color seamlessness in multi-projector displays using constrained gamut morphing
DESCRIPTION
Color Seamlessness in Multi-Projector Displays Using Constrained Gamut Morphing. IEEE Visualization, 2009 Behzad Sajadi Maxim Lazarov Aditi Majumder M. Gopi. Registration Problem. Color: Brightness & Chrominance. Brightness: 1D Chrominance (x, y): 2D 3D color gamut. - PowerPoint PPT PresentationTRANSCRIPT
Color Seamlessness in Multi-Projector Displays Using Constrained Gamut
Morphing
IEEE Visualization, 2009
Behzad SajadiMaxim LazarovAditi Majumder
M. Gopi
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Registration Problem
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Color: Brightness & Chrominance Brightness: 1D Chrominance (x, y): 2D
3D color gamut
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Color Variation Visualization
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Overview Prior Art Motivation Algorithm Results
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Prior Art: Overlap Blending
Proj1 Proj2 Proj1 Proj2Overlap Region Overlap Region
Raskar et al SIGGRAPH 1998; Li et al IEEE Computer Graphics and Applications, 2000; Chen et al SPIE Projection Displays, 2001
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Prior Art: Overlap blending Assumes
Uniform brightness in each projector All projectors have similar brightness Projectors are linear devices
Addresses the overlaps only No measurement or correction of intra
or inter projector brightness variation
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BeforeCorrection
OverlapBlending
Prior Art: Overlap Blending
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Prior Art: Measurement with High Resolution Camera
Single ProjectorBrightness Profile
Multi ProjectorBrightness Profile
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Prior Art: Strict Brightness Uniformity
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IEEE TVCG 2003, PROCAMS 2003 Majumder and Stevens
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Prior Art: Strict Brightness Uniformity
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Significant Contrast/ Dynamic Range Compression
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Before
After Strict Brightness Uniformity
Prior Art: Strict Brightness Uniformity
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Prior Art: Constrained Brightness Smoothing Smoothing is sufficient for perceptual
seamlessness Non-linear filtering Maximize dynamic range Solved using dynamic programming
ACM Transactions on Graphics 2005 Majumder and Stevens
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Before
After Strict Brightness Uniformity
Prior Art: Constrained Brightness Smoothing
IEEE TVCG 2003, PROCAMS 2003 Majumder and Stevens
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Before
After Constrained Brightness Smoothing
ACM Transactions on Graphics 2005 Majumder and Stevens
Prior Art: Constrained Brightness Smoothing
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Overview Prior Art Motivation Algorithm Results
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Motivation: Does it solve the problem?
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Motivation: Our Contribution Chrominance is constant within
projector Chrominance varies across projectors
and in overlaps Brightness smoothing does not
guarantee chrominance smoothing Constrained chrominance
smoothing in addition to brightness smoothing
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3D Gamut Morphing
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Motivation: Key Insight Smooth transition of chrominance
across overlap region Blending of the chromaticity coordinates Only need to manipulate the brightness
proportions of overlapping projectors Manipulate brightness to address
chrominance variation
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Overview Prior Art Motivation Algorithm Results
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Algorithm: Chrominance profile before registration
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Algorithm: Chrominance Gamut Morphing
ChrominanceGamut Morphing
Horizontal Blending
Vertical Blending
New BrightnessProfiles
Horizontal BlendingAttenuation Map
Vertical BlendingAttenuation Map
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Algorithm: Horizontal Blending
Before Chrominance Blending
After Horizontal Blending
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Algorithm: Vertical Blending
After Horizontal Blending
After Vertical Blending
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Algorithm: PipelineProjector Brightness
ProfilesProjector
Chrominance Gamut
Chrominance MorphingAttenuation Map
Chrominance Gamut Morphing
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Algorithm: Chrominance gamut morphing Modifies brightness profiles Removes C0 brightness discontinuity
Before Correction After Horizontal Blending After Vertical Blending
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Algorithm: Perceptual Brightness Constraining Does not guarantee imperceptible
brightness changes Apply Majumder et. al. 2005 to constrain
the brightness variations Retains chrominance gamut morphing
After Vertical BlendingAfter Brightness Constraining
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Algorithm: Bezier-based Brightness Smoothing Brightness profile is not derivative
continuous after Majumder et. Al. 2005 Assures Cn intensity continuity Retains chrominance gamut morphing
After Vertical BlendingAfter Brightness ConstrainingAfter Bezier-based Smoothing
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Algorithm: Brightness Smoothing
BrightnessSmoothing
PerceptualBrightness Constraining
Vertical Bezier-basedBrightness Smoothing
New BrightnessProfiles
Brightness SmoothingAttenuation Map
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Algorithm: Offline Correction Pipeline
Chrominance Gamut Morphing
Projector BrightnessProfiles
ReconstructChrominance Gamut
New BrightnessProfiles
Brightness SmoothingFinal AlphaMask (A)
White BalancingPrior to Correction
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Color Variation Visualization
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Algorithm: Online Image Correction
Apply Alpha Mask
Apply Projector Transfer Function
InputImage
Custom Linearization Function
Linearize Input Image
Final AlphaMask (A)
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Overview Prior Art Motivation Algorithm Results
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Results: More General Pictures
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Results: Extends to any Geometry
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BeforeCorrection
OverlapBlending
Final Result
Majumderand Stevens
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Results: Comparison
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Conclusion First method that
Complete 3D color registration Addresses spatial variations in both
chrominance and brightness High quality display with commodity
projectors
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Future Work Extend to non-developable surfaces Address intra-projector color
variations
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Questions?
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Prior Art: Color Seamlessness Brightness Chrominance
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