MATLAB: How to detect and fill a special region

blackfillingImage Processing Toolboxregionremove blob

Hi.

Regarding the following image:

what I want is detecting and then removing (I mean making them black as elsewhere) the white regions. Please note that the image is binary one and it is only a part of an image. The whole image contains other white and black regions (so it might not be easy to use imfill).

what can I do?

1. Is there any function in MATLAB that can automatically detect them and make them black?

2. If not, the user shall select them from screen, right? if yes, how to make the inside black? (I know I can select them by roipoly or similar functions, but I do not know how to make inside the regions black while keeping outside the same)?

By the way! If needed, I can also work on grayscale image instead of binary, whichever is easier or more efficient.

I hope I described my problem clearly.

Thanks so much for your time.

Steven

Best Answer

Two ways, you can either have the user lassoo the object and erase inside of where they drew, as shown in my demos attached below. Or, you can call ginput and have the user click on a blob and then, after you've called regionprops, figure out which blob they clicked on by looking at PixelIdxList and then using ismember() to erase the containing, or closest, blob.

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