Why StegaStamp can only encode 56bits (7 characters) with ECC?

tancik / StegaStamp

Invisible Hyperlinks in Physical Photographs

http://www.matthewtancik.com/stegastamp

MIT License

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Why StegaStamp can only encode 56bits (7 characters) with ECC? #41

Open linzissu opened 2 years ago

linzissu commented 2 years ago

Dear tancik:

I got the following error when running encode_image.py:

Error: Can only encode 56 bits (7 characters) with ECC.

I'm confused about why it can only encode 56 bits (7 characters) with ECC.

Thanks in advance! 😄

tancik commented 2 years ago

The total message budget is 100 bits but some of the bits need to be used for error correction. We use BCH codes which you can learn more about here - https://en.wikipedia.org/wiki/BCH_code