Query A ti Q i g ffor M bil ti S h yS Sensing Mobile Location Search Active bl L Felix X. Yu Rongrong Felix l X Yu Shih‐Fu h h Fu Chang Fu h g Feli Y Rongrong Rongrong Ji Shih F Chang Chan Digital Video and Multimedia Laboratory, Columbia University, 10027, New York, United States d and d Multimedia l d Laboratory b l b Universityy, 10027, New Yorkk, United d States Digital g l Video y, Columbia Abstract • • System Architecture y System Architecture Problem Justification Problem Justification P bl J tifi ti Wh h first fi f il to find fi d the h right igh target q g ((up p to 50% When the queryy fails likelihood), likelihood) how should the user form his/her search strategy in the subsequent interaction? We propose a novel Active Query Sensing system to suggest the best way for sensing the surrounding scenes while forming the queryy for th second dq f location l ti search. h search • • • • • Most locations are recognizable only with a subset of the ie s views. views Each location has a unique subset of preferred views for g iti recognition. recognition Location Dependence Dependence:: different locations have different degrees off “difficulty” difficulty d g “diffi lty”. Locations of the same search difficulty do not significantly l t together. t g th cluster together There is no single dominant view that can successfully ll locations. l ti recognize g i all locations iterations Failure rates over successive query iterations. • • Application Application Scenario A li ti SScenario i User Interface User U Interface I t f NAVTEQ 0.3M NYC Data Set Q 0 3M NYC Data D t Set S t NAVTEQ • Experiment E p i t Offline analysis: to discover the best query view(s) for each location indexed by the system. system user Online process: to estimate the most likely view of the first query (which has failed); to suggest optimal view change to the user. • • h data d i b i g off 50,000 0,000 locations l i 300,000 images 50 The set consists off about 300,000 in Manhattan collected Q street view imaging g g system. y h ll d by by the h NAVTEQ A system Online Analysis li Analysis l i Online Offline Analysis Offline ff Analysis • • • First q queryy First query view view (estimated) ( d)) Conclusions l i and d Future Works k Conclusions and Future Works • Geographical Distribution of NAVTEQ Data Set g p Q Data Set Geographical Distribution of NAVTEQ Problem Problem Formulation P bl FFormulation l ti • Most Most salient view salient view pti j k image A U i unlikely lik ly to t take t k “junk “jjunk i g ” with ith no hope h p for f Assumption: User is image” fi di g the th true t t g t The Th first fi t q f l can be b used d target query y even unsuccessful, unsuccessful finding target. query, “p b ” to t narrow down d th solution l ti space. space p as “probe” probe the • S Suggestion: ti t turn right i ht 90 degrees d Suggestion: turn right 90 degrees • Examples of a p es o ju junk images ages Examples of “junk” images • Configuration Cameras Configuration of Cameras C fi ti off C • • To the search T simulate i l h mobile bil location l i h scenarios, i , we manually lly scenarios i from f G gl Street S Vi i 226 randomly d ly chosen h cropped pp d q queries Google View in l i d by by the h above b i d routes in i NYC. locations covered mentioned NYC F h location, l location ti i query images i g d from f i i g For each six are cropped viewing angles orientations used database This gl similar i il to t the th view i i t ti d in i the th database. d t b Thi 1 356 images results with tags. lt in i 1,356 i ith angles l and d ground d truth t th locations l ti t RESEARCH POSTER PRESENTATION DESIGN © 2011 P t P t ti www.PosterPresentations.com • • We developed Sensing that W have h d l d a novell Active A ti Query Q S i system t th t actively ti l gg h best b q gy if/when if/ h the h first fi visual i lq ffails il suggests the queryy strategy queryy fails. This the first effort in activelyy gguidingg users to achieve more f ff satisfactory experience in using mobile visual search. search We measurementt based to W develop d l saliency li b d on score distributions di t ib ti t di t the th robustness b t h query view i and d the th search h difficulty diffi lt off predict off each each h location. llocation i h future, f h idea to multi‐view l view object bj search. h , we willll extend the In the future multi search Th t ways y for f estimating ti ti g the th first fi t query q y view i There are two ways for estimating the first query view. There are two Examples of query images p of q g Examples queryy images • q q A subsequent queryy should maximize the discriminabilityy ((uncertainty y reduction)) over candidate locations, locations, narrowed down byy h q l dy been b taken k , by by selecting l i g the h best b view i q the queryy already taken, queryy view. Train view classifiers offline Without showing process details p Wi h h i g mathematical h i l details, d il , we found f d the h above b b wellll approximated pp i t d by by can be View e alignment a g e t based on o the t e image age matching atc g • • W simulate i l t the th first fi t query with ith a randomly d l chosen h i i angle. angle l We viewing Only query succeed O ly 47% off the h random d i g succeed, d, resulting l i g in i a 53% q y images failure rate after the first q queryy query. We evaluate the performance of reducing the failure rates in s bseq ent queries q eries by b using sing different active acti e query q er strategies. strategies subsequent Th performance f i achieved hi d by b the th saliency li b d AQS scheme h i The gain based is quite q query. i impressive i p i – 12% error rate after f only ly one additional ddi i lq queryy ggrade the The offline measures of saliencyy can also be used to “grade” searchability of each location, location indicating the locations where the system performs more robustly. t f b tl LN is the candidate locations narrowed down by the first query. query We use a majority view j y votingg mechanism to estimate the optimal p angle change and suggest the user turns to the most salient view. view • A ideal id l score distribution di ib i is i the h one that h has h maximal i l separation p i An between the scores of the p positive results and those of the negative g ones ones. b using sing the reference image of Predict online search performance by h {location, {l ti {location i } to t retrieve ti th same location: l ti each view} the Whi h view i ill be b the th best b t query? y? Which will g Acknowledgement W thank th k NAVTEQ for f providing idi g th i g data d t set t Dr D Xi Chen Ch We the NYC image set, Dr. Xin help and Bach help, d Dr. D Jeff J ff B h for f their th i generous g h l and d Tongtao T gt Zhang Zh g for f d ig i g the th mobile bil interface. iinterface t f designing