I have searched a lot to know how can we test an object exist in an image. I am searching for the name of the scientific/ technology that can provide this. As an example I can mention Instagram where you upload an image and Instagram writes: This image may contain sea, people, car. Is this content based image retrieval? Do I need local feature extraction for it? Are they based on deep learning or do they work by something like SIFT?
Whatever I studied was just able to receive a query image and search a database to say that which image is "similar" to that, not which image contains it.