How do I get the area of the blob with subpixel accuracy?

  • Hello,


    My name is Ryuji Narita from LINX Corporation in Japan.


    I want to get the Area of Blob with sub pixel in VisualApplets but I have no idea.

    If you have any ideas, could you share it with me?

  • Hello,


    It is not possible to get an object area in sub-pixel precision. Area is always returned in unit pixels, because a single pixel is part of an object or not, since the VA blob analysis is working on binary images.


    Concerning sub-pixel precision and blob analysis it is normally about:

    The object's center of gravity (COG) position is getting returned by not nomalized sub-pixel precision,
    which means you have to divide the COG x & y components by the area to get sub-pixel precision.
    Simply add fixed point precision bits to the required division.


    Best regards,

    Björn Rudde
    Field Application Engineer
    - Basler AG
    chat