Remove the System.Drawing dependency

THIRD-PARTY-NOTICES.TXT

@@ -84,4 +84,4 @@ Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
-limitations under the License.
+limitations under the License.

build/ci/job-template.yml

@@ -68,11 +68,11 @@ jobs:
     steps:
     # Extra MacOS step required to install OS-specific dependencies
     - ${{ if and(contains(parameters.pool.vmImage, 'macOS'), not(contains(parameters.name, 'cross')))  }}:
-      - script: export HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK=TRUE && brew update && brew install mono-libgdiplus && brew unlink libomp && brew install $(Build.SourcesDirectory)/build/libomp.rb --build-from-source --formula
+      - script: export HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK=TRUE && brew update && brew unlink libomp && brew install $(Build.SourcesDirectory)/build/libomp.rb --build-from-source --formula
         displayName: Install MacOS build dependencies
     # Extra Apple MacOS step required to install OS-specific dependencies
     - ${{ if and(contains(parameters.pool.vmImage, 'macOS'), contains(parameters.name, 'cross'))  }}:
-      - script: brew update && brew install mono-libgdiplus && brew install libomp && brew link libomp --force
+      - script: brew update && brew install libomp && brew link libomp --force
         displayName: Install MacOS ARM build dependencies
     - ${{ if and( eq(parameters.nightlyBuild, 'true'), eq(parameters.pool.vmImage, 'ubuntu-18.04')) }}:
       - bash: echo "##vso[task.setvariable variable=LD_LIBRARY_PATH]$(nightlyBuildRunPath):$LD_LIBRARY_PATH"

build/vsts-ci.yml

@@ -121,7 +121,7 @@ jobs:
   pool:
     vmImage: macOS-12
   steps:
-  - script: brew update && brew unlink [email protected] && brew install mono-libgdiplus && brew install $(Build.SourcesDirectory)/build/libomp.rb --build-from-source --formula && brew link libomp --force
+  - script: brew update && brew unlink [email protected] && brew install $(Build.SourcesDirectory)/build/libomp.rb --build-from-source --formula && brew link libomp --force
     displayName: Install build dependencies
   - script: ./restore.sh
     displayName: restore all projects
@@ -157,7 +157,7 @@ jobs:
       rm -rf /usr/local/bin/2to3
     displayName: MacOS Homebrew bug Workaround
     continueOnError: true
-  - script: brew update && brew unlink [email protected] && brew install mono-libgdiplus && brew install libomp && brew link libomp --force
+  - script: brew update && brew unlink [email protected] && brew install libomp && brew link libomp --force
     displayName: Install build dependencies
   - script: ./restore.sh
     displayName: restore all projects

docs/building/unix-instructions.md

@@ -65,13 +65,12 @@ macOS 10.13 (High Sierra) or higher is needed to build dotnet/machinelearning. W
 On macOS a few components are needed which are not provided by a default developer setup:
 * cmake 3.10.3
 * libomp 7
-* libgdiplus
 * gettext
 * All the requirements necessary to run .NET Core 3.1 applications. To view macOS prerequisites click [here](https://docs.microsoft.com/en-us/dotnet/core/install/macos?tabs=netcore31#dependencies).
 
 One way of obtaining CMake and other required libraries is via [Homebrew](https://brew.sh):
 ```sh
-$ brew update && brew install cmake https://github.com/raw/dotnet/machinelearning/main/build/libomp.rb mono-libgdiplus gettext && brew link gettext --force && brew link libomp --force
+$ brew update && brew install cmake https://github.com/raw/dotnet/machinelearning/main/build/libomp.rb gettext && brew link gettext --force && brew link libomp --force
 ```
 
 Please note that newer versions of Homebrew [don't allow installing directly from a URL](https://github.com/Homebrew/brew/issues/8791). If you run into this issue, you may need to download libomp.rb first and install it with the local file instead.

docs/samples/Microsoft.ML.Samples/Dynamic/Trainers/MulticlassClassification/ImageClassification/LearningRateSchedulingCifarResnetTransferLearning.cs

@@ -78,10 +78,10 @@ public static void Example()
             {
                 FeatureColumnName = "Image",
                 LabelColumnName = "Label",
-                // Just by changing/selecting InceptionV3/MobilenetV2 
-                // here instead of 
+                // Just by changing/selecting InceptionV3/MobilenetV2
+                // here instead of
                 // ResnetV2101 you can try a different architecture/
-                // pre-trained model. 
+                // pre-trained model.
                 Arch = ImageClassificationTrainer.Architecture.ResnetV2101,
                 Epoch = 182,
                 BatchSize = 128,
@@ -92,8 +92,8 @@ public static void Example()
                 ReuseTrainSetBottleneckCachedValues = false,
                 // Use linear scaling rule and Learning rate decay as an option
                 // This is known to do well for Cifar dataset and Resnet models
-                // You can also try other types of Learning rate scheduling 
-                // methods available in LearningRateScheduler.cs  
+                // You can also try other types of Learning rate scheduling
+                // methods available in LearningRateScheduler.cs
                 LearningRateScheduler = new LsrDecay()
             };
 
@@ -111,7 +111,7 @@ public static void Example()
 
             // Train the model.
             // This involves calculating the bottleneck values, and then
-            // training the final layer. Sample output is: 
+            // training the final layer. Sample output is:
             // Phase: Bottleneck Computation, Dataset used: Train, Image Index:   1
             // Phase: Bottleneck Computation, Dataset used: Train, Image Index:   2
             // ...
@@ -271,8 +271,9 @@ public static string DownloadImageSet(string imagesDownloadFolder)
             // get a set of images to teach the network about the new classes
             // CIFAR dataset ( 50000 train images and 10000 test images )
             string fileName = "cifar10.zip";
-            string url = $"https://aka.ms/mlnet-resources/" +
-                "datasets/cifar10.zip";
+
+            // https://github.com/YoongiKim/CIFAR-10-images
+            string url = $"https://github.com/YoongiKim/CIFAR-10-images/archive/refs/heads/master.zip";
 
             Download(url, imagesDownloadFolder, fileName);
             UnZip(Path.Combine(imagesDownloadFolder, fileName),

docs/samples/Microsoft.ML.Samples/Dynamic/Transforms/ApplyONNXModelWithInMemoryImages.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Drawing;
 using System.Linq;
 using Microsoft.ML;
 using Microsoft.ML.Data;
@@ -26,8 +25,8 @@ public static void Example()
             // input /output of the used ONNX model.
             var dataPoints = new ImageDataPoint[]
             {
-                new ImageDataPoint(Color.Red),
-                new ImageDataPoint(Color.Green)
+                new ImageDataPoint(red: 255, green: 0, blue: 0), // Red color
+                new ImageDataPoint(red: 0, green: 128, blue: 0)  // Green color
             };
 
             // Convert training data to IDataView, the general data type used in
@@ -91,7 +90,7 @@ private class ImageDataPoint
 
             // Image will be consumed by ONNX image multiclass classification model.
             [ImageType(height, width)]
-            public Bitmap Image { get; set; }
+            public MLImage Image { get; set; }
 
             // Expected output of ONNX model. It contains probabilities of all
             // classes. Note that the ColumnName below should match the output name
@@ -104,12 +103,19 @@ public ImageDataPoint()
                 Image = null;
             }
 
-            public ImageDataPoint(Color color)
+            public ImageDataPoint(byte red, byte green, byte blue)
             {
-                Image = new Bitmap(width, height);
-                for (int i = 0; i < width; ++i)
-                    for (int j = 0; j < height; ++j)
-                        Image.SetPixel(i, j, color);
+                byte[] imageData = new byte[width * height * 4]; // 4 for the red, green, blue and alpha colors
+                for (int i = 0; i < imageData.Length; i += 4)
+                {
+                    // Fill the buffer with the Bgra32 format
+                    imageData[i] = blue;
+                    imageData[i + 1] = green;
+                    imageData[i + 2] = red;
+                    imageData[i + 3] = 255;
+                }
+
+                Image = MLImage.CreateFromPixels(width, height, MLPixelFormat.Bgra32, imageData);
             }
         }
     }

docs/samples/Microsoft.ML.Samples/Dynamic/Transforms/ApplyOnnxModel.cs

@@ -1,4 +1,5 @@
 using System;
+using System.IO;
 using System.Linq;
 using Microsoft.ML;
 using Microsoft.ML.Data;
@@ -10,8 +11,9 @@ public static class ApplyOnnxModel
         public static void Example()
         {
             // Download the squeeznet image model from ONNX model zoo, version 1.2
-            // https://github.com/onnx/models/tree/master/squeezenet or use
-            // Microsoft.ML.Onnx.TestModels nuget.
+            // https://github.com/onnx/models/tree/master/squeezenet or
+            // https://s3.amazonaws.com/download.onnx/models/opset_8/squeezenet.tar.gz
+            // or use Microsoft.ML.Onnx.TestModels nuget.
             var modelPath = @"squeezenet\00000001\model.onnx";
 
             // Create ML pipeline to score the data using OnnxScoringEstimator
@@ -56,7 +58,7 @@ public static void Example()
         // inputSize is the overall dimensions of the model input tensor.
         private const int inputSize = 224 * 224 * 3;
 
-        // A class to hold sample tensor data. Member name should match  
+        // A class to hold sample tensor data. Member name should match
         // the inputs that the model expects (in this case, data_0)
         public class TensorData
         {

docs/samples/Microsoft.ML.Samples/Dynamic/Transforms/ImageAnalytics/ConvertToGrayScale.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Drawing;
 using System.IO;
 using Microsoft.ML;
 using Microsoft.ML.Data;
@@ -9,7 +8,7 @@ namespace Samples.Dynamic
     public static class ConvertToGrayscale
     {
         // Sample that loads images from the file system, and converts them to
-        // grayscale. 
+        // grayscale.
         public static void Example()
         {
             // Create a new ML context, for ML.NET operations. It can be used for
@@ -20,7 +19,7 @@ public static void Example()
             // list of the files from the dotnet/machinelearning/test/data/images/.
             // If you inspect the fileSystem, after running this line, an "images"
             // folder will be created, containing 4 images, and a .tsv file
-            // enumerating the images. 
+            // enumerating the images.
             var imagesDataFile = Microsoft.ML.SamplesUtils.DatasetUtils
                 .GetSampleImages();
 
@@ -42,7 +41,7 @@ public static void Example()
             }).Load(imagesDataFile);
 
             var imagesFolder = Path.GetDirectoryName(imagesDataFile);
-            // Image loading pipeline. 
+            // Image loading pipeline.
             var pipeline = mlContext.Transforms.LoadImages("ImageObject",
                 imagesFolder, "ImagePath")
                 .Append(mlContext.Transforms.ConvertToGrayscale("Grayscale",
@@ -67,23 +66,23 @@ private static void PrintColumns(IDataView transformedData)
                 .Schema))
             {
                 // Note that it is best to get the getters and values *before*
-                // iteration, so as to faciliate buffer sharing (if applicable), and
+                // iteration, so as to facilitate buffer sharing (if applicable), and
                 // column -type validation once, rather than many times.
                 ReadOnlyMemory<char> imagePath = default;
                 ReadOnlyMemory<char> name = default;
-                Bitmap imageObject = null;
-                Bitmap grayscaleImageObject = null;
+                MLImage imageObject = null;
+                MLImage grayscaleImageObject = null;
 
                 var imagePathGetter = cursor.GetGetter<ReadOnlyMemory<char>>(cursor
                     .Schema["ImagePath"]);
 
                 var nameGetter = cursor.GetGetter<ReadOnlyMemory<char>>(cursor
                     .Schema["Name"]);
 
-                var imageObjectGetter = cursor.GetGetter<Bitmap>(cursor.Schema[
+                var imageObjectGetter = cursor.GetGetter<MLImage>(cursor.Schema[
                     "ImageObject"]);
 
-                var grayscaleGetter = cursor.GetGetter<Bitmap>(cursor.Schema[
+                var grayscaleGetter = cursor.GetGetter<MLImage>(cursor.Schema[
                     "Grayscale"]);
 
                 while (cursor.MoveNext())
@@ -94,8 +93,8 @@ private static void PrintColumns(IDataView transformedData)
                     grayscaleGetter(ref grayscaleImageObject);
 
                     Console.WriteLine("{0, -25} {1, -25} {2, -25} {3, -25}",
-                        imagePath, name, imageObject.PhysicalDimension,
-                        grayscaleImageObject.PhysicalDimension);
+                        imagePath, name, $"Width={imageObject.Width}, Height={imageObject.Height}",
+                        $"Width={grayscaleImageObject.Width}, Height={grayscaleImageObject.Height}");
                 }
 
                 // Dispose the image.

docs/samples/Microsoft.ML.Samples/Dynamic/Transforms/ImageAnalytics/ConvertToGrayScaleInMemory.cs

@@ -1,6 +1,6 @@
 using System;
-using System.Drawing;
 using Microsoft.ML;
+using Microsoft.ML.Data;
 using Microsoft.ML.Transforms.Image;
 
 namespace Samples.Dynamic
@@ -11,16 +11,17 @@ public static void Example()
         {
             var mlContext = new MLContext();
             // Create an image list.
-            var images = new[] { new ImageDataPoint(2, 3, Color.Blue), new
-                ImageDataPoint(2, 3, Color.Red) };
+            var images = new[]
+            {
+                new ImageDataPoint(2, 3, red: 0, green: 0, blue: 255),    // Blue color
+                new ImageDataPoint(2, 3, red: 255, green: 0, blue: 0) };  // red color
 
             // Convert the list of data points to an IDataView object, which is
             // consumable by ML.NET API.
             var data = mlContext.Data.LoadFromEnumerable(images);
 
             // Convert image to gray scale.
-            var pipeline = mlContext.Transforms.ConvertToGrayscale("GrayImage",
-                "Image");
+            var pipeline = mlContext.Transforms.ConvertToGrayscale("GrayImage", "Image");
 
             // Fit the model.
             var model = pipeline.Fit(data);
@@ -37,15 +38,31 @@ public static void Example()
             {
                 var image = dataPoint.Image;
                 var grayImage = dataPoint.GrayImage;
-                for (int x = 0; x < grayImage.Width; ++x)
+
+                ReadOnlySpan<byte> imageData = image.Pixels;
+                (int alphaIndex, int redIndex, int greenIndex, int blueIndex) = image.PixelFormat switch
+                {
+                    MLPixelFormat.Bgra32 => (3, 2, 1, 0),
+                    MLPixelFormat.Rgba32 => (3, 0, 1, 2),
+                    _ => throw new InvalidOperationException($"Image pixel format is not supported")
+                };
+
+                ReadOnlySpan<byte> grayImageData = grayImage.Pixels;
+                (int alphaIndex1, int redIndex1, int greenIndex1, int blueIndex1) = grayImage.PixelFormat switch
                 {
-                    for (int y = 0; y < grayImage.Height; ++y)
-                    {
-                        var pixel = image.GetPixel(x, y);
-                        var grayPixel = grayImage.GetPixel(x, y);
-                        Console.WriteLine($"The original pixel is {pixel} and its" +
-                            $"pixel in gray is {grayPixel}");
-                    }
+                    MLPixelFormat.Bgra32 => (3, 2, 1, 0),
+                    MLPixelFormat.Rgba32 => (3, 0, 1, 2),
+                    _ => throw new InvalidOperationException($"Image pixel format is not supported")
+                };
+
+                int pixelSize = image.BitsPerPixel / 8;
+
+                for (int i = 0; i < imageData.Length; i += pixelSize)
+                {
+                    string pixelString = $"[A = {imageData[i + alphaIndex]}, R = {imageData[i + redIndex]}, G = {imageData[i + greenIndex]}, B = {imageData[i + blueIndex]}]";
+                    string grayPixelString = $"[A = {grayImageData[i + alphaIndex1]}, R = {grayImageData[i + redIndex1]}, G = {grayImageData[i + greenIndex1]}, B = {grayImageData[i + blueIndex1]}]";
+
+                    Console.WriteLine($"The original pixel is {pixelString} and its pixel in gray is {grayPixelString}");
                 }
             }
 
@@ -67,23 +84,30 @@ public static void Example()
         private class ImageDataPoint
         {
             [ImageType(3, 4)]
-            public Bitmap Image { get; set; }
+            public MLImage Image { get; set; }
 
             [ImageType(3, 4)]
-            public Bitmap GrayImage { get; set; }
+            public MLImage GrayImage { get; set; }
 
             public ImageDataPoint()
             {
                 Image = null;
                 GrayImage = null;
             }
 
-            public ImageDataPoint(int width, int height, Color color)
+            public ImageDataPoint(int width, int height, byte red, byte green, byte blue)
             {
-                Image = new Bitmap(width, height);
-                for (int i = 0; i < width; ++i)
-                    for (int j = 0; j < height; ++j)
-                        Image.SetPixel(i, j, color);
+                byte[] imageData = new byte[width * height * 4]; // 4 for the red, green, blue and alpha colors
+                for (int i = 0; i < imageData.Length; i += 4)
+                {
+                    // Fill the buffer with the Bgra32 format
+                    imageData[i] = blue;
+                    imageData[i + 1] = green;
+                    imageData[i + 2] = red;
+                    imageData[i + 3] = 255;
+                }
+
+                Image = MLImage.CreateFromPixels(width, height, MLPixelFormat.Bgra32, imageData);
             }
         }
     }