Tuesday, March 4, 2014

COMP6021 Class 21

the one with all the colours



Image digitization

HSB
RGB


COMP6023 DWEB1/ITM1 Class 22



We looked at some more at the RGB colour system. Then we examined the Lab colour system and saw how subsampling the colour comment of an image was not as noticeable  as subsampling the luminance component.

We looked at the CMYK system used in printing.

[Recoding failed]

I spoke a bit about image compression. I explained image subsampling and interpolation.

We began to look at pixel depth reduction when my laptop failed. We will pick up again from this point in the next class.

COMP6023 DWEB1/ITM1 Class 21



We looked at digitising black & white images and considered the impact the sample rate (dpi) and number of quantisation level (bit per pixel) have on the quality.

We looked at the HSB & RGB colour systems

COMP6021/COMP6023 Image Submampling

When an image is subsampled the missing pixels have to be accounted for by the receiver. This can be accomplished by increasing the size of the pixels that are present, or by interpolating the missing pixels. The different is illustrated in these images. You need to click on them to see them at full size.





Monday, March 3, 2014

COMP6021 Online Lesson - Digitization




We are currently considering how real world things are digitised. This video might be useful.

Digital Colour




This week in class we will be looking at how colour is represented digitally. This video explains the Hue Saturation Brightness (HSB) system.





This video outlines the Lab and CMYK systems.

COMP6023 Google Spam Detection: What is a "paid link"?


What's a "paid link"?

COMP6023 Google's Search Spam Dectection

Last week we spoke a little bit about Google's spam detection. Here are two interesting discussions about that work.


What's it like to fight web spam at Google?





COMP6023 DCOM1 Class 21



We looked at digitising grey scale images an looked at coding colour. I explained the HSB and RGB colour systems.

We will look at the Lab system in the next class.

COMP6023 DNET1/COM1c Class 21



We looked at digitising grey scale images an looked at coding colour. I explained the HSB, RGB, and Lab colour systems.

COMP6021 Online class: Image Digitization


COMP6021 Online Class: Subsampling & Interpolation


Thursday, February 27, 2014

COMP6023 DCOM1A Timetable Change

COMP6023 Lab DCOM1A Monday 1600-1800 will be in C134x from now on. Students will discover Photoshop there.

COMP6023 DCOM1 Class 18



SEO
Analytics

COMP6021 Class 20

the one with the thermometers






We looked at Digitisation and saw how both the number of quantization levels and the sample rate can affect the fidelity of the digital representation of the analogue values.

COMP6023 Interesting Job Ad

http://www.irishtimes.com/jobs/featured-position-cpl/digital-marketing-manager-1.1705239

Note the requirement for SEO knowledge in this current job ad.

Wednesday, February 26, 2014

COMP6021 Class 19 Lab

Students saved GIFs with various settings for use in the assignment.

COMP6021 Class 18

the one with the LZW



We looked at Lempel-Ziv-Welch coding.


Students worked on an LZW exercise. The answer was Ando Masahashi




I did a Huffman coding question on the board from a past exam paper.


COMP6023 DOM1B Classes 19 & 20

Students worked on generating the GIF data required for Assignment 2.

COMP6023 ITM1 Classes 19 & 20

Students worked on Assignment 2 by saving the images as GIFs with different numbers of colours, with and without dithering.