Apart from the multitudes of traditional image segmentation techniques (Watershed, Clustering or Variational methods), newer Segmentation schemes using Deep Learning are actively being used, which provide better results and are better for real-time applications, owing to minimum computation overheads involved.
The following blog provides a detailed review of recent advancements in this field: Review of Deep Learning Algorithms for Image Semantic Segmentation
For the traditional methods, this Wikipedia article provides a nice summary:
Image Segmentation