Go Back   Steve's Digicams Forums >

LinkBack Thread Tools Search this Thread
Old Feb 1, 2005, 10:20 PM   #1
judge_dredd's Avatar
Join Date: Oct 2004
Posts: 41

Hey everyone,

This may be a bit of a daft question, but here goes. I know that jpegs are a lossy format and that say editing a jpeg and saving it can result in some lost quality. As for the amount of quality lost I'm not really sure but I'm guessing you would have to edit and save a high quality jpeg many times before it visually degraded. The question I have, is does this degradation apply if you are simply copying the jpeg, say from a computer to a cd-r to another computer. I don't really think so but I just want to double check.

judge_dredd is offline   Reply With Quote
Sponsored Links
Old Feb 2, 2005, 12:41 AM   #2
Senior Member
Norm in Fujino's Avatar
Join Date: Jan 2004
Posts: 824

No, merely copying the photo doesn't cause the photo to be opened and resaved, so nothing is lost. FWIW, when modifying a JPEG photo in PSP or PS, be sure to set the compression ratio for the lowest (highest quality) value if you want to get the best results when resaving, and also save to a new (different) name from the original so that you leave the original intact and unmodified.
Norm in Fujino is offline   Reply With Quote
Old Feb 2, 2005, 4:57 AM   #3
Senior Member
Stevekin's Avatar
Join Date: Jun 2004
Posts: 1,611

While all of this is true, you might also want to consider saving in the native format to your editing software. ie, PSD in Photoshop. This is a lossless format and enables you to keep all of your editing, layers etc, until you are sure you have finished. And remember to do as Norm in Fujino said, save as 'different name' to keep your originals. I tend to just add EDIT to the end of the file name for convenience.

Stevekin is offline   Reply With Quote
Old Feb 2, 2005, 9:03 AM   #4
judge_dredd's Avatar
Join Date: Oct 2004
Posts: 41

Thanks guys,

Great advice.

judge_dredd is offline   Reply With Quote
Old Feb 2, 2005, 4:31 PM   #5
Senior Member
BillDrew's Avatar
Join Date: Jun 2002
Location: Hay River Township, WI
Posts: 2,512

Good points above. I'd add that you should save a dopy of your original exactly as it comes from the camera with no editing or changes of any kind. That is your digital "negative": don't mess with it.

If you have the unaltered orginal, it doesn't much matter what you do with the copies. You can always go back and start over no matter how badly you mess up the editing or if you save it at 500x400 pixels with very high compression.
BillDrew is offline   Reply With Quote
Old Feb 2, 2005, 5:32 PM   #6
JimC's Avatar
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378

You may want to take a look at Mike Chaney's October 2004 Tech Corner Article:

JPEG Images: Counting your Losses

BTW, as BillDrew already mentioned, always keep your originals and work with copies. It's too easy to mess something up. Even if you're not concerned about degradation,you may be later, and a better way to edit the originals may come out.

Youcan also lose some information about camera settings contained in IPTC/EXIF headers with many image editors when saving files.

JimC is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -5. The time now is 11:16 PM.