Abstract: By introducing a gradient field into the bilateral filter,the trilateral filter favorably preserves image details at the cost of high computational consumption.In this paper,we present a fast trilateral filtering algorithm based on intensity-layer decomposition.The proposed approach accelerates the gradient filtering in three stages: decomposing the image intensity into several layers,computing two intermediate images for each layer,and performing Gaussian filtering on these intermediate images.Experimental results show that our approach is about 10 times faster than the standard solution in the context of tone mapping,and achieves similar image quality.