scholarly journals A Novel Approach for Detail-Enhanced Exposure Fusion Using Guided Filter

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Harbinder Singh ◽  
Vinay Kumar ◽  
Sunil Bhooshan

In this paper we propose a novel detail-enhancing exposure fusion approach using nonlinear translation-variant filter (NTF). With the captured Standard Dynamic Range (SDR) images under different exposure settings, first the fine details are extracted based on guided filter. Next, the base layers (i.e., images obtained from NTF) across all input images are fused using multiresolution pyramid. Exposure, contrast, and saturation measures are considered to generate a mask that guides the fusion process of the base layers. Finally, the fused base layer is combined with the extracted fine details to obtain detail-enhanced fused image. The goal is to preserve details in both very dark and extremely bright regions without High Dynamic Range Image (HDRI) representation and tone mapping step. Moreover, we have demonstrated that the proposed method is also suitable for the multifocus image fusion without introducing artifacts.

Author(s):  
Jin Wang ◽  
Shenda Li ◽  
Qing Zhu

Abstract With wider luminance range than conventional low dynamic range (LDR) images, high dynamic range (HDR) images are more consistent with human visual system (HVS). Recently, JPEG committee releases a new HDR image compression standard JPEG XT. It decomposes an input HDR image into base layer and extension layer. The base layer code stream provides JPEG (ISO/IEC 10918) backward compatibility, while the extension layer code stream helps to reconstruct the original HDR image. However, this method does not make full use of HVS, causing waste of bits on imperceptible regions to human eyes. In this paper, a visual saliency-based HDR image compression scheme is proposed. The saliency map of tone mapped HDR image is first extracted, then it is used to guide the encoding of extension layer. The compression quality is adaptive to the saliency of the coding region of the image. Extensive experimental results show that our method outperforms JPEG XT profile A, B, C and other state-of-the-art methods. Moreover, our proposed method offers the JPEG compatibility at the same time.


2020 ◽  
Vol 10 (18) ◽  
pp. 6262
Author(s):  
Feiran Chen ◽  
Jianlin Zhang ◽  
Jingju Cai ◽  
Tao Xu ◽  
Gang Lu ◽  
...  

The detail enhancement and dynamic range compression of infrared (IR) images is an important issue and a necessary practical application in the domain of IR image processing. This paper provides a novel approach to displaying high dynamic range infrared images on common display equipment with appropriate contrast and clear detail information. The steps are chiefly as follows. First, in order to protect the weak global details in different regions of the image, we adjust the original normalized image into multiple brightness levels by adaptive Gamma transformation. Second, each brightness image is decomposed into a base layer and several detail layers by the multiscale guided filter. Details in each image are enhanced separately. Third, to obtain the image with global details of the input image, enhanced images in each brightness are fused together. Last, we filter out the outliers and adjust the dynamic range before outputting the image. Compared with other conventional or cutting-edge methods, the experimental results demonstrate that the proposed approach is effective and robust in dynamic range compression and detail information enhancement of IR image.


2013 ◽  
Vol 2013 ◽  
pp. 1-18 ◽  
Author(s):  
Harbinder Singh ◽  
Vinay Kumar ◽  
Sunil Bhooshan

We develop a multiexposure image fusion method based on texture features, which exploits the edge preserving and intraregion smoothing property of nonlinear diffusion filters based on partial differential equations (PDE). With the captured multiexposure image series, we first decompose images into base layers and detail layers to extract sharp details and fine details, respectively. The magnitude of the gradient of the image intensity is utilized to encourage smoothness at homogeneous regions in preference to inhomogeneous regions. Then, we have considered texture features of the base layer to generate a mask (i.e., decision mask) that guides the fusion of base layers in multiresolution fashion. Finally, well-exposed fused image is obtained that combines fused base layer and the detail layers at each scale across all the input exposures. Proposed algorithm skipping complex High Dynamic Range Image (HDRI) generation and tone mapping steps to produce detail preserving image for display on standard dynamic range display devices. Moreover, our technique is effective for blending flash/no-flash image pair and multifocus images, that is, images focused on different targets.


2013 ◽  
Vol 710 ◽  
pp. 665-669
Author(s):  
Hui Zhang ◽  
Hua Wang ◽  
Jian Zhong Cao ◽  
Xiao Dong Zhao ◽  
Yang Jie Lei ◽  
...  

This paper presents an improved high dynamic range image tone mapping method based on fast bilateral filtering. The algorithm first applied a bilateral filtering to the luminance channel of the image, the image is decomposed into an HDR base layer and an LDR detail layer. Then the HDR base layer is blurred with bilateral filtering again, get the details portion of the base layer, at the same time the dynamic range of the global base layer is compressed. Finally, the detail component and the compressed HDR base layer are recombined and the result is tone-mapped image for displaying. For color image, the color restoration converts luminance value into RGB color. Experimental results show that the proposed technique performed better than the conventional bilateral filtering, preserving more details and enhancing local contrast, giving decent visual effect and avoiding additional artifacts.


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