atom feed7 messages in com.googlegroups.aforgeRe: Blob Detection
FromSent OnAttachments
sirynMay 9, 2008 1:44 am 
Nicolae PMay 9, 2008 5:38 am 
Andrew KirillovMay 9, 2008 6:16 am 
sirynMay 10, 2008 1:54 am 
Andrew KirillovMay 11, 2008 7:59 am 
sirynMay 11, 2008 2:00 pm 
CaversanMay 20, 2008 7:31 am 
Subject:Re: Blob Detection
From:Caversan (
Date:May 20, 2008 7:31:57 am

Hi syrin,

I guess there is not a method to do this, and pixel to pixel comparation its not a good idea, usually. You can use the VerticalIntensityStatistics and HorizontalIntensityStatistics to compare them. It is a good approximation. There are another methods with filters and trasnsformations to achieve more accured results.

Hope this helps,

On 11 maio, 18:00, siryn <> wrote:

hahahaha... Thanks for everything but i did get it figured out. I ended up using the euclidean filter which works wonders. I also have one more question, is there anything in the AForge library which will be able to compare 2 blobs and return where they are smilar or not?? maybe as a percentage or a decimal.

Thank you very much for an awesome library.

On May 11, 4:59 pm, Andrew Kirillov <> wrote:


Sorry, but now I don't understand you completely. You have all the tools, but you don't know to achieve your goal ...

1) Color filter to keep only red objects; 2) Binarize or at least grayscale; 3) Blob counter. Now you will have only objects, which are red on the original picture.

With best regards, Andrew

On May 10, 4:54 pm, siryn <> wrote:

Hi Andrew

I've use HSL and managed to extract all the color out and only red items remain but i am unsure of how to get the blob detector to only detect the red colour. The color red that is detected remains red and the rest of the colour in the image becomes grayscaled, but i noticed that when using the blob detection the whole thing becomes grayscale anyway... Does this defeat the objective of finding the red areas??

What i really need to know is how to only get the blob detector to return the red blob. I stuggled to find samples of all of your Color filtering and HSL can you point me in the right direction?

On May 9, 3:16 pm, Andrew Kirillov <> wrote:


I would suggest you to check ColorFiltering, HSLFiltering, etc. classes from AForge.Imaging.Filters namespace - these classes will allow to keep only required color (red, for example) and remove all other.

With best regards, Andrew

On May 9, 4:44 pm, siryn <> wrote:

I have a question, i have a webcam which would detect motion and instead of detecting the whole moving item i want it just to identify a blob say thats red in colour.

So if me as a human is wearing a red cap or red armband or red something it will only identify that red object as a blob. I'm not to sure how to do this as if there is motion it will just pick up the whole moving object.

If you could help me i would greatly appreciate it.- Hide quoted text -

- Show quoted text -- Ocultar texto entre aspas -