Ground-level temperature-emissivity based contrast enhancement with uncooled multiband LWIR cameras

Robert Grimming, Ronald Driggers, Kyle Renshaw, Orges Furxhi

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Optimal longwave infrared (LWIR) scene contrast occurs when reflections from other sources are minimized, leaving only thermal emission. Applying contrast enhancement to LWIR imagery based on pixel values' spatial distribution without regard to underlying temperature and emissivity is a non-physics-based approach. For a physics-based approach, something must be known about the temperature or the objects' emissivity under observation. In remote sensing applications, atmospheric conditions are measured allowing for calculated values for downwelling and path radiance to be obtained. Then, an iterative process can be performed using well-established TES algorithms to determine temperature and emissivity within specific bands. In this paper, we propose a method using a three-band LWIR imaging system with a partial sky view to collect in-scene data to apply contrast enhancement based on spectral differences between bands. Unlike traditional contrast enhancement methods, temperature variations between each band are considered and implemented using relatively inexpensive uncooled microbolometer cameras. We detail the process used for calibrating and determining brightness temperatures with sub-band LWIR filtered cameras. Using absolute sky radiance correlated to MODTRAN6 models, we estimate objects' emissivity profiles in a scene and propose an algorithm for applying contrast enhancement.

Original languageEnglish (US)
Title of host publicationInfrared Imaging Systems
Subtitle of host publicationDesign, Analysis, Modeling, and Testing XXXII
EditorsGerald C. Holst, David P. Haefner
ISBN (Electronic)9781510643178
StatePublished - 2021
Externally publishedYes
EventInfrared Imaging Systems: Design, Analysis, Modeling, and Testing XXXII 2021 - Virtual, Online, United States
Duration: Apr 12 2021Apr 16 2021

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferenceInfrared Imaging Systems: Design, Analysis, Modeling, and Testing XXXII 2021
Country/TerritoryUnited States
CityVirtual, Online


  • Contrast enhancement
  • Infrared imaging
  • LWIR
  • Multiband
  • Uncooled microbolometers

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


Dive into the research topics of 'Ground-level temperature-emissivity based contrast enhancement with uncooled multiband LWIR cameras'. Together they form a unique fingerprint.

Cite this