Infrared camera testing with Imatest
Night-vision helmets and scopes, security systems, and ballistic missile tracking telescopes are just a few of the many mission-critical devices that depend on infrared (IR) camera systems. As with any camera system, ensuring the quality of IR cameras requires testing of the images they produce.
For companies that develop IR cameras, image quality testing may be required at many stages: comparing component parts (e.g., IR sensors, lenses) to determine which is best suited for a given product; evaluating alternative R&D prototypes; assessing image quality in pre-production runs; ensuring that final products coming off the manufacturing line meet pass/fail quality thresholds.
Likewise, organizations that use IR camera systems typically need to benchmark competing supplier devices, conduct acceptance testing on random samples of supplied products, and verify proper camera functioning after initial setup, and after periodic maintenance.
Until now, limitations in IR test charts and analysis software have left IR image testing techniques lagging well behind testing techniques used with visible light cameras.
- The high cost of materials historically used to produce IR test charts typically resulted in small charts, often not exceeding 100 square inches. In many cases, the materials used to make these charts cannot scale to large size at any cost.
- Outdated test chart patterns — most companies producing IR test charts still use the outdated 1951 USAF Resolution test chart pattern. Unfortunately, this pattern for measuring sharpness was designed before the advent of computer-based analysis of digital image quality, so it relies on subjective human perception (i.e., eyeballing it) to determine sharpness based on which lines on the chart are visible to a person.
- Limited software support for objectively analyzing image quality
Imatest’s Infrared SFRplus test charts, in combination with the Imatest Master or Image Sensor software packages, eliminates these problems, offering:
- Large chart size: the chart measures 1 meter high by 1.3 meters wide, with a sturdy 0.3 cm aluminum substrate designed to support camera testing not only in the lab, but also in harsh outdoor field conditions.
- Reasonable cost: many thousands of dollars less than other IR test charts and analysis software
- Support for a wide range of IR wavelengths: advanced infrared pigments are mixed with specialized enamels to deliver needed contrast in visible light through MWIR
- A modern test chart pattern designed for computer-based analysis delivers high-resolution slanted edges across the entire test chart, enabling variations in sharpness to be accurately and objectively measured across the full plane of the camera’s image sensor. The pattern also supports analysis of other key IR image quality factors, including noise and distortion.
- Proven software delivering trusted measurements. The IR Edition software is built on Imatest’s Master Edition, the world’s most popular software for measuring digital image quality. IR-specific testing capabilities, such as the ability to process negative SFRplus images typically captured by MWIR cameras, are continuously being added to the IR Edition.
- Easy integration with many IR Camera systems: The IR Edition can be be used to capture images directly from most IR cameras, speeding and simplifying the process of analyzing image quality. Such integration offers the additional benefit of enabling optimal camera focus, as demonstrated in this video (using an image sensor demo kit).