What does iPhoto do to pictures when it imports?

Discussion in 'Mac Apps and Mac App Store' started by Cattywampus_, Nov 8, 2007.

  1. Cattywampus_ macrumors 6502

    Joined:
    Apr 19, 2006
    #1
    I just imported all my pictures from my what used to be manually managed photo folders. I am now going to let iPhoto manage it.

    But,

    When it imports a picture and rotates it to the correct perspective, it creates a modified file. Fair enough. But the file size changes.

    An original 8.1mpx picture taken portrait on my 350D is about 4.4MB - once imported into iPhoto, the modified file is about 3.3MB.

    Is iPhoto lowering the quality of my pictures?
     
  2. MisterMe macrumors G4

    MisterMe

    Joined:
    Jul 17, 2002
    Location:
    USA
    #2
    The short answer is "Yes." JPEG is a lossy compression algorithm. There is no way to edit a JPEG without losing data. The loss should be small. Editing a JPEG one or twice should result in no noticeable degradation of quality. Do it a lot, and you will notice. If this is an issue for you, then you need to switch your pictures to a non-lossy format.

    That said, what you are seeing is most likely due to the fact that the JPEG compression algorithm is more efficient for your pictures in their rotated orientation. You can expect others to have larger file sizes after rotation.
     
  3. Zuplar macrumors regular

    Zuplar

    Joined:
    Oct 28, 2007
    Location:
    OKCity
    #3
    what i don't understand with iPhoto is that it seems to save the photo several times while i am editing it. like i can search for the picture afterwards and find my original, and then find several edited copies. is there a way i can just get it to save the original and then export the new edited one? i just hate have redundant pictures of the same thing when all i need is the original and the newly edited one.
     
  4. kkat69 macrumors 68020

    kkat69

    Joined:
    Aug 30, 2007
    Location:
    Atlanta, Ga
    #4
    Most likely the "duplicated" image is basically a back up of the original prior to editing. All should be kept in the Photo Library file/database.

    This allows you to "Revert to Original" option when right clicking on a picture.
     
  5. Zuplar macrumors regular

    Zuplar

    Joined:
    Oct 28, 2007
    Location:
    OKCity
    #5
    ok well that explains that.
     

Share This Page