CreateLeadDC() on RasterImage returning null pointer on certain images

In a directory of 317 images I have 3 gifs that cause an error because CreateLeadDC() on those images returns a null pointer. I'll attach one of those images.

This is the code I'm using:

IntPtr hDC = IntPtr.Zero;
try
{
hDC = canvas.CreateLeadDC();
using (Graphics g = Graphics.FromHdc(hDC))
{
this.TopZone.CalculateSize(g, renderingWidth);
this.BottomZone.CalculateSize(g, renderingWidth);
}
}
finally
{
if (hDC != IntPtr.Zero)
RasterImage.DeleteLeadDC(hDC);
}
}


Your help is greatly appreciated.

The attached image has a pixel depth (color resolution) of 7 bits per pixel. This value is correct for GIF images and for LEAD bitmaps in memory, but it is not compatible with GDI. You can try to load it at 8 or 24 BPP, or convert it using the ColorResolutionCommand class.