Picasa - Quick Question

Discussion in 'Mac Apps and Mac App Store' started by KettyKrueger, Feb 2, 2009.

  1. KettyKrueger macrumors 6502

    KettyKrueger

    Joined:
    Feb 17, 2007
    Location:
    UK
    #1
    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.
     
  2. Razeus macrumors 601

    Joined:
    Jul 11, 2008
    #2
    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.
     
  3. KettyKrueger thread starter macrumors 6502

    KettyKrueger

    Joined:
    Feb 17, 2007
    Location:
    UK
    #3
    Thanks. But will I loose any quality by saving changes to disk? I'm kind of paranoid!
     
  4. Razeus macrumors 601

    Joined:
    Jul 11, 2008
    #4
    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.
     
  5. tilman macrumors regular

    Joined:
    Feb 28, 2006
    #5
    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.
     
  6. KettyKrueger thread starter macrumors 6502

    KettyKrueger

    Joined:
    Feb 17, 2007
    Location:
    UK
    #6
    Thanks. So modifying any image is subject to quality loss?
     
  7. KettyKrueger thread starter macrumors 6502

    KettyKrueger

    Joined:
    Feb 17, 2007
    Location:
    UK
    #7
    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?
     
  8. tilman macrumors regular

    Joined:
    Feb 28, 2006
    #8
    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.
     
  9. KettyKrueger thread starter macrumors 6502

    KettyKrueger

    Joined:
    Feb 17, 2007
    Location:
    UK
    #9
    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.
     
  10. KettyKrueger thread starter macrumors 6502

    KettyKrueger

    Joined:
    Feb 17, 2007
    Location:
    UK
    #10
    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?
     
  11. KettyKrueger thread starter macrumors 6502

    KettyKrueger

    Joined:
    Feb 17, 2007
    Location:
    UK
    #11
    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?
     
  12. cycler15 macrumors member

    Joined:
    Nov 11, 2008
    #12
    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?
     

Share This Page