OutOfMemoryException in Image Resizing - image

Question

We are using a .net dll (http://imageresizing.net/download) for imageresizing on runtime. It works perfectly. However, it happen after some time (between 1-7 days) that system started to raise exception in the even viewer:
Exception information:
Exception type: OutOfMemoryException
Exception message: Insufficient memory to continue the execution of the program.
And after that exception the website usually stop working with the error throwing "System.OutOfMemoryException".
And if we "recycle" the application pool in which the website is running, it clears the problem and website get back to normal immediately without any code change.
Before imagereiszing dll, we were using our custom code and same problem happen with that too. Following is the code.
private Bitmap ConvertImage(Bitmap input, int width, int height, bool arc)
{
if (input.PixelFormat == PixelFormat.Format1bppIndexed ||
input.PixelFormat == PixelFormat.Format4bppIndexed ||
input.PixelFormat == PixelFormat.Format8bppIndexed)
{
Bitmap unpackedBitmap = new Bitmap(input.Width, input.Height);
Graphics g = Graphics.FromImage(unpackedBitmap);
g.Clear(Color.White);
g.DrawImage(input, new Rectangle(0,0,input.Width, input.Height));
g.Dispose();
input = unpackedBitmap;
}
double aspectRatio = (double)input.Height / (double)input.Width;
int actualHeight = CommonMethods.GetIntValue(Math.Round(aspectRatio * width, 0));
Bitmap _imgOut;
if (actualHeight > height)
{
ResizeImage resizeImage = new ResizeImage(width, actualHeight, InterpolationMethod.Bicubic);
Bitmap _tempBitmap = resizeImage.Apply(input);
Bitmap _croppedBitmap = new Bitmap(width, height);
Graphics _crop = Graphics.FromImage(_croppedBitmap);
_crop.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
_crop.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
_crop.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
_crop.DrawImageUnscaledAndClipped(_tempBitmap, new Rectangle(0, 0, width, height));
_crop.Dispose();
_imgOut = _croppedBitmap;
}
else
{
ResizeImage resizeImage = new ResizeImage(width, height, InterpolationMethod.Bicubic);
_imgOut = resizeImage.Apply(input);
}
// Draw the arc if it has been requested
if (arc)
{
Graphics _arc = Graphics.FromImage(_imgOut);
_arc.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
_arc.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
_arc.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
_arc.DrawArc(new Pen(Color.White, 24), new Rectangle(-13, -13, 50, 50), 180, 90);
_arc.Dispose();
}
// job done
return _imgOut;
}
We are resizing image like: www.mysite.com/images/myimage.jpg?width=196&height=131
Looking forward.
Farrukh

Answer 1

When you encounter an OutOfMemoryException (regardless of where it occurs), it can be caused by a memory leak anywhere in the application. Having debugged dozens of these instances with WinDbg, I've never found any that ended up being due to a bug in http://imageresizing.net.
That said, there's an easy way to determine whether it is a problem with http://imageresizing.net or not; create a separate application pool and subfolder application in IIS for your images and image resizing. Install nothing there except the image resizer. Next time you encounter the error, log on to the server and find out which w3wp.exe instance is responsible for the massive memory usage.
If it's in the ImageResizer app pool, go collect your $20-$50 bug bounty from http://imageresizing.net/support. If not, you need to figure out where you're leaking stuff in your main application.
If you're working with System.Drawing anywhere else in the app, that's the first place to look. Check your code against this list of pitfalls.
If you're positive you're disposing of every System.Drawing.* instance in a using or finally clause, then read this excellent article a few times to make sure you're not failing on any of the basics, then dig in with DebugDiag and/or WinDBG (see bottom of article).