Products            Buy            Support Forum            Professional            About            Codec Central

quantize 16-bit PNG or TIFF to 10-bit, 12-bit, or 14-bit PNG to save space on an IS?

  • Time
  • Show
Clear All
new posts
  • Lynx_TWO
    dBpoweramp Enthusiast
    • Aug 2009
    • 81

    quantize 16-bit PNG or TIFF to 10-bit, 12-bit, or 14-bit PNG to save space on an IS?

    I had an idea the other day&*8230;

    So, let's say we have all these 16-bit TIFFs for an Image / Frame Sequence, but we know that this is the final master, color grading is done, and so anything over 10, 12, or 14 bits will be a waste of space, right? So why not have an option to quantize those final 16-bit-per channel (48-bit RGB) mastered images to 10-bit (30-bit RGB, 1024 levels per channel), 12-bit (36-bit RGB, 4096 levels per channel), or 14-bit (42-bit RGB, 16384&*8236; levels per channel) before converting to 16-bit PNG? That way the color quantize is already done, we get to store a lossless backup in the smallest space possible since PNG will only store the actual bit depth in a 16-bit PNG image (or at least from my tests in Photoshop that is indeed what seems to happen), and when newer video compression schemes come out you have a lossless-but-highly-compressed source.

    I used ximagic on a TIFF file from an image sequence, used kMeans quantization to 8-bit (24-bit RGB, 256 levels per channel), 10-bit (30-bit RGB, 1024 levels per channel), and 12-bit (36-bit RGB, 4096 levels per channel)

    kMeans for Color Quantization: https://lmcaraig.com/color-quantization-using-k-means

    Results with file size are shown below. I used LZW compression on the TIFF files and Mixed Prediction Method on the PNG files.
    Per one frame

    Filetype 8-bit result (KB) 10-bit result (KB) 12-bit result (KB) 16-bit result (KB)
    TIFF [1080p] 2,533 3,807 4,556 10,613
    PNG [1080p] 2,202 3,002 3,352 8,166
    TIFF [2160p] 8,431 13,301 16,388 45,853
    PNG [2160p] 4,519 7,344 9,014 27,550

    Based on size differences and current folder of Frame Sequence Images

    Sequence Type 8-bit archive (TB) 10-bit archive (TB) 12-bit archive (TB) 16-bit archive (TB)
    TIFF - HD 0.34 0.52 0.62 1.44
    PNG - HD 0.3 0.41 0.46 1.11
    TIFF - HD @ 60fps 0.86 1.29 1.55 3.61
    PNG - HD @ 60fps 0.75 1.02 1.14 2.78
    TIFF - 4K 1.15 1.81 2.23 6.23
    PNG - 4K 0.62 1 1.23 3.74
    TIFF - 4K @ 60fps 2.86 4.52 5.57 15.58
    PNG - 4K @ 60fps 1.53 2.5 3.06 9.36

    Per average of the total folder size of all rendered frames. For 12-bit video you are talking cutting your archive of the original frames by 2/3

    Is this a solid idea or am I way off base?
    P.S. Image converter does not seem to be optimized to handle large sets of images such as these. When I clicked on the folder to select all the images, dBpoweramp Image Converter starting using the hard drive for about 5 hours before I finally ended the process and split things up into smaller batches[/SIZE]
    Last edited by Lynx_TWO; June 26, 2020, 03:19 PM. Reason: Edited for clarity