What is a task type?
This is likely to be a challenging task, and if you're not familiar with image classification, I suspect it may be beyond what you can reasonably do right now.
I would suggest you investigate classical image processing techniques.  You might try applying morphological operators, such as closing (dilation followed by erosion) or opening followed by thresholding.  You may need to experiment.  If you search on Stack Overflow and Signal Processing sites, you'll find many examples.
See also blob detection and watershed segmentation.