TIFF vs. JPG

[tech4all]

You know how TIFFs are uncompressed while JPGs are compressed? What exactly is the difference between the uncompressed and the compressed, besides the file size?

Thanks for any info /emoticons/thumbsup.gif

[PrintDriver]

when the file is compressed into jpg format there is a loss of image data. If a file has been jpg compressed multiple times you will start to see loss of detail, especially in the darker areas of the image (at least that's where I see it most).

You don't want to be using jpg's for print if you can help it. Usually an image that has been compressed only once (like most stock image downloads), or even twice, will be ok - but it's still better to avoid it.

Tiffs can be compressed as well. A lot of times we use LZW compression to get tifs to emailable size. It's a good idea to warn the recipient if you do it though. Especially if the recipient is your print vendor.

PrintDriver is a large format digital print dude. His advice/opinions may not apply to the 4color/offset/web world of printing

[tech4all]

Thanks for the reply.

I took two pictures with my digital camera today (one JPG and one TIFF). I reallly couldn't find any difference between the two. Is there something specific I should be looking for?

It isn't so much 'how', but 'why'.

[PrintDriver]

This explains it very well:

www.wfu.edu/~matthews/misc/graphics/formats/formats.html (http://www.wfu.edu/~matthews/misc/graphics/formats/formats.html)

PrintDriver is a large format digital print dude. His advice/opinions may not apply to the 4color/offset/web world of printing

[ylaenna]

PD, I've heard that using LZW compression is a no-no. The article says that LZW is lossless, so what's so bad about it? Isn't an LZW-compressed TIFF smaller than one that isn't? Is it because it's not supported across the board?

THINGS GO WELL AH MAHT BE SHOWIN HER MAH OH FACE...

[PrintDriver]

You can use it. But many times it can't be printed in that format. Well, at least where I'm at.
If you absolutely have to do it, tell your printer so he doesn't waste time ripping something that will come out wrong.
(We always check anyway.)

Also, some programs can't open LZW compressed tifs.

PrintDriver is a large format digital print dude. His advice/opinions may not apply to the 4color/offset/web world of printing

[ylaenna]

Ah ok, was just curious. I only used it a couple of times to try to squeeze every little byte out of that humongous file size, but with FTP, really, another dozen megs isn't that big a deal. Thanks.

THINGS GO WELL AH MAHT BE SHOWIN HER MAH OH FACE...

[DavidFletcher]

Tiff V's Jpeg....

You can actually see the image data loss if you look closely...

What jpeg does > In terms of colour and position, it takes a group of closely related pixels, maybe9 varying shades of blue all positioned next to one another and basically adjusts them all to the same shade of blue. This cuts down on the data hence making the overall file size smaller. Great for email and hard disk space. The trade off is a huge loss in terms of quality which becomes ever more noticable when enlarged, especially on prints.!!


The bottom line

Use tiff if you want good prints...Use tiff at 72ppi if you want good screen images....Use jpeg if you want to email those screen images