Added GeoImage

MapControl/WinUI/GeoImage.WinUI.cs

@@ -0,0 +1,76 @@
+// XAML Map Control - https://github.com/ClemensFischer/XAML-Map-Control
+// © 2022 Clemens Fischer
+// Licensed under the Microsoft Public License (Ms-PL)
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Threading.Tasks;
+using Windows.Graphics.Imaging;
+using Windows.Storage;
+#if WINUI
+using Microsoft.UI.Xaml.Media.Imaging;
+#else
+using Windows.UI.Xaml.Media.Imaging;
+#endif
+
+namespace MapControl
+{
+    public partial class GeoImage
+    {
+        public static async Task<Tuple<BitmapSource, Matrix>> ReadGeoTiff(Uri sourceUri)
+        {
+            StorageFile file;
+
+            if (!sourceUri.IsAbsoluteUri || sourceUri.IsFile)
+            {
+                file = await StorageFile.GetFileFromPathAsync(
+                    sourceUri.IsAbsoluteUri ? sourceUri.LocalPath : Path.GetFullPath(sourceUri.OriginalString));
+            }
+            else
+            {
+                file = await StorageFile.GetFileFromApplicationUriAsync(sourceUri);
+            }
+
+            using (var stream = await file.OpenReadAsync())
+            {
+                WriteableBitmap bitmap;
+                Matrix transform;
+
+                var decoder = await BitmapDecoder.CreateAsync(stream);
+
+                using (var swbmp = await decoder.GetSoftwareBitmapAsync())
+                {
+                    bitmap = new WriteableBitmap(swbmp.PixelWidth, swbmp.PixelHeight);
+                    swbmp.CopyToBuffer(bitmap.PixelBuffer);
+                }
+
+                var query = new List<string>
+                {
+                    PixelScaleQuery, TiePointQuery, TransformQuery, NoDataQuery
+                };
+
+                var metadata = await decoder.BitmapProperties.GetPropertiesAsync(query);
+
+                if (metadata.TryGetValue(PixelScaleQuery, out BitmapTypedValue pixelScaleValue) &&
+                    pixelScaleValue.Value is double[] pixelScale && pixelScale.Length == 3 &&
+                    metadata.TryGetValue(TiePointQuery, out BitmapTypedValue tiePointValue) &&
+                    tiePointValue.Value is double[] tiePoint && tiePoint.Length >= 6)
+                {
+                    transform = new Matrix(pixelScale[0], 0d, 0d, -pixelScale[1], tiePoint[3], tiePoint[4]);
+                }
+                else if (metadata.TryGetValue(TransformQuery, out BitmapTypedValue tformValue) &&
+                         tformValue.Value is double[] tform && tform.Length == 16)
+                {
+                    transform = new Matrix(tform[0], tform[1], tform[4], tform[5], tform[3], tform[7]);
+                }
+                else
+                {
+                    throw new ArgumentException("No coordinate transformation found in \"" + sourceUri + "\".");
+                }
+
+                return new Tuple<BitmapSource, Matrix>(bitmap, transform);
+            }
+        }
+    }
+}