Non-Invasive Forehead Segmentation in Thermographic Imaging

Abstract

The temperature of the forehead is known to be highly correlated with the internal body temperature. This area is widely used in thermal comfort systems, lie-detection systems, etc. However, there is a lack of tools to achieve the segmentation of the forehead using thermographic images and non-intrusive methods. In fact, this is usually segmented manually. This work proposes a simple and novel method to segment the forehead region and to extract the average temperature from this area solving this lack of non-user interaction tools. Our method is invariant to the position of the face, and other different morphologies even with the presence of external objects. The results provide an accuracy of 90% compared to the manual segmentation using the coefficient of Jaccard as a metric of similitude. Moreover, due to the simplicity of the proposed method, it can work with real-time constraints at 83 frames per second in embedded systems with low computational resources. Finally, a new dataset of thermal face images is presented, which includes some features which are difficult to find in other sets, such as glasses, beards, moustaches, breathing masks, and different neck rotations and flexions.

A Review of the State of the Art in Non-Contact Sensing for COVID-19

“…Thermography has been recommended as an early detection strategy for COVID-19 among large amounts of people in places such as in airports [98]. Deep learning has been applied to thermal images where classifications on new images can be made in under a second [99,100].…”

Investigation of the Impact of Infrared Sensors on Core Body Temperature Monitoring by Comparing Measurement Sites

“…Sharma and Yadav [21] proposed a noncontact temperature algorithm for face detection in a video sequence and validated its performance against standard temperature device. Rodriguez-Lozand et al [22] proposed a novel method to segment the forehead region of the human beings and to calculate the mean temperature of these area. With this simple and accurate method, the thermal face images in different features are presented.…”

Video-Based Elevated Skin Temperature Detection

“…Existing methods of detecting elevated skin temperature can be classified into contact-based methods and non-contactbased [12], [13] methods. Contact-based approaches for elevated skin temperature detection utilize photoplethysmography (PPG) [14] techniques to monitor changes in blood flow patterns under the skin to determine the amplitude of skin temperature oscillation.…”