Improved techniques for infrared imaging and gas detection are provided. In one example, a system includes a sensor array configured to receive infrared radiation from a scene comprising a background portion and a gas. The sensor array includes a first set of infrared sensors configured with a first spectral response corresponding to a first wavelength range of the infrared radiation associated with the background portion. The sensor array also includes a second set of infrared sensors configured with a second spectral response corresponding to a second wavelength range of the infrared radiation associated with the gas. The system also includes a read out integrated circuit (ROIC) configured to provide pixel values for first and second images captured by the first and second sets of infrared sensors, respectively, in response to the received infrared radiation. Additional systems and methods are also provided.