Watermark detection using Deep Learning I have images with and without watermark. There is only one type of watermark. I have tried VGG16 transfer learning, but results were bad. 

What are the methods to do image classification if it has a watermark or not?
You could consider finding watermark an object detection problem, not an image classification problem. Faster R-CNN and "You only look once" (YOLO) are both general object detection architectures.