An image detail enhancement method and apparatus that is suitable for
different types of digital images, regardless of their signal frequency
range or noise level. The detail enhancement apparatus has multiple
filters termed, detail filter bank. A detail filter can be e.g. a high
pass filter (HPF) or a band pass filter (BPF). In a detail filter bank,
each detail filter has a pass band covering a specific frequency range
and can therefore be used to obtain the detail signal in the
corresponding frequency range from the original signal. The detail
signals from those detail filters can then be processed before added back
to the original signal as enhancements. This provides image detail
enhancement that is suitable for different types of digital images
(regardless of their signal frequency range or noise level).