A hand held thermal imaging camera comprising: an infrared camera module ; a user interface ; a display ; a processor in communication with the user interface, the display, and the infrared camera module, the processor being configured to capture infrared images via the infrared camera module; and a memory in communication with the processor and including instructions for performing an optical gas imaging process, wherein the instructions cause the processor to, upon a detected actuation from the user interface: (a) perform a non-uniformity correction process to reduce or eliminate fixed pattern noise from infrared image data from the infrared camera module; (b) capture infrared images of an infrared scene via the infrared camera module at a plurality of times, each of the captured infrared images being subject to the non-uniformity correction; (c) register the plurality of captured infrared images via an image stabilization process to form a plurality of stabilized captured infrared images; (d) perform an optical gas imaging process on the plurality of stabilized captured infrared images to generate optical gas image data emphasizing change in the infrared scene, by subtracting stabilized captured infrared images from one another; and (e) generate a display image including the generated optical gas image data for presentation on the display. an infrared camera module ; a user interface ; a display ; a processor in communication with the user interface, the display, and the infrared camera module, the processor being configured to capture infrared images via the infrared camera module; and a memory in communication with the processor and including instructions for performing an optical gas imaging process, wherein the instructions cause the processor to, upon a detected actuation from the user interface: (a) perform a non-uniformity correction process to reduce or eliminate fixed pattern noise from infrared image data from the infrared camera module; (b) capture infrared images of an infrared scene via the infrared camera module at a plurality of times, each of the captured infrared images being subject to the non-uniformity correction; (c) register the plurality of captured infrared images via an image stabilization process to form a plurality of stabilized captured infrared images; (d) perform an optical gas imaging process on the plurality of stabilized captured infrared images to generate optical gas image data emphasizing change in the infrared scene, by subtracting stabilized captured infrared images from one another; and (e) generate a display image including the generated optical gas image data for presentation on the display. (a) perform a non-uniformity correction process to reduce or eliminate fixed pattern noise from infrared image data from the infrared camera module; (b) capture infrared images of an infrared scene via the infrared camera module at a plurality of times, each of the captured infrared images being subject to the non-uniformity correction; (c) register the plurality of captured infrared images via an image stabilization process to form a plurality of stabilized captured infrared images; (d) perform an optical gas imaging process on the plurality of stabilized captured infrared images to generate optical gas image data emphasizing change in the infrared scene, by subtracting stabilized captured infrared images from one another; and (e) generate a display image including the generated optical gas image data for presentation on the display. <EOS>