JPG or PNG

[Blazaro]

What does most source filmmakers use while exporting a poster jpg or png?

[Zappy]

Of those two, definitely PNG, but Steam may or may not allow the file size of that.
Now, as I was saying before you removed your previous thread right after asking me a question...

Originally posted by Heisenberg:

But does JPG reduces visual quality?

Yes. If you want to know how much it does so, just look at a random in-game screenshot on Steam for any game. Steam screenshots are all JPG, of about the same quality as JPG exports from Source FilmMaker I believe.

[stug]

I use PNG.

[Blazaro]

Originally posted by Zappy:

Definitely PNG, but Steam may or may not allow the file size of that.
Now, as I was saying before you removed your previous thread right after asking me a question...

Originally posted by Heisenberg:

But does JPG reduces visual quality?

Yes. If you want to know how much it does so, just look at a random in-game screenshot on Steam for any game. Steam screenshots are all JPG, of about the same quality as JPG exports from Source FilmMaker I believe.

Thank you but do you have any tips to lower the file size without changing to JPG? and lowering the resolution

[Zappy]

Originally posted by Heisenberg:

Thank you but do you have any tips to lower the file size without changing to JPG? and lowering the resolution

For reducing the file size, not really, but try reading this: https://zoompf.com/blog/2014/11/png-optimization (Even then, it's might not be enough, and it's often not worth it over just exporting as JPG.)

[Pte Jack]

To reduce the size of a PNG, I usually take them into GIMP and re-export them with a compression value of 9.

[Blazaro]

Originally posted by Pte Jack:

To reduce the size of a PNG, I usually take them into GIMP and re-export them with a compression value of 9.

Thanks a lot man! i will try it for sure

[Pipann]

I'm silly; because I have a larger screen now in which SFM can fit a 1080p viewport, I just printscreen, paste in photoshop, crop the UI out and save as JPEG. :P

I prefer JPEG over PNG when I upload images to the internet, because they're space savers and they don't have to look ugly per-say. I just set the quality to max when I save. It's still smaller than a lossless PNG. Of course, there are exceptions, for example when the image must be transparent. Then I just use PNG.

[Zappy]

Originally posted by Pipann:

I'm silly; because I have a larger screen now in which SFM can fit a 1080p viewport, I just printscreen, paste in photoshop, crop the UI out and save as JPEG. :P -

Unless you run Source FilmMaker with the command-line parameters "-sfm_resolution 1080" (or 2160) and/or "-w 1920 -h 1080" (or 3840 and 2160), that will basically be an aliased upscaling of a 1280x720 image. Though, I don't know whether the "-sfm_resolution" or "-w X -h X" parameter(s) will be what changes it, or if you need both... or if neither of them do anything in this regard.

[Pipann]

Nah, I do use the "-sfm_resolution 1080" command. I love it.

And yes, I do believe you need both. I'm not currently at my homestation so I can't double check, but I'm pretty sure that's it.

Edit: alright, finally home. And yup, parameters are as follows: http://i.imgur.com/CihTclV.png

[Wayne]

JPG is a minimal loss compression codec, meaning that it won't be flawless like PNG, which is an uncompressed format. Personally, JPG is so good at compressing without losing visual quality, that if you ARE worried about space, then it's not at all a bad option. People saying to export it to another program and compress it are doing the same exact thing as a JPG already has done. If you want the space, go JPG. If you have plenty of space, go PNG.

Edit: I shopuld have mentioned. Since PNG is uncompressed, you can convert PNG to JPG, but cant convert JPG to PNG. If you convert a compressed file to an uncompressed codec, it will still have the same loss. If you are worried about space, PNG still makes sense, because you can always turn it into JPG if you ever need extra space.

[Marco Skoll]

Originally posted by Jelly Bowl:

PNG, which is an uncompressed format

... let me interrupt you there.

PNG definitely supports compression. However, unlike JPG, it uses lossless compression. (Larger files, but higher quality).
(To avoid any petty arguments about whether it can or can't be compressed, see Wikipedia: https://en.wikipedia.org/wiki/Portable_Network_Graphics )

It also supports different levels of compression, depending on which compression codec is used, and how long you're prepared to let the computer spend optimising the compression.

[Wayne]

Originally posted by Marco Skoll:

Originally posted by Jelly Bowl:

PNG, which is an uncompressed format

... let me interrupt you there.

PNG definitely supports compression. However, unlike JPG, it uses lossless compression. (Larger files, but higher quality).
(To avoid any petty arguments about whether it can or can't be compressed, see Wikipedia: https://en.wikipedia.org/wiki/Portable_Network_Graphics )

It also supports different levels of compression, depending on which compression codec is used, and how long you're prepared to let the computer spend optimising the compression.

It may support compression, but it is normally by default, lossless.

[Marco Skoll]

Lossless does not mean uncompressed: https://en.wikipedia.org/wiki/Lossless_compression

If I take a basic text file, a ZIP, 7z or RAR compression can probably compress that to well under half its original size. However, if I then uncompress that file again, the original text file is reconstructed, perfectly - in other words, lossless.

This is analogous to PNG. Compressed, but with no data loss.

A JPG compression is a bit like putting it back and forth through Google Translate first. It's probably roughly the same (machine translation is getting better), but there will be errors.

[Pte Jack]

The reason I prefer PNG is that the PNG supports an Alpha channel, where JPGs don't, PNGs give me a RGBA channels JPGs only the RGB. If you use programs like GIMP to re-render the PNG, you can set compression, which will reduce size of the PNG.

[Marco Skoll]

PNG is also usually quite efficient for computer generated images.

JPG deals well with real life photos, because it generally ignores the fine grain you get from the minute imperfections of the camera's sensor & electronics - something that PNG struggles to efficiently compress.

However, for things like SFM renders or other digital artwork (such as via graphics tablet), PNG is fairly efficient, because there isn't that electronic noise to cope with.