Best Image Compression?

[A.Kelly]

While I've been doing a lot of network renders lately, I've not been very happy with the quality of the results I'm getting from the final animations.

Since I'm having to render the images frame by frame and then make an image sequence of those images - set the sequence as a back drop, and then just render an empty scene. (which I'm sure is old news) anyway, the only thing I can think of is the compression of the images of the first render, combined with the compression of the animation itself that makes the quality so grainy. My question is - should I not compress the images of the first render ( i.e. jpg) and if so.. what is the best image format to use?

[Ben_Chapé]

hi
well all that reminds me an Old post (http://vbulletin.newtek.com/showthread.php?s=&threadid=3290) , hope it'll help :D

[Adrian@Stufish]

Compress-decompress-recompress-getamess.
(sorry)
Iwould say never compress your original images - buy a new HD if you have to, but the compression atifacts, however small, will magnify in your movie re-compression. - I suspect that this is could be considered due to the single frame ompression 'knowing nothing about the adjacent frames'. There's not much size difference between the main image formats, so the choice is first, do you need and alpha chanel (32bit) or not (24bit) and then ,what image viewing editing package might you want to use.
(I have found that the degree of compression used by LW to save JPGs is sufficient to cause problems, whereas the 'maximum quality' JPG compression in Photoshop dows not.)

[cgolchert]

Use png.

It is the smallest format that isn't going to chew your image up. It is either 24 or 32 bit depending on what you save. Actually I know of quite a few bigger studios using it.

[electroNIX]

png [spell: ping] has less artifacts than .jpg but is slightly larger, but it can have transparency...

I would go also with uncompressed original images... you never know what you need them for in the future.

[dnauert]

I'm just currious about why you go back and re-render the image sequence in an empty scene. If you need the animation as an avi or quicktime just check the box for that when you do your first pass with the image sequence, that way you have both done at the same time.

[cgolchert]

You can't render to an animation file from a network.

And depending on what the scene is like it is better to render individual frames. You risk loosing all your frames if there is a crash when saving out the final frame to the file.

[Adrian@Stufish]

In other words, animation files are assembled sequentially, mostly using as much information from the previous frame (pixels that havn't changed) as possible.
When you render on a network, different frames on different machines render at different speeds, so after a while the frames are not being added in sequence.
If there being saved individually into a directory that's fine - their names put them in order, But if you add them to a movie file in the order they're finished it gets pretty dissapointing - and you can't rescue it.

[A.Kelly]

Thanks for the reply's everyone. Sorry I haven't posted back earlier. I'll give your suggestions a try and see if it makes much of a difference. it really sucks to render so many frames like that only to know that they're pretty much a lost cause now. :) Live and learn I guess. But again - Thanks!

[dnauert]

If you are rendering over a network I understand that the movie file won't work, but what about using a utility like graphic convert to take all of your sequential files and put them into one movie file. This will of course cause a recompression your files into the codec that you choose but if you are doing that anyway with lightwave this could save you some time. I do this all the time to get files rendered on a PC to work on a Mac based nonlinear editor with a proprietary codec. Do a search on cnet.com for graphic convert and give it a shot.

[dnauert]

If you are rendering over a network I understand that the movie file won't work, but what about using a utility like graphic convert to take all of your sequential files and put them into one movie file. This will of course cause a recompression your files into the codec that you choose but if you are doing that anyway with lightwave this could save you some time. I do this all the time to get files rendered on a PC to work on a Mac based nonlinear editor with a proprietary codec. Do a search on cnet.com for graphic convert and give it a shot.

[Alliante]

Every NLE that I've used has Image Sequence Import capability (Premiere, Vegas Video, Final Cut Pro, etc).

Should be no problem.

There are probably a few free utilities as well.

You could also probably hack Lightwave to do it too by rendering background frame sequences to a .mov file (I'd rather use another program though for that)

[emarufino]

And there is any settings for jpg format? for example in photoshop i set the compression amount in %.

[Lightwolf]

png [spell: ping] has less artifacts than .jpg but is slightly larger, but it can have transparency...
Actually, it has no artifacts at all.

There is lossy (JPEG) and lossless compression (PNG, TGA).
And some image formats support both (EXR and TIF for example).

Cheers,
Mike

[Lightwolf]

And there is any settings for jpg format? for example in photoshop i set the compression amount in %.
Nope, there isn't.

As mentioned earlier, it's also not recommended as a format for final renders.

Deliver, yes (i.e. web, previews for customers) - but not as an intermediate that will be processed further.

Cheers,
Mike