16421: vision sensors lecture 7: high dynamic range imaging instructor: s. narasimhan wean 5312, t-r...
TRANSCRIPT
![Page 1: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/1.jpg)
High Dynamic Range Imaging
and Tone Mapping
![Page 2: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/2.jpg)
Paul Debevec’s SIGGRAPH Course
![Page 3: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/3.jpg)
![Page 4: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/4.jpg)
![Page 5: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/5.jpg)
![Page 6: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/6.jpg)
![Page 7: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/7.jpg)
![Page 8: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/8.jpg)
![Page 9: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/9.jpg)
The Problem of Dynamic Range
• Dynamic Range: Range of brightness values measurable with a camera
(Hood 1986)
High Exposure Image Low Exposure Image
• We need about 5-10 million values to store all brightnesses around us.• But, typical 8-bit cameras provide only 256 values!!
• Today’s Cameras: Limited Dynamic Range
![Page 10: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/10.jpg)
Images taken with a fish-eye lens of the sky show the wide range of brightnesses.
High Dynamic Range Imaging
• Capture a lot of images with different exposure settings.
• Apply radiometric calibration to each camera.
• Combine the calibrated images (for example, using averaging weighted by exposures).
(Debevec)
(Mitsunaga)
![Page 11: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/11.jpg)
SceneRadiance L Lens Image
Irradiance E
CameraElectronics
Scene
ImageIrradiance E
Relationship between Scene and Image Brightness
Measured Pixel Values, I
Non-linear Mapping!
Linear Mapping!
• Before light hits the image plane:
• After light hits the image plane:
Can we go from measured pixel value, I, to scene radiance, L?
![Page 12: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/12.jpg)
Radiometric Calibration
•Important preprocessing step for many vision and graphics algorithms such as photometric stereo, invariants, de-weathering, inverse rendering, image based rendering, etc.
EIg :1
•Use a color chart with precisely known reflectances.
Irradiance = const * ReflectanceP
ixel V
alu
es
3.1%9.0%19.8%36.2%59.1%90%
• Use more camera exposures to fill up the curve.• Method assumes constant lighting on all patches and works best when source is far away (example sunlight).
• Unique inverse exists because g is monotonic and smooth for all cameras.
0
255
0 1
g
?
?1g
![Page 13: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/13.jpg)
![Page 14: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/14.jpg)
![Page 15: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/15.jpg)
![Page 16: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/16.jpg)
![Page 17: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/17.jpg)
![Page 18: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/18.jpg)
![Page 19: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/19.jpg)
![Page 20: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/20.jpg)
![Page 21: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/21.jpg)
[Greg Ward]
![Page 22: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/22.jpg)
[Greg Ward][Greg Ward]
![Page 23: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/23.jpg)
![Page 24: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/24.jpg)
![Page 25: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/25.jpg)
![Page 26: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/26.jpg)
![Page 27: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/27.jpg)
![Page 28: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/28.jpg)
![Page 29: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/29.jpg)
![Page 30: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/30.jpg)
![Page 31: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/31.jpg)
![Page 32: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/32.jpg)
![Page 33: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/33.jpg)
![Page 34: 16421: Vision Sensors Lecture 7: High Dynamic Range Imaging Instructor: S. Narasimhan Wean 5312, T-R 1:30pm – 3:00pm](https://reader035.vdocuments.us/reader035/viewer/2022062314/56649ecb5503460f94bd9a20/html5/thumbnails/34.jpg)