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Using the Historic HVS Image 2020 Water Maze Tracking System

This is a reprint of the old notes for the historic HVS Image 2020 hardware based tracker. The system is no longer supported  and this is more of a sort of laboratory palaeontology as records suggest that it was replaced in the late 20th century by the 2100. However as late as 2013 over 50 new research papers cite the use of the HVS Image 2020 as so many are still in circulation.

CONTROLS ON HVS2020

HVS2020 tracker  will not work until you have it connected to a PC 
and 2020 series software is loaded and run.  The software prompts you. 
Start in the Test-cross mode. Then calibrate an Send the (electronic) 
Mask. Now select TRACK - at this point you can start to detect a high-
contrast subject, ie black on white, or white on black. You should see a 
white frame around the image on the monitor. If it is off-center 
horizontally, please contact Helpdesk.

DARK switch: Press down if your subject is dark (or hooded).

TRACK control: Adjust until you see 2 white Track-Bars extending 
away from the subject, down and to the right).

WINDOW controls: There are no Window controls on HVS2020 - the 
detection-area is defined by the electronic mask sent from the PC. (This 
note for ex-VP118, VP200 users.)

CROSS controls: Two knobs, move cross during Calibrate.

Track/Cross Select Cross to calibrate, TRACK to track within the 
Mask.

MASK switch-position: Is contained within the Track position. (This 
note for ex-VP118, VP200 users.)

(Electronic Mask defines the detection-area for Water, Field and Maze.  
It is a light-colored area which appears on the video monitor screen, in 
response to 'Send Mask' in the software. This note for ex-VP118 users.)


POWER-ON switch: Rear of HVS2020, up = power.

FUSE (should never blow), but if it does, use 250ma "anti-surge". Do 
not up-rate this !

SETTING-UP YOUR HVS IMAGE 2020 TRACKER


WHICH PC ?  Minimum Intel Pentium 90MHz  recommended Intel Pentium 150MHz or better with MS DOS 3.1 or better

0. MOUNT YOUR CAMERA  with its base (fixing-point) towards 
you. Avoids operator-disorientation when viewing the screens !

CONNECT Video OUT from the camera to the IN socket of the 
tracker. cable.  If you are using a VCR, connect it  between the camera 
and the tracker (please, not European SCART signals).

CONNECT tracker OUT to the Video In of the video monitor. Select 
75 ohm termination (back of monitor). On the monitor, set the Contrast 
(Picture) control a little less than usual. Set the Brightness control a 
little more. This helps you to see the artefacts which the tracker 
superimposes on the picture.

CONNECT camera, monitor and tracker to you power line supply. 
Please connect all items to same power outlet cluster (including the 
camera !). Switch on all units.

IF YOU connect a video monitor ahead of  the tracker, be sure to set 
the video monitor to High impedance input (not 75 ohm).

RAISE all switches of  the tracker. This is the default setting.

SEE a TV image on the video monitor. If you do not, try connecting 
camera direct to monitor.

SEE THE TRACKER VIEWPORT superimposed on the picture. There 
is a white frame around the central area. The central area is the 
Viewport, and is where tracking takes place.  In the U.S. you might find 
that the viewport is not centered very well in the horizontal. Please 
contact Helpdesk for advice on how to adjust this. 

7. ALSO SEE a white cross superimposed. If you do not, rotate the two 
Cross controls until you do.

8. CHECK THAT you have connected the tracker serial cable to your 
PC. The tracker is now in the Cross mode  and ready to send data to 
your PC. 
  
10. WE FIT  a 9-pin AT-style serial connector on the serial cable; if 
your PC has a 25-way input, you can buy an adaptor at any PC store eg 
Radio Shack. Please note that often, if your PC has 2 ports, COM1 is 
located higher on the panel. If there are 9 and 25 way connectors, 
COM1 is usually the 9-way connector.  

From Setup-PC in the software, usually the HVS software will locate 
the correct Coms port and lock-onto it. 

11.  Water 2020 software presently supports an Air-switch , which is an 
option for starting and stopping trials. Connect to the inlet on the back 
of HVS2020. For multiple-switches and wall or pool-mounted 
switches, contact Helpdesk. If your air-switch wears-out, contact 
Helpdesk or you can buy the item as an 'Air Release' from your local 
photo-specialist store.

16. MOUNT YOUR VIDEO CAMERA firmly and securely over the 
field or pool. If the camera is at all wobbly, you will be wasting your 
time !  Also, the camera must point vertically down. Tripod mounting, 
at a slant, will not work !  

Please don't have other experiments  hooked-up to the camera-support!  
Best to mount your camera high - this keeps it away from knocks. Don't 
hang your camera using chains (it has been done !). Run cables high, 
otherwise people bump into them &  pull the camera out of line.

MASK: All series 2020 software sends an electronic mask. There are 
no plastic masks used !

COLOR of arena. If your animal is white, paint the field or maze in 'flat' 
black. If animal is dark or hooded, use a white pool, or paint your  field 
or maze in 'flat' white.

PLACE TECHNO-RAT animal in your pool, field or maze. Move it 
around eg to pool N S E W, center. Avoid a situation where the 
"animal" or any part of the scene is completely "washed out"; this 
means "too much light"; dim the lights, or adjust the aperture (iris)  on 
the camera.


 THE TRACK-BARS: You should see 2 light-colored bars, extending 
right & down from the subject. (Ex-VP118 users, you don't see a 
"pattern" of the subject).

 ROTATE 'TRACK' CONTROL  until you see 'Track-Bars'. Too much 
rotation detects background material also. Too little does not detect 
anything. Best setting is midway between these.

YOU WILL ALSO SEE the true image on the video monitor. You will 
find this is a help in setting up your field, maze or pool.

AND NOW AT LAST you are ready to go ahead and use your 
software package. We advise you to practice with Techno-Rat first.


The HVS VP112 - close relative of the 2020



VIDEO TRACKING APPLICATIONS NOTES  

CAMERA ?

COLOR OR BLACK AND WHITE ? Mono is good. Color is not 
required. Color will work, but the spatial and light sensitivity is 
generally less than for equivalent black and white cameras.

CCD (SOLID STATE): We recommend 1/3" CCD: it is very adequate 
for video tracking. CCD does not compensate automatically for varying 
illumination, so please do exclude daylight. CCD is usually quite 
sensitive, eg 1 lux, works well in white light or red light, and has some 
sensitivity in the near infra-red.  

AUTO-IRIS, PLEASE NO ! : Your camera dealer will encourage you to 
buy an auto-iris lens for your CCD camera - please don't accept this 
kind offer ! Auto-iris may de stabilize detection in the VP. (Auto-iris 
lens can be recognized because it has a cable coming out.)

VIEWPOINT:
Maybe your camera is on a tripod, viewing the field or pool at a slant. 
Sorry, this is bad news, as the image will be distorted. BEST place for 
your camera is directly overhead of your field, and central. Fixed to the 
ceiling is good, as your colleagues can't knock it out of line. FIRM 
fixing is vital - cameras which wobble or slowly swivel round will cause 
you big problems. We can supply a camera fixing bracket.

FIELD OF VIEW:
The pool, field or maze surface  must be comfortably within the tracker 
"Viewport". The Viewport is the area between the 2 vertical white 
bands, and is the area for tracking. To change the field of view, move 
the camera nearer or further, or select a lens with a different focal 
length. We can advise, or supply a lens.

"Field of view" is not an exact science !  Please be prepared to move 
your camera vertically. For Water Maze we supply a lens with 
f=2.6mm for 1/3" CCD. This places the camera ~1.8m (6ft) above a 
1.8m diameter pool (and pro-rata). To work out water-ceiling height, 
add that 1.8m to the camera-tracker ~ 0.2m ,. So  height ~ 2m. The aim 
is to have the pool water surface fitting comfortably inside the tracker 
viewport, as seen on the video monitor.


ILLUMINATION: Refer also to the picture above.

A good way to illuminate an open field (open-top box, or raised 
platform) is by means of two ordinary fluorescent strip-lights on the 
ceiling. Avoid shadows from sides of box. There is a natural tendency 
for illumination to be less at the sides and corners of a field - if tracking 
becomes unreliable at the sides or corners of the field, direct more light 
there.

Similar remarks apply also to a white "milk" maze (pool). Striplights 
are good - they will reflect in the pool, but that does not matter, because 
your tracker  is looking for a dark "target".

For a dark (water) pool, reflections, especially off ripples, can be a big 
problem for all video trackers.  Use very diffuse up-lighting. A good 
way is to paint your room white and up-lights. The lights should not be 
visible in the video image (monitor screen).

Adjust the iris (brightness) ring on your camera, to get a clear bright 
image, but not so bright that white objects get  "washed-out".


OUT OF FOCUS - A USEFUL TRICK !

If you find that the tracker is detecting subject-tail or other artefacts, try 
using "out of focus". It's like a free low-pass optical filter ! 
You defocus the camera, then re-adjust the Track control to get back 
reliable tracking.  This is the same as introducing a low-pass spatial 
filter.  For hooded rats, defocus only enough so you don't detect the 
animal's back. 

TECHNICAL  NOTE ON TV STANDARDS

Only for techno-enthusiasts !

In North America the TV line standard is 525/60. The TV FIELD rate 
is 60 per second, and this sets the maximum rate for VPs. There are 
525/2 TV LINES in each TV FIELD; HVS trackers use ~230 of those.  
This gives a resolution of 256 pixels wide , and ~230 deep. This is 
more than enough resolution for "activity" work, including  water maze.

In Europe the standard is 625/50, giving a maximum rate of 50/sec. 
Resolution is 256 x 256 pixels. By default, HVS2020 slows the data 
rate to 10/sec in all countries, good for 2020 series software. 

Enthusiasts who want to write their own software and track fast animals 
such as flying insects, contact Helpdesk for directions how to select the 
highest data-rates from HVS2020.



TROUBLE-SHOOTING 

      
DO NOT OPEN THE TRACKER:
DANGER OF ELECTRIC SHOCK

       

IS THE SYSTEM SET UP PROPERLY ?
Please re-read this User Guide. Did you connect a video monitor ahead 
of the tracker?  that can  attenuate the video signal.  European users, 
please don't use SCART connectors !

IS THE SYSTEM POWERED ?
Ensure that all items are connected to line power, and switched-on. The 
tracker switches-on from the rear.


IS THE SYSTEM CONNECTED ?
Check that all the BNC (coax) cables are firmly plugged in. Also that 
the HVS Serial Cable is connected through to your PC.
.
AT THIS POINT...
Raise all switches on your tracker.  You should see a picture of your 
field/pool on the video monitor. IF YOU DO NOT, please check video 
camera and video monitor, by connecting them directly together. Please 
look at any switches on these items. If there is a SYNC switch on 
either, select INTERNAL.

ARE YOUR BNC (COAX) CABLES GOOD ?
Bad cables are the main cause of problems. They disconnect inside the 
cable-plug. If in doubt, test all cables using camera & monitor. Save 
yourself lots of trouble - dump  all suspect cables !

HAVE YOU GOT ENOUGH ILLUMINATION ?
The image of your arena should be clear and free from "snow".  Place 
Techno Rat in your arena. Contrast sahould be white on black or black 
on white. Adjust the iris (brightness) control on the camera lens. You need a 
clear contrast image. But the white should not be so bright that it is 'washed 

out' (saturated)

1 comment:

  1. You can find more information about the original HVS Image 2020 tracking system here http://hvsimage.com/hvs-image-2020/

    ReplyDelete

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