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KettyKrueger

macrumors 6502a
Original poster
Feb 17, 2007
509
4
UK
If I make a quick edit with Picasa, say Red-Eye Removal, then commit changes to disk (essentially over-writing my original file), will that create an exact copy of my original file plus the edit? By over-writing the original file I won't loose any quality for the rest of the picture, will I?

Thanks.
 
If I make a quick edit with Picasa, say Red-Eye Removal, then commit changes to disk (essentially over-writing my original file), will that create an exact copy of my original file plus the edit? By over-writing the original file I won't loose any quality for the rest of the picture, will I?

Thanks.

when you make an edit, picasa will make a folder called Originals and place your NON-edited version in that folder. Your Picasa interface will show the EDITED version. In the upper right hand corner at the top of your library, there is a "save to disk" button. Once you push that, your edits will become permanent and your Originals will be gone forever.
 
when you make an edit, picasa will make a folder called Originals and place your NON-edited version in that folder. Your Picasa interface will show the EDITED version. In the upper right hand corner at the top of your library, there is a "save to disk" button. Once you push that, your edits will become permanent and your Originals will be gone forever.

Thanks. But will I loose any quality by saving changes to disk? I'm kind of paranoid!
 
Thanks. But will I loose any quality by saving changes to disk? I'm kind of paranoid!

not that i know of. you can make a copy of your photo, edit one of them and check the file sizes. i've never had an issue with quality.
 
not that i know of. you can make a copy of your photo, edit one of them and check the file sizes. i've never had an issue with quality.

If we are talking lossy compression like JPEG, then file size is not an indicator of quality loss. Every time you re-encode data that are compressed with a lossy compression scheme, you loose some quality. The amount of loss of course depends on the compression level.

However, as far as I know, Picasa will only re-encode the affected 8x8 blocks of the image, and not re-encode the rest. So the quality loss will be limited to the areas that you touched. And it will match the quality settings of the original image.
 
If we are talking lossy compression like JPEG, then file size is not an indicator of quality loss. Every time you re-encode data that are compressed with a lossy compression scheme, you loose some quality. The amount of loss of course depends on the compression level.

However, as far as I know, Picasa will only re-encode the affected 8x8 blocks of the image, and not re-encode the rest. So the quality loss will be limited to the areas that you touched. And it will match the quality settings of the original image.

Thanks. So modifying any image is subject to quality loss?
 
Been reading upon JPEG. I understand that 100% quality will show extremely minor artifacts. Is this the figure that is shown under 'get info' then 'JPEG quality'? If so, what is the number in the bracket next to it?

So most of my pictures are in the high 90's, so they will have, as stated above, extremely minor artifacts, is this correct?

Moving on to another topic but what file sizes do RAW formats produce, typically?
 
Thanks. So modifying any image is subject to quality loss?

Yes, it is. But that doesn't mean you shouldn't modify your images at all. If you quality settings are high to begin with, and you don't do it 10 times to the same area of the image, the quality loss might be so insignificant that it doesn't matter. Only you can be the judge.
 
Yes, it is. But that doesn't mean you shouldn't modify your images at all. If you quality settings are high to begin with, and you don't do it 10 times to the same area of the image, the quality loss might be so insignificant that it doesn't matter. Only you can be the judge.

Thanks. Would you recommend keeping copies of all original pictures, no matter how poor they look? Or would you make the essential edits and save over the original??

By essential, I mean if a photo is really low on colour, add some saturation. The 'bones' if you will :p

Are 'lossless rotation' software any good? Just downloaded Xee, not played with it yet but just wondered if it was a gimmick.

Cheers for the help.
 
Are 'lossless rotation' software any good? Just downloaded Xee, not played with it yet but just wondered if it was a gimmick.

Cheers for the help.

Would converting my JPEGs to a lossless format, editing then exporting be a good solution to quality loss? I can delete the lossless files afterwards obviously. But would that essentially give me a nice, editing image without ANY quality loss whatsoever?
 
Please ignore my above questions, not important now.

However, can anyone confirm that Picasa does lossless rotation?

I've been searching high and low but can't find anything official.

Also, is it likely that Picasa will get a 'Places' funtionality at all?
 
when you make an edit, picasa will make a folder called Originals and place your NON-edited version in that folder. Your Picasa interface will show the EDITED version. In the upper right hand corner at the top of your library, there is a "save to disk" button. Once you push that, your edits will become permanent and your Originals will be gone forever.

I don't think you are correct. I just edited a picture and removed the red eye. I went back to the original pic in the original folder and clicked on that pic. The original, un-edited, picture displayed.

Where is it storing the edited pics?
 
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