Week 5 Notes

Wikipedia: Data Compression
http://en.wikipedia.org/wiki/Data_compression

Data compression (source coding)- process of encoding information using fewer bits

- In order to work both the sender & receiver must understand encoding.
- Decreases cost by decreasing disk space
- Must be decompressed again to use, and this can change the material
- Lossless compression is when you exploit statistical redundancy, reversible so to not loss data
- When it can’t find a pattern, it won’t compress, so you can’t always use this.
- Ex: run length encoding (long codes are replaced by simple ones)
- Used for connection bandwidth in a computer network
- Lossy data (perceptual coding) compression is when you ‘round off less important information’ and involves a loss of fidelity. The problem is it is not always reversible and you can lose data. Will make the file smaller, but you will inevitably lose information.
- Used a lot with digital cameras
- Audio and speech compression is also possible

http://dvd-hq.info/data_compression_1.php
Data Compression- focus on video, images, audio

This article is a much more descriptive look at data compression. There are lots of examples and it breaks compression down nicely so that it makes sense even if you are not very familiar with the information. Although, even through repeated attempts I have been unable to access the part two; I am not sure if anyone else had this problem or not.
-Advantages: store more information in a smaller space, takes a shorter amount of time to send/ save that information
- Contains the same amount of information, but it is stored differently
- There are also several different examples and explanations for moving pictures.
- MPEG- Moving Picture Experts Group- several different types that use similar techniques
Since I am not very familiar with how videos work this was more confusing for me than the still images. I thought it was interesting how the author said that the articles are not ‘thorough’, because I thought they were very detailed. Although as a beginner it would make sense that this would be a ton of information.

http://www.firstmonday.org/issues/issue9_5/galloway/index.html
Imaging Pittsburgh: Creating a shared gateway to digital image collections of the Pittsburgh region. – Edward Galloway
This article is a description of a Pittsburgh photography project which collected between 7,000-10,000 pictures of mid-nineteenth and mid-twentieth century Pittsburgh under a two year grant in 2004. The pictures depict people, places, and events in the Pittsburgh region with the goal of the project for a primary web based access site for users to view the collection. The images came from over 20 different collections, and represent the changing people and times of Pittsburgh. Although there were many challenges with creating the collection, including metadata, the project seems to be quite a success. Being from Pittsburgh, I really enjoyed the article and I can’t wait to check out the website. The collection is a very unique look at Pittsburgh, and the Teeny Harris collection is actually one of the main factors that piqued my interest in Records and Archive Management!

http://www.lita.org/ala/mgrps/divs/acrl/publications/crlnews/2007/jun/youtube.cfm
You Tube and Libraries: It could be a beautiful relationship- Paula Webb

This article begins by describing You Tube, and walks you through the steps of setting up an account as a library. She also reviews the advantages of not only You Tube as an entity, but also ways in which it can benefit your library; including instructional videos and open links to your library to help users with access difficulties and general support. Brief examples of how libraries could use You Tube as a beneficial tool are also included in the article. The article is short, but does a good job of making you think of unique ways to make a library look more ‘hip’ with what students are using.