PNG (Portable Network Graphics) Specification, Version 1.2

_PNG Working Group (1999-07) _

This Page: copswiki.org/Common/M1727
Media Link: http://www.libpng.org/pub/png/spec/1.2/png-1.2.pdf

More Info: ElectionIntegrity, OpenBallotInitiative

The PNG image standard is a proposed format for The OpenBallotInitiative. It has many positive features:

• CRC error detection on chunk by chunk basis.
• Excellent data compression, not lossy
• Embedded text capability.
• Amenable to inclusion of additional metadata, such as:
• ballot number
• precinct number
• ballot type
• page of the ballot
• MD5 or other SHA digest of the entire image.

But there are drawbacks

• Not a multi-image format (does not natively support multi-page ballots)