Starting with version 0.9.8, QuickSnap has the ability to sense chages in its images. This means that you can now record a movie frame whenever the scene changes. Using this feature you can log all the visitors to a location, combined with the time-stamping option, this provides interesting security possibilities. This document describes how to use QuickSnap to do this.
Step 1 : Set up QuickCam
Make sure your QuickCam is operating. The best way to check this is to run the QuickPICT program supplied by Connectix. If this prgram runs, then so should QuickSnap.
Step 2 : Launch QuickSnap
Launch in the usual manner and you should see the viewfinder window appear with the Camera scene therein. Adjust the size of this window and make sure you QuickCam is pointing at the desired location.
Step 3 : Set up the movement settings
There are three settings which directly affect the images; both lie in the "movement settings" dialog (accessed fron the Video Menu). They are "Motion Threshold", "time between frames" and "Audio Alert". Time between frames is the interval between successive images which will be examined for motion (I recommend using at about 5 seconds here to allow QuickSnap time to adjust the exposure when the light intensity changes).
Movement Sensitivity is a threshold above which QuickSnap decides movement has occured (I recommend a value in the range 20 - 40 here). The last motion score is drawn in the lower left of the viewfinder window when the camera is recording in security mode -- you can watch this value to decide on a motion sensitivity suited to your needs.
Audio Alert allows you to switch on a noise when movement is detected.
Step 4 : Choose A Video Compressor
Choose "Video Compression..." from the Video Menu to change these settings. These settings are preserved in the application preferences so you need only set them once. If you want small size images, I recommend the Cinepak compressor, or the PhotoJPEG compressor at low image quality. For high quality images, the animation compressor is lossless and fast.
Step 5 : Start Recording
To start recording with movement detection mode choose "Security Cam" from the video menu. Whenever movement is detected above the movement threshold, an image is taken and added to the movie.
Step 6 : Finish Recording
To finish recording either Quit QuickSnap or choose "Stop Recording" from the Video Menu. The movie is stored in QuickTime format and can be viewed by any quicktime movie player. If double clicked it will start up the QuickMooV application provided by Connectix.
Step 7 : Pay Shareware Fee
QuickSnap has a built in limit of 10 movement frames. That means that using movement recording, you are limited to 10 movements (no matter how long they are apart). This restriction is removed when you register you program and pay your shareware fee (I have to eat). The shareware fee is US$25 and for this you will get a nice letter, the latest version and a licence to download future updates. Registration can be done by email (tim@jurgen.physics.utoronto.ca).
