Methods and apparatus for reducing noise in images acquired with a scanning beam device are disclosed. A representative method may include scanning a beam of light over a surface in a scan with a variable velocity. Light backscattered from the surface may be detected at different points in time during the scan at a substantially constant rate. Reduced-noise representations of groups of the detected light that each correspond to a different position in an image of the surface may be generated. The reduced-noise representations may be generated for groups having multiple different sizes. The image of the surface may be generated by representing the different positions in the image with the reduced-noise representations of the corresponding groups. Other methods and apparatus are disclosed.