Lossless picture compression format?

[c-Row]

So, with FLAC or Apple Lossless we can compress our songs to roughly half the size without losing quality and the ability to convert them back to the original WAV files with no loss.

Are there any lossless picture compression formats? I got a huge collection of scanned press cuttings, but they come at a whoopy 16 GB (all in PSD), so storing them in a more efficient format would be handy.

 

[Blue Velvet]

LZW TIFF which can also save in layers...

It became very widely used after it became part of the GIF image format in 1987. It may also (optionally) be used in TIFF files

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

PSD is also inherently a lossless compression file; you may need to experiment with a few files to see which is best. You may also find it useful to convert them to RGB beforehand if they're CMYK at the mo.

 

[design-is]

You probably tried already or it doesn't suit you, but have you tried just zipping them? I always find it dramatically reduces files sizes of uncompressed images when I need to send or upload files to printers.

 

[Eraserhead]

PNG, is lossless I believe and should be small enough for what you want to do.

 

[Blue Velvet]

PNG doesn't support CMYK and it also only supports 24-bit RGB, not 48-bit if anyone is working with 16 bit images... it's designed for the web, really.

Zipping picture files is equivalent to LZW compression; there isn't anything more to be gained without throwing data away in a lossy compression format like JPG and makes retrieval awkward if you don't have access to an unzipping utility at the time.

 

[Eraserhead]

I was wondering why you didn't mention png in your first post, now I know .

 

[Jim Campbell]

LZW TIFF which can also save in layers...

Indeed. Also 1-bit black and white images (which is fine for line art and mono logos at 600dpi or so) practically disappear as far as file size is concerned when you use LZW.

Be aware that I have found some printers whose RIPs throw a real wobbly with LZW TIFFs ... if you're supplying files to a third party make sure you supply some documentation explaining that your TIFFs have LZW in order to save them a bit of time troubleshooting if they have problems.

TIFFs will also hold an alpha channel, which you can use instead of a clipping path, although a path will usually give a cleaner result.

Cheers!

Jim

 

[Blue Velvet]

Be aware that I have found some printers whose RIPs throw a real wobbly with LZW TIFFs ...

Have printers in NZ not yet arrived in the 21st century yet?*
I rarely send out native files these days; all PDFs instead.

Still, to have a printer that can't RIP an LZW TIFF in pre-press smacks of OS 8 and 9 days...

All other LZW info very pertinent too.


*Kiwi, me

 

[c-Row]

You probably tried already or it doesn't suit you, but have you tried just zipping them? I always find it dramatically reduces files sizes of uncompressed images when I need to send or upload files to printers.

Unfortunately I'd like to organize them in a separate iPhoto library as well, so just zipping them isn't an option.

 

[Jim Campbell]

Have printers in NZ not yet arrived in the 21st century yet?*

Nothing so exotic - I'm a UK boy.

However, graphic design has stopped being my profession and become an occasionally paying hobby in the last few years, meaning that I mostly do bits and pieces of stationery for friends that end up getting output by ... let's be honest ... less than state-of-the-art print outlets!

I've had to beat some of 'em with a stick to persuade them that PDFs are anything less than the devil's own work. I'm afraid that they do still exist ...

Cheers!

Jim

 

[snickelfritz]

I'm afraid I don't understand why the picture clippings could not be saved in png format.
Seems to me this would reduce the file size immensely.

 

[Blue Velvet]

I'm afraid I don't understand why the picture clippings could not be saved in png format.
Seems to me this would reduce the file size immensely.

Depends on how they're going to be used at a later date and what quality the scans are. PNG would be fine if they're not going to be printed, as in go to press or be placed in a page layout programme, something I assume is always an option when questions are asked in this forum... especially when the OP says he has 16Gb worth as PSD files.

 

[snickelfritz]

I agree with the sentiment regarding the use of RGB web graphics in CMYK layouts.
I doubt that black text on white would undergo much color shift or degradation if converted to CMYK, especially considering these are scans of material that would have to be descreened before placement in a layout anyway.

ie: this material is, for all intents and purposes, already damaged and degraded to a large extent due to the printing and scanning processes.
The color space is hardly an issue.