Simple blob finder without Vision package

[torekp]

In case this is useful to anyone else who is also too cheap to spring for Machine Vision...

 

I implemented a simple blob finding algorithm based on Blob Detection - The Lab Book Pages.  It takes a 2D array of DBL, which should be easy to create from any monochrome image.  You can set a range of values to count as "foreground"; the default is 1 to +Inf.  I use an intensity graph to display the input, which results in an apparent rotation of your image.  Mentally rotate the intensity graph 90 degrees to the right, to see your original image, e.g. if you created the data by reading a picture file and selecting one color.  The output "blobs" will be oriented like your original image.  Values of 0 in the output indicate no blob, i.e. nothing there.  Values 1 or greater are the blob numbers, in the order encountered.

 

Labview 2012; OpenG array package required.

 

Use blob_find_DBL.vi by itself (it's in Common\Calculations) or with test_blob_find.vi (in Common\tests, and you will need a PNG file to read).

Common.zip