A presentation of Color Harmonization by Daniel Cohen-Or from Tel Aviv University for my CSci 8980 Computer Science Design class taught by Gary Meyer at the University of Minnesota in Fall 2009.

1. Color Harmonization
Daniel Coher-Or Olga Sorkine Ran Gal Tommer Leyvand, Ying-Qing Xu
Tel Aviv University, Microsoft Research Asia
A MXMLLN Montgomery Presentation
The The
Great Great
Wave Wave
Off Off
Kanagawa Kanagawa
Hokusai Hokusai

2. Introduction Contributions Results Critique
Ou t lin e
●
Introduction
– Motivation
– Previous Work
•Contributions
– Histogram Matching
– Color Shifting
●
Results
●
Applications
●
Limitations
●
Critique
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3. Introduction Contributions Results Critique
M o t iv a t io n ::C o lo r Ha r m o n y
The authors define harmonic colors as sets of color that have some
special order and relationship in color space resulting in a aesthetic
visual appearance.
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4. Introduction Contributions Results Critique
P r e v io u s Wo r k
Previous applications
include mostly commercial
design products that
provide users with sets of
harmonic colors
None have the ability to
harmonize an input image
One solution attempts to automate part of the design process by
introducing harmonic rules to assist the user. [MEIER, B.J 1988.
ACE: a color expert system for user interface design.]
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5. Introduction Contributions Results Critique
P r e v io u s Wo r k
The authors utilize Itten's color model where color harmony is defined
as the relationships between hues on the color wheel. [Figure 2]
In addition, the set of
80 color schemes
defined as
combinations of the 8
hue [Figure 2] and 10
tone distributions that
Matsuda produced
from his
psychophysical
experiments are the
foundation of this
research.
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6. Introduction Contributions Results Critique
Im p le m e n t a t io n ::His t o g r a m M a t c h in g
The main goal of Color Harmonization is to transform the color
histogram of an image to match one of the eight hue distribution
templates.
¿What makes the image disharmonious?
¿How would you traditionally determine the closest template?
¿Which template would you suggest?
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7. Introduction Contributions Results Critique
Im p le m e n t a t io n ::His t o g r a m M a t c h in g
Disharmonies
The cyans, purples, and small amount
of bright green are outliers in the
predominantly dark blue and bright
yellow and orange image.
¡There is no rainbow template!
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8. Introduction Contributions Results Critique
Im p le m e n t a t io n ::His t o g r a m M a t c h in g
●
F(X, (m, a)) measures the harmony of the image X with respect to a
scheme (m, a)
●
M(X,Tm) defines the best harmonic scheme for the template Tm
●
B(X) is the best harmonic scheme for the image X
is the closest hue in the template Tm, oriented at angle a, to
pixel p.
H(p) is the hue channel
S(p) is the saturation channel
|·| is the arc distance on the hue wheel
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9. Introduction Contributions Results Critique
Im p le m e n t a t io n ::C o lo r Sp lit t in g
Color artifacts appear if a color from the
hue histogram is halfway between the
template borders [Figure d]
*Situation mostly arises when user inputs
desired template
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10. Introduction Contributions Results Critique
Im p le m e n t a t io n ::C o lo r Sp lit t in g
Binary labeling segmentation using graph-cut optimization
For each set of pixels Ω, minimize the energy E(V), the sum of the
distance between the pixel hue H(p) and hue assignment H(v(p)),
E1(V), and the grouping of adjacent pixels, E2(V)
N is the set of neighboring pixels in Ω
δ(v(p), v(q))) is 1 if labels of pixels
p and q are diferent, else 0
Smax(p,q) is the greater saturation
between the two pixels
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11. Introduction Contributions Results Critique
Im p le m e n t a t io n ::C o lo r Sh if t in g
After pixels are assigned a region in the template, the hues are
shifted to fit in the region
Density of hues is preserved around hue at the center of the region
C(p)
Gσ(x) ε (0, 1] with standard deviation σ and mean 0
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12. Introduction Contributions Results Critique
Re s u lt s ::In t e r [ f a c e , a c t io n ]
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13. Introduction Contributions Results Critique
Re s u lt s ::A p p lic a t io n s
The applications for Color Harmonization are extensive
Anywhere digital design tools are used, there is a place for a
color harmony recommendation system
Interior Design
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14. Introduction Contributions Results Critique
Re s u lt s ::A p p lic a t io n s
Graphic Design
Harmonize with respect to foreground
Harmonize with respect to background
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15. Introduction Contributions Results Critique
Re s u lt s ::A p p lic a t io n s
Graphic Design
Harmonize with respect to color scheme
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16. Introduction Contributions Results Critique
Re s u lt s ::Dis c u s s io n
Underlying algorithms give more weight to highly saturated pixels
Unsaturated hues lead to less striking or noticeable results
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17. Introduction Contributions Results Critique
Re s u lt s ::Lim it a t io n s
No support for divided or interrupted hue regions
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18. Introduction Contributions Results Critique
C r it iq u e
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