Use TemporaryDefines for the defines instead.

Author: dlemstra

src/Magick.NET/Helpers/TemporaryDefines.cs

@@ -9,10 +9,10 @@ namespace ImageMagick;
 
 internal sealed class TemporaryDefines : IDisposable
 {
-    private readonly MagickImage _image;
+    private readonly IMagickImage _image;
     private readonly List<string> _names = new();
 
-    public TemporaryDefines(MagickImage image)
+    public TemporaryDefines(IMagickImage image)
     {
         _image = image;
     }

src/Magick.NET/MagickImageCollection.cs

@@ -442,19 +442,14 @@ public void Complex(IComplexSettings complexSettings)
     {
         Throw.IfNull(nameof(complexSettings), complexSettings);
 
-        using var imageAttacher = new TemporaryImageAttacher(_images);
+        using var temporaryDefines = new TemporaryDefines(_images[0]);
 
         if (complexSettings.SignalToNoiseRatio is not null)
-            _images[0].SetArtifact("complex:snr", complexSettings.SignalToNoiseRatio.Value.ToString(CultureInfo.InvariantCulture));
+            temporaryDefines.SetArtifact("complex:snr", complexSettings.SignalToNoiseRatio.Value.ToString(CultureInfo.InvariantCulture));
 
+        using var imageAttacher = new TemporaryImageAttacher(_images);
         var images = _nativeInstance.Complex(_images[0], complexSettings.ComplexOperator);
         ReplaceImages(images);
-
-        if (complexSettings.SignalToNoiseRatio is not null)
-        {
-            foreach (var image in _images)
-                image.RemoveArtifact("complex:snr");
-        }
     }
 
     /// <summary>