Simple question: pixels vs file size

Discussion in 'Photoshop' started by Arizona, Sep 12, 2004.

  1. Arizona

    Arizona Guest

    Why would a 2510 by 1960 image take 14.1MB in its uncompressed mode?
    What's the math?
     
    Arizona, Sep 12, 2004
    #1
    1. Advertisements

  2. Arizona

    Sanders Guest

    ****************
    The math is:
    2510 x 1960 x bit depth (8) x number of channels (3) / 8192 = Kilobytes
    Divide that by 1000 for MB.

    --sanders
    e-mail?Please erase theboard
     
    Sanders, Sep 12, 2004
    #2
    1. Advertisements

  3. 2510 x 1960 = 4919600 pixels.
    One pixel is 3 bytes if the image is 8 bits per pixel, so
    4919600 pixels = 14758800 bytes = 14.0751 MB.
     
    Johan W. Elzenga, Sep 12, 2004
    #3
  4. Arizona

    anyone Guest

    What's 8192?
     
    anyone, Sep 12, 2004
    #4
  5. Arizona

    Sanders Guest

    To be precise: There are 8,192 bits in a kilobyte, not 8,000
    --sanders
    e-mail?Please erase theboard
     
    Sanders, Sep 12, 2004
    #5
  6. Oops. Read "if the image is 8 bits per COLOR", not per pixel.
     
    Johan W. Elzenga, Sep 12, 2004
    #6
  7. I always thought there were 1024 bits in a kilobyte.
     
    L. M. Rappaport, Sep 13, 2004
    #7
  8. Arizona

    Aki Ahonen Guest

    1024 bits in kilobit
    bit=1/8Byte
    so 1kilobyte=1024x8bits

    --Aki Ahonen
     
    Aki Ahonen, Sep 13, 2004
    #8
  9. Arizona

    Carlos Guest

    Hi
    That is correct.
    This is incorrect. You must divide by 1024 for Mbytes.

    Carlos
     
    Carlos, Sep 13, 2004
    #9
  10. Arizona

    Carlos Guest

    Hi
    1 byte = 8 bits
    1 Kbyte = 1024 bytes = 8 x 1024 bits = 8192 bits.

    Carlos
     
    Carlos, Sep 13, 2004
    #10
  11. You're right - I should know better.
     
    L. M. Rappaport, Sep 14, 2004
    #11
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.