Will a JPEG file loose IQ if it is edited in a 8 bit colour software

[henrik_jacobsen]

I am on my slow way to digital photograpy and was looking for a free software

to make editing (cropping, removal of red-eyes, sharpening, change contrast

etc) and was in the first place interested in GIMP because that program will

probably exist in a free version for many years. BUT, then I searched the

photo.net to find some comments on this (and other free programs). I found out

that some programs inclusive the GIMP only works with 8 bit colour dept (don't

know what it means but I did understood that it was a problem and it was not as

good as Photoshop).

 

My question is: If I use a free software like GIMP which only have 8 bit colour

dept, will I loose image quality on my pictures for ever - i.e. it can not be

changed back if I later will use Photoshop?

 

I actually decided to begin with Picasa since that program should be easy to

use. I don't know if that program works with 8 bit colour. How can one find out

whether a program works with 8 or 16 bits colour?

 

Is there other ImageQuality irreversible damage to my pictures if I use a

freeware program instead of Photoshop?

 

/Henrik

[bobmichaels]

You can always save your original and never overwrite it. Just save any adjusted files with a different name. Then you will always go back with the option of starting fresh with a different image editor.

 

8 bit vs. 16 bit makes no difference if you're saving the original capture as a JPG. JPG's are 8 bit files so you will never have the real advantages of working in 16 bit. But it might not make that much difference in your prints anyway.

[rogerb1]

I have found that editing with an 8-bit editor will definately result in loss of quality, particularly if you're adjusting tones or gradients.

If you start out with jpeg then any editing will reduce the quality, no matter what editor you use due to the fact that jpeg is an 8-bit file format and this is irreversible.

If you shoot raw then, by all means, save your raw files. If & when you get a full-blown 16-bit editor then you can always re-process them (that is, if you still have an interest!).

[twmeyer]

"<i>Will a JPEG file loose IQ if it is edited in a 8 bit colour software</i>"<p>yes, as Ray says. <p>You can tell if the editor is 8 bit, if it offers no other option (see the help files). Always store unedited original files on high quality CDs, if you want to keep them. Re-burn (copy) them every 5 years, if you care... t

[ronald_moravec1]

8 bit JPEGS can stand simple editing but get unsmooth tones with more complicated work.

 

JPEGS are by definition 8 bit.

 

Always save the original file. When you open and close it it uncompresses and

recompresses. Do it enough and you will get artifacts.

 

Open the original, and "save as" a .psd ( xxx.psd instead of xxx.JPEG ). I rename mine so

I don`t have to see the file extention to know what they are. , xxx psd.psd. Return to this

saved final .psd each time you make a JPEG and name the JPEG with the name, resolution

and size, ie xxx 300 4x6.JPEG.

[henrik_jacobsen]

OK, thanks for the help. I think I better have to read some basic stuff about editing before I start with this project.