Zero-Shot Learning and its Applications from Autonomous Vehicles to COVID-19 Diagnosis: A Review

Rezaei, Mahdi; Shahidi, Mahsa

The challenge of learning a new concept without receiving any examples beforehand is called zero-shot learning (ZSL). One of the major issues in deep learning based methodologies is the requirement of feeding a vast amount of annotated and labelled images by a human to train the network model. ZSL is known for having minimal human intervention by relying only on previously known concepts and auxiliary information. It is an ever-growing research area since it has human-like characteristics in learning new concepts, which makes it applicable in many real-world scenarios, from autonomous vehicles to surveillance systems to medical imaging and COVID-19 CT scan-based diagnosis. In this paper, we present the definition of the problem, we review over fundamentals, and the challenging steps of Zero-shot learning, including recent categories of solutions, motivations behind each approach, and their advantages over other categories. Inspired from different settings and extensions, we have a broaden solution called one/few-shot learning. We then review thorough datasets, the variety of splits, and the evaluation protocols proposed so far. Finally, we discuss the recent applications and possible future directions of ZSL. We aim to convey a useful intuition through this paper towards the goal of handling computer vision learning tasks more similar to the way humans learn.