Week 5 Reading

Since the readings are becoming more technical, I will be taking bullet notes of the articles.
Data Compress- Wikipedia

• compressed data is process of encoding info using less bits
• reduces consumption of resources (ie. hard disk space and bandwidth)
• must be decompressed to use
• Lossy data compression obtain best fidelity for a given amount of compression, accept some loss of data, unlike lossless
• data compression connected to statistical inference

Data Compressions basics article

• data compression = more stuff in same place, faster transfer, less bandwidth
• Run-length encoding replaces "runs" w/ single character and # of how many
• for pictures, instead of sorting pixel color data by pixel, sort it by channel
• compression codes based on algorithms
• "dictionary-based compressors" replace repeated source data with references to its previous appearance
• Entropy coding: encoding that assigns shorter codes to common data blocks.
• "intraframe" compression: frame is compressed independently
• file has beginning and end, stream doesn't have either defined (video)
• delta compression used for video- seems to remove the color and majority of image, but shrinks file size.
• motion compensation is technique for compression of full-motion video

This article used a lot of technical terms that I'm not aware with. I'm hoping the lecture will clarify a lot of it. I do understand the concept of compression, and have compressed documents on my own before. I just didn't know the coding/encoding that was involved, especially for different media formats.

Imaging Pittsburgh article-

• Pitt received grant w/ 2 other institutions to create public web access to photographic collection
•  20 photographic collections, min of 7,000 individual images, 10,000 will be online by end of project
• Users can- search image collection, browse, read about collections & content, order reproductions, etc.
• Experience communication problems, through institutions and in regards to goals and missions
• Used subject headings of doc. in selection process
• Metadata challenge- decided on using controlled vocab terms 

 YouTube and Libraries-
Since this article wasn't technical at all, I can sum up the content and purpose.  The author was suggesting that libraries us YouTube as a means of creating informational videos about the services offered by their libraries and linking it to the institutions' website.  This is actually a great suggestion by the author, for it could provide quick and easy guidance for patrons on how to access and utilize library resources.  It would be quick and easy for most tech/internet-savvy users to use.  Patrons who are not technically inclined could also benefit from the service because they can watch videos that would instruct them on the institutions' technical resources, such as online databases and journals.