On 2019-08-09 01:19 PM, Russell Reiter wrote:
Jpegs are an exported file format created from aggregated image data collected by the CCD. They are digital files and subject to transmission errors just like any other signal. My 13 megapixel phone saves image data directly as a jpg file. Sure the raw data has been manipulated before writing the original, but that is much different than having an image recorded using raw format and then exporting a copy in a lossy format in order to save space.
Perhaps you need to learn about some of the technology. Some media, such as CDs & DVDs use forward error correction, to ensure data is copied correctly. When you transfer data over a network, there is a checksum used with TCP, with IP(v4) and a CRC check at the Ethernet level. On top of that some applications provide their own integrity check. So, it would be very difficult for an error to propagate. Now, I am aware some media will deteriorate with time, so the sensible thing to do is make periodic backups.