Iso-thermal Masking for Thermal Image Edge Enhancement






Austin A. Richards and Charles W. Handley



Deleting clutter when overlaying thermal images onto regular images by enhancing detection and display of objects of interest in images.



Thermal infrared cameras capture thermal images and provide an output image or a video stream to a user. In some systems, captured thermal images are sometimes blended or overlaid onto additional images produced by a non-thermal imager such as an image intensifier. The combination of non-thermal images with thermal images is often intended to give a viewer the ability to more quickly locate objects of tactical interest within a scene. However, it can sometimes be difficult to combine multi-wavelength image data in this way without generating visible artifacts that are generally considered undesirable clutter for the viewer. If care is not taken, this can be distracting or dangerous for a viewer, particularly in tactical situations. As a result, there is a need for improved techniques for infrared image processing.



Systems and methods are disclosed herein to provide, according to various embodiments, enhanced detection and display of objects of interest in images. For example, a camera may include an infrared image capture component such as a thermal image capture component and/or a non-thermal image capture component such as an image intensifier or other low light visible and/or near infrared (VIS/NIR) image capture component. Thermal images may be captured using the thermal image capture component. Non-thermal images may be captured using the non-thermal image capture component. The thermal images may be processed by performing a temperature based masking operation such as an isothermal masking operation prior to performing edge detection operations on the thermal images to generate a thermal edge image. The thermal edge image may be blended or overlaid with the non-thermal image and/or the thermal image to highlight objects of interest in an imaged scene. By providing edge images generated using an isothermal masking process, an edge-enhanced image generated from the thermal images and/or non-thermal images may be provided that guides the user’s eye to the objects of interest without including high-gradient clutter that could otherwise draw the user’s attention away from the objects of interest.

I150007FL01 Publication Jan2016