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Nope. I rechecked the PNG specification, and it explicitly states that the high bits must be zero: "If the image bit depth is less than 16, the least significa

• randy408 5y ago
  It makes sense to treat it as an error but the ISO standard is too vague on this and the libpng developers never "fixed" this[1], it issues a warning but otherwise just masks off the high bits. Firefox has a workaround[2][3], Chrome doesn't. FWIW I do the same in my library[4], handling it as an error is problematic because it would mean the chunk gets discarded and then you can't even retrieve the values. [1] https://sourceforge.net/p/png-mng/mailman/png-mng-implement/thread/3.0.6.32.20080410073319.013c7e20%40mail.comcast.net/#msg19070368 https://sourceforge.net/p/png-mng/mailman/png-mng-implement/... [2] https://bugzilla.mozilla.org/show_bug.cgi?id=428045 https://bugzilla.mozilla.org/show_bug.cgi?id=428045 [3] https://searchfox.org/mozilla-central/source/image/decoders/nsPNGDecoder.cpp#556-558 https://searchfox.org/mozilla-central/source/image/decoders/... [4] https://libspng.org/ https://libspng.org/