Single Image Haze Removal Using Dark Channel Prior參考
-
Upload
yin-chieh-li -
Category
Documents
-
view
26 -
download
9
Transcript of Single Image Haze Removal Using Dark Channel Prior參考
![Page 1: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/1.jpg)
Single Image Haze Removal
Using Dark Channel Prior
Kaiming He
Jian Sun
Xiaoou Tang
The Chinese University of Hong Kong
Microsoft Research Asia
The Chinese University of Hong Kong
![Page 2: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/2.jpg)
Hazy Images
• Low visibility
• Faint colors
![Page 3: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/3.jpg)
Goals of Haze Removal
• Scene restoration
• Depth estimation
depth
![Page 4: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/4.jpg)
Haze Imaging Model
)1( tt AJI
TransmissionScene radianceHazy image
Atmospheric light
![Page 5: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/5.jpg)
Transmission
Haze Imaging Model
)1( tt AJI
Depth
td ln
![Page 6: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/6.jpg)
Ambiguity in Haze Removal
input
scene
radiance
depth
….
![Page 7: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/7.jpg)
Previous Works
• Using additional information
– Polarization filter [Shwartz et al., CVPR’06]
– Multiple images [Narasimhan & Nayar, CVPR’00]
– Known 3D model [Kopf et al., Siggraph Asia’08]
– User-assistance [Narasimhan & Nayar, CPMCV’03]
![Page 8: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/8.jpg)
Previous Works
• Single image
– Maximize local contrast [Tan, CVPR 08]
![Page 9: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/9.jpg)
Previous Works
• Single image
– Maximize local contrast [Tan, CVPR 08]
![Page 10: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/10.jpg)
Previous Works
• Single image
– Maximize local contrast [Tan, CVPR 08]
– Independent Component Analysis [Fattal, Siggraph 08]
![Page 11: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/11.jpg)
Previous Works
• Single image
– Maximize local contrast [Tan, CVPR 08]
– Independent Component Analysis [Fattal, Siggraph 08]
![Page 12: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/12.jpg)
Priors in Computer Vision
• Smoothness prior
• Sparseness prior
• Exemplar-based prior
Ill-posed
problem
well-posed
problem
prior
Dark Channel Prior
![Page 13: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/13.jpg)
Dark Channel
• min (rgb, local patch)
![Page 14: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/14.jpg)
Dark Channel
• min (rgb, local patch)
– min (r, g, b)
min (r, g, b)
![Page 15: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/15.jpg)
Dark Channel
• min (rgb, local patch)
– min (r, g, b)
– min (local patch) = min filter
15 x15
darkest dark channel
![Page 16: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/16.jpg)
Dark Channel
• min (rgb, local patch)
– min (r, g, b)
– min (local patch) = min filter
dark channel
))(Jmin(min)(J c
}bg,r,{c)(yyx
x dark
– Jc: color channel of J
– Jdark: dark channel of J
![Page 17: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/17.jpg)
Dark Channel
• min (rgb, local patch)
– min (r, g, b)
– min (local patch) = min filter
dark channel
)Jmin(minJ c
cdark
– Jc: color channel of J
– Jdark: dark channel of J
![Page 18: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/18.jpg)
A Surprising ObservationHaze-free
![Page 19: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/19.jpg)
A Surprising ObservationHaze-free
![Page 20: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/20.jpg)
A Surprising ObservationHaze-free
![Page 21: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/21.jpg)
A Surprising ObservationHaze-free
![Page 22: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/22.jpg)
A Surprising ObservationHaze-free
![Page 23: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/23.jpg)
A Surprising ObservationHaze-free
![Page 24: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/24.jpg)
A Surprising Observation
0
0.2
0.4
0.6
0.8
1
0 64 128 192 256
Prob.
Pixel intensity of dark channels
86% pixels
in [0, 16]
5,000 haze-free
images
![Page 25: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/25.jpg)
Dark Channel Prior
• For outdoor haze-free images
0)Jmin(min c
c
![Page 26: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/26.jpg)
What makes it dark?
• Black object
• Colorful object
• Shadow
![Page 27: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/27.jpg)
Dark Channel of Hazy Image
• The dark channel is no longer dark.
hazy image dark channel
![Page 28: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/28.jpg)
Transmission Estimation
)1( tt AJIHaze imaging model
tt 1A
J
A
Ic
c
c
c
Normalize
tt
1)A
Jmin(min)
A
Imin(min
c
c
cc
c
c
Compute dark channel
![Page 29: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/29.jpg)
tt
1)A
Jmin(min)
A
Imin(min
c
c
cc
c
c
Compute dark channel
Transmission Estimation
0)Jmin(min c
c
Dark Channel Prior
0
![Page 30: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/30.jpg)
Compute dark channel
tt
1)A
Jmin(min)
A
Imin(min
c
c
cc
c
c
Transmission Estimation
Estimate transmission
)A
Imin(min1
c
c
ct
![Page 31: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/31.jpg)
Transmission Estimation
input I testimated
)A
Imin(min1
c
c
ct
Estimate transmission
![Page 32: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/32.jpg)
Transmission Optimization
)1( tt AJIHaze imaging model
)1( BFIMatting model
+Refined
transmission
+
tri-map
![Page 33: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/33.jpg)
Transmission Optimization
• L - matting Laplacian [Levin et al., CVPR ‘06]
• Constraint - soft, dense (matting - hard, sparse)
LtttttT
2~)(
Data term Smoothness term
![Page 34: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/34.jpg)
Transmission Optimization
before optimization
![Page 35: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/35.jpg)
Transmission Optimization
after optimization
![Page 36: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/36.jpg)
hazy image dark channel
brightest pixels
Atmospheric Light Estimation
brightest pixel
A: most hazy
![Page 37: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/37.jpg)
Scene Radiance Restoration
)1( tt AJI
Scene radiance TransmissionHazy image
Atmospheric
light
![Page 38: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/38.jpg)
Results
input
![Page 39: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/39.jpg)
Results
recovered image
![Page 40: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/40.jpg)
Results
depth
![Page 41: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/41.jpg)
Results
input
![Page 42: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/42.jpg)
Results
recovered image
![Page 43: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/43.jpg)
Results
depth
![Page 44: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/44.jpg)
Results
input
![Page 45: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/45.jpg)
Results
recovered image
![Page 46: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/46.jpg)
Results
depth
![Page 47: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/47.jpg)
Comparisons
input [Fattal Siggraph 08]
![Page 48: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/48.jpg)
Comparisons
input our result
![Page 49: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/49.jpg)
Comparisons
input [Tan, CVPR 08]
![Page 50: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/50.jpg)
Comparisons
input our result
![Page 51: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/51.jpg)
input our result[Kopf et al, Siggraph Asia 08]
Comparisons
![Page 52: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/52.jpg)
Results: De-focus
recovered scene radiance
input
depth
![Page 53: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/53.jpg)
input
depth
Results: De-focus
de-focus
![Page 54: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/54.jpg)
Results: Video
output
input
![Page 55: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/55.jpg)
Results: Video
output
input
![Page 56: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/56.jpg)
input our result transmission
• Inherently white or grayish objects
Limitations
![Page 57: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/57.jpg)
• Haze imaging model is invalid
– e.g. non-constant A
input our result
Limitations
![Page 58: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/58.jpg)
Summary
• Dark channel prior
– A natural phenomenon
– Very simple but effective
– Put a bad image to good use
![Page 59: Single Image Haze Removal Using Dark Channel Prior參考](https://reader035.fdocuments.us/reader035/viewer/2022062216/55cf9a6b550346d033a19ed4/html5/thumbnails/59.jpg)
Thank you