Help me understand jpeg file sizes (for iPod album art)

Discussion in 'Art, Media & Photography' started by Max Dread, Feb 1, 2014.

  1. Max Dread

    Max Dread SS.org Regular

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    Hi all

    I know nothing about photography, jpegs, etc etc. But i recently bought an iPod Classic 160GB and will be putting music with album art onto it. I've been told the iPod's display is 320x320. In the ripping program I am using, I can specify a file size for tagged art. I want the art on the iPod to take up as little room as possible (save that for music!), but to still be of good quality.

    So....

    1. Would there be much difference visually between, say, a file of 200x200 and one of 320x320? At what size will a difference start to be noticed on the iPod?

    2. I know that jpegs can be compressed. Are there any other ways their files sizes can be reduced? And when compressing, how much can you get away with?

    To put it another way... I'm using dbPoweramp for all my ripping and there's a DSP add-on that allows you to specify album Pixel Size and File Size. To achieve the file size, compression is used. So I can actually use the Ripper to produce artwork of a specified pixel and file size. But what's gonna be the best choice for the iPod?

    Cheers

    Max
     
  2. Tang

    Tang Master of Chihuahuas

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    Any jpg that's 320x320 even at the best quality is going to be tiny (under 500kb, more than likely. If there's an option, set jpg compression to 5 and that should be suffience quality for your purpose.
     
  3. Max Dread

    Max Dread SS.org Regular

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    There is no option for jpeg compression is terms of numbers (like "5"). Just an option to restrict the final file size...

    In terms of sizes, 500kb might seems small on the face of it. But if I have let's say 2200 albums to put on the iPod, that's around 1GB worth of art. So I'd prefer to go much smaller if possible. ESPECIALLY if it will make no difference to how the artwork looks.

    When a jpeg is compressed, which element of the file changes?

    Cheers
     
  4. Winspear

    Winspear Tom Winspear

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    The average computer screen is displaying around 90 dots per inch. So really given that the size of art on an ipod is about 1x1 inch, 90x90 pixels would give you the same image resolution at the same viewing distance as a laptop screen. Below that you'll start to notice a difference.

    Haven't tested this theory at all but DPI/viewing distance is what's used to determine print quality and what I've found important in computer displays and image size on the computer.
     

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