What is Deep learning approach to count the number of Diamonds in an image? I am working on a project which involves counting the number of diamonds in the provided image. I have a set of images and a VIA annotated .json file which has all the annotations. How do I proceed with this problem.

what approach to start i.e Object detection vs Instance segmentation ?
what models to choose from MaskRCNN,U-Net, etc (Please suggest) ?

Please guide.
Thanks
I say that go with Object Detection. Because you already have annoted images. And segmentation applied to locate objects and boundaries (lines, curves, etc.) in images. . In Recent days EfficientDet Works very well in object detection. And for implementation look here. Best of luck.