O.S. Losless compression format for pictures.

[greylica]

Here in my work we faced a new challenge for standardization of our assets inside our doors. I did a study for most of the O.S. native file formats with and without loss of quality compression, but, there is somethings that we need to be cleared to decide the situation.
All of our work is made with Blender in Linux software, we make our models, textures and so on. But, every enterprise that works with images, have to have assets of Images for demonstration to clients normally.
Then we ran to study what is better to make our own standards, but also, this format have to be lossless and acessible to every system in the world.
Well, we find out that png is the best solution, but, we yet don know if the compression system of the png act different in outer systems than Unix/Linux.
Initially we wanted to store with no compression, but, the files get too big that we cant'generate previews even on Linux augmenting the amount of the Mb to show these bigger files.
JPG, is good but proprietary, and then is discarded, and other proprietary file formats where discarded too.

Well, I don know if it has to be in O.T. then I post here. That's the question:

PNG works lossless in every Operating System so we can make PNG our standard ?
( I know that depends first on the library of the O.S. but I want someone out there that know if there is differences between O.Ses to decompress it )

and finally,
Is PNG with higher compression still lossless ?

Thanks for the help.

 

[JonnyBlaze]

png is lossless in all operating systems. have you looked at using tiff?

read up here, there might be some good information for you.

http://en.wikipedia.org/wiki/PNG

 

[greylica]

I read Tiff specifications carefully, and others like TGA too, but seems the PNG is the clear winner, we are testing here all of the morning, and even with compression 9 in Gimp and other formats of compression in other software, we didn't noticed artifacts or deformations in colors with bigger images ( cinema 2K, cinema 4K, premium poster 3feet or premium poster bulding 40feet ) or little images for sample.
However, in 2000 and XP, we have to implement another PNG library to show better images under some circumstances, but it's easy to solve with an simple installation of Gimp.

We will have to face another thing too, the conversion of computer to cinema 2K here in Brazil is made with TGA formats, when job is done , we will have to convert to this file format. But there is no problem at all, we can use very older and very cheaper prorietary software to do, like Photo Styler 93 with batch job

The best free file format PNG is now our standard to store images. And no worries with patents.

 

[zephyrprime]

Png is lossless. That is common knowledge. You don't need to perform a study or anything.

You could also try Jpeg2000 lossless mode. It's the only lossless image format that can attain higher compression than png. Jpg also has a lossless mode but it is rarely used and it's compression is generally inferior to png. Tiff can use the same lossless zlib compression as png but it lacks png's pre-filtering which generally allows png to attain higher compression levels.

 

[greylica]

What really matter to us here is when our animation get's done, and when we put it on the streets, no one will have the right to come here claiming that we are using illegal software or violating any kind of software patents, but we still need high quality and lossless compression if possible.

The primary goal of this is that we need organized assets, with a format that will never cause problems for all of us, then we will store or own created assets with a format that is legal, good, have high quality, but, need to be completely free from crap as well.

If, another format , even uncompressed , completely free where the only choice, we will run with the free format instead of any proprietary format.

PNG file format satisfies everything that we need for static image file format, and surprised us compared to JPG.
Microsoft touched TIFF file format in the past, is sufficient for us to leave this format to oblivion.
We will only need TGA when the Job gets done.
Other proprietary file formats that possibly have to get used, like MPG or HDV will be studied carefully when the job is finally done.

Again, and again, free software is helping our enterprise more than we are expecting.

Thanks too for the answers.

 

[greylica]

duplicated post, erasing...

 

[drag]

With image formats it's a bit weird.

For professional work the 'standard' is Tiff format. Tiff format is a bit strange though as there realy is no hard and fast standard. I don't know how it is anymore, but it used to be that each vendor of a major image program had their own 'tiff' format. There are lossless tiff versions, then there are lossy tiff formats, uncompressed images, LWZ compressed images, photoshop tiffs, and all sorts of other ones.

So it's a bit of a mess. A tiff from one program may not nessicarially work in another program.

With Linux you have a couple tiff image format libraries that different applications use. It can handle most formats well, but not all. For example a couple years ago my brother was taking photography classes and I tried to open a cdrom of his containing digital copies of his film. It was recorded in a tiff format and some of them openned, some of them didn't, and others openned but had lots of images issues with artifacts and bad colors. It just depended on which version of 'tiff' he used at the time.


Meanwhile PNG is a hard and fast standard. It's a web standard and software libraries for it have a very liberal license and good support has been added to most applications because of this.

One of the major exceptions is, even though it's a standard for many many years now and Microsoft can freely use png libs to make image applications that flawlessly support PNG, is Microsoft Internet Explorer.

Which is why you don't see PNG format used much more often and you still see the vastly inferior Giff in common usage. (Advantages over giff image format is that it supports the full RGBA color range, along with proper alpha layer support and better compression. The alpha layer support is important because with giff you can choose only one color to be transparent, with png you can make nice gradiants of transparency for doing stuff like making a single image work well with smooth edges irregardless of the color of the background. With Giff you have to make a new image for each background)


I found this page:
http://www.libpng.org/pub/png/pngstatus.html


Keep in mind that you need to make sure that all your applications support PNG properly and that any third party you plan on working with doesn't have a problem with PNG format.

Tiff is probably still the accepted standard, but I've been out of the loop for a long time so I don't know anymore. Still though it would probably be a good idea to download tiff images off the internet and figure out how to best deal with them when you run across them.

 

[Brazen]

Originally posted by: greylica

Other proprietary file formats that possibly have to get used, like MPG or HDV will be studied carefully when the job is finally done.

OGG would be the answer to that! You have to install a codec for it, but it's free and easy.

 

[drag]

Ogg Theora kinda sucks.

With things like PNG and Ogg Vorbis they are superior to what has come before them (namely Giff and mp3), but with Ogg Vorbis, unfortunately it's inferior to what has come before it (namely Mpeg4 variations).

There are a couple cool things being worked on like Snow from the ffmpeg project or Dirac from the BBC, but those are no were near mature yet.

Probably would be best to go with just regular old 'Divx'-style mpeg for maximum portability as a end release. I don't know what sort of legal issues that causes for the country Grelica is from though. In the US it would cause me to probably have to go out and purchase licenses if I intended for commercial redistribution.

For a 'working' format that is intended to be as lossless as possible there is a quicktime variant used by Cinelerra that is designed to work well well. (not compatable with most media players. It's for internal use only sort of thing) But I don't know much about what other people use besides just raw DV formats.