As you have enought variance in the target  appearance (single, multi etc.) I think you could try to experiment with an object detection approach.
Please check
  
      

      Roboflow Blog – 16 Jul 20
  

  
    

How to Train a TensorFlow 2 Object Detection Model 4

  With the recent release of the TensorFlow 2 Object Detection API, it has never been easier to train and deploy state of the art object detection models with TensorFlow leveraging your own custom dataset to detect your own custom objects: foods, pets,...