Collection of some Object detection and segmentation models.

You can train them on your custom dataset.

Mask RCNN (Modified Matterport's Mask RCNN) The pretrained models can be downloaded and fine tuned for your own dataset. Even with hundreds of images satisfactory results can be obtained but the more images, better are the results.
YOLO v3 The original weights are from here and it can used for custom data training.
U-Net