Press Release

LET’S DRAW!: NEW DEEP LEARNING TECHNIQUE FOR REALISTIC CARICATURE ART
Data-driven method leverages deep learning AI for photo-to-caricature translation
TOKYO, Japan, 16 October 2018 – Caricature portrait drawing is a distinct art form where artists sketch aperson’s face in an exaggerated manner, most times to elicit humor. Automating this technique poseschallenges due to the amount of intricate details and shapes involved and level of professional skills it takes
to transform a person artistically from their real-life selves to a creatively exaggerated one.
A team of computer scientists from City University of Hong Kong and Microsoft, have developed an innovative
deep learning-based approach to automatically generate the caricature of a given portrait, and to enable
users to do so efficiently and realistically.
“Compared to traditional graphics-based methods which define hand-crafted rules, our novel approachleverages big data and machine learning to synthesize caricatures from thousands of examples drawn byprofessional artists,” says Kaidi Cao, lead author, who is currently a graduate student in computer science at
Stanford University but conducted the work during his internship at Microsoft. “While existing style transfer
methods have focused mainly on appearance style, our technique achieves both geometric exaggeration andappearance stylization involved in caricature drawing.”
The method enables users to automate caricaturesof portraits, and can be applied to tasks such as
creating caricatured avatars for social media, anddesigning cartoon characters. The technique also
has potential applications in marketing, advertisingand journalism.
Cao collaborated on the research with Jing Liao ofCity University of Hong Kong and Lu Yuan ofMicrosoft, and the three plans to present their work
at SIGGRAPH Asia 2018 in Tokyo from 4 December to 7 December. The annual conference features the mostrespected technical and creative members in the field of computer graphics and interactive techniques, andshowcases leading edge research in science, art, gaming and animation, among other sectors. (Image courtesyof Kaidi Cao)
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In this work, the researchers turned to a well-known technique in machine learning, Generative Adversarial
Network (GAN), for unpaired photo-to-caricature translation to generate caricatures that preserve theidentity of the portrait. Called “CariGANs”, the computational framework precisely models geometric
exaggeration in photos (shapes of faces, specific angles) and appearance stylization (look, feel, pencil strokes,shadowing) via two algorithms the researchers have labeled, CariGeoGAN and CariStyGAN.
CariGeoGAN only models the geometry-to-geometry mapping from face photos to caricatures andCariStyGAN transfers the style appearance from caricatures to face photos without any deformation to thegeometry of the original image. The two networks are separately trained for each task so that the learningprocedure is more robust, notes the researchers. The CariGANs framework enables users to control theexaggeration degree in geometric and appearance style by dragging slides or giving an example caricature.
Cao and collaborators conducted perceptual studies to evaluate their framework’s ability to generate
caricatures of portraits that are easily recognizable and not overly distorted in shape and appearance style.
For example, one study assessed how well the identity of an image is preserved using the CariGANs method
in comparison to existing methods for translating caricature art. They demonstrated, through several
examples, that existing methods resulted in unrecognizable caricature translation. Study participants foundit too difficult to match the resulting caricatures with the original subjects because the end results were far
too exaggerated or unclear. The researchers’ method successfully generated clearer, more accurate caricature
depictions of portrait photos, as if they were hand drawn by a professional artist.
Currently, the focus of this work has centered on caricatures of people, primarily headshots or portraits. Infuture work, the researchers intend to explore beyond facial caricature generation into full body or more
complex scenes. They are also interested in designing improved human-computer interaction (HCI) systems
that would give users more freedom and user control on the machine learning-generated results.
For the authors’ paper, titled “CariGANs: Unpaired Photo-to-Caricature Translation”, and supplementarymaterial, visit the team’s project page.
To register for SIGGRAPH Asia, and for more details of the event, visit http://sa2018.siggraph.org.
– end –Notes to editors:•For more information on the Technical Papers Program, click here.

•For media accreditation to SIGGRAPH Asia 2018, please register here.
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About SIGGRAPH Asia 2018
The 11th ACM SIGGRAPH Conference and Exhibition on Computer Graphics and Interactive Techniques in Asia
(SIGGRAPH Asia 2018) will be held in Tokyo, Japan at the Tokyo International Forum from 4 to 7 December
2018. The annual event held in Asia attracts the most respected technical and creative people from all over
the world who are excited by research, science, art, animation, gaming, interactivity, education and emerging
technologies.
The four-day conference will include a diverse range of juried programs, such as the Art Gallery, Computer
Animation Festival, Courses, Emerging Technologies, Posters, Technical Briefs, Technical Papers and Virtual &Augmented Reality. A three-day exhibition held from 5 to 7 December 2018 will offer a business platform forindustry players to market their innovative products and services to the computer graphics and interactive
techniques professionals and enthusiasts from Asia and beyond. For more information, please visit
http://sa2018.siggraph.org. Find us on: Facebook, Twitter, Instagram and YouTube with the official event
hashtag, #SIGGRAPHAsia.

About ACM SIGGRAPH
The ACM Special Interest Group on Computer Graphics and Interactive Techniques is an interdisciplinary
community interested in research, technology, and applications in computer graphics and interactivetechniques. Members include researchers, developers, and users from the technical, academic, business, andart communities. ACM SIGGRAPH enriches the computer graphics and interactive techniques community
year-round through its conferences, global network of professional and student chapters, publications, andeducational activities. For more information, please visit www.siggraph.org.

About Koelnmesse
Koelnmesse Pte Ltd is one of the world's largest trade fair companies. Its more than 80 trade fairs andexhibitions have the broadest international scope in the industry, as 60 percent of the exhibitors and 40
percent of the visitors come from outside Germany. The Koelnmesse events include leading global trade fairs
for 25 sectors, such as Imm Cologne, Anuga, IDS, INTERMOT, Interzum Cologne, Photokina, Gamescom, andthe International Hardware Fair Cologne. Koelnmesse is ACM SIGGRAPH’s event organizer for the last 10
editions of SIGGRAPH Asia. For more information, please visit www.koelnmesse.com.sg.

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Media Contacts
Hitoshi Kasai
Head of Communications, SIGGRAPH Asia 2018
MIACIS Associates
hitoshi.kasai@siggraph.org
Jamie Huang
Marketing & Media Partnerships, SIGGRAPH Asia 2018
Koelnmesse Pte Ltd
jamie.huang@siggraph.org

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