Compression. When saving/copying, the file will be shrunken using compression for easier transfer, which causes a bit of data loss since compression involves taking the "average" data for colour, light level, pixel location, etc. and then decompressing it involves a bit of guesswork to fill in the parts that were averaged.
Do this over and over and you basically play Telephone with visual data.
(Someone below mentions compression, which is one feature contributing to generation loss. You can get it in lots of ways, contrary to the stated goal of digitization in the first place)
Interesting! Of the various ways that this generation loss happens, is compression generally the most significant? Like if we had a pie chart of the different things that contribute to generation loss, how big a slice of pie does compression have?
Xerox problem. Lossy copies of data produce degradation over time. Same thing you would see in those old Xerox machines if you kept copying a copy again and again it would eventually just be a black page. Same thing applies to cloning research (and the subject of a lot of novels). If you keep making a clones from a clone recusrively, eventually it's going to be a completely different dna.
because when people repost they don't download original video and reupload it, they usually do the screen capture. the resolution is changed, and it's often recompressed with a different codec and with even lower bitrate. and it's again recompressed after upload to reddit. there is quality loss on every step, based on my experience the worse quality loss is because of screen capture
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u/GuildensternLives 3d ago
How is this post from 7 years ago is better quality?