Ask Your Question
0

What method to use for detecting irregular black blobs?

asked 2017-08-14 02:17:31 -0600

PiMac gravatar image

Hi, I would like to detect if there is a black blob in a picture below (school project for detecting defects in fruits): image description

Right now I just detect if there is a circulat shape (houghcircles) and put 1 if there is and 0 if not - it isn't very accurate. I have to detect the black blobs but some of the blobs are false positive. I have been thinking about teaching an algorithm the good and bad pictures to get the best accuracy. I have only used knn for digit detection would it be a good choice to use it in this exercise? Can you suggest anything other to use?

Thank you!

edit retag flag offensive close merge delete

Comments

Where is the original image you're trying to process ?your circles change position ?

Ziri gravatar imageZiri ( 2017-08-14 03:59:16 -0600 )edit

My original image is just a plastic form with holes in it. You put fruits in it and backlight shines through them. I just cut out the holes and put them onto a black backgroud so it is easier to see the different holes. The placement is static so the holes are at the same places.

PiMac gravatar imagePiMac ( 2017-08-14 06:02:37 -0600 )edit

1 answer

Sort by ยป oldest newest most voted
0

answered 2017-08-14 04:05:21 -0600

Ziri gravatar image

updated 2017-08-14 04:06:49 -0600

  • Suggestion :

If you can detect circles position (or only one circle position ) you can create a predefined mask where Blobs are perfect (separate) white circle then detect holes using findContours and CV_RETR_CCOMP parameter .

edit flag offensive delete link more

Comments

Thanks but since some of the blobs are false-positives I really would like someone to suggest a method that can be fed a learning set of images. I am not very advanced in such tasks but I will start with kNN classification algorithm and see how it goes.

PiMac gravatar imagePiMac ( 2017-08-14 06:06:59 -0600 )edit

SVM is better if you have small data. but the most important to increase accuracy is feature extraction method you'll be using for training.

Ziri gravatar imageZiri ( 2017-08-14 06:42:22 -0600 )edit

Question Tools

1 follower

Stats

Asked: 2017-08-14 02:17:31 -0600

Seen: 783 times

Last updated: Aug 14 '17