1 files changed, 2 insertions, 0 deletions

diff --git a/NesTiler/FastBitmap.cs b/NesTiler/FastBitmap.cs
index fb92468..5910f43 100644
--- a/NesTiler/FastBitmap.cs
+++ b/NesTiler/FastBitmap.cs
@@ -1,4 +1,5 @@
 using SkiaSharp;

+using System;

 using System.Collections.Generic;

 using System.Drawing;

 using System.Linq;

@@ -17,6 +18,7 @@ namespace com.clusterrr.Famicom.NesTiler
         {

             Width = skBitmap.Width;

             Height = height <= 0 ? skBitmap.Height - verticalOffset : height;

+            if (skBitmap.Height - verticalOffset - Height <= 0) throw new InvalidOperationException("Invalid image height.");

             var pixels = skBitmap.Pixels;

             colors = skBitmap.Pixels.Skip(verticalOffset * Width).Take(Width * Height).Select(p => Color.FromArgb(p.Alpha, p.Red, p.Green, p.Blue)).ToArray();

         }