METHOD AND SYSTEM FOR REAL-TIME NOISE REMOVAL AND IMAGE ENHANCEMENT OF HIGH-DYNAMIC RANGE IMAGES

摘要

A method and system for real-time noise removal and image enhancement of high- dynamic range (HDR) images. The method comprises receiving an input image I, the input image I comprising a HDR image, and operating processing circuitry for (i) applying a first edge-preserving filter (e.g. guided filter) to the input image I, thereby generating a first image component B1 and a first set of linear coefficients ā_i,1; (ii) applying a second edge-preserving filter (e.g. guided filter) to the input image I, thereby generating a second image component B₂ and a second set of linear coefficients ā_i2; (iii) generating a plausibility mask P from a combination of the first set of linear coefficients ā_i,1 and the second set of linear coefficients ā_i2, the plausibility mask P indicating spatial detail within the input image I; and (iv) generating an output image O based on first image component B₁, the second image component B₂ and the plausibility mask P. Generating an output image O may comprise generating an output image O based on the summation of the second image component B₂ and a detail image component D' derived from the first image component B₁ and the plausibility mask P. The detail image component D' may be given by D' = λΡ. D, where D = B₁ - B₂, and λ is a gain factor for adjusting the contrast of details in D. An intermediate image O' may be derived by O' = B₂ + D'. The method may include mapping the intermediate image to the output image by histogram generation, classification of grayscale values within the intermediate image O', and determining output image O from Formula (I).