On Thu, Nov 18, 2021, 7:17 AM John Rose <[email protected]> wrote:
Is this better: > Lossy + lossless = less lossy? > No, it's more lossy. Not that lossiness has a numeric value, but if it did, a reasonable measure would be the percent reduction in size. The part we discard typically has higher Kolmogorov complexity due to being mostly random noise that can't be compressed losslessly. Analog color TV (NTSC, used in the USA from 1953 to 2009) used lossy only compression to reduce the bandwidth of the chroma signal at 3.5-4.5 MHz above the luma signal to fit it in the allocated 6 MHz bandwidth originally designed to transmit 525 lines grayscale x 30 interlaced frames per second. That's a lossiness of 2/3. It works because the eye is less sensitive to fine detail in color than in brightness. Digital TV transmits 6 channels of 1920 x 1080 x 60 fps x 3 colors x 8 bits per pixel in the same 6 MHz band. That's 3 billion bits per second in a 1 MHz band, or 99.97% compression. Lossless video can only be compressed about 50%, so that's 99.94% lossiness, if you want to define it that way. ------------------------------------------ Artificial General Intelligence List: AGI Permalink: https://agi.topicbox.com/groups/agi/T5ff6237e11d945fb-Mef8f8e908207206bd1b51f6f Delivery options: https://agi.topicbox.com/groups/agi/subscription
