bwlabel doesn't find a blob

Hi all,

I have an image which I applied filtering on it and eneded up with the image on the right. I use bwboundaries and bwlabel to obtain the boundaries and blobs in this figure.

I clearly see that boundary #6 can correspond to a blob but bwlabel doesn't find this blob and shows the total number of lobs in this image as 5 instead of 6. Can somebody help please?

Thanks

Answer 1

[KALYAN ACHARJYA]

Yes, total number of blobs in this image is 5 (in context of 8-connected objects)

L=bwlabel(BW) returns the label matrix L that contains labels for the 8-connected objects found in BW.

By default 8 connected (you can choose 4 connected also)

[parinaz nazeri]

How should I filter the image so that boundary 6 corresponds to a blob?

[KALYAN ACHARJYA]

Where is the 6th blob? See the morphological operation (maybe helps) before get the blobs' properties.

Have to apply the following:

[L, numberOfBlobs] = bwlabel(binaryimage,4) % see the total blobs results

[parinaz nazeri]

Thank you I solved my issue by using imfill on the ~image!

[Image Analyst]

imfill() would give you a totally white image with just one blob. The blobs are the white things, you know, not the black things. What do you want to label? The white things or the black regions? If you want black, you have to invert your image.

[parinaz nazeri]

Thanks! Yes, I used the inverted image and it worked fine!