Hi PICer,

I would ask to you if you continue to receive the EMAIL from PICLIST.

Starting from your following message I do not have received any new PICLIST
EMAIL.

Thanks for your answer.

Leonardo De Palo

leo.depalo@pometia.it
cacciavite@pometia.it

-----Messaggio originale-----
Da: Russell McMahon <apptech@CLEAR.NET.NZ>
A: PICLIST@MITVMA.MIT.EDU <PICLIST@MITVMA.MIT.EDU>
Data: gioved“ 29 ottobre 1998 8.43
Oggetto: Re: Video Project Idea


>I have been thinking of something very similar but using analog
>detection.
>I envisaged having a row and column "window" - the detector starts
>functioning at start of the column "window" in the first row in the
>row window and does so on successive rows until the row at the bottom
>of the row window is reached. By varying the windows' start and stop
>bound you get a rectangle which can be positioned anywhere on the
>screen. You then control an analog gate which sums the analog value
>to produce a mean level. If anything changes substantially in the
>target window the change can be detected. This is nowhere near as
>potentially sophisticated as using an A2D on all data but is simpler
>by far.
>
>Line scan times are typically around 64 microseconds with some of
>this unused at either end of the line - say 50uS active as rough
>value for working.
>To get useful A2D results you need a fastish A2D (eg 10 samples at
>5uS or 50 samples at 1uS each). Worse though is that your processor
>needs to handle this data rate which is a severe demand. A 20 MHz PIC
>will handle 5 instructions per uS. A SCENIX at 50MHz will handle 50.
>
>With my method a PIC would "almost" handle the gating and a SCENIX
>certainly would.
>(Maybe a Starfire clone goes even faster :-))
>Analysis of the analog signal would be far easier (albeit less
>useful) than keeping up with the data from an A2D.
>
>You could consider using a hardware buffer and a fastish A2D and
>crunching the data subsequently but you would probably be better off
>with a processor aimed at data intensive processing. Some of the
>modern DSPs are VERY fast and quite cheap. Maybe a 17xx PIC would
>suffice.
>
>I recently read a security magazine where they discussed video
>analysis systems. Some systems will track areas of only a few pixels
>to deduce direction and speed of the intruder.
>
>
>
>regards
>
>        Russell McMahon
>
>From: Ralph Landry <rlandry@haywood.main.nc.us>
>>I've been trying to get the concept of a video project idea down and
>>would like some advice.  I'd like to use PIC to monitor a user
>adjustable
>>area of a  B/W video camera that is used in a security system.
>>I think what I need to do is define an area of the screen and use an
>A/D to
>>digitize the area, then if movement occurs in that area it would
>then either
>>sound an alarm or perhaps have the ability to "learn" your remote
>control
>>keys for "record" and "stop".  It could then start and stop your VCR
>for a
>>user selectable duration.
>>Anyone have ideas as a good PIC to use for such an application??  Or
>>might be interested in a joint venture project??
>