manga colorization
TRANSCRIPT
M a n g a Co lo r iza t io n
Y in g g e QuT ie n -Ts in W o n g
Ph en g -A n n H e n g
The Chinese University of Hong Kong
MXMLLN Montgomery
Ou t l in e
Paper•Introduction
– Motivation– Previous Work
•Contributions– Pattern Segmentation– Colorization
●ResultsCritique
•Motivation•Technique Generalization
MXMLLN Montgomery
Introduction Contributions Results Critique
b
M o t iv a t io n
ProblemI. 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.,
I.Half-toning
II.Screening
III.Hatching
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Pr ev io u s W o r k
User-Directed Colorization●User scribbles color in desired regions●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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Pr ev io u s W o r k
Semi-Automated Colorization●Colorization by matching swatches of greyscale image to reference color image●Auto regression filtering from the relationship between A and A', applied to input image B to create B'●Colorization by transferring color from an example segmented image using high-level pixel context
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MXMLLN Montgomery
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Pr ev io u s W o r k
Limitations●Works for intensity continuity, like photographs and videos ●Is unable to handle pattern continuity, like illustrations
Pr ev io u s W o r k
Texture-Based Segmentation●Texture is classified, segmented, and synthesized based on texture properties of repeated elements:
● Size● Aspect ratio● Orientation● Brightness● Density
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Im p lem en 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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Co n t r ib u t io n s
Pattern-continuous regions● Uniformly sample along user scribble to compute pattern features:
● Cluster feature patterns● Identify major cluster● Find average of major cluster
● Allows some error in scribbling over unintended areas
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Co n t r ib u t io n s
Pattern-continuous regions● Propagate color until pattern reaches abrupt change● This step allows both splitting and merging between boundaries
● Disjoint regions can be colored with single scribble
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Co n t r ib u t io n s
Intensity-continuous regions● Leak proofing prevents propagation from leaking through gaps
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Co n t r ib u t io n s
Colorization● Stroke-preserving colorization
● Colorization is achieved by bleeding out from strokes and patterns
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Co n t r ib u t io n s
Colorization● Pattern-to-shading
● Hatching and screening shading effects can be portrayed smoothly by color shading
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Co n t r ib u t io n s
Colorization● Multi-color transition
● Colors are blended together based on their distance from the user scribble
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Res u lt s
Limitations● System regards overlapped patterns as distinct
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Cr it iq u e
Motivation● Mangas are not colored because of the extensive printing cost● Many techniques, such as hatching and screening shading, may actually be less labor intensive in color
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Cr it iq u e
Technique generalization● The authors never identify other applications of their technique
● 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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