Posted by Spex on 11/22/06 09:58

Jan Panteltje wrote:
> On a sunny day (21 Nov 2006 14:14:07 -0800) it happened "Mike Kujbida"
> <kujfam@xplornet.com> wrote in
> <1164147247.491244.232250@k70g2000cwa.googlegroups.com>:
>
>> Jan Panteltje wrote:
>>> On a sunny day (21 Nov 2006 13:38:13 -0800) it happened "Mike Kujbida"
>>> <kujfam@xplornet.com> wrote in
>>> <1164145093.775293.55280@h48g2000cwc.googlegroups.com>:
>>>
>>>> The downconverted HD will look much better than straight SD because
>>>> you're starting with a higher quality to begin with.
>>> This is not correct, 'aliasing' will occur.
>>> For aliasing, in the simplest form, think how to put 10 dots on a line in 7.
>>>
>>>
>>> 1 2 3 4 5 6 7 8 9 0
>>>
>>> a b c d e f g
>>>
>>> Never quite fits now does it?
>>
>> Sorry Jan but my own personal experience (as well as that of several
>> users on various Vegas forums) tells me otherwise.
>> I borrowed a friend's Z1 one day and did some test shoots of water
>> flowing down a stream into a pond. I locked the camera on a tripod and
>> shot in both SD & HDV. I then brought this footage into Vegas 3 ways,
>> SD, HDV & HDV downconverted. I also rendered the HDV footage to
>> SD,again in Vegas.
>> I then looked closely at all 4 shots on my reference monitor (JVC
>> TM-H150CGU - 750 line SD monitor). To my eyes, the downconverted HDV
>> (either way) looked better than the straight SD footage.
>>
>> Mike
>
> Well I cannot argue with [anybodies] experience.
> Maybe there are other factors at work, but the theory stands.

Your theory is ill thought out.

You are overlooking the fact that the people who write NLE editing and
compression software know a little bit more about their subject than
many give them credit for?

The images are not subjected to a rudimentary resize and compression
algorithm as your example implies. The images are in fact resized
generally with sub-pixel accuracy, anti-aliased, then sent to the
compressor.

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