10 Feb
2011
10 Feb
'11
11:54 p.m.
On 2011 Feb 10, at 11:04 PM, Rod Smallwood wrote:
The picture element measurement consists of the number
of horizontal
lines
multiplied by the horizontal resolution determined by the ability to
distinguish the transitions of a square wave as it increases in
frequency.
This is the basis or principle laid out in the 1940 book for the
horizontal resolution. For the vertical they give analyses that reduce
the resolution by a factor relative to the number of scan lines.
Various other considerations such as worthwhile H/V resolution ratios
(in addition to the aspect ratio) are included.
Normally it was done by sweeping a square wave,
increasing in frequency
along each line from left to right.
It's really a measure of video bandwidth. My last job as an engineer
before
moving to DEC was designing character based VDU's.