Technical Note Counting FW 6.30

Transcription

1 Bsch Security Systems Technical Nte Cunting FW 6.30 April 21rst, 2016 Cunting with Essential Vide Analytics 6.30 / Intelligent Vide Analytics 6.30 Summary This technical nte describes hw t cunt with Essential Vide Analytics 6.30 and Intelligent Vide Analytics 6.30, what the best perspective is, hw t set it up, hw t get the data frm the camera, and what the best practices are. Applicatins Determine cnversin rates in shps Alert n queue lengths befre cashiers Cunt vehicles fr traffic mnitring What can be cunted? Via the GUI, tw dedicated cunting tasks are available with FW 6.30: Cunter: Occupancy: Cunt all bjects crssing a specified line The line can cnsist f up t 16 edge pints r 15 segments An alarm can be raised if the cunter reaches a maximal value and shuld be reset via RCP+ Cunt all bjects currently in a specified field The field can have up t 16 vertices and edges An alarm can be raised if a predefined threshld is reached Bth cunter can be applied t arbitrary bjects and restricted accrding t the bjects prperties, e.g. by the bject class t separate vehicles frm bikes and pedestrians. Cunting peple crssing a line (tp) r currently inside a field (bttm). 3D peple tracking mde allws t accurately separate clse and slightly ccluded peple even in well-ppulated scenes Via the VCA task script language, cunter can be applied t any event (like entering a field) defined there and any bject state pssible. It is als pssible t define a virtual rm there via up t three entry and exit lines. See the tech nte n VCA task script language fr further details and examples. Peple cunting is supprted via a special 3D peple tracking mde fr accurate results even in well-ppulated scenes. Limitatins General bjects need t be well separated fr the cunter t wrk accurately. If bjects cclude each ther, they will be cmbined int a single bjects, skewing the results. Shadws, reflectins, mving backgrund like vegetatin and light changes will decrease perfrmance. Use 3D peple tracking t accurately separate peple even in well-ppulated scenes. 3D peple tracking requires accurate calibratin. It assumes that every mving bject is a persn r grup f persns, including shpping carts, and will thus generate extra cunts fr nn-persn bjects.

2 2 Bsch Security Systems, Inc. Intrusin Perspective: Why bird s eye view is preferred Frnt view: A lt f peple are ccluded by ther peple Very hard t detect & separate peple in the rear Psitin in the rm cannt be determined Nt usable fr cunting at all Slight tilting: Peple are mstly ccluded Very hard t detect & separate peple in the rear Psitin in the rm very ambiguus Nt usable fr cunting at all Mre tilting: Peple are partly ccluded Psitin in the rm can be determined Human can cunt here manually Autmated cmputer cunting limited by peple density Bird s eye view: All peple can be seen and separated easily Psitin in the rm easy t determine Max. quality f the cunting results

3 3 Bsch Security Systems, Inc. Intrusin Peple cunting best practices: Planning camera field f view Checklist Use birds eye view if pssible Camera height ~3-6 meter (als depending n camera lens) Unifrm illuminatin Ambient light Indr nly N reflecting surfaces N mving backgrund, e.g. drs, glass windws, escalatrs, shpping card / basket cllecting pints, N baggage, shpping carts, cars, Max number f persns in scene at nce fr Intelligent Vide Analytics: 10 (CPP4) / 20 (CPP6/7), fr Essential Vide Analytics: 10 (CPP7) Use straight passageways where pssible Cmments See the fllwing chapter fr explanatin. Nte that perfrmance will decrease the mre the camera view differs frm birds eye view (90 tilt angle). Less height and the peple walk thrugh the bserved area t fast t be detected and cunted prperly. Mre height and the peple becme t small, reducing accuracy. Changing illuminatin triggers false fregrund especially at edges up t a glbal change where nthing is prcessed anymre Shadws f persns mve with them and might be cunted falsely. N shadws are visible in ambient light. T keep illuminatin stable, unifrm and ambient. Reflectins f persns mve with them and might be cunted falsely. Mving backgrund always yields false fregrund segmentatin. Take these areas ut f the sensitive area r cmpletely ut f the image. Besides generating false peple themselves, they can als delay the detectin f bjects entering nearby. E.g. a track started by a persn mving thrugh a dr might stay at the dr, delaying the detectin f the persn. All nn-persn bjects f size similar t r larger than persns will be cunted as persns. If mre persns are in the camera scene at nce, real-time perfrmance can n lnger be guaranteed. This means that single frames might be drpped, thugh bject tracks will be cntinued. This may lwer verall perfrmance. Avid scenes where peple enter, directly turn arund a crner and immediately leave the camera image befre the algrithm had a change t detect and track them rbustly. Avid scenes where peple liter and thus crss the cunting line several times.

4 4 Bsch Security Systems, Inc. Intrusin Technlgy: Backgrund Subtractin & 3D Mdels Backgrund Subtractin Essential Vide Analytics and Intelligent Vide Analytics are currently based n a technique named backgrund subtractin. There, a backgrund image is learned (and updated ver time) and any difference t the backgrund is classified as mving fregrund. Advanced prcessing allws fr illuminatin invariance up t sme pint. Unfrtunately, unwanted disturbers like trees, shadws, reflectins, pening drs and mre are als changes in cmparisn t the backgrund 3D peple tracking: Object Separatin via persn mdels Backgrund subtractin f a grup f bjects results in a single fregrund blb. Further separatin f the bjects is necessary fr cunting. Fr this, all bjects are interpreted as persns r grups f persns. 3D persn mdels are calculated accrding t camera calibratin and fitted t the extracted fregrund. Gd separatin results (and thus als cunting accuracy) depend n a gd calibratin. T initialize and separate bjects, enugh fregrund has t be generated t supprt the fit f the 3D persn mdel t the fregrund. This may delay the detectin f persns.

5 5 Bsch Security Systems, Inc. Intrusin Calibrating the camera Calibratin is needed if 3D peple tracking is t be used fr accurate results fr peple cunting, r if 3D tracking is needed t autmatically generate bject classes t filter the cunts. T calibrate the camera fr a bird s eye view perspective, pen the Calibratin Dialg and fix all parameters. Tune the parameters manually using the descriptin belw. The grid visualizatin can be used fr verificatin by aligning a cube with vertical structures, r with tiles n the grund. Fr final verificatin, set the calibratin, enable 3D (peple) tracking mde (see als Enabling Peple Cunting) and check the fit f the resulting 3D persn mdel shapes n peple walking thrugh the bserved scene (see als Example Cnfiguratins). Nte that especially the 3D persn mdel size will later influence peple cunting accuracy and shuld be used t tune a trade-ff between separatin f peple piggy-backing and adding false psitives n baggage. Parameter Tilt Angle Rll Angle Elevatin Fcal length Cmment 90 = Birds eye view 0 = Fully frntal view Vertical line alignment <-> \ / Left/right camera rtatin Vertical line alignment \\ <-> <-> // Please measure camera height Can be used fr 3D persn mdel size fitting See camera lens Can be used fr 3D persn mdel size fitting Please nte that certain bjectives induce a distrtin, which cannt be crrected and makes calibratin mre difficult. The tile pattern in the image n the right is a gd example fr that, fr a perfect calibratin all lines shuld be straight. In these cases, apprximate as gd as yu can, and fcus n the area with the cunting line.

6 6 Bsch Security Systems, Inc. Intrusin Enabling peple cunting Set the fllwing parameters: Parameter Value Effect & Cmments 3D peple cunting On Use 3D persn mdel, interpret everything as persns, separate all persns. Will nly be available if camera is calibrated. Nise suppressin Off Nise suppressin can delay detectin and will nt wrk well in crwds. Sensitvity (Intelligent Vide Analytics n CPP6/7 nly) Max Initialize new persns immediately instead f validating them ver time. Needed especially fr bird s eye view as the peple are nly in the FOV fr a shrt time.

7 7 Bsch Security Systems, Inc. Intrusin Example Cnfiguratins Example 3D Shapes Cnfiguratin Status What T D 3D peple tracking nt enabled Enable 3D peple tracking 3D peple tracking is enabled and the 3D persn mdel is visible 3D persn mdels t large 3D persn mdels indicates frntal view in cntrast t the images BEV Set Tilt t ~90 Adapt elevatin / fcal length 3D peple tracking is enabled and the 3D persn mdel is visible 3D persn mdels t small, several 3D persn mdels n ne persn 3D persn mdels indicates frntal view in cntrast t the images BEV Set Tilt t ~90 Adapt elevatin / fcal length 3D peple tracking enabled and the 3D persn mdel is visible 3D persn mdels t small, several Adapt elevatin / fcal length 3D persn mdels n ne persn 3D persn mdels indicate BEV calibratin which fits the image 3D peple tracking enabled and the 3D persn mdel is visible 3D persn mdels fits the persn very well 3D persn mdels indicate BEV calibratin which fits the image

8 8 Bsch Security Systems, Inc. Intrusin Setup f Cunting Lines / Fields T set up a peple cunter, create a cunter task r an ccupancy task. Cunting lines r fields can be defined via the crrespnding wizard. Nte that the lines and fields will be shwn in the camera image and can be changed there. Set the cunting lines / fields up thus that bjects can be well detected bth befre and after crssing the line / field brder. This ensures bservatin f the persn crssing f the line / field brder with high quality needed fr high cunting accuracy. Make sure the cunting lines / fields are large enugh that peple can t slip by. Nte that the center f the bject shape is used t determine line / field brder crssing. Nte that all visualizatins in the camera image can be selected and dragged arund. Examples Cmments Line t clse t brder. Objects entering will nt have generated enugh fregrund t be detected. Nt suitable fr cunting. Enugh rm befre and after the cunting line. Objects will be detected with high accuracy befre crssing the cunting line and the crssing itself will be bserved with high quality. Well set up fr cunting. Set the debunce time f line r field t 0.1. Debunce time is useful t avid alarm flickering in case f bjects mving alng a detectin line r field brder. In rder t d this, it enfrces a certain duratin f the detected bject befre and after crssing the line. In a bird s eye view (BEV), the camera is very clse t the persns and thus the persns remain nly a shrt time within the mnitred area. Therefre the duratin needed fr debunce is ften nt available, and thus a large debunce time cuts dwn the number f crrectly cunted peple. A shrt debunce time, hwever, is needed t nt cunt peple several times which stp at the cunting line.

9 9 Bsch Security Systems, Inc. Intrusin D nt wrry if the checkbx f the final cunter task is nt set and can t be activated - this means nly that the cunter will generate n alarm. If an alarm is needed, yu can add it in the cunter task wizard. Otherwise, just ignre the checkbx as the cunting will wrk nnetheless.

10 10 Bsch Security Systems, Inc. Intrusin Accessing the cunter data: CBS Bsch Clud Based Security and Services (CBS) ffers a mnthly and daily custmer traffic reprt: Accessing the cunter data: RCP+, VCA metadata Remte Cntrl Prtcl plus (RCP+) is a remte cntrl prtcl including the ability t send read and write cmmands t a device, and t subscribe fr messages. Defined cunters can be read ut and reset via RCP+ cmmands. It is best practice t reset the cunter values regularly s they will nt generate an verflw f the cunter values. The VCA metadata stream including all detected and tracked bjects as well as the cunter data is encded in the prprietary Vide Cntent Descriptin (VCD) Frmat and fully accessible via Remte Cntrl Prtcl plus (RCP+) and Real Time Streaming Prtcl (RTSP). Via ONVIF and in the ONVIF metadata descriptin frmat, a reduced set f the VCA metadata including the events and bject bunding bxes is available. As the VCA metadata cntains the full infrmatin abut all detected and tracked bjects, this can be used t define further cunters r generate heatmaps in any client able t read the VCA metadata. Cntact the Integratin Partner Prgram ( fr a full dcumentatin r exemplary surce cde. Bsch Sicherheitssysteme GmbH Rbert-Bsch-Ring Grasbrunn Germany