Method and system for real-time noise removal and image enhancement of high dynamic range images

摘要

The invention relates to a method and system for real-time noise removal and image enhancement of high dynamic range (HDR) images. The method includes obtaining an input image I, the input image I comprising an HDR image, and operating processing circuitry for (i) applying a first edge-preserving filter (eg, guided filter) to the input image I, thereby producing a first image component B1 and a first set of linear coefficients ᾱi, 1 are generated; (ii) applying a second edge preserving filter (eg, guided filter) to the input image I, thereby producing a second image component B2 and a second set of linear coefficients ᾱi, 2; (iii) generating a plausibility mask P from a combination of the first set of linear coefficients ᾱi, 1 and the second set of linear coefficients, the plausibility mask P indicating a spatial detail in the input image I; and (iv) generating an output image O based on the first image component B1, the second image component B2 and the plausibility mask P. Generating an output image O may include 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 'can be given by D' = λP · D, where D = B1 - B2 and λ is a gain factor for adjusting the contrast of details in D. An intermediate image O 'can be derived by O' = B2 + D '. The method may include mapping the intermediate image to the output image by histogram generation, grading gray levels in the intermediate image O ', and obtaining the output image O from the formula (I).