installation of asl eye tracking system
Contents
1. s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 8 A separate power supply connects to a DC power input connector labeled DC in 13 5V marked 2 in Figure 4 on the rear panel and plugs into a standard AC wall outlet Two of the real panel connectors are used for the Eye Tracking System They are colour coded to make easier the assembly a The connector labeled Video OUT coded in yellow outputs a PAL composite video signal marked 3 in Figure 4 It is a phono socket b The connector labeled VISCA in coded in yellow blue allows the Control Unit to control the Pan Tilt Optics Module marked 4 in Figure 4 It is an 8 pin mini DIN socket The appropriate lead to connect with the Camera connector of the Control Unit is provided and colour coded Figure 4 Pan Tilt rear panel An IR remote control unit provides manual control for Pan Tilt positioning lens focus and zoom and various other features built into the pan tilt camera It is shown in Figure 5 Francesc Tinto Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 9 Figure 5 Pan Tilt remote control 3 3 Floor Mounted Scene Camera FMSC The scene camera is used to produce a video image of the same scene the subject views This video scene image provides the reference frame for the eye point of gaze measurement The colour scene came2. 3 Pupil and CR Discrimination The first stage in recognition of the pupil and CR by the eye tracker is performed by edge detection logic Threshold levels for pupil and CR edge detection are adjusted with the slide switches labeled Pupil and CR The current discriminator levels are shown by the slide switch positions with the far left slide switch positions indicating that no edges will be noticed and positions at the right of the slides indicating even dim edges may be detected A white circle designating the pupil outline and black circle designating the CR outline are displayed on the Eye Monitor a If it is not already checked check the Illuminator check box on the program screen to turn on the illuminators b Be sure the Pan Tilt Tracking radio button near the bottom left of the e5000 screen is set to manual c Start with pupil and CR discriminator slide switches all the way to the left d Begin to increase the pupil discriminator level by moving the slide switch to the right White dots will begin to appear on the eye monitor As the discriminator is turned up further these white dots begin to form an outline within the pupil and when the discriminator is turned up far enough the dots will form a line that circumscribes the pupil At this point white recognition cross hairs should appear through the center of pupil e Move the discriminator to the right just far enough so that a solid white cir
3. at a TV Screen and the nterface PC and the Video Monitors are placed behind the subject This allows the person in control of the Eye Tracking System to control the nterface PC the Video Monitors but also the subject and the Pan Tilt Optics In addition if the system is placed in that way the subject cannot be distracted b mer MNAC e ee el e a a Figure 1 Placement of the Eye Tracking System Francesc Tinto Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 4 3 Connections The ASL Eye Tracking System Model 504 is supplied with a user manual that explains how to make the connections between all the devices coming with it All the connectors are labeled and both connectors and cables are colour coded in order to facilitate the assembly The following section gives a short review of how to make the assembly of the Eye Tracking System We show how to connect it to the Video Cassette Recorder in order to record on tapes analog storage the output video signal coming from it Finally shows how to connect it to the Matrox Marvel G400 TV graphic card in order to record the output video signal into streaming video files digital storage For further information please refer to the device manufacturer manuals 3 1 Model 5000 Control Unit The control unit houses the processing board that receives video from eye and scene cameras reco
4. control program along with the other eye tracker data It is a female 25 pin D type connector The connector labeled Controller coded in green allows the data transfer between the Control Unit and the nterface PC marked 7 in Figure 2 It is a male 9 pin D type connector The interface cable is provided and it is also colour coded green It is connected to the Interface PC by its serial port NOT STANDARD USE The connector labeled Head Tracker is an RS232 port that allows communication between the Control Unit and the optional Magnetic Head Tracking MHT control unit marked 8 in Figure 2 It is a male 9 pin D type connector The connector labeled Eye Out coded in orange provides the image of the eye coming from the Pan Tilt Optics marked 9 in Figure 2 It is a BNC connector The Control Unit outputs a PAL composite video signal that can be displayed in one of the Video Monitors The interface cable is provided and it is also colour coded orange The connector labeled Scene Out coded in blue provides the image of the scene coming from the Scene Camera or the Scan Converter where the Contro Unit has added a cross hair pointing to the centre of eye gaze marked 10 in Figure 2 It is a BNC connector The Control Unit outputs a PAL composite video signal that can be displayed in one of the Video Monitors The interface cable is provided and it is also colour coded blue The magnetic head t
5. erence er ren 17 VCR video o tput GCC aes A aria acelin hai 18 Input sockets of Marvel G400 TV detail ccc ccccccessseeseeeeseeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeees 19 Output sockets of Marvel G400 TV detall oooonnnnnnncucununononanonanononononocnnnnonnnnonnnnnnnnnnnnnnnnnnnnnononnnnnos 19 Target PALESTINA ai 23 Conficuration controls SEUA io 27 Francesc Tinto Garcia Moreno School of Computer Science Queen s University of Belfast
6. the Check Target Points window or the Save target points and Quit button to save the points and close the Set Target Points window 4 2 2 Subject Setup and Calibration Subject set up consists of seating the subject in an appropriate position obtaining a suitable eye image on the eye monitor and setting the pupil and CR discriminators properly 4 2 2 1 Subject Seating Any stationary chair can be used but to the extent that the type of chair can minimize subject motion eye tracking accuracy will be maximized 4 2 2 2 Obtaining an Eye Image a Check the Illuminator check box on the program screen to turn on the illuminators b Be sure the Pan Tilt Tracking radio button near the bottom left of the e5000 screen is set to manual c Use the Zoom buttons on the Pan Tilt remote control to move the Zoom until the system is able to focus on the eye of the subject d Use the Cursor buttons on the Pan Tilt remote control to aim the pan tilt camera at the eye e Once the pan tilt module is aimed at the eye pull down the Pan Tilt menu and select Set Home This will cause the program to memorize the current position of the pan tilt module Subsequently selecting Home from the Pan Tilt menu will cause the module to return to this memorized position Francesc Tint Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 23 4 2 2
7. tracker will continue to function normally even if the cable to the interface PC is disconnected Run the interface program esw n exe which is located in the C ASL Software EYEPOS V5 70 folder If the nterface PC is correctly connected to the Contro Unit and software has successfully been uploaded to the Control Unit the Online light near the top left of the interface program screen should be green 4 2 1 Setting Up Calibration Target Points During the calibration procedure it will be necessary for the subject to look at nine target points that are at known positions The actual distribution of the nine points is usually taken from the scene monitor and entered into memory with the eye tracker set target points function The target pattern used is a Powerpoint slide displayed on the stimulus monitor Display PC or TV Screen If this is the case the slide can be recorded on a video tape for several minutes using Matrox Marvel G400 TV video card Francesc Tinto Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 23 Optimally the middle vertical and horizontal points should be co linear and perpendicular All points must be numbered from left to right 1 3 for the top row 4 6 for the middle row and 7 9 for the bottom row Figure 18 shows the target pattern used for calibration a C O O o O O Figure 18 Target pattern u
8. 2 in Figure 15 for S Video b Ne Francesc Tint Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 18 Figure 15 VCR video output detail b Ensure that the input channel is set to A3 3 8 Matrox Marvel G400 TV The Matrox Marvel G400 TV is all in one graphics video capture and video editing card The external box makes it easier to connect other video devices without having to grasp and reach behind your computer The Matrox Marvel G400 TV is provided with software that allows the storage of inputted signal in streaming video digital format There are two input and output sockets offering the possibility to use either Composite video or S Video formats The input sockets are on the front of the external box as shown in Figure 16 The composite video socket is marked 1 and the S Video socket is marked 2 Francesc Tint Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 19 Figure 16 Input sockets of Marvel G400 TV detail For inputting the signal coming from the Scene out of the Control Unit you must use the Composite video input When the signal comes from the VCR either Composite video or S Video can be used The output sockets are on the back of the external box as shown in Figure 17 The composite video socket is marked 1 and the S Video socket is m
9. INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM MODEL 504 WITH PAN TILT OPTICS maal af A COMPUTER SCIENCE Yy The Queen s University of Belfas Francesc Tint Garcia Moreno March August 2001 Copyright 2001 Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM l Summary l COMPONENTS 2 it 2 2 Placing all the devices Sit AA AORA E 3 CORNE ON e si os 4 aul Mode S000 onto dat tais 4 32 Pan Talt Eye Camera Opics Moodle dc T 3 3 Floor Mounted Scene Camera EMS Ciao 9 3 4 SCA CONN CI CB dd 10 3 5 Bye Tracker a PC sarrado o ar eas ai 12 II A O A a dutuectald es 13 3 7 Video Cassette Recorder VOR zerina a EE E E eee os alate 15 30 Matrox Marvel GAO Via sacs ica 18 A Usina Ane Eye Tracking System as 21 4 1 Upload Software to the Control Unit tc 21 4 2 E5000 User IEA Proptamiccs ascot nncdtei comedies e e 22 4 2 1 Setting Up Calibration Target Points isrscscie ena iaia aaa e a aiaia aai 22 4 2 2 Subject Setuprand Calibration dias 24 AL AUDE ee a a a a conse eek oueetcaes 24 4222 Obaman Eye Tma te e e a a ok oeekeaee 24 4225 Pupil io A i a a eed aes 25 422A Subject C AMIA OA a a a a a case 26 4 2 3 Daa Recordin i E AE O o T 27 Francesc Tint Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 2 1 Components 1 ASL Eye tracking system Model 504 with Pan Tilt optics including V BR W N Model 5000 co
10. a at any time by clicking one of the numbered mark buttons icons labeled O through 9 on the shortcut bar d Stop recording by clicking the recorder stop icon black square on the shortcut bar The file name will change back to black letters and the paused message will reappear Start and stop recording as many times as desired Each interval of continuous data between a start and stop recording is referred to as a data segment Eye point of gaze coordinates pupil diameter and XDAT values are simultaneously recorded on the data file with a common time line Francesc Tint Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 29 Figure Table Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 Placement ofthe Eye Trackin SSA iia 3 Back panc lof Contool AAA A AAA AAA esas 5 Pon Te A TNO AAA T A eaters 7 cid A EN 8 ia A A A IN ENE 9 SCOE aM leas 9 SAME A lts 10 Scan CONVE remote COME oo dod 11 Seal POR orhe Merite O al ek ellis al lect dei tal leah ute dates 12 Bache Or the Ey and Scene Me 14 VOR Va CO oi VS AAA tne at Aas EEN EA cela lalediads 15 INPUT SBLECTE WTA ticas 16 VER COM Ol parcial et ears ae ese esas 16 oY ao als rl An et ee ke ee ne ee eee nee erent nn ee enna ne ce
11. adjusted during the calibration procedure if necessary The calibration procedure tends to work best when performed rapidly If the procedure takes too long subjects become fatigued and have difficulty maintaining accurate fixations on the target points 4 2 3 Data Recording Eye position vertical and horizontal coordinates pupil diameter and 16 bits of external data called XDAT see ASL manual can easily be recorded on the Interface PC hard disk A field of data consisting of the Francesc Tinto Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 28 elements just listed is recorded every 60th of a second 60 Hz update rate a Open a new data file by selecting new from the pull down File menu or by clicking the new file icon on the shortcut bar Specify a directory eyd extension will automatically be appended to the file name Initially the and file name If Save as Type is left set to Eyedat file a file name will be displayed in black letters with the message paused after the file name b To start recording data on the file click the record icon right arrow icon on the shortcut bar The file name will change to red letters and the message following the file name will change to recording The disk bytes free indicator will also change as disk space is used up c Add one of 10 manual mark flags to the dat
12. arked 2 Figure 17 Output sockets of Marvel G400 TV detail Francesc Tint Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 20 When the Eye Gaze Tracking system is connected to the input socket it is possible to output its signal into the VCR Either Composite video or S Video can be used Francesc Tint Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 21 4 Using the Eye Tracking System The EYEPOS E5000 software package contains software that must be uploaded to the model Contro Unit as well as a user interface program that runs on the nterface PC Make sure that all the devices of the system are switched on before uploading the software to the Contro Unit and launching the interface program 4 1 Upload Software to the Control Unit Use the power switch to power cycle the Contro Unit off and back on again to be sure that it is reset Switch on the power switch at the rear of the pan tilt module Upload software to the model 5000 eye tracker control unit by running Load bat The upload program will begin to execute in a command line box The PC monitor will display UPLOAD Vn n Program Pattern upload program for ASL ETE Loading path E5nnn BXT nnnnn bytes bytes left nnnnn The bytes left number will count down to zero and then the PC mon
13. cle forms about the pupil and white cross hairs designate the center of pupil Observe the eye monitor for several seconds as the subject looks around to be sure that recognition is maintained even when the pupil is at its smallest If the pupil is very dim and difficult to They are slightly displaced to the right of the actual pupil and CR features Furthermore note that the white cross hairs which indicates the pupil center actually appear at the center of the white discrimination circle rather than at the center of the pupil image Similarly the black cross hairs appear at the center of the black circle rather than the CR image This offset is purely cosmetic and has no effect on point of gaze computation or display It is caused by a slight time delay between detection of an edge point and display of the corresponding dot on the monitor and makes the discrimination outlines easier to see It is the true feature edge coordinates that are being detected Francesc Tinto Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 26 distinguish from surrounding features move the illumination slide switch to the right to increase illumination intensity f If the pupil discriminator is too far to the right other areas may be mistakenly recognized as the pupil and the recognition cross hairs may jump to these areas Should this happen lower the pupil discriminator setting by movi
14. ctor labeled Analog I O provides two channels of analog output marked 3 in Figure 2 One analog channel outputs a voltage corresponding to the horizontal eye position coordinate and the other outputs a voltage corresponding to the vertical eye position coordinate The voltages are proportional to the horizontal and vertical positions of the point of gaze cursor on the scene monitor and the digital gaze coordinates It is a male 9 pin D type connector NOT STANDARD USE The connector labeled Serial Out is an RS232 port that allows the output of the eye tracker data marked 4 in Figure 2 It is a male 9 pin D type connector The connector labeled Remote Scene coded in white can receive the signal coming from the Scene Camera or the Scan Converter marked Francesc Tint Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 6 f g h j 5 in Figure 2 It is a female 9 pin D type connector The incoming video signal must be in PAL composite standard and can be inputted using a cable with a phono plug or a BNC plug An adaptor is provided to make it possible NOT STANDARD USE The connector labeled X Dat provides access to a parallel digital port that is used as a means of inputting external data marked 6 in Figure 2 Sixteen bits of parallel TTL level positive true data from any source can be recorded by the E5000
15. e 13 A3 must appear on the display of the VCR as shown in Figure 14 REC Figure 13 VCR control panel detail Francesc Tint Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 17 PLAYER PASSIVE acl Ri ton cand ATT RECORDER 2 Figure 14 VCR display detail e Getting the scene video image from the Matrox Marvel G400 TV There are two ways of connecting the VCR with the Matrox Marvel G400 TV Either S Video or Composite video signal can be used Using S Video provides best quality a Use a phono to phono plug lead for composite video signal or S Video lead otherwise Connect the appropriate cable to the video input of the VCR The socket is labeled AV3 VIDEO IN if you want to use composite video and AV3 S VIDEO IN if you are using S Video marked 2 in Figure 11 Set the INPUT SELECT switch to LINE for composite video or S VIDEO for S Video c Choose the right input channel using the and buttons placed on the control panel on the front of the VCR A3 must appear on the display of the VCR Outputting the scene video image to Matrox Marvel G400 TV a Use a phono to phono plug lead for composite video signal or S Video lead otherwise The output sockets are on the back of the VCR and they are labeled VIDEO OUT marked 1 in Figure 15 for composite video and S VIDEO OUT marked
16. gnizes features in the video eye image and computes line of gaze communicates with the Interface PC controls the pan tilt mechanism and superimposes feedback outlines cross hairs and cursors on the eye and scene video signals for monitor display When an optional magnetic head tracker is used this processing board also communicates with the head tracker and can use the head position data to assist with control of the pan tilt mechanism Basic use of the device requires the connectors labeled Controller Camera Remote Scene Eye Out Scene Out and 12V DC IN Other connectors support various options or secondary functions such as communications with a head tracker and data output to an external device Francesc Tint Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 5 a b C d e Figure 2 Back panel of Control Unit Locate the 12VDC power supply module and connect it to the DC Power connector on the Control Unit marked I in Figure 2 Connect the other side to an AC power outlet The power supply is input rated for 100 240 VDC 50 or 60 Hz The LED on the Control Unit front panel should remain off until the power switch is switched on For use with Pan Tilt Optics be sure that the slide switch on the rear panel marked 2 in Figure 2 is in the P T position NOT STANDARD USE The conne
17. he CR is properly recognized as the subject looks about the field of view of interest If the black dots form about more than one geometrically satisfactory corneal reflection the computer software will select the one closest to the pupil for recognition 8 When the Eye Calibration window is active the interface program Scene Display and the Scene Monitor both show the location of the next target point to be entered Francesc Tinto Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 21 c When data for point 9 is entered the Eye Calibration window will automatically close and calibration computations will be made and stored d To confirm accuracy of calibration ask the subject to look at each target point again If one or more target points are not correct either repeat the entire calibration procedure or just part of it Figure 19 shows the discrimination panel in the interface program screen with all controls set in a usual good working configuration Discrimination Pupil Figure 19 Configuration controls setting During the calibration procedure it is important to look at the eye monitor It is very important to be sure that stable recognition cross hairs continue to properly indicate the pupil center and the corneal reflection CR If not make the appropriate correction to the discriminator settings The discriminator settings can and should be
18. in blue The inputted video signals are looped through to a BNC output on the back of the monitors marked 3 in Figure 10 This output can be used Francesc Tinto Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 15 to connect with the Video Cassette Recorder or the Matrox Marvel G400 TV using a BNC to phono plug lead 3 7 Video Cassette Recorder VCR The only requisite for choosing a VCR is that it must have a composite line input The model used is a Panasonic Super VHS VCR AG 4700 Signal can be recorded from different sources and outputted to other devices Getting the scene video image from the Eye Tracking System a Use a BNC to phono plug lead to connect the output of the Scene Monitor as explained in point 6 to the composite video input of the VCR The socket is labeled AV3 VIDEO IN and is placed on the front of the VCR marked 1 in Figure 11 Figure 11 VCR video input AV3 detail b Ensure that the switch labeled INPUT SELECT on the front of the VCR is set to LINE as shown in Figure 1 2 Francesc Tinto Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 16 S VIDEO LINE Figure 12 INPUT SELECT switch detail c Choose the right input channel using the and buttons placed on the control panel on the front of the VCR see Figur
19. instead of the Display PC the scan converter is not necessary The composite output of the TV Set can be directly inputted into the Remote Scene connector of the Control Unit using a phono to phono plug lead 3 5 Eye Tracker Interface PC This computer serves as the user interface device and as a data recording device a Use the provided cable to connect the port labeled Controller on the Control Unit to the COM1 port on the Interface PC as shown in Figure 9 Both plugs of the lead are colour coded in green Figure 9 Serial port of the Interface PC b ASL always supplies an Eye Tracker Interface program which runs on this computer and it is a required part of the system2 Eye Tracker software is shipped on a CD Follow the directions on the label to System requirements for the Interface PC are an IBM compatible PC capable of operation with Windows 95 Windows 98 Windows ME Windows NT Windows 2000 or DOS However a computer that can run only DOS is limited to using only the DOS version of ASL s Eye Tracker Interface Program The computer must also have available COM1 or COM2 serial ports using standard interrupts and device addresses The minimum recommended system 1s a 200 MHz Pentium but slower systems will probably work adequately as well Francesc Tint Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 13 install the EYEPOS eye trac
20. itor will display Done Loading path E5nnn LXR nnnnn bytes bytes left nnnnn The bytes left value will count down to zero and the monitor will display The ASL Manual notes that Load_nt bat must be executed instead of Load bat when using Windows NT operating system During the tests we have noticed that Load_nt bat does not work properly and Load bat must be used anyway Using Load bat the system will still work properly Francesc Tinto Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 22 Done This operation must last a minute and a half approximately If the upload is not successful the command line box will be closed before the end or an error message will appear on it If this is the case try to run the batch file again so that the upload succeeds Sometimes it is useful to switch the Control Unit off and on again in order to reset it Once the control unit has been loaded the on board software will continue to run until power is turned off 4 2 E5000 User Interface Program The user interface PC software is needed to change settings such as pupil and corneal reflection discrimination thresholds launch procedures such as calibration and to record data on the nterface PC All eye tracking functions are performed by the Control Unit Once proper settings are established and if data is not being recorded on the nterface PC the eye
21. ker operating software EYENAL offline data analysis software and ACCESS C language subroutines for reading binary data files recorded by the EYEPOS software The CD will also copy to the hard disk the install files for FixPlot the fixation scan path plotting program As a default the CD will create a directory named ASL software with subdirectories named EYEPOS EYENAL ACCESS and FIXPLOT containing the corresponding software files To actually install FixPlot run setup exe in the FIXPLOT directory 3 6 Monitors Two 9 black and white monitors AD 910A model are supplied by ASL to display the image of the eye coming from the Pan Tilt Optics and the image of the scene coming from the Scene Camera or the Scan Converter where the Control Unit has added a cross hair pointing to the centre of eye gaze Francesc Tint Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 14 e s WIND hs Figure 10 Back of the Eye and Scene Monitors c Connect a video cable from the eye monitor video input marked 1 in Figure 10 to the Control Unit connector labeled Eye Out A BNC to BNC lead is provided both plugs are colour coded in orange d Connect a video cable from the scene monitor video input marked 2 in Figure 10 to the Contro Unit connector labeled Scene Out A BNC to BNC lead is provided both plugs are colour coded
22. ng the slide switch left g Move the CR slide switch right until a black outline forms about the CR and black recognition cross hairs designate the center of the CR h When the pupil and CR are properly recognized for a given eye image set the Pan Tilt Tracking radio button to Auto to enable automatic pan tilt tracking The pan tilt camera should be able to follow slow head motions Auto focus should keep the eye image in proper focus over a range of several inches 4 2 2 4 Subject Calibration The raw data measured by the Eye Tracker is the separation between the pupil center and the corneal reflection CR The relation between these raw values and eye line of gaze differs for each subject and for different optical unit and scene camera positions The purpose of the eye calibration is to provide data that will allow the Eye Tracker processor to account for individual subject differences The objective is to have the subject look at each of the nine calibration points This procedure must be performed for every subject a Pop up the eye calibration window by selecting Eye Calibration from the Calibrate pull down menu b Tell the subject to look at the point number as prompted on the Eye Calibration window Be sure that pupil and CR discrimination are correct and click the Store Data for Current Point button The Tell subject to look at point number value will automatically increment Be sure that t
23. ntrol unit and plug in power supply Pan tilt optics eye camera optics module Scene camera with tripod or scan converter Two video monitors one for the eye image and one for the scene image Cables for connecting the model 5000 control unit to the Interface PC to the pan tilt optics and scene camera and to the two monitors Control and analysis software Two PCs an interface PC and a Display PC Matrox Marvel G400 TV video card Panasonic Video Cassette Recorder AG 4700 Cables for connecting the model 5000 control unit to the Video Cassette Recorder and VCR to Matrox Marvel G400 TV Francesc Tint Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 3 2 Placing all the devices Before unpacking the ASL Eye Tracking System it is recommended to think about how to place it for having best results The most important thing to consider is where to place the subject whose eye gaze we want to track There must be no windows or intense sources of light in front of the subject In addition the ambient light must be as stable as possible There is another point of consideration the nterface PC and the two Video Monitors can be a distraction for the subject of the experiment lt is recommended to keep them out of the subject s view The recommended placement is shown in Figure 1 The computers are placed forming an L while the subject looks at the Display PC or
24. power supply is provided within the Scan Converter package b The connector labeled PC In is a VGA input socket marked 2 in Figure 7 It is the only video signal input socket available in this model Connect this socket to the monitor output socket on the Display PC using the computer lead supplied c The connector labeled PC Out is a VGA output socket marked 3 in Figure 7 Internally the video signals are looped through allowing use even when the units power is off Connect the computer monitor s video lead to this socket d The connector labeled Composite Video Out is a PAL composite video output marked 4 in Figure 7 The appropriate phono to phono plug lead is supplied This is the output that is used to connect with the Remote Scene connector of the Control Unit e NOT STANDARD USE The connector labeled S Video Out is an S Video output marked 5 in Figure 7 An S Video lead is supplied f NOT STANDARD USE The connector labeled RGB Out is an RGB output marked 6 in Figure 7 The appropriate lead is supplied its plugs are 15 pin male D type to SCART An IR remote control unit is provided allowing the user to change the Scan Converter settings It is shown in Figure 8 Figure 8 Scan Converter remote control Francesc Tint Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 12 If a 7V Screen is used
25. ra provided by ASL as part of the standard model 504 system is powered directly from the Control Unit is equipped with an 8 mm lens and includes a standard photography tripod to support the camera Figure 6 Scene Camera Francesc Tint Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 10 The Scene Camera has two connectors a The power input connector marked 1 in Figure 6 b The PAL composite video output connector marked 2 in Figure 6 It is a phono socket and it is colour coded in white The appropriate lead to connect with the Remote Scene connector of the Control Unit is provided and colour coded 3 4 Scan Converter Alternately if eye tracking subjects will be looking at a computer screen the system may include a Scan Converter in place of the Scene Camera The scan converter converts the VGA computer screen image being viewed by the subject to a PAL composite video signal that can be input to the eye tracker Contro Unit as the scene video image The Scan Converter used is a Vine Micros Ltd CORIOscan Connect All the connectors are located on the rear panel Figure 7 Scan Converter Francesc Tinto Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 11 a The DC power input connector is labeled Power marked 1 in Figure 7 The appropriate
26. racking option MHT is a small unit that determines head position and orientation with good accuracy in six degrees of freedom The head tracker can be used by the Control Unit to assist in determining positions for the pan tilt mechanism Francesc Tinto Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 7 k The connector labeled Camera coded in red white receives the signal coming from the Pan Tilt Optics marked 11 in Figure 2 It is a male 25 pin D type connector The interface cable is provided and it is also colour coded red white 3 2 Pan Tilt Eye Camera Optics Module The Pan Tilt module is shown in Figure 3 The eye camera is mounted on a moving platform A ring of near infrared LEDs around the lens opening provides eye illumination In order to get optimal conditions the Pan Tilt module must be placed just in mont of the stimulus monitor and centred horizontally ra DA P Aa Sea o J n ES at gt gt a 4 Figure 3 Pan Tilt module A main power switch and all the necessary connectors are located on the base non moving platform rear panel accept for the illuminator power connector marked 1 in Figure 4 which is located at the rear of the moving platform The Control Unit powers the illuminator A suitable plug comes with the cable provided Francesc Tint Garcia Moreno School of Computer Science Queen
27. sed for calibration Select Set Target Points from the Calibrate pull down menu Be sure to drag the Set Target Point window to some position where it does not cover up any of the Scene POC graphics display on the main Window If the Set Target Point window is present whenever the mouse cursor enters the Scene POG Display area it changes to a cross and its position coordinates with respect to the Scene Display are shown as Scene X nnn Y nnn on the Set Target Points Window When the mouse is moved within the Scene Display the cursor on the Scene Monitor is also displayed in the corresponding position The Set Target Point window indicates the target point number that will be specified the next time the mouse is left clicked specify position for Move the mouse within the Scene POG area on the computer screen to position the cursor on the Scene Monitor over point 1 and left click to enter point 1 Similarly click on points 2 9 in sequence to enter the other points gt Generally the points cover about 80 percent of the monitor screen area and are separated by 15 20 degrees visual angle horizontally and 10 15 degrees vertically Francesc Tint Garcia Moreno School of Computer Science Queen s University of Belfast INSTALLATION AND SETUP OF ASL EYE TRACKING SYSTEM 24 d Once all target points have been entered click Save target points and Check to save the points and bring up
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