Error smoothing through global source non-uniformity correction

Abstract

A method of determining a temperature of an element in a scene includes providing a set of targets each characterized by a target temperature and measuring pixel output values for pixels in a detector array for the targets in the set of targets. Measuring pixel output values is performed at a plurality of detector temperatures. The method also includes mapping each pixel output value to one of a plurality of constant values, each of the plurality of constant values being associated with one of the target temperatures, assembling a scene temperature profile using the mapped pixel output values, and obtaining an image of the scene including the element, wherein the element is associated with a pixel of the detector array. The method further includes determining a pixel value associated with the element and computing the temperature of the element using the scene temperature profile.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is a divisional of U.S. utility application Ser. No. 14 / 534,008 filed on Nov. 5, 2014, now allowed, the contents of which are incorporated by reference in their entirety for all purposes.BACKGROUND OF THE INVENTION[0002]The electromagnetic spectrum encompasses radiation from gamma rays, x-rays, ultra violet, a thin region of visible light, infrared, terahertz waves, microwaves, and radio waves, which are all related and differentiated in the length of their wave (wavelength). All objects, as a function of their temperatures, emit a certain amount of radiation. For example, the higher an object's temperature, the more infrared radiation the object emits.[0003]Thermal cameras have many applications, particularly when light and visibility are low. For example, thermal cameras have been used in military applications to locate human beings or other warm entities. Warm-blooded animals can also be monitored using thermographic i...

AI Technical Summary

Benefits of technology

The present invention provides techniques for improving non-uniformity correction in infrared images by utilizing factory calibration data obtained using a shutter or a thermal reference source. Linear and quadratic non-uniformity correction techniques are applied, and multiple non-uniformity corrections are integrated to provide enhanced performance. The invention offers improved response time in thermal imaging systems and is applicable to a wide variety of imaging systems.

Problems solved by technology

The difference in gain and offset values among detectors can produce fixed pattern noise in the image.

Images