Detecting and classifying small objects in thermal imagery using a deep neural network

In recent years the rise of deep learning neural networks has shown great results in image classification. Most of the previous work focuses on classification of fairly large objects in visual imagery. This paper presents a method of detecting and classifying small objects in thermal imagery using a deep learning method based on a RetinaNet network. The result shows that a deep neural network with a relative small set of labelled images can be trained to classify objects in thermal imagery. Objects from classes with the most training examples (cars, trucks and persons) can with relative high confidence be classified given an object size of 32x32 pixels or smaller.