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View Full Version : image formats What to uses and where ?



t4d
07-06-2006, 11:28 PM
HI all

maybe this could be answered with afew good links,
I done alittle google time but did find anything SO asking here


what image format is the best Tga, Jpeg, Png etc etc and why do you uses what you uses


For me I just uses Tga for anything and for alpha channels etc
for jobs where i may be sending over the net OR Just need RGB is what i uses Jpeg

some may :twak: at my uses of Jpg but I havn't seen any problems so far ....

anyway Like to get more Image format opinion :)

BazC
07-07-2006, 12:00 AM
Tiff and psd are my workhorses, .png if I need to keep file size down but maintain quality and of course jpg for web use.

ShawnStovall
07-07-2006, 12:25 AM
I find the for screen shots work best with .png(compared to .jpg).

BeeVee
07-07-2006, 01:58 AM
PNG all the way baby, and Baz? They work on the web too, it's just that in their wisdom the folk at Microsoft didn't think they needed to include the alpha channel that PNGs can do, so they don't look as nice under IE as Fx, but then JPGs can't have an alpha channel anyway.

They are also extremely useful for LightWave use. Mike Wolf and I explain the reasons why in this handy PDF I like to call "Tut".

B

Red_Oddity
07-07-2006, 03:00 AM
Textures : most of the times TGA (handy for greyscale as you can use the 8bit feature and have LW allocate just that amount for that one 8 bit channel in memory)

Output : EXR, always (LW does need some serious work on the plugin though, as basically ALL the good features are missing at this point)

Clients : usually JPEG (remember folks, clients are morrons, plain and simple, they don't know how to open PSD, TIFFs, or any other format that has been out there for more than 10 years but JPEG (or MPEG-1 for movies))

faulknermano
07-07-2006, 03:01 AM
i use a combination of TGA, HDR, and PSD, and i'm slowly trying to get into PNG. PSD is probably my most commonly used format, since i can get modifications in very quickly. TGA is for cross-platform convenience from Maya to LW and vice-versa. my complaint with PNG is that Photoshop saves PNG very slowly so it's probably good when everything is finalised.

BazC
07-07-2006, 03:07 AM
PNG all the way baby, and Baz? They work on the web too,

True! I can quickly get a smaller file size using jpg though. I use Photoshop's save for web function, it may be that I just don't understand the png options! :D

Lightwolf
07-07-2006, 05:35 AM
Hm, internally only lossless file formats:
- Intermediates (i.e. render ouputs that go into compositing) OpenEXR or TGA (bascially because TGA is so extremely simple and common)
- To customers: JPEGs for previews, TIFF for print related work, DPX for film related work, OpenEXR if they compose.

Cheers,
Mike

lilrayray77
07-07-2006, 07:55 AM
Could someone please explain the uses of cineon(.cin) and and SGI(.rgb)? I tryed rendering to both, and cineon messed up all of the colors, and none of my sofware could read .rgb.

Lightwolf
07-07-2006, 08:02 AM
Could someone please explain the uses of cineon(.cin) and and SGI(.rgb)? I tryed rendering to both, and cineon messed up all of the colors, and none of my sofware could read .rgb.

Well, there a couple of compositing apps that can read the SGI RGBs, Fusion for example.
I wouldn't render cineons directly from LW. They are expected to store logarithmic colours (which LW doesn't produce anyhow), and it also has been superseeded by DPX.
If you need DPX/CIN for you final image to transfer to film I recommend going into a compositing app, do a lin->log conversion and save. Oh yeah, and plenty of testing if you go to film as well...

Cheers,
Mike

tischbein3
07-07-2006, 08:24 AM
....
just that in their wisdom the folk at Microsoft didn't think they needed to include the alpha channel that PNGs can do

Well, in fact they did,

but they also thought it would be much more easier, intuitive and funnier to exchange:

<img src= your image here></img>

with

<DIV ID="oDiv" STYLE="height:400; width:400; filter:progid:DXImageTransform.Microsoft.AlphaImag eLoader(
src=your mage here, sizingMethod='scale');" >
</DIV>

(not to speak about the little script you need to differ between the browsers)

:)

Auger
07-07-2006, 10:48 AM
PNG all the way baby, and Baz?
B

How do you save alphas in PNGs coming out of Photoshop? I can't quite seem to figure that one out.

Jon

papou
07-07-2006, 06:59 PM
Auger, alpha is embedded into png like tga32. (photoshop and tga alpha was stange before, i don't now if it's repeared now)
i use png for black and white image (matte, etc...), i use it too when i need to optimize my LAN bandwidth.
Don't use jpg if you use field rendering or if an Avid must import them..
Rpf is a format i like to play with.
I use tga most of time.
i had a good result with YUV format when i want no banding nice gradients.

a++

Captain Obvious
07-07-2006, 07:55 PM
PNG, PSD, OpenEXR.

Auger
07-07-2006, 08:46 PM
Auger, alpha is embedded into png like tga32. (photoshop and tga alpha was stange before, i don't now if it's repeared now)
i use png for black and white image (matte, etc...),

Papou,

When I save an alpha-embedded TGA from Photoshop and reload it into PS the alpha channel is there. If I save a PNG from PS and reload it the alpha is not there.

When saving a PNG there's not an option for choosing between 16-bit, 24-bit or 32-bit like there is when saving TGAs...

:bangwall:

Thanks,

Jon

lilrayray77
07-07-2006, 09:28 PM
Papou,

When I save an alpha-embedded TGA from Photoshop and reload it into PS the alpha channel is there. If I save a PNG from PS and reload it the alpha is not there.

When saving a PNG there's not an option for choosing between 16-bit, 24-bit or 32-bit like there is when saving TGAs...

:bangwall:

Thanks,

Jon


I have the choice between saving to 24 or 32 bit. Maybe your missing plugins? Anyway, I have only had luck with saving 24bit, otherwise I end up with a half black/half white images.

tischbein3
07-07-2006, 11:05 PM
When saving a PNG there's not an option for choosing between 16-bit, 24-bit or 32-bit like there is when saving TGAs...

:bangwall:

Thanks,

Jon

ps elements here, so this might be wrong suggestions:

a)Don't store it into an alpha channel, instead, delete the background layer and save it the "normal" way
b) in pse there is an option "save for web" wich do features additional options

hope this helps

ps: seems good old iff gets outfashioned here

pat-lek
07-08-2006, 01:13 AM
I have a question;

When i use the .psd for export the render of Lightwave, i always find it darker when i open it in photoshop (7) on my mac.

Is it just me? (or my mac), or have you the same résult?

Another thing, if i had to convert the render from FGB to CMJN (quadri, for print); Sometimes, i have somes surprises.

Red_Oddity
07-08-2006, 03:40 AM
Be very carefull what you choose as Color Profile, otherwise your PSDs look totally off in other software besides Photoshop

ScottSullivan
10-26-2006, 11:26 PM
I know this is sort of an old thread, but found it searching for threads about EXR and DPX. Just recently, I listened to a podcast about the entire workflow using DPX.

I thought it was a very good show and decided to share it with everyone. It's over at Digital Production Buzz (http://www.digitalproductionbuzz.com/)

Their latest (October 19, 2006) podcast has an interview with a company called Glue Tools. In it, they discuss how they use DPX files.

(And one item that stuck out was the bit about colors being off that Lightwolf already addressed as being related to log v. linear references to color in the files.)

Warm regards,
Scott

gatz
10-27-2006, 01:44 AM
If you your creating for Flash. Another reason to use PNGs is that its the best way to get an alpha'd image into Flash. PNGs are smaller than PSDs and the methods seem to translate better (ie a multiplied drop shadow will overlay correctly)

This may change when Adobe allows PSDs to be imported as compositions with layers intact.

rg

Snosrap
10-27-2006, 12:28 PM
PNG all the way baby,

I'm with BeeVee on this! I always save renders as PNG32 and of course layered .cpt and .psd's out of Corel or PhotoShop.

Cheers
Snos

Andyjaggy
10-27-2006, 02:16 PM
It realy depends what and how you are going to use the image. I use TIFFwhen saving final versions of images and photographs, I use PNG when using the image for any type of multimedia authoring, JPG for web use, and PSD is obviously the working file that I use when working on an image. Overall I would have to say PNG is the most versatile and coolest of all the formats.

shrox
10-27-2006, 02:35 PM
I use uncompressed jpgs for most texture maps, tiff or targa for output.

T-Light
10-27-2006, 05:14 PM
Png 32 for alpha work, png 24 or 32 when passing to dfx etc, jpg when rendering tests (stills or anim), png or high quality jpg for full colour image maps, bmp 8bit for bump/spec.

Puguglybonehead
10-27-2006, 11:27 PM
TGA or IFF for textures (though I sometimes use TIFFs, just too lazy to convert them). I should probably start using PNGs and PSD for texturing. TIFFs for still output (again should probably start using the others). TGAs for frames (along with a simultaneous .mov file - usually MPEG4)

BeeVee
10-30-2006, 02:13 AM
Hey Brent,

You know that PNG works as 8-bit when using 8-bit values? Kinda of like a built-in GIF version. :D It will take less room than those nasty BMPs on your hard drive...

B

starbase1
10-30-2006, 03:29 AM
Hey Brent,

You know that PNG works as 8-bit when using 8-bit values? Kinda of like a built-in GIF version. :D It will take less room than those nasty BMPs on your hard drive...

B


I can confirm this - after hitting all sorts of limits with very large image maps and / or lots of them, I switched to mainly 8 bit PNG wherever I could. Saves a ton of memory and renders a LOT faster. It feels like a major hardware upgrade... And I was pleasantly surprised at how good the result looks - the variations diue to light and different maps having different image pallettes make it very hard to spot.

Everything in my elven village and dragon threadf was done with 256 colour PNG maps.

Nick

T-Light
10-30-2006, 05:31 AM
BeeVee-

You know that PNG works as 8-bit when using 8-bit values? Kinda of like a built-in GIF version. It will take less room than those nasty BMPs on your hard drive...
This comes from way too many late nights, and missing png in the drop down image lists for index colour images. Just checked and there it is :help:

Could have sworn it wasn't there before :D Thanks :)

SP00
10-30-2006, 08:10 AM
PNG, PNG, PNG!!!! umm.... and HDR too!!!

PNG is a loseless compression format, so you get a small file size without losing quality.

PNG 24-bit, without alpha channels
PNG 32-bit, with alpha channels.

If you want more color range, go with HDR.

If I had to use 2 formats, PNG and HDR is it. From there, I use photoshop to convert it to any other format.