The invention relates to a fast image filtering method based on space filling curves and extreme points. The fast image filtering method based on the space filling curves and the extreme points comprises the following steps: a first step is that a
source image to be filtered is input; a second step is that a
Hilbert curve is generated; a third step is that pixel points in a two-dimensional
image domain are subjected to sequencing according to an order indicated by the
Hilbert curve, and a one-dimensional pixel
point sequence is generated; a fourth step is that a maximum envelope and a minimum envelope of the one-dimensional pixel
point sequence are calculated, and the obtained envelopes are subjected to fine
processing; a fifth step is that the maximum envelope and the minimum envelope after the fine
processing are used as input values, and an image base and image details after a
smoothing filtering process are obtained through calculation of a mean value; and a sixth step is that one-dimensional filtering results of the image base and the image details are subjected to counter-Hilbert sequencing, an original two-dimensional image is divided into a smooth part and a detail part, and therefore filtering is finished. The fast image filtering method based on the space filling curves and the extreme points can extremely reduce interpolation errors and lower the complexity of the filtering, and can achieve a quasi-real-
time effect.