Design of Hue-Preserving Color Blending 4 observations: • Luminance closely tied to transparency perception... Design of Hue-Preserving Color Blending 4 observations: • Luminance clo
Trang 1Hue-Preserving Color Blending
Trang 2 Motivation
Background & Related Work
Design & Mechanics
Results
Trang 3 Color and transparency are crucial in visualization
Color labelling of differently classified materials
vol
♦ Region 1
♦ Region 2
♦ Region 3 data
Trang 4 Perceptual transparency is affected by:
• Luminance
Trang 5 Perceptual transparency is affected by:
• Luminance
Trang 6 Perceptual transparency is affected by:
• Luminance
• Chromaticity
Trang 8Related Work
Wang et al., Color Design for Illustrative Visualization, Vis’08
• Reduce false colors by using opposite colors
Trang 9 A complete computational and parameter free model for generic image compositing
• No constraints on color choices
• Guarantee hue preservation for color overlays
Trang 10Design of Hue-Preserving Color
Blending
Trang 11Design of Hue-Preserving Color
Blending
4 observations:
• Luminance closely tied to transparency perception
Trang 12Design of Hue-Preserving Color
Blending
4 observations:
• Luminance closely tied to transparency perception
• Luminance critical for shape perception
• Color plays a major role in visual grouping & labelling
Trang 13Design of Hue-Preserving Color
Blending
4 observations:
• Luminance closely tied to transparency perception
• Luminance critical for shape perception
• Color plays a major role in visual grouping & labelling
• Color plays an unclear role in transparency perception
Trang 14Design of Hue-Preserving Color
Blending
4 observations:
• Luminance closely tied to transparency perception
• Luminance critical for shape perception
• Color plays a major role in visual grouping & labelling
• Color plays an unclear role in transparency perception
Design criteria:
Trang 15Design of Hue-Preserving Color
Blending
4 observations:
• Luminance closely tied to transparency perception
• Luminance critical for shape perception
• Color plays a major role in visual grouping & labelling
• Color plays an unclear role in transparency perception
Design criteria:
• Exhibit the same behavior for the luminance channel
Trang 16Design of Hue-Preserving Color
Blending
4 observations:
• Luminance closely tied to transparency perception
• Luminance critical for shape perception
• Color plays a major role in visual grouping & labelling
• Color plays an unclear role in transparency perception
Design criteria:
• Exhibit the same behavior for the luminance channel
Trang 17Design of Hue-Preserving Color
Blending
4 observations:
• Luminance closely tied to transparency perception
• Luminance critical for shape perception
• Color plays a major role in visual grouping & labelling
• Color plays an unclear role in transparency perception
Design criteria:
• Exhibit the same behavior for the luminance channel
• Employ constant hue to facilitate visual grouping
• Avoid artificial color discontinuities
Trang 18Mechanics of Hue-Preserving
Color Blending
Trang 19Mechanics of Hue-Preserving
Color Blending
Traditional color summation operator: “+”
Trang 20Mechanics of Hue-Preserving
Color Blending
Traditional color summation operator: “+”
Our new hue-preserving operator: “ ”
Trang 21Mechanics of Hue-Preserving
Color Blending
Traditional color summation operator: “+”
Our new hue-preserving operator: “ ”
Trang 22Mechanics of Hue-Preserving
Color Blending
Traditional color summation operator: “+”
Our new hue-preserving operator: “ ”
Design criteria requirements:
Trang 23Mechanics of Hue-Preserving
Color Blending
Traditional color summation operator: “+”
Our new hue-preserving operator: “ ”
Design criteria requirements:
• Luminance(C1 C2) = Luminance(C1+C2)
Trang 24Mechanics of Hue-Preserving
Color Blending
Traditional color summation operator: “+”
Our new hue-preserving operator: “ ”
Design criteria requirements:
• Luminance(C1 C2) = Luminance(C1+C2)
• Hue(C1 C2) ∈ { Hue(C1), Hue(C2) }
Trang 25Mechanics of Hue-Preserving
Color Blending
Traditional color summation operator: “+”
Our new hue-preserving operator: “ ”
Design criteria requirements:
• Luminance(C1 C2) = Luminance(C1+C2)
• Hue(C1 C2) ∈ { Hue(C1), Hue(C2) }
• Use varying saturation to change between dominant
colors
Trang 26 Luminance is added: Lnew=L1+L2
New chromatic components Hnew and Snew are determined
Trang 27Determining Hnew and Snew
Trang 28Determining Hnew and Snew
Trang 29Determining Hnew and Snew
Trang 30Determining Hnew and Snew
Examine the relative “strengths”
of the input colors
• Dominant color then
becomes hue of blended
Trang 31Determining Hnew and Snew
Examine the relative “strengths”
of the input colors
• Dominant color then
becomes hue of blended
Trang 32Determining Hnew and Snew
Examine the relative “strengths”
of the input colors
• Dominant color then
becomes hue of blended
Trang 33Hue-Preserving Blending Algorithm
Trang 34Hue-Preserving Blending Algorithm
Trang 35Hue-Preserving Blending Algorithm
Trang 36Hue-Preserving Blending Algorithm
Trang 37Hue-Preserving Blending Algorithm
Trang 38Hue-Preserving Blending Algorithm
Trang 39Hue-Preserving Blending Algorithm
Trang 40Hue-Preserving Blending Algorithm
Trang 41 Alpha blending 2 colors
• Cnew = (1-α)C1 αC2
Trang 42 Color compositing
Trang 43Volume Rendering Results
Back-to-front: Cdst (1- αsrc) Cdst + Csrc
Trang 44Traditional Hue-preserving
Trang 45Traditional Hue-preserving
Trang 46Traditional Hue-preserving
Trang 47Traditional Hue-preserving
Trang 48Traditional Hue-preserving
Trang 49Traditional Hue-preserving
Trang 51Traditional Hue-Preserving
Trang 52Traditional Hue-preserving
Trang 53 Gray color is ambiguous
Traditional Hue-preserving
Trang 54 Gray color is ambiguous
Traditional Hue-preserving
Trang 55 Gray color is ambiguous
Traditional Hue-preserving
Trang 56 Gray color is ambiguous
Traditional Hue-preserving
Trang 57 Gray color is ambiguous
Traditional Hue-preserving
Trang 58 Gray color is ambiguous
Traditional Hue-preserving
Trang 59 Gray color is ambiguous
Traditional Hue-preserving
Trang 60 Gray color is ambiguous
Traditional Hue-preserving
Trang 61 Gray color is ambiguous
Hue-preserving blending is order-dependent
Traditional Hue-preserving
Trang 62Future Direction
User study
• To empirically evaluate our method
• To optimize transparency perception
Applications outside direct volume visualization
Trang 63 A new color blending technique that preserves the input hues
• Achromatic channel completely preserved
• Chromatic channel favors dominant hue
Motivated by perceptual principles
No restrictions on input color hues
Improves visual color labelling of volume data when using colors that are similar in hue