hd resolutiuon woes...

ushere wrote on 10/26/2006, 4:46 AM
back again.... and thanks for the previous advice everyone - much appreciated.

so, i took two examples

www.hannakay.com/test-pics/

as stills they looked great in both 720p / 1080i+p (i'm in pal land)

then i did a simple motion move (with and without 'reduce interlace flicker') 10sec each - that panned across 'sturt', and on 'stalking', then top to bottom on 'stalking'.

in sd the results were as i expected - smooth if not that sharp.

at 720p as still they look fantastic, but artifact'ed on the pans, with some 'minor jerking'.

at 1080, again they looked brilliant as stills, but totally unacceptable with the artifactng and stuttering on all moves.

does this mean i'm going to have to stay with sd? i mean i have a pretty clear idea of creating smooth, clean moves in v6 / 7, and monitoring the effects but this artifacting on high res pictures (and i haven't even tried cross-hatched drawings!!!) is totally unacceptable.

video is great, no problems in that dept at either 720p or 1080, but my main clients are pretty serious artists who supply me with high res images - and accept the softening associated with sd - but the few i've shown the test to have all said they'd prefer sd if that's the best hd has to offer.

i would really, really appreciate some feedback about this problem....

thanks

leslie

Comments

farss wrote on 10/26/2006, 5:32 AM
The "b" image I'd imagine could cause major grief, there's a lot of fine detail in there.

OK, how are you viewing the output, what are you encoding to?

First place to start is by reducing the resolution using Gaussian Blur, typically 0.001 to 0.003 should cure most problems, should only need it in the vertical direction.

However you shouldn't see any problems on a progressive display such as an LCD, that's why I asked what are you looking at this on.
Serena wrote on 10/26/2006, 6:03 AM
I'll have to try 'sturt' myself before commenting. Is that image the same resolution as the original you're working with? I presume you're not talking about interlace artifacts seen on a progressive display?
farss wrote on 10/26/2006, 7:03 AM
Actually good point. I've had so much grief with those kinds of things in the past I always assume they're the issue. These could well be but there's more to 'interlacing' problems than just de-interlacing artifacts although the ones I've had only show up on interlaced displays.

But pan accross a very high resolution image could perhaps be causing both the encoder and decoder issues.

Just speculation on my part but encoding a panned hires still to HDV might be a very different thing to encoding in a HDV camera. The camera has probably got low pass filtering either due to the optics or a separate optical low pass filter. There's also possibly electronic low pass filtering as well and quite likely some smarts in the encoder. I've notice that the HDV cameras seems to drop resolution when things get too hard to encode rather than let macroblocking set in.
Now the HDV encoder in Vegas could well not have any of these smarts in it and that'd be fine if the input to the encoder is HDV from a camera. A panned still image hm, don't know about that one.

I've done panned hires stills to both SD and HD but only to uncompressed HD and it looked fine but ate every disk I had :)

Bob.
riredale wrote on 10/26/2006, 8:40 AM
I'm not sure I understand your situation, but I know in my own experience that any time I had a video where the image looked great if there was no motion but horrible if there was motion my first suspicion was interlace order.
ushere wrote on 10/26/2006, 4:11 PM
thanks gents (are there any female editors in this group?),

to answer questions, in no particular order -

a. monitoring is on pc screen (haven't got round to hd tv yet, nor likely to till price falls to a 'rural' level ;-)

b. tried field order, but using wrong order certainly stood out!!!

c. encoding to 720p / 1080i 50 interm.

d. use Gaussian blur regularly, to great effect, and yes, it helped with vertical tilt - but still having 'jerky' look to pan on sturt desert picture.

e. as i wrote, no problem with camera pans of 'detailed' paintings....

again, thanks for your interest,

leslie

ps. bob are you around tuesday am? am in sydney and will try and pop in if i have time.
Serena wrote on 10/26/2006, 4:21 PM
>>are there any female editors in this group?

Well now, a little sexism there?

I've just put sturt into V7, set it as a 30 sec progressive clip and scanned across in that time. Set format to match output format and set preview to best/full. No gaussian blur needed. No problem, beautiful image. Rendered to W9 and still great. If you're looking at preview with less than full resolution you'll see all manner of artifacts because there is so much detail.

You may want to be more specific on your processing of the still (scan speed, framing, etc).

Serena (f)
farss wrote on 10/26/2006, 4:25 PM
Sure thing, I'll be around Tuesday.
Drop me an email.
ushere wrote on 10/26/2006, 5:02 PM
serena - no sexism, just curiosity - i learnt my skills from a really talented female film editor. she was all you could ask for in a teacher, and most of all, she understood me, and my sometimes inane, obscure, stupid questions!!! she also taught me patience and organization, two things i've found indispensable as an editor.

as an aside, i have to say that after 30+ years in the business, i have found working with women directors much better and easier than most male ones - maybe it's working in a chauvinistic profession (als), but they have no fear of asking questions, listening to advice, and telling a client when he's wrong. and that's not counting patience and organization.

a. on sturt it was a simple full frame pan, left to right, over 10secs (in pal)

b. bob, will email...

thanks,

leslie
Serena wrote on 10/26/2006, 5:51 PM
That's quite OK, Leslie. There wasn't any offence taken and I was just having a dig that you hadn't noticed that a number of women post on this site!

I still can't find a problem with your still even at the faster pan rate and setting to interlaced (either in V7 or in wmv9 render). At 10 seconds, which is a satisfactory pan rate, there is a discernable jerkiness that is removed by 0.001 horizontal gaussian blur (which you need to remove when you stop the pan at the end).

You haven't commented on your preview setting.
vicmilt wrote on 10/26/2006, 6:33 PM
Serena - what's a "sturt"?

Ushere - have you considered SHOOTING your stills with a camera?

Once upon a time that's all we did- with a computer controlled table called a Warren Smith, coupled with a computer moved camera and zoom lens.

You don't really NEED that kind of rig. A steady hand and two or three takes ought to get you right in the ballpark.

Just a thought.

BTW - I'll often shoot stills of artwork rather than scanning - way faster and easier - this is a twist on that process - essentially to avoid the "crabbiness" of computer moves and redigitization.

v
Serena wrote on 10/26/2006, 6:49 PM
Hi Vic,

One of the images was identified as "sturt". I presume it is the Sturt Desert in NE of the state of South Australia (looks like it). On my machine panning over the image is fine provided one sets preview to high resolution.

Serena
ushere wrote on 10/26/2006, 7:34 PM
thanks serena (it's hard to tell gender from screen names...).

preview was set to best auto - but that wasn't what i was judging by - i simply rendered and played out through media player / vlc / power dvd. your .001 WORKS. i had been a little heavy handed using .01, which was noticable.

sturt desert, nw of new south wales ;-)

yes v, i did consider shooting them, problem is many of the original artworks are simply not available (sold, exhibiting overseas/interstate), and many that are in the studio are simply too big (and i mean BIG) to try anything without a jib, tracks, or steadycam, all of which are out of budget. i'm stuck with high res pics.

finally, i asked in my original post, what would your thoughts be re 720p vs 1080i50. i'm leaning towards 720p for both practicality (on timeline, etc.,) and adequate quality?

thanks yet again,

leslie
Serena wrote on 10/26/2006, 8:01 PM
How are you delivering the product? I presume you have live video as well as stills? I like to maintain highest quality as far as possible through post and leave reductions to rendering. If you are to deliver hi-def for progressive screens, there I find interlace artifacts truly horrible (I run 1080i through DVFilmMaker to generate a quality progressive video stream). But this aspect is critically dependent on display characteristics -- if interlaced then 1080i is fine. If rendering to DVD for TV display, 1080i is fine.
fldave wrote on 10/26/2006, 8:27 PM
720p looks great on my 1080i 65" tv. 1080 definitely looks better, though.

Experimenting with 720p (NTSC) one day, I found that 720-60p looked wonderful. It was downconverted from 1080-30i footage, lots of motion that converted well.

Depends on your delivery method, of course.
ushere wrote on 10/27/2006, 2:57 AM
as yet delivery is unknown - though i suspect it will be standard pal dvd. i would hazard a guess that most will be viewed on regular tv's, and a minority on lcd / plasma. NO hd. that's why i was asking abot 720p.

as fldave points out - 720p looks great, and doesn't do anywhere near as much 'artifacting' than does 1080i with the hi res pics...

leslie

ps generally the only live footage is a studio style interview with the artist - ie. talking head, so there's no big deal there whether in sd or hd, though framing is usually neater in 4:3 than 16:9
Serena wrote on 10/27/2006, 6:12 AM
>>>'artifacting' than does 1080i with the hi res pics

I haven't any experience that supports your view, but it's be a dull world if we all agreed.
DavidSinger wrote on 10/27/2006, 10:19 AM
"finally, i asked in my original post, what would your thoughts be re 720p vs 1080i50. i'm leaning towards 720p for both practicality (on timeline, etc.,) and adequate quality?"

Rueben's Rule Of Thumb (RROT): If your end product is going to TV (PAL being less-compressed than NTSC) then your final footage is going to be compressed unmercifully and differently by the various station engineers. Mark Rueben this past month made a convincing argument that 720p compresses (via MPG4) cleaner than does 1080p than does 1080i. However, if your end product is going straight to DVD, then the decision would be more based on the quality of what comes out of your camera, because *you'll* get to select how to compress it down to the DVD/Web format. Then there's the "interpretive" firmware in those various playing devices that can handle HDV. Most players/projectors down-rez 1080i/p to 720p anyway, which would be still another level of compression out of your hands. Why fight 'em?

I shoot/edit in 1080i because that's what the camera provides. Then I seriously consider how the delivery vehicles/engineers will mess with the signal to cram it into their already-jammed bandwidth - and I render separately/differently for each particular medium. It makes me feel like I have *some* control over the viewing experience.