This disclosure describes embodiments of systems and methods that can identify and image leaks and spills while simultaneously viewing the unchanging background. In one embodiment, the system includes an image capture device and an image processing device, which receives a first image frame and a second image frame from the image capture device. The image processing device can identify a region of variation in the second image frame that corresponds to a change in a scene parameter (e.g., temperature) as between the first image frame and the second image frame. These embodiments provide a normal dynamic range thermal image that can be colorized to identify the leak or spill as the leak or spill develops over time. The systems and methods can minimize false alarms, addressing potential issues that arise in connection with meteorological events (e.g., precipitation), noise sources, and relative motion between the image capture device and the scene.