TienDaiIFHDR

Project Title

Image Fusion for High Dynamic Range/ All-in-focus Applications

Introduction

Dynamic range of a scene is defined as the ratio of the highest to the lowest luminance. The real world scenes often have a very wide range of luminance, sometimes exceeding 10 orders of magnitude. Fig. 1 shows a high dynamic range ( HDR ) scene with a dynamic range of about 167, 470:1. To reproduce these scenes presents a challenge for conventional digital capture and display devices, which suffer a limited dynamic range of only 2 orders of magnitude.

The most common solution to address this problem is to take a sequence of low dynamic range ( LDR ) images of the same scene under different exposure intervals to capture all the radiance information and then render the captured stack to display. There are generally two pipelines. One way is to firstly estimate the camera response function from the image sequence to recover the true radiance of the original scene ( recorded as a 32 bit float radiance map ) [ 1, 2 ], and then tone map the created radiance map for display on LDR reproduction media ( usually 8 bit per channel ) [ 3, 4, 5 ]. Although this way gives very satisfying result, it's computationally expensive and time consuming. The other way is to fuse the captured images directly without the intermediate step of creating radiance map [ 6, 7 ], which is usually referred as "Exposure Fusion ( EF )" [7]. EF produces HDR-like images, which are comparable to those tone-mapped results, at a much lower computational cost. Due to its effectiveness and computational efficiency, EF is adopted by most of HDR applications on mobile platform, which has limited computational power [8].

Fig.1. Multi-exposed image stack of a high dynamic range scene

Methods

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Results

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Conclusions

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References

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Appendix I - Code and Data

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Appendix II - Work Partition

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