File sizes for images.

Discussion in 'Digital Discussion & Q&A' started by Jacki, Mar 7, 2010.

  1. Jacki

    Jacki TPF Noob!

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    I was browsing through the pictures I have taken so far with my G11, and I noticed that the size of the images varies a lot...anywhere from under 2GB to a little over 6GB. Is this standard, or am I missing something? I have PP'd them, but I don't see why that would make the file size vary so much.
     
  2. JimmyO

    JimmyO TPF Noob!

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    Take 2 one page "word" documents. Fill them both up but for the second one use double spacing, the size will be smaller.

    It all has to do with how much detail is in the photo.
     
  3. Garbz

    Garbz No longer a newbie, moving up!

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    Firstly I assume you mean MB (MegaByte as opposed to GigaByte). JPEG is a lossy compression technique that varies greatly depending on how much compressible information is in an image. The eye is more sensitive to fine detail in light shades and the colour green. JPEG compression takes advantage of that fact and will remove the most detail in shadow areas as well as compress the blue channel the most.

    The result is dark pictures / blue pictures will be significantly smaller than light red / yellow / green photos, and this doesn't even take into account that different images have different levels of detail that needs to be compressed.
     

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