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by trustingtrust 1369 days ago
A bad bit wouldn’t even be noticeable in an image. Changing one bit would make literally no difference. Artifacts look like something the compression algorithm has messed up. Also since the images are actually intact according to Google this is likely just the compression algorithm used to browse the images.

Update: my limited knowledge on this is proof I’m wrong.
2 comments
can16358p 1369 days ago
A bad bit might have no visible effect at all (e.g. Affecting part of EXIF metadata, or a totally black pixel turning again very close to total black) or can corrupt the whole image (flipping a bit in the file header or cosine quantization table).

It totally depends.

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mahathu 1369 days ago
As a total layman when it comes to storage: Don't they use forward correcting codes to make sure a single bad bit can reliably be detected and flipped without affecting the data at all? Or are these used only for data transmission?
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d110af5ccf 1369 days ago
The vast majority of file formats do not do such things. Such a concern is (typically) out of scope for that layer.

Even most data transmission components don't use forward correcting codes. They typically just have error detection.

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rainbowzootsuit 1369 days ago
I've encountered older digital photos where a small corruption affects all of the remaining parts of the image as it is presumably recorded in some linear fashion as shown in this Wikipedia entry's "Visual example."

https://en.wikipedia.org/wiki/Data_degradation

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