A Tone Mapping Method for HDR Images Based on Multi-Scale Morphology

Abstract

The invention discloses a multi-scale morphology-based HDR image tone mapping method, the method comprising: S1, inputting the HDR image to be compressed; S2, constructing the logarithmic image of the HDR image to be compressed; S3, performing the logarithmic image processing on the logarithmic image Dynamic range compression and multi-scale decomposition to obtain the first Gaussian pyramid and the first Laplacian pyramid; S4, using a one-dimensional boundary-preserving polishing operator to extract the enhanced detail layer of the first Gaussian pyramid, and the details of the first Gaussian pyramid Add layer by layer to the layer corresponding to the first Laplacian pyramid to obtain the second Laplacian pyramid; S5, perform dynamic range compression reconstruction on the second Laplacian pyramid, and obtain detail enhancement after dynamic range compression image; S6, performing exponential transformation on the detail-enhanced image to obtain a first LDR image; S7, performing color correction on the first LDR image to obtain an LDR image to be output. The invention can realize effective compression of the dynamic range of the HDR image, and can meet certain real-time application requirements.

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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