Monday, 29 April 2013

Web Publishing week 11

This is the eleventh week of posting on my blog. It is also the last post required for the assignment. In this week I am going to summarise previous ten weeks based on statistic data about viewers of my blog, gathered by Google. The most of them were coming from Ireland (626), there was few visitors from Germany (64) and United States (44). One person from China came across my blog - probably accidentally. A bit more than half (57%) were using Firefox browser. Next positions on the list accrue to: Chrome (17%), Internet Explorer (11%) and Safari (10%). The vast majority of visitors were using Windows (85%) operating system and only (9%) Macintosh OS.

The most of traffic to my blog I got was coming from Colin's blog site and I suppose it was generated by colleagues - students from my class. Second source of traffic came from my own blog which may indicate that my own logins can have potential to mislead in the data interpretation. It would be preferred to not record of those in order to keep statistics more accurate.

 As with the end of posting on the blog I am getting closer to end of the second semester. There is still few days left for studying before final exams time comes. Hopefully when everything is over we will get good summer this year.

Monday, 22 April 2013

Web Publishing week 10

       This week we were told about logs as tools for keeping records and how Google Analytics tool works. Colin explained what information are being recorded in logs (i.e. IP address, time, request, result) and how data can be interpreted into form more readable for human with an example of Google Analytics. Because it has no access to logs on servers other than Google, it is necessary to add special code to each page on web site to allow Google tracking information about traffic related to particular page. All information about users of web page can be presented in statistical form that allows to draw conclusions about different aspects of individual viewers. It can be very useful for advertising and managing purposes
       This week labs we mostly spent finishing our assignments and trying to catch up with projects. There is one more week left for posting on the blog and AdWords post-campaign report to write. After all of that it will be the time to concentrate on exams coming soon.

Monday, 15 April 2013

Web Publishing week 9

         This week we were told about video compression. It has important role to play in video processing because raw data in movie would take huge amount of memory to store. Practical reasons force use of various method of compression. We can distinguish two forms of these:
Intraframe - reduces size of data based on algorithms processing within frame, and
Interframe - operates on several frames and reduces these data that repeats itself between frames.
First one brings down to jpeg encoding, second one involves more sophisticated methods of image processing:
- coding only the differences between frames,
- dividing entire frame into blocks,
- applying motion compensation which searches for moving blocks in the frame between frames.
 Then we looked into M.P.E.G. standard of compression. It uses I-Frames (Intraframe compression) and P-Frames (Interframe compression) and extends to B-Frames (Bi-directional prediction) which takes information from previous and future frame to get current frame.

       Second hour of our lecture Colin talked about podcasting as a one of successors of blogging and RSS feeds that include audio or video content. Podcasting allowed authors to reach broad range of recipients and facilitated looking for programs. It became significant part of Internet that even Apple established directory of podcasts available via iTunes. Podcasts issue also some copyright issues due to being downloaded before played. That differentiate it from streaming where content is played on the run while being sent.

Wednesday, 10 April 2013

Some Mother's Son - movie review

Director:  Terry George
Starring:   Helen Mirren
               Fionulla Flangan
               Aidan Gillen
               David O'Hara
               John Lynch
Time:      112 minutes

       Events that happened in Belfast prison in 1981 became a background for scenario of "Some Mother's Son" film. Directed by Terry George movie tells a story about Bobby Sands, one of IRA's collaborators. After being seized and placed in prison Bobby starts hunger strike against the way that IRA's prisoners are treated. He demands to recognise him and his associates as prisoners of war, not as criminals. Before the end of the movie we find out results of their actions. Mainstream of events is the source of information about political situation between Ireland and England as well as moral dilemmas of people involved in strike.

Tuesday, 26 March 2013

Web Publishing week 8

          At the begin of the week we had short recap about how dithering works and where it is applied. Then we were explained in detail about two types of image compression standards: GIF (Graphics Interchange Format) and JPEG (Joint Photographic Experts Group).
Colin introduced some of its properties and used algorithms that are responsible for reducing size of the image file. For GIF example of compression these are:
- Run Length Encoding - which replaces sequences of the same value with single
   value of data and number of its occurrences,
- transparency - there can be only one transparent colour,
- influence of different factors on final result of compression (i.e. how dithering
   reduces effectiveness of Run Length Encoding),
- what kind of images are good for GIF type processing (logos, images: with large
   areas of plain colours and small amount of colours).
And for JPEG it would be:
- DCT (Discrete Cosine Transform) - which transforms image from spatial domain to
   frequency domain involving following math's equation:

- no transparency available,
- image divided to blocks of 8x8 pixels (at high compression ratio lines dividing
   blocks get distinguishable)
- suitable for natural images,
- bad in preserving plain colours, edges and text.
We also discussed how human eye perceive colours (chrominance) and its brightness (luminance) and how does it apply to image compression.
We were introduced to PNG image codding format which was created as an alternative to GIF when patent issues arose around using it.

      After long preparations our google AdWords campaign is ready for action. It was quite difficult to work on this assignment partly because of the topic it relates to. Marketing and business studies are not our strongest skill so more efforts were necessary to accomplish first part of the challenge. Hopefully, as we go through next steps, it will allow us to enjoy whole assignment in a greater extent. Whichever result we will achieve, it will be great experience of something new that may allow us to use that knowledge in future.

Monday, 18 March 2013

Web Publishing week 7

      This week Colin was talking about images and different ways of reducing its file size. He introduced to us two types of compression:
- lossy - where we achieve higher compression rate but it is occupied with loss                 of information that does not allow to reconstruct exact replica of the image (applies to photography).
- lossless - with lower compression rate but using decompression allows us to get             exact replica of compressed image(used in medical and technical imaging, art).
He also explained dependencies between size of image file and its colour depth (number of  available colours) or image's resolution. He showed different techniques that can be applied to achieve reduced file size with still good quality of image:
 (1) reducing amount of colours to those appearing the most often,
(2) colour coding with support of look up tables,
(3) using dithering for getting smooth transition between colours. Dithering mixes          pixels of adjacent colours in aid to get blurred transition between them.
(4) sub-sampling  which removes some of the data from the original image and then       displaying it by applying methods that restore its appearance:
     - increasing pixel's size
     - interpolating missing pixels.

     Interestingly, RGB24 system provides us 16,777,216 different colours, while an image in Full HD quality (with resolution 1920 x 1080 pixels) gives exactly 2,073,600 pixels on the screen. The conclusion is that even with so high quality image there is no space to display so many colours at one time.

Monday, 11 March 2013

Web Publishing week 6

      This week we were introduced to second assignment. Our job is to convert uncompressed image file into two compressed types: JPEG and GIF. Then we need to investigate how different parameters of compression (i.e. number of colours) influence quality of these images.
      Colin also presented closer look on search engine optimisation (SEO) topic. He explained what SEO techniques can be applied. He also differentiated between which are adequate in aid to improve page's rank and which should be avoided in case of bringing more harm than benefits.
We were also shown some properties of AdWords. Quite condensed and interesting knowledge about can be found on:
i.e. placing an ad depending from user's location or language, and
restrictions that apply to some keywords for example related to hacking.