Retinex algorithm deals with the removal of unfavorable illumination effects from a given image.Solving it is typically done by introducing a regularization that forces a spatial smoothness on the illumination

which is computational expensive.In this paper we propose a non-iterative retinex algorithm based on a recent"guided image filter".Assuming a spatial smoothness on the reflectance

a method using two guided image filters is applied to eliminate artifacts caused by noise.Then

a multi-resolution framework combining guided image filtering and wavelet thresholding

is presented.Our framework is very effective in achieving a trade-off between detail enhancement and color constancy.Compared to other enhancement algorithms

our results verify the new approach's efficiency in eliminating artifacts caused by noise

detail enhancement

and color constancy.