A system for filtering an image using a bilateral filter includes a receiver and a bilateral filter. The receiver is for receiving an image having a plurality of pixels. The bilateral filter is run in constant time and comprises a pixel value range determinor and a spatial filter. The pixel value range determinor is configured to determine a range of pixel values of the plurality of pixels. The spatial filter is configured to spatially filter at least one of the plurality of pixels. The spatial filter is further configured to perform over a plurality of pixel values in the range of pixel values.