WYSIWG – not quite More than displayed information in files Tracking changes – helps but may not be for final consumption Metadata – information about data, document fingerprints How do bits represent the original information? Image and audio documents follow rules and arbitrary conventions (.doc, mp3, pdf, odt, etc.) Modeling to rendering. Information is lost Analog to digital, digital signal processing/editing (photoshop, remastering, etc.) Sometimes not a model of anything in reality (virtual walk through) Wikileaks, NSA Snowden (2013) MP3 are compressed and quality is lost ITEC 102

Is more sampling better? pixels – picture elements Raster and bitmap representations Bits can represent different information More bits per pixel can provide richer image/information, oversampling Text vs. an image of text Resolution of the device relates to quality Compression – lossless and lossy Temporal and spatial coherence allow compression Processing power needed to reconstruct “on the fly” – video feeds Technology life cycle – from records to MP3 codecs ITEC 102

Data formats Protocols allow the transfer of bits File formats – commercial vs. open (doc, odt, jpg, etc.) Backward compatibility – hardware and software Does data go away? – wiping a disk clean, data degradation Hiding information Steganography – sending messages in imperceptible ways Cryptography – sending information in indecipherable ways “state of the art” in technology is < 2 years Preserving the web – www.archive.org TCP/IP, net is not hardware as much as it is protocols ITEC 102