OutOfMemoryException in Image Resizing

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

How much RAM is available? Memory fragmentation can reduce the amount of large available blocks even if no memory leaks occur. The best way to avoid this to make sure you have enough RAM to support your scenario. Also, are you using the DiskCache plugin? If not, there's your problem. — Lilith River, May 10 '12 at 14:44
Thanks for the reply. RAM on server is:16GB and yes we are using DiskCache plugin with the imageresizer. — Moftak Solutions, May 11 '12 at 06:19
You're asking 2 different questions here - 1) What's wrong with my code, 2) Why am I having an problem with ImageResizer. Are you still using your old code? It does have many memory leaks. — Lilith River, May 11 '12 at 12:32

score 2 · Answer 1 · edited May 23 '17 at 12:18

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).

OutOfMemoryException in Image Resizing

1 Answers1