Burst photography for high dynamic range and low-light imaging on mobile cameras
| Autor: | Jonathan T. Barron, Dillon Sharlet, Florian Kainz, Samuel W. Hasinoff, Andrew Adams, Ryan Geiss, Jiawen Chen, Marc Levoy |
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| Rok vydání: | 2016 |
| Předmět: |
Pixel
Aperture Computer science business.industry Dynamic range Noise reduction Wiener filter Photography ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION 020207 software engineering 02 engineering and technology Tone mapping Computer Graphics and Computer-Aided Design Computational photography symbols.namesake Color depth 0202 electrical engineering electronic engineering information engineering symbols RGB color model 020201 artificial intelligence & image processing Computer vision Artificial intelligence business High dynamic range |
| Zdroj: | ACM Transactions on Graphics. 35:1-12 |
| ISSN: | 1557-7368 0730-0301 |
| Popis: | Cell phone cameras have small apertures, which limits the number of photons they can gather, leading to noisy images in low light. They also have small sensor pixels, which limits the number of electrons each pixel can store, leading to limited dynamic range. We describe a computational photography pipeline that captures, aligns, and merges a burst of frames to reduce noise and increase dynamic range. Our system has several key features that help make it robust and efficient. First, we do not use bracketed exposures. Instead, we capture frames of constant exposure, which makes alignment more robust, and we set this exposure low enough to avoid blowing out highlights. The resulting merged image has clean shadows and high bit depth, allowing us to apply standard HDR tone mapping methods. Second, we begin from Bayer raw frames rather than the demosaicked RGB (or YUV) frames produced by hardware Image Signal Processors (ISPs) common on mobile platforms. This gives us more bits per pixel and allows us to circumvent the ISP's unwanted tone mapping and spatial denoising. Third, we use a novel FFT-based alignment algorithm and a hybrid 2D/3D Wiener filter to denoise and merge the frames in a burst. Our implementation is built atop Android's Camera2 API, which provides per-frame camera control and access to raw imagery, and is written in the Halide domain-specific language (DSL). It runs in 4 seconds on device (for a 12 Mpix image), requires no user intervention, and ships on several mass-produced cell phones. |
| Databáze: | OpenAIRE |
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