[MPM]

sorry that this questions a bit dumb but i couldn't find it in the FAQ
what the best format to save images in?(TIFF,Targa,jpg)
when i was on mac i had trouble with alot of files i saved that weren't in TIFF when i switched to PC so i'm wondering what is the most universal format that saves all necessary info about an image
thanx

[faustgfx]

psd is fairly decent. (duh).



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sky high with a heartache of stone you never see me 'cos i'm always alone

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icq#35983387

[Sumaleth]

.jpg is the most widely used format, mostly because it can reduce the file size of an image *considerably*. However, unlike most other formats, jpeg is a -lossy- format. That means to get the file size down it'll throw information in the picture away.

That sounds harsh but it does it carefully enough that the images still generally look good. And most programs give you options for how much compression you want - the less compression the nicer the image looks (not so much stuff thrown away), but the larger the file size. Likewise, high compression can really get the size down but at some point you start seeing nasty jpeg 'artifects' (little squares).

I generally save out everything as a TIF from photoshop, then load that image into Paint Shop Pro and then save it out as a jpeg from there. The PSP jpeg saver is infinitely better than the one in PS5.5 (I don't know about PS6).

I keep the TIF around even when I've saved a jpg just in case i want to do some more work on the image. It's better to work on a non-jpeg'd version if possible.

Of course, if you are using Photoshop and you are using layers then you'll need to save in PSD format.

.png is gaining popularity because it's not lossy like jpg (ie. the image is unchanged), but it generally provides better compression than TIF or TGA. And web browsers are starting to support png as standard. Still, the file size differences between png and jpg are huge.

.gif is generally used if images are small and use less than 256 colors. Although jpeg with minimum compression will look just as good yet produce smaller file sizes.

Where .gif comes into it's own is in special effects for the web, such as animations and things that need transparency.

So, to the question - it really depends what you are doing and what you want to use the images for.

Row.

[Ben Barker]

Here is the rundown:

PSD is the best. It has internal, lossless compression, loads fast and saves fast, and supports layers, channels etc. Only downside is that most other programs don't support PSD directly.

TIFF is the standard for print images. It supports LZW compression. The only thing you have to know about LZW compression is that it sucks. It's lossless, but slow, and makes little artifacts sometimes. Never use it. TIFF is also an older file format, so you have to specify PC or Mac.

BMP is the standard image format for windows paint. 8-bit, 16-bit, and 24-bit varieties. No real perks, except it is widely compatible, and will definitely be viewable on any Windows machine. Mac too, probably.

PIC (pict) is the Mac equivalent of BMP. It is a little bit better. I think it supports alpha channel and jpg compression, though it's less prevalent than BMP, obviously. I don't see much of this format.

JPG is the standard web graphic. Never save you graphics as JPG until the very, very end. Why? JPG has additive damage on its compression. Even at the highest quality setting, it will compress it again every time you save, and your image will get crappier and crappier.

Targa (TGA) was the first 32 bit image format, and it's still around because it's so solid. I don't know much about it beyond it's 32 bit capabilities. I always assumed it was just like BMP with 32 bits (i.e. no compression). Anyone know more about it?

So, you should save your files in PSD until the last minute. Then, you can save images for print in TIFF (if you are sending it to a printing house), save Windows images in BMP, or web graphics in JPG. If you need an alpha channel for transparency, go for targa.


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Damn, Sumaleth beat me.
BTW Sumaleth, with the new fastsky and r_clear in Q3 1.27, you awesome story (with orange goo in the void) has been outdated. Now it's black. Oh well, now it's nostalgic

[This message has been edited by Ben Barker (edited December 14, 2000).]

[TheMilkMan]

I would suggest TGA because it is 32 bit and loss less and it supports an alpha channel!

[faustgfx]

color profile info, man.



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sky high with a heartache of stone you never see me 'cos i'm always alone

[email protected] /
icq#35983387

[[Shizo]]

Hmm PSD is lossless? I think its not 32bit lossless though, because when i tried to save a picture of GRADIENT on it as PSD, and then opened it, i saw pretty bad color dithering on there.

TGA is good too. JPEG with highest compression is what you want to use for final artwork because even macs can read JPEG *cough*

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Nothing really matters to me

[kaylon]

Please dont forget PNG, nice file format, as fair compression and keeps clean images and supports alpha channels. Also new browsers support it for web graphics.

[A.Buttle]

TIFF or TGA, if you want other people to be able to use it that don't have Photoshop. PSD, otherwise.

Ben, TGA's are 32 bit because they support an alpha channel. 8 (Red) + 8 (Green) + 8 (Blue) = 24 (RGB) + 8 (Alpha) = 32-bit

[Shizo], were you at 100% zoom? Sometimes smooth color transitions look really bad at odd magnifcations like 33%.

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Larry Flint's right! You guys suck!

Joe Dillingham
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Three Times A Day

[Frost]

TGA or PNG for me, at least for archiving. When you need to use it in a game, you can convert to a compressed (lossy) format at that time. There are also forms of texture compression such under Direct-X, OpenGL, etc., even on GameCube (S3TC), etc.

It's best to work in full lossless quality and thrash it later if you need to -- or else you'll be screwed if you need non-damaged bitmap data after it's been saved as lossy.

Both PNG (lossless compression) and TGA (no compression in most common formats) support 32-bit, so it also stores alpha info (if needed). Libraries are available on the net for PNG loads and saves, TGA support is easy as heck to program.