HDR image tone mapping method based on multi-scale morphology

Abstract

The invention discloses an HDR image tone mapping method based on multi-scale morphology. The method comprises the following steps: S1, inputting an HDR image to be compressed; S2, constructing a logarithm image of the HDR image to be compressed; S3, performing dynamic range compression multi-scale decomposition on the logarithm image to obtain a first Gaussian pyramid and a first Laplace pyramid;S4, extracting an enhanced detail layer of the first Gaussian pyramid by adopting a one-dimensional boundary polishing operator, and adding the detail layer of the first Gaussian pyramid to a layer corresponding to the first Laplacian pyramid layer by layer to obtain a second Laplacian pyramid; S5, performing dynamic range compression reconstruction on the second Laplace pyramid to obtain a detail enhanced image after dynamic range compression; S6, performing exponential transformation on the detail-enhanced image to obtain a first LDR image; and S7, performing color correction on the first LDR image to obtain a to-be-output LDR image. Effective compression of an HDR image dynamic range can be realized, and certain real-time application requirements can be met.

Description

technical field [0001] The present invention relates to the technical field of image processing, in particular to a multi-scale morphology-based HDR image tone mapping method. Background technique [0002] Compared with LDR (English full name is "Low Dynamic Range", Chinese full name is "low dynamic range") images, HDR (English full name is "High Dynamic Range", Chinese full name is "High Dynamic Range") images can express more scene details Contrast information with brightness has been widely used in digital image technology. Dedicated HDR display devices are expensive and cost-effective. When an HDR image is displayed on an LDR display device, it cannot truly reproduce the complete light and shadow effects of the original scene, but a good tone mapping method can achieve effective compression of the dynamic range of the HDR image and solve the problem of dynamic range mismatch to meet more practical applications need. [0003] Generally speaking, methods related to tone...

AI Technical Summary

Problems solved by technology

In 2003, Drago proposed a tone mapping method based on the logarithmic transformation, because the logarithmic transformation is more similar to the human eye's perception of light, but the method loses serious details and cannot efficiently compress the dynamic range.

The disadvantage of the local tone mapping method is that it requires a large amount of calculation and is prone to "halo" effects.

In 1993, a local method was first proposed by Chiu et al. This method obtains the local brightness variation coefficient through the sensitivity of the human visual system to brightness changes, but this method cannot achieve ideal results in extremely bright and extremely dark areas.

In 2002, Reinhard et al. proposed a local method for adaptively adjusting brightness based on the photographic model. This method runs faster and realizes the controllable operation of color, contrast and global brightness, but it is easy to cause halo or loss of details.

During the operation of this method, the image will be divided into different layers according to the actual needs, and the related processing of the image will be completed in the layering process, but because the process cannot be finely grasped, it will cause halo phenomenon when the image is synthesized

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