1. A method for reducing scintillation in an image of a scene, the method comprising: receiving an input sequence of images of the scene; grouping a first number of images that occur in sequence within the input sequence of images of the scene into a first subset of images; grouping a second number of images that occur in sequence within the input sequence of images of the scene into a second subset of images; generating a first combined image by applying an arithmetic algorithm to the first subset of images; generating a second combined image by applying the arithmetic algorithm to the second subset of images; creating a composite mask based on at least the first combined image and the second combined image; generating a composite image using the composite mask and at least one of the first combined image or the second combined image; and outputting the composite image.