Presentation of Manga Colorization by Yingge Qu at The Chinese University of Hong Kong for my CSci 8980 Computer Science Design class taught by Gary Meyer at the University of Minnesota in Fall 2009.
More than Just Lines on a Map: Best Practices for U.S Bike Routes
Manga Colorization
1. M a n g a C o lo r iza t io n
Y in g g e Q u
T ie n -Ts in W o n g
Ph e n g - A n n H e n g
The Chinese University of Hong Kong
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2. Introduction Contributions Results Critique
O u t lin e
Paper
•Introduction
– Motivation
– Previous Work
•Contributions
– Pattern Segmentation
– Colorization
●
Results
Critique
•Motivation
•Technique Generalization
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3. Introduction Contributions Results Critique
M o t iv a t io n
Problem
I. Manga are seldom colored due to the time and labor involved.
II. The fine artistic details used to create the visual content and
atmosphere are ill-suited for digital colorization techniques, i.e.,
b
I.Half-toning
II.Screening
III.Hatching
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4. Introduction Contributions Results Critique
Pr e v io u s W o r k
User-Directed Colorization
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User scribbles color in desired regions
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Using constraint quadratic optimization problem, colorization is
achieved under the assumption that adjacent pixels with similar
intensities should be similarly colored
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5. Introduction Contributions Results Critique
Pr e v io u s W o r k
Semi-Automated Colorization
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Colorization by matching swatches of greyscale image to
reference color image
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Auto regression filtering from the relationship between A and A',
applied to input image B to create B'
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Colorization by transferring color from an example segmented
image using high-level pixel context
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6. Introduction Contributions Results Critique
Pr e v io u s W o r k
Limitations
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Works for intensity continuity, like photographs and videos
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Is unable to handle pattern continuity, like illustrations
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7. Introduction Contributions Results Critique
Pr e v io u s W o r k
Texture-Based Segmentation
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Texture is classified, segmented, and synthesized based on
texture properties of repeated elements:
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Size
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Aspect ratio
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Orientation
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Brightness
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Density
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8. Introduction Contributions Results Critique
Im p le m e n t a t io n
Color propagation employs a zero surface, geometric,
level set method
For more details, please refer to the text
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9. Introduction Contributions Results Critique
C o n t r ib u t io n s
Pattern-continuous regions
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Uniformly sample along user
scribble to compute pattern
features:
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Cluster feature patterns
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Identify major cluster
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Find average of major cluster
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Allows some error in scribbling
over unintended areas
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10. Introduction Contributions Results Critique
C o n t r ib u t io n s
Pattern-continuous regions
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Propagate color until pattern
reaches abrupt change
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This step allows both splitting
and merging between boundaries
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Disjoint regions can be colored
with single scribble
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11. Introduction Contributions Results Critique
C o n t r ib u t io n s
Intensity-continuous regions
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Leak proofing prevents
propagation from leaking
through gaps
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12. Introduction Contributions Results Critique
C o n t r ib u t io n s
Colorization
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Stroke-preserving
colorization
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Colorization is achieved by
bleeding out from strokes
and patterns
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13. Introduction Contributions Results Critique
C o n t r ib u t io n s
Colorization
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Pattern-to-shading
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Hatching and
screening shading
effects can be
portrayed
smoothly by color
shading
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14. Introduction Contributions Results Critique
C o n t r ib u t io n s
Colorization
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Multi-color transition
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Colors are blended
together based on their
distance from the user
scribble
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15. Introduction Contributions Results Critique
Re s u lt s
Limitations
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System regards overlapped
patterns as distinct
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16. Introduction Contributions Results Critique
C r it iq u e
Motivation
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Mangas are not
colored because of
the extensive
printing cost
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Many techniques,
such as hatching and
screening shading,
may actually be less
labor intensive in
color
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17. Introduction Contributions Results Critique
C r it iq u e
Technique generalization
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The authors never identify other applications
of their technique
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More broadly than manga, their work is
suitable for any intensity-homogenous
images and videos.
●
Including additional applications broadens
the scope and reader base of a publication
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