Lossless trickery

Question

Level 1

0 points

Lossless trickery

Not sure where to post this, but it seems a likely spot. Does anyone know if Apple’s Image Capture, Preview, iPhoto, or even Adobe Bridge perform an actual lossless rotation of a JPEG image?

I came across an seemingly interesting app called Xee ( http://wakaba.c3.cx/s/apps/xee.html ), which is touted by some as being more versatile than Preview.

One of the claims on the site is that it will ‘Losslessy rotate and crop JPEG images. This lets you edit your digital photographs without losing quality by re-compressing them like most other editors do.’

Lossless rotation is what caught my imagination.

Apple Help doesn’t exactly say how it does it -- or if it does it at all. Does any one know if the above Apple apps can perform the lossless trick?

iMac G4, Mac OS X (10.5.2)

Posted on Mar 12, 2008 7:45 PM

Reply

Answer 1

Old Toad

Level 10

216,500 points

Mar 12, 2008 8:29 PM in response to innesjohn

Innesjohn:

Welcome to the Apple Discussions. I just downloaded and tried Xee and it truly does do a lossless rotation and save.

TIP: For insurance against the iPhoto database corruption that many users have experienced I recommend making a backup copy of the Library6.iPhoto database file and keep it current. If problems crop up where iPhoto suddenly can't see any photos or thinks there are no photos in the library, replacing the working Library6.iPhoto file with the backup will often get the library back. By keeping it current I mean backup after each import and/or any serious editing or work on books, slideshows, calendars, cards, etc. That insures that if a problem pops up and you do need to replace the database file, you'll retain all those efforts. It doesn't take long to make the backup and it's good insurance.
I've created an Automator workflow application (requires Tiger), iPhoto dB File Backup, that will copy the selected Library6.iPhoto file from your iPhoto Library folder to the Pictures folder, replacing any previous version of it. It's compatible with iPhoto 08 libraries and Leopard. iPhoto does not have to be closed to run the application, just idle. You can download it at Toad's Cellar. Be sure to read the Read Me pdf file.

Reply

Answer 2

innesjohn Author

Level 1

0 points

Mar 12, 2008 10:10 PM in response to Old Toad

Thank you Old Toad! That's great. Yes, I've downloaded Xee myself, but not tried it yet; you are more adventurous than me. I'll also give your Automator workflow a go -- as you say it works with iPhoto 08 & Leopard -- & I will first read the Read Me pdf.

It is really curious to me that Apple haven't incorporated the 'lossless' rotation into any of their apps as yet. Or have they? Maybe someone will let us know.

Meantime, someone has just given me a misc. list of other apps that will do the lossless trick, on:

http://sylvana.net/jpegcrop/losslessapps.html

Thanks again.

Message was edited by: innesjohn

Reply

Answer 3

Old Toad

Level 10

216,500 points

Mar 13, 2008 10:03 AM in response to innesjohn

Apple's rotation feature does not add very much compression. A 2.6 MB file ends up at 2.3MB with just rotation. I found a site of a professional photography firm that discussed jpg compression and their contention is that there's too much made of it. A one time edit and subsequent compression is very difficult to discern from the original file for normal use. Since the largest print I've made is 8 x 10 I don't worry about it. If you have Photoshop or Photoshop Elements you can use it to edit, saving as a .psd file and not worry about jpg compression if that's a concern. It all depends on the final use of the image.

OT

Reply

Answer 4

innesjohn Author

Level 1

0 points

Mar 13, 2008 10:40 PM in response to Old Toad

Thanks, OT. Yes, I tend to agree. There is quite a bit of hysteria out there about JPEGs & the degradation suffered by doing even a simple edit like a rotation. I recently read -- & doubtless should re- & re-read -- an excellent article by pro photgrapher Steve Bohne about this & other related subjects called 'Should you capture digital photos in RAW or JPEG?', at:

http://graphicssoft.about.com/od/digitalphotography/a/raworjpeg.htm

He dusts out a lot of cobwebs. Well worth a visit. Thanks again. BTW I've tried out Xee & it's worth its weight!

Message was edited by: innesjohn

Reply

Answer 5

Old Toad

Level 10

216,500 points

Mar 14, 2008 9:17 AM in response to innesjohn

Thanks for the article. I can't find the link to the one I originally read and learned about jpg compression and with the bottom line of "not to worry". I'll use this article in future posts when users are worried about it.

OT

Reply

Answer 6

innesjohn Author

Level 1

0 points

Mar 14, 2008 4:42 PM in response to Old Toad

I have found tons of good advice on graphics generally from Graphics Software on about.com. One of the links contains a whole mine on various pix formats incl. JPEG, here:

http://graphicssoft.about.com/sitesearch.htm?terms=JPEG%20compression&SUName=gra phicssoft&TopNode=4454&type=1

Especially this, an excellent article in 2 parts by the site guide Sue Chastain:

http://graphicssoft.about.com/od/formatsjpeg/a/jpegmythsfacts.htm

Cheers

Reply