Realistic Graphics Lab

Visu­al Com­put­ing Sem­in­ar (Spring 2018)

Food @ 11:50am,
Talk @ 12:15am
Tizian Zeltner

General information

The Visu­al com­put­ing sem­in­ar is a weekly sem­in­ar series on top­ics in Visu­al Com­put­ing.

Why: The mo­tiv­a­tion for cre­at­ing this sem­in­ar is that EPFL has a crit­ic­al mass of people who are work­ing on subtly re­lated top­ics in com­pu­ta­tion­al pho­to­graphy, com­puter graph­ics, geo­metry pro­cessing, hu­man–com­puter in­ter­ac­tion, com­puter vis­ion and sig­nal pro­cessing. Hav­ing a weekly point of in­ter­ac­tion will provide ex­pos­ure to in­ter­est­ing work in this area and in­crease aware­ness of our shared in­terests and oth­er com­mon­al­it­ies like the use of sim­il­ar com­pu­ta­tion­al tools — think of this as the visu­al com­put­ing edi­tion of the “Know thy neigh­bor” sem­in­ar series.

Who: The tar­get audi­ence are fac­ulty, stu­dents and postdocs in the visu­al com­put­ing dis­cip­lines, but the sem­in­ar is open to any­one and guests are wel­comed. There is no need to form­ally en­roll in a course. The format is very flex­ible and will in­clude 45 minute talks with Q&A, talks by ex­tern­al vis­it­ors, as well as short­er present­a­tions. In par­tic­u­lar, the sem­in­ar is also in­ten­ded as a way for stu­dents to ob­tain feed­back on short­er ~20min talks pre­ced­ing a present­a­tion at a con­fer­ence. If you are a stu­dent or postdoc in one of the visu­al com­put­ing dis­cip­lines, you’ll prob­ably re­ceive email from me soon on schedul­ing a present­a­tion.

Where and when: every Wed­nes­day in BC03 (next to the ground floor at­ri­um).  Food is served at 11:50, and the ac­tu­al talk starts at 12:15.

How to be no­ti­fied: If you want to be kept up to date with an­nounce­ments, please send me an email and I’ll put you on the list. If you are work­ing in LCAV, CVLAB, IVRL, LGG, LSP, IIG, CHILI, LDM or RGL, you are auto­mat­ic­ally sub­scribed to fu­ture an­nounce­ments, so there is noth­ing you need to do.
You may add the sem­in­ar events to Google Cal­en­dar (click the '+' but­ton in the bot­tom-right corner), or down­load the iC­al file.


Date Lecturer Contents
07.03.2018 Gershon Elber

Title: Sci­ence Art Syn­ergy - the CAD/CAM way

Ab­stract: The art work of M.C. Es­cher needs no in­tro­duc­tion. We have all learned
to ap­pre­ci­ate the im­possib­il­it­ies that this mas­ter of il­lu­sion's
art­work presents to the lay­man's eye. Nev­er­the­less, it may come as a
sur­prise for some, but many of the so-called 'im­possible' draw­ings of
M. C. Es­cher can be real­ized as ac­tu­al phys­ic­al, tan­gible,
three-di­men­sion­al ob­jects. These ob­jects will re­semble the Es­cher's
draw­ings when viewed from a cer­tain view­ing dir­ec­tion.

In this talk, I will dis­cuss sev­er­al artist­ic­ally-re­lated ap­plic­a­tions
where com­puter aided geo­met­ric design can have an im­pact.  In­deed, we
will start by present­ing some in­triguing three-di­men­sion­al so-called
“im­possible mod­els”, fol­low­ing draw­ings and art-work made by Es­cher
and oth­ers, which were de­signed us­ing a vari­ety of geo­met­ric mod­el­ing
and com­puter graph­ics tools and we will por­tray a mod­el­ing pack­age to
syn­thes­ize many of these so called “im­possible mod­els”.  Then, we will
ex­am­ine oth­er ap­plic­a­tions, in­clud­ing glass laser etch­ing and the
mak­ings of tan­gible-mo­sa­ics.

P.S. This talk im­poses no pre­requis­ites bey­ond an open mind.

14.03.2018 Agata Mosinska

Title: Bey­ond the Pixel-Wise Loss for To­po­logy-Aware De­lin­eation

Ab­stract: De­lin­eation of cur­vi­lin­ear struc­tures is an im­port­ant prob­lem in Com­puter Vis­ion with mul­tiple prac­tic­al ap­plic­a­tions. With the ad­vent of Deep Learn­ing, many cur­rent ap­proaches on auto­mat­ic de­lin­eation have fo­cused on find­ing more power­ful deep ar­chi­tec­tures, but have con­tin­ued us­ing the ha­bitu­al pixel-wise losses such as bin­ary cross-en­tropy. In this pa­per we claim that pixel-wise losses alone are un­suit­able for this prob­lem be­cause of their in­ab­il­ity to re­flect the to­po­lo­gic­al im­pact of mis­takes in the fi­nal pre­dic­tion. We pro­pose a new loss term that is aware of the high­er-or­der to­po­lo­gic­al fea­tures of lin­ear struc­tures. We also in­tro­duce a re­fine­ment pipeline that it­er­at­ively ap­plies the same mod­el over the pre­vi­ous de­lin­eation to re­fine the pre­dic­tions at each step while keep­ing the num­ber of para­met­ers and the com­plex­ity of the mod­el con­stant. 

When com­bined with the stand­ard pixel-wise loss, both our new loss term and our it­er­at­ive re­fine­ment boost the qual­ity of the pre­dicted de­lin­eations, in some cases al­most doub­ling the ac­cur­acy as com­pared to the same clas­si­fi­er trained with the bin­ary cross-en­tropy alone. We show that our ap­proach out­per­forms state-of-the-art meth­ods on a wide range of data, from mi­cro­scopy to aer­i­al im­ages.

21.03.2018 Adam Scholefield

Title: New tools for loc­al­isa­tion and map­ping

Ab­stract: User po­s­i­tion­ing, self-driv­ing cars and oth­er autonom­ous ro­bots are all ex­amples of the ubi­quity of loc­al­isa­tion and map­ping. It is well stud­ied in the forms of an­gu­la­tion and lat­er­a­tion—for known land­mark po­s­i­tions—and, more gen­er­ally, sim­ul­tan­eous loc­al­isa­tion and map­ping (SLAM) and struc­ture from mo­tion (SfM)—for un­known land­mark po­s­i­tions. In this talk, I will re­view ex­ist­ing ap­proaches and dis­cuss some nov­el pri­ors for these prob­lems. In par­tic­u­lar, I will place an em­phas­is on geo­met­ric­al tech­niques us­ing Eu­c­lidean dis­tance matrices (EDM)s and dis­cuss ex­ten­sions to bet­ter fit prac­tic­al ap­plic­a­tions. In ad­di­tion, I will at­tempt to ab­stract the key es­sence of loc­al­isa­tion and map­ping prob­lems, which will al­low us to de­rive fun­da­ment­al per­form­ance lim­its.

28.03.2018 Gerard Pons-Moll

Title: Re­con­struct­ing and Per­ceiv­ing Hu­mans in Mo­tion

Ab­stract:  For man-ma­chine in­ter­ac­tion it is cru­cial to de­vel­op mod­els of hu­mans that look and move in­dis­tin­guish­ably from real hu­mans. Such vir­tu­al hu­mans will be key for ap­plic­a­tion areas such as com­puter vis­ion, medi­cine and psy­cho­logy, vir­tu­al and aug­men­ted real­ity and spe­cial ef­fects in movies. 

Cur­rently, di­git­al mod­els typ­ic­ally lack real­ist­ic soft tis­sue and cloth­ing or re­quire time-con­sum­ing manu­al edit­ing of phys­ic­al sim­u­la­tion para­met­ers. Our hy­po­thes­is is that bet­ter and more real­ist­ic mod­els of hu­mans and cloth­ing can be learned dir­ectly by cap­tur­ing real people us­ing 4D scans, im­ages, and depth and in­er­tial sensors. Com­bin­ing stat­ist­ic­al ma­chine learn­ing tech­niques and geo­met­ric op­tim­iz­a­tion, we cre­ate real­ist­ic mod­els from the cap­tured data. 

We then lever­age the learned di­git­al mod­els to ex­tract in­form­a­tion out of in­com­plete and noisy sensor data com­ing from mon­ocu­lar video, depth or a small num­ber of IMUs. 

I will give an over­view of a se­lec­tion of pro­jects where the goal is to build real­ist­ic mod­els of hu­man pose, shape, soft-tis­sue and cloth­ing. I will also present some of our re­cent work on 3D re­con­struc­tion of people mod­els from mon­ocu­lar video, and real-time joint re­con­struc­tion of sur­face geo­metry and hu­man body shape from depth data. I will con­clude the talk out­lining the next chal­lenges in build­ing di­git­al hu­mans and per­ceiv­ing them from sens­ory data. 

Bio:  Ger­ard Pons-Moll ob­tained his de­gree in su­per­i­or Tele­com­mu­nic­a­tions En­gin­eer­ing from the Tech­nic­al Uni­versity of Cata­lonia (UPC) in 2008. From 2007 to 2008 he was at North­east­ern Uni­versity in Bo­ston USA with a fel­low­ship from the Voda­fone found­a­tion con­duct­ing re­search on med­ic­al im­age ana­lys­is. He re­ceived his Ph.D. de­gree (with dis­tinc­tion) from the Leib­n­iz Uni­versity of Han­nov­er in 2014. In 2012 he was a vis­it­ing re­search­er at the vis­ion group at the Uni­versity of Toronto. In 2012 he also worked as in­tern at the com­puter vis­ion group at Mi­crosoft Re­search Cam­bridge. From 11/2013 un­til 09/2015 he was a postdoc and later from 10/2015-08/2017 Re­search Sci­ent­ist at Per­ceiv­ing Sys­tems, Max Planck for In­tel­li­gent Sys­tems. Since 09/2017 he is head­ing the group Real Vir­tu­al Hu­mans at the Max Planck In­sti­tute for In­form­at­ics.

His work has been pub­lished at the ma­jor com­puter vis­ion and com­puter graph­ics con­fer­ences and journ­als in­clud­ing Sig­graph, Sig­graph Asia, CVPR, ICCV, BMVC(Best Pa­per), Euro­graph­ics(Best Pa­per), IJCV and TPAMI. He serves reg­u­larly as a re­view­er for TPAMI, IJCV, Sig­graph, Sig­graph Asia, CVPR, ICCV, ECCV, ACCV, SCA, ICML and oth­ers. He co-or­gan­ized 1 work­shop and 3 tu­tori­als: 1 tu­tori­al at ICCV 2011 on Look­ing at People: Mod­el Based Pose Es­tim­a­tion, and 2 tu­tori­als at ICCV 2015 and Sig­graph 2016 on Mod­el­ing Hu­man Bod­ies in Mo­tion, and the work­shop People­Cap at ICCV'17.

His re­search in­terests are 3D mod­el­ing of hu­mans and cloth­ing in mo­tion and us­ing ma­chine learn­ing and graph­ics mod­els to solve vis­ion prob­lems.


East­er break

11.04.2018 Merlin Nimier-David
18.04.2018 Peng Song

Title: An In­ter­lock­ing Meth­od for 3D As­sembly Design and Fab­ric­a­tion

Ab­stract: 3D as­sem­blies such as fur­niture in­volve mul­tiple com­pon­ent parts. Rather than re­ly­ing on ad­di­tion­al fasten­ers such as nails and screws to con­nect the parts, com­pon­ent parts can be in­ter­locked in­to a steady as­sembly based on their own geo­met­ric ar­range­ments. This talk re­vis­its the no­tion of 3D in­ter­lock­ing, and ex­plores the gov­ern­ing mech­an­ics of gen­er­al 3D in­ter­lock­ing as­sem­blies. From this, con­struct­ive ap­proaches are de­veloped for com­pu­ta­tion­al design of vari­ous new in­ter­lock­ing as­sem­blies such as puzzles, 3D prin­ted ob­jects and fur­niture. These in­ter­lock­ing as­sem­blies are ready for fab­ric­a­tion and their stead­i­ness have been val­id­ated in our ex­per­i­ments.

25.04.2018 Hanjie Pan
02.05.2018 Delio Vicini

Title: Learn­ing Light-Trans­port us­ing Vari­ation­al Auto En­coders

09.05.2018 Helge Rhodin
16.05.2018 Julian Panetta

Title: Ro­bust Elast­ic Metama­ter­i­al Design for Ad­dit­ive Fab­ric­a­tion

23.05.2018 Tizian Zeltner

Title: The Lay­er Labor­at­ory: A Cal­cu­lus for Ad­dit­ive and Sub­tract­ive Com­pos­i­tion of An­iso­trop­ic Sur­face Re­flect­ance

30.05.2018 Sami Arpa