How high can ‘bit_acc’ reach without BCH code？

[LeeeLiu]

Hello, tancik!

1. Excuse me, if you don't use BCH code, what is the decoding accuracy (bit_acc)?

2. Every 12 bytes (96 bits), only 5 bits can be corrected, right?

• In encode_image.py and decode_image.py, The BCH parameters you use are:

  BCH_POLYNOMIAL = 137
  BCH_BITS = 5
  

• According to the bchlib source code, my understanding is,
  The entire packet can only be corrected by 5 bits, right?
  In your case, packet is 12 bytes (96 bits), data is 7 bytes (56 bits, embedded link length)

[tancik]

1. Table 1 of the paper has a breakdown of bit accuracy for different camera / printer pairs - https://arxiv.org/abs/1904.05343
2. Yep, you are correct.

[LeeeLiu]

Oh, I see. Your reply is very helpful. Thanks！

…

---Original--- From: "Matthew Tancik"<notifications@github.com&gt; Date: 2021/1/5 06:45:44 To: "tancik/StegaStamp"<StegaStamp@noreply.github.com&gt;; Cc: "Author"<author@noreply.github.com&gt;;"LeeeLiu"<lily516@foxmail.com&gt;; Subject: Re: [tancik/StegaStamp] How high can ‘bit_acc’ reach without BCH code？ (#31) Table 1 of the paper has a breakdown of bit accuracy for different camera / printer pairs - https://arxiv.org/abs/1904.05343 Yep, you are correct. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub, or unsubscribe.