On Sat, 11 Jun 2005 08:10:42 +0100, Austin Shackles
<
[email protected]> wrote:
>On or around Sat, 11 Jun 2005 01:01:43 +0100, "Danny Boy"
><[email protected]> enlightened us thusly:
>
>>Maybe you should Take Your Self & Learn Some Respect For Others
>>Jb
>
>maybe you should learn not to top-post.
>
>I'm inclined to agree with Martyn: I seriously doubt that the cameras
>contain technology capable of reading a moving barcode at several meters
>distance. The barcode is in fact read in the post office when it's issued,
>and at the same time they scan one on your renewal form or registration
>document, which matches up the tax disc with your vehicle in the database.
>That bit is right, however.
>
>I presume eventually there'll be a printer to put the vehicle details on the
>disc, but in our PO they still write it by hand.
I can get off the shelf readers that will read very small barcodes at
up to 100 Hz and/or 6 m/s subject speed. In the real world that
requires
a) a very high-quality code (print quality)
b) perfect lighting (strobe flash usually)
c) careful optimisation of subject position and reader position
d) a 'matchcode' function - i.e. if it doesn't read or the barcode <>
'1234' stop the line, rather than transmit to host, read database,
apply logic and send back 'OK' or 'fail'
So, whilst it might be possible "Tomorrow's World" style to read a
barcode at 50 meters (easy), or read a barcode at highish speed (easy)
or read a barcode through glass (easy) or read a damaged barcode
(easy) or read a barcode in an unknown position (easy), doing all of
the above for hundreds of subjects per minute in many thousands of
locations is neither feasible nor even 'on the map' as far as I know.
--
Tim Hobbs
'58 Series 2 88" aka "Stig"
'77 101FC Ambulance aka "Burrt"
'03 Volvo V70
