Week 5 reading notes

Data compression
(http://en.wikipedia.org/wiki/Data_compression)

“Data compression or source coding is the process of encoding information using fewer bits (or other information-bearing units) than an unencoded representation would use, through use of specific encoding schemes.”

“Compression is useful because it helps reduce the consumption of expensive resources, such as hard disk space or transmission bandwidth. On the downside, compressed data must be decompressed to be used, and this extra processing may be detrimental to some applications.”

I found this article fairly interesting. I knew the basic premise of data compression but didn’t know how often this process was used; it was more than I thought. It also explained the difference between different types of compression:

“Lossless compression algorithms usually exploit statistical redundancy in such a way as to represent the sender's data more concisely without error. Lossless compression is possible because most real-world data has statistical redundancy.”

“Another kind of compression, called lossy data compression or perceptual coding, is possible if some loss of fidelity is acceptable…. Lossy data compression provides a way to obtain the best fidelity for a given amount of compression. In some cases, transparent (unnoticeable) compression is desired; in other cases, fidelity is sacrificed to reduce the amount of data as much as possible.”

Overall data compression sounds like a very useful way to save storage space or bandwidth, but care must be made to ensure the right process is used with different types of data so that least amount of fidelity is lost in the process.

Data compression basics
(http://dvd-hq.info/data_compression_1.php)

I liked how at the beginning of the article they clarified that the information in it was meant for an audience of all backgrounds, not just information theory or programming, and also how they separated the more complex (or less relevant, as they called it) points from the main body of the article.

“The fundamental idea behind digital data compression is to take a given representation of information (a chunk of binary data) and replace it with a different representation (another chunk of binary data) that takes up less space (space here being measured in binary digits, better known as bits), and from which the original information can later be recovered. If the recovered information is guaranteed to be exactly identical to the original, the compression method is described as "lossless". If the recovered information is not guaranteed to be exactly identical, the compression method is described as "lossy".”

The articles were a long read with a lot of specific details, but I thought it was all well-organized and would be a great resource to go back to if we ever needed it.

Imaging Pittsburgh: Creating a shared gateway to digital image collections of the Pittsburgh region
by Edward A. Galloway
(http://firstmonday.org/htbin/cgiwrap/bin/ojs/index.php/fm/article/view/1141/1061)

“The main focus of our project is to create a single Web gateway for the public to access thousands of visual images from photographic collections held by the Archives Service Center of the University of Pittsburgh, Carnegie Museum of Art, and the Historical Society of Western Pennsylvania.”

“An obvious benefit for users working with the collections as a group is the ability to obtain a wider picture of events and people, not too mention changes to localities, infrastructure, and land use. This is an important facet to mention since the collections document many different perspectives of the city throughout time.”

I particularly enjoyed reading this article – not only because it deals with digitizing and making available large numbers of images of the history of Pittsburgh, but that it’s a type of project I feel that I’d love to work on someday. I’m fascinated with the history of Pittsburgh to begin with, and I’d love to look through their online collection in my free time to explore more of the history of the city.

YouTube and libraries: It could be a beautiful relationship
by Paula L. Webb
(http://www.lita.org/ala/mgrps/divs/acrl/publications/crlnews/2007/jun/youtube.cfm)

The link in the syllabus to the article didn’t work, so I had to do a bit of searching to find it – I got it eventually, though!

This article is about the idea of libraries using Youtube to help reach out to people over the internet, explaining how beneficial it is for libraries to put out videos explaining how to use their services, and any other information new users might find useful before visiting the library in person.

Most of this article is explaining features about Youtube that I already know and have used. It’s kind of a broad suggestion to make, since any company out there can use this idea to their advantage, but I still think it would be useful. It would be extremely easy for users to view tutorials and instructional videos about a library on Youtube, and might save a lot of time instead of going in and asking in person first.