Make SkiaImageExtensions public to allow conversion of PdfPig pdf images to SkiaSharp images

Author: BobLd

UglyToad.PdfPig.Rendering.Skia.Tests/RenderImagesTests.cs

@@ -0,0 +1,41 @@
+// Copyright 2024 BobLd
+//
+// Licensed under the Apache License, Version 2.0 (the "License").
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// 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.
+
+using System.IO;
+using UglyToad.PdfPig.Rendering.Skia.Helpers;
+using Xunit;
+
+namespace UglyToad.PdfPig.Rendering.Skia.Tests
+{
+    public class RenderImagesTests
+    {
+
+        [Fact]
+        public void PdfPigImageAsSkiaImages()
+        {
+            using (var document = PdfDocument.Open(Path.Combine("SpecificTestDocuments", "Shadows.at.Sundown.-.Lvl.11_removed.pdf"), SkiaRenderingParsingOptions.Instance))
+            {
+                var page = document.GetPage(1);
+                foreach (var pdfImage in page.GetImages())
+                {
+                    var skImage = pdfImage.GetSKImage();
+                    
+                    Assert.NotNull(skImage);
+                    Assert.True(skImage.Width > 0);
+                    Assert.True(skImage.Height > 0);
+                }
+            }
+        }
+    }
+}

UglyToad.PdfPig.Rendering.Skia/Helpers/SkiaImageExtensions.cs

@@ -24,7 +24,10 @@
 
 namespace UglyToad.PdfPig.Rendering.Skia.Helpers
 {
-    internal static class SkiaImageExtensions
+    /// <summary>
+    /// SkiaSharp image extensions.
+    /// </summary>
+    public static class SkiaImageExtensions
     {
         private static bool IsValidColorSpace(IPdfImage pdfImage)
         {
@@ -56,7 +59,7 @@ private static bool HasAlphaChannel(this IPdfImage pdfImage)
             return pdfImage.MaskImage is not null || pdfImage.ImageDictionary.ContainsKey(NameToken.Mask);
         }
 
-        public static int GetRasterSize(this IPdfImage pdfImage)
+        internal static int GetRasterSize(this IPdfImage pdfImage)
         {
             int width = pdfImage.WidthInSamples;
             int height = pdfImage.HeightInSamples;
@@ -379,6 +382,19 @@ private static bool TryGetGray8Bitmap(int width, int height, ReadOnlySpan<byte>
             return false;
         }
 
+        /// <summary>
+        /// Converts the specified <see cref="IPdfImage"/> to an <see cref="SKImage"/> instance.
+        /// </summary>
+        /// <param name="pdfImage">The PDF image to convert.</param>
+        /// <returns>
+        /// An <see cref="SKImage"/> representation of the provided <paramref name="pdfImage"/>.
+        /// If the conversion fails, a fallback mechanism is used to create the image from raw bytes.
+        /// </returns>
+        /// <exception cref="ArgumentNullException">Thrown if <paramref name="pdfImage"/> is <c>null</c>.</exception>
+        /// <remarks>
+        /// This method attempts to generate an <see cref="SKImage"/> using the image's data and color space.
+        /// If the generation fails, it falls back to creating the image using encoded or raw byte data.
+        /// </remarks>
         public static SKImage GetSKImage(this IPdfImage pdfImage)
         {
             if (pdfImage.TryGenerate(out var bitmap))