使用AFORGE.NET ProcessImage的OutOfMemoryException

Question

I have a large System.Drawing.Bitmap (14399 X 10799) that I am trying to process using AFORGE.NET. My algorithm works very well with a smaller image but with this size of image I receive an OutOfMemoryException when I call Process().

Before calling Process(), my task manager reports that the application is using 613MB, at the time of the exception, it is using 609MB.

I have tried setting my platform target to x64 but this does not seem to affect the occurence of the exception.

I suspect that the exception is not related to the memory but something else, how can I circumvent it?

// lock image
        BitmapData bitmapData = bitmap.LockBits(
            new Rectangle(0, 0, bitmap.Width, bitmap.Height),
            ImageLockMode.ReadWrite, bitmap.PixelFormat);

        // step 1 - turn background to black
        ColorFiltering colorFilter = new ColorFiltering();

        colorFilter.Red = new IntRange(0, 64);
        colorFilter.Green = new IntRange(0, 64);
        colorFilter.Blue = new IntRange(0, 64);
        colorFilter.FillOutsideRange = false;

        colorFilter.ApplyInPlace(bitmapData);

        // step 2 - locating objects
        BlobCounter blobCounter = new BlobCounter();

        blobCounter.FilterBlobs = true;
        blobCounter.MinHeight = 5;
        blobCounter.MinWidth = 5;

        blobCounter.ProcessImage(bitmapData); //Crash
        Blob[] blobs = blobCounter.GetObjectsInformation();
        bitmap.UnlockBits(bitmapData);

Exception of type 'System.OutOfMemoryException' was thrown.

Answer 1

The memory usage could be quite high if your image contains a lot of blobs. Have you tried with a blank image of the same size ?

If it is really caused by your image having too many blobs, you could try to add more constraints on your blob filtering.

Answer 2

i had simillar issue, just use the ResizeBilinear filter or any other resize filter in Aforge.Imaging.Filters (you don't need the full quality image if you are processing it just to get some information)and any modification you want to make for the source image it's done by scaling back the points for objects you found and below is a simple method to get a temporary scaled down image for processing

 Bitmap ResizeMyImage(Bitmap Source, int scalefactor)
        {
            int newHeight = Source.Height / scalefactor;
            int newWidth = (int)(Source.Width * (newHeight / (float)Source.Height));
            ResizeBilinear filter = new ResizeBilinear(newWidth, newHeight);
            return filter.Apply(Source);
        }