CgBI
From Just Solve the File Format Problem
(Difference between revisions)
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(It is "pngff" and not "ffpng" that supports this format) |
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− | + | '''CgBI''' is the informal name of a [[PNG]]-like image file format developed by Apple. It is also called '''iOS optimized PNG''', and other similar names. | |
− | '''CgBI''' is the informal name of a [[PNG]]-like image file format developed by Apple. It | + | |
− | It is not compatible with PNG. | + | It is not compatible with PNG. PNG decoders that don't support it should fail completely, due to an unknown "critical chunk". |
== Identification == | == Identification == | ||
− | Files begin with the standard 8-byte PNG signature. A private "CgBI" chunk appears before the "IHDR" chunk. | + | Files begin with the standard 8-byte [[PNG#Identification|PNG signature]]. A private "CgBI" chunk appears before the "IHDR" chunk. Usually or always, ASCII "{{magic|CgBI}}" appears at offset 12. |
+ | |||
+ | == Software == | ||
+ | * [[XnView]] | ||
+ | * [[Farbfeld Utilities]]: pngff | ||
+ | * [http://www.jongware.com/pngdefry.html pngdefry] (C) | ||
+ | * https://github.com/briancollins/PNGNormalizer (C) | ||
+ | * https://github.com/jongwook/libpng (libpng patch) | ||
+ | * https://github.com/jakubknejzlik/cgbi-to-png (CoffeeScript) | ||
+ | * https://github.com/swcai/iphone-png-normalizer (Ruby) | ||
+ | * [http://howett.net/pincrush/ Pincrush] (encoder) | ||
== External links == | == External links == |
Latest revision as of 06:52, 16 December 2017
CgBI is the informal name of a PNG-like image file format developed by Apple. It is also called iOS optimized PNG, and other similar names.
It is not compatible with PNG. PNG decoders that don't support it should fail completely, due to an unknown "critical chunk".
[edit] Identification
Files begin with the standard 8-byte PNG signature. A private "CgBI" chunk appears before the "IHDR" chunk. Usually or always, ASCII "CgBI
" appears at offset 12.
[edit] Software
- XnView
- Farbfeld Utilities: pngff
- pngdefry (C)
- https://github.com/briancollins/PNGNormalizer (C)
- https://github.com/jongwook/libpng (libpng patch)
- https://github.com/jakubknejzlik/cgbi-to-png (CoffeeScript)
- https://github.com/swcai/iphone-png-normalizer (Ruby)
- Pincrush (encoder)