A multi-resolution filter is provided that may be used to attenuate
aliasing artifacts in a digital input signal, such as a digital image
acquired by a digital camera. The multi-resolution filter reduces the
resolution of the digital input signal and filters the reduced resolution
signal using a median filter. The output of the median filter is provided
to an interpolation filter, which increases the resolution of the median
filter's output to produce a digital output signal in which aliasing
artifacts from the digital input signal have been attenuated. The
multi-resolution filter may be advantageously applied to the chrominance
channels of digital images to attenuate aliasing artifacts without
undesirably blurring sharp luminance and color boundaries in the digital
image. Furthermore, the computational expense associated with the median
filter is diminished by reducing the resolution of the digital input
signal before filtering it using the median filter.