageLoaderTransform.Arguments() { Column = new ImageLoaderTransform.Column[1] { new ImageLoaderTransform.Column() { Source = "ImagePath", Name = "ImageReal" } }, ImageFolder = imageFolder }, data); var cropped = ImageResizerTransform.Create(env, new ImageResizerTransform.Arguments() { Column = new ImageResizerTransform.Column[1] { new ImageResizerTransform.Column() { Source = "ImageReal", Name = "ImageCropped", ImageHeight = imageHeight, ImageWidth = imageWidth, Resizing = ImageResizerTransform.ResizingKind.IsoCrop } } }, images); var pixels = ImagePixelExtractorTransform.Create(env, new ImagePixelExtractorTransform.Arguments() { InterleaveArgb = false, Column = new ImagePixelExtractorTransform.Column[1] { new ImagePixelExtractorTransform.Column() { Source = "ImageCropped", Name = "ImagePixels", UseAlpha = true } } }, cropped); IDataView backToBitmaps = new VectorToImageTransform(env, new VectorToImageTransform.Arguments() { InterleaveArgb = false, Column = new VectorToImageTransform.Column[1] { new VectorToImageTransform.Column() { Source = "ImagePixels", Name = "ImageRestored", ImageHeight = imageHeight, ImageWidth = imageWidth, ContainsAlpha = true } } }, pixels); var fname = nameof(TestBackAndForthConversionWithAlphaNoInterleaveNoOffset) + "_model.zip"; var fh = env.CreateOutputFile(fname); using (var ch = env.Start("save")) TrainUtils.SaveModel(env, ch, fh, null, new RoleMappedData(backToBitmaps)); backToBitmaps = ModelFileUtils.LoadPipeline(env, fh.OpenReadStream(), new MultiFileSource(dataFile)); DeleteOutputPath(fname); backToBitmaps.Schema.TryGetColumnIndex("ImageRestored", out int bitmapColumn); backToBitmaps.Schema.TryGetColumnIndex("ImageCropped", out int cropBitmapColumn); using (var cursor = backToBitmaps.GetRowCursor((x) => true)) { var bitmapGetter = cursor.GetGetter <Bitmap>(bitmapColumn); Bitmap restoredBitmap = default; var bitmapCropGetter = cursor.GetGetter <Bitmap>(cropBitmapColumn); Bitmap croppedBitmap = default; while (cursor.MoveNext()) { bitmapGetter(ref restoredBitmap); Assert.NotNull(restoredBitmap); bitmapCropGetter(ref croppedBitmap); Assert.NotNull(croppedBitmap); for (int x = 0; x < imageWidth; x++) { for (int y = 0; y < imageHeight; y++) { var c = croppedBitmap.GetPixel(x, y); var r = restoredBitmap.GetPixel(x, y); Assert.True(c == r); } } } } Done(); }