Blob counter - counts objects in image, which are separated by black background.

Namespace:  AForge.Imaging
Assembly:  AForge.Imaging (in AForge.Imaging.dll) Version: (


public class BlobCounter : BlobCounterBase


The class counts and extracts stand alone objects in images using connected components labeling algorithm.

Note:The algorithm treats all pixels with values less or equal to BackgroundThreshold as background, but pixels with higher values are treated as objects' pixels.

For blobs' searching the class supports 8 bpp indexed grayscale images and 24/32 bpp color images that are at least two pixels wide. Images that are one pixel wide can be processed if they are rotated first, or they can be processed with RecursiveBlobCounter. See documentation about BlobCounterBase for information about which pixel formats are supported for extraction of blobs.

Sample usage:

// create an instance of blob counter algorithm
BlobCounter bc = new BlobCounter( );
// process binary image
bc.ProcessImage( image );
Rectangle[] rects = bc.GetObjectsRectangles( );
// process blobs
foreach ( Rectangle rect in rects )
    // ...

Inheritance Hierarchy


See Also