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Wednesday, May 8

  1. page Images, Sounds and Presentations edited ... Image Processing Software Advanced programs such as Adobe Photoshop allow the mainpulation of…
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    Image Processing Software
    Advanced programs such as Adobe Photoshop allow the mainpulation of photographs in a far more complex manner. Digital imaging software allows the removal unwanted properties of the photo e.g. blemishes etc. These tasks were previously done with magnifying glasses and tiny brushes prior to the digitising of images. Image processing software goes a lot further, photos are not just retouched. Through this software we are able to modify images to the point of distorting them, applying special effects and fabricate the images. We also can now put together composite photographs by merging several images.
    bitmap
    Bitmap and Vector Graphics
    Bitmap graphic images are a collection of bits that are mapped form an image. The image consists of a matrix of individual dots (pixels) which all have their own color. The colour of each pixel can be expressed by grayscale or RGB colour. A graphic composed entirely of pixels each with its own color properties is ideal for photographic images where there are thousands, even millions of different colors. Complex fills, shading and gradient effects can easily be rendered. The Bitmap image offers as much freedom as an empty canvas.
    Grayscale is a range of shades of gray without apparent color. The darkest possible shade is black and the lightest possible shade is white. Today grayscale images (as photographs) intended for visual display (both on screen and printed) are commonly stored with 8 bits per sampled pixel, which allows 256 different intensities (i.e., shades of gray) to be recorded. RGB stands for the three primary colors of light - Red, Green, and Blue.
    RGB can be described as the computer's native color space for capturing images and displaying them. As human eyes are sensitive to these primary colors - red, green, and blue - all colors are perceived as a combination of these three colors. RGB values are changed into intensities which are used for display purposes. In RGB color model, a color is represented by indicating how much each ingredients of red, green, and blue should be included in it. Each can differ from the minimum (no color) to the maximum (full intensity). When all the colors are at the minimum value, then the displayed color will be black. And when all the colors are at their maximum value then the displayed color will be white. The number of colours on a RGB scale depends on the number of levels of red green and blue.
    If you have 8 levels each then you can get 8*8*8 or 512 levels. 8 = 2^3, so 8*8*8 = 2^9 so this would be called 9 bit colour depth.
    Typical colour depths are 8 bit (256 colours) 16 bit (about 65 thousand) 24 bit (about 16 million) and 32 bit (over 4 billion different colours)
    Vector graphics are images that are completely described using a mathematical definition. Each line is made up of either a vast collection of points with lines interconnecting all of them or just a few control points which are connected. Vector graphics are mathematical creations. For this reason, the programs that are used to create them save instructions on how the image should be drawn, rather than how it looks. This is the key difference between the two types of graphics. Because the computer has a description of how the image should look, it can be redrawn at any size, in any position, without losing any quality. A vector graphic resized to 5 times its original dimensions is simply reproduced, exactly, at the new size. It can also be freely manipulated without losing coherence, like a rubber band that can be stretched an infinite number of ways. Vector graphics are ideal for producing artwork which frequently needs to be presented in different sizes or colors. Logos especially fall into this category. A logo produced with a vector application can be blown up to fit on a billboard or scaled down to adorn a letterhead with no loss of quality.
    Vector versus Bitmap
    {http://www.adobe.com/devnet/flash/articles/beg_drawing/fig01.gif}
    {http://patriottruckleasing.com/body-images/220px-VectorBitmapExample.png} The vector image doesn't lose its quality with magnification or enlargement
    Pixels and Resolution
    Computerized images are made up of pixels, which are small squares of digital information with a colour value. A pixel has no inherent size because its size will depend on the resolution of the image. With two files of the same dimensions, a file with a resolution of 150 pixels per inch will have larger pixels than a file of 300 pixels per inch. The images in image editing programmes are known as bitmap images, sometimes referred to as raster images.
    The number of pixels per inch needs to be associated with the dimensions of the image in order to give the image resolution. The more data that is recorded by a digital camera or scanner, the higher will be the resolution of the image file. 300ppi in itself is not necessarily a higher resolution than 150ppi; it means nothing until the image dimensions are included.
    An image of 150 ppi for an image size of 8" x 10" would be written:
    8"x10" @ 150ppi, which is 1200 pixels x 1500 pixels or 20.3x25.4cm @ 60ppcm
    An image of 300 ppi for an image size of 8" x 10" would be written:
    8"x10" @ 300ppi, which is 2400 pixels x 3000 pixels or 20.3x25.4cm @ 120ppcm
    In this example, 8x10 @ 300ppi is going to be a higher resolution than 8x10 @ 150ppi.
    However, 8x10 @ 150ppi will not be a lower resolution than 4x5 @ 300ppi.
    The two are exactly the same; they both have a file size of 5.16 megabytes (5.16 Mb).
    The 8x10 @ 150 file could be resized to make it 4x5 @ 300ppi and the two will look and reproduce exactly the same.
    The relationship of pixels to area might become clearer if we compare it to tiling a floor. With tiles half a metre square, a floor area of 2 metres by 2 metres would require 16 tiles. An area of 4 metres by 4 metres would require 64 tiles – four times as many. Pixels and files sizes work the same way.
    A monitor screen also has a resolution, such as 800 x 600 or 1024 x 768, measured in pixels. If an image has a pixel dimension of 800 x 600 then it will fit on to a 800 x 600 screen whereas it will appear small on a screen set at 1024 x 768.
    Double-clicking on the Zoom tool in the toolbox, enlarges the image to 100% which means the pixels of the image will be matched with the pixels of the screen.

    Digital Forgery Activity
    {Digital Forgery Task.docx}
    (view changes)
    8:36 pm

Friday, March 2

  1. page Security edited ... Encryption How Encryption Works - HowStuffWorks.com
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    Encryption
    How Encryption Works - HowStuffWorks.com

    (view changes)
    9:27 pm

Friday, November 25

  1. page Personal and Public Communications edited ... - Advantages / Disadvantages You can then compare your notes with those posted on the wiki …
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    - Advantages / Disadvantages
    You can then compare your notes with those posted on the wiki
    Start of Thursday's lesson.
    Below is an exam question from 2010. Use your notes and discuss this with someone else in the class. Look up any additional things that haven't been covered in order to answer the questions. There are additional notes on teleconferencing in the 2009 Case Study section.
    {E Learning Question.pdf}
    {E Learning Ans.pdf}

    Smart Phones and Convergence - Complete by Beginning of Thurs w.2
    Work through the wiki and respond to the following:
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    (d) Discuss the advantages of multi function PDA equipment to businesses and their
    employees. Evaluate these advantages. [10 marks]
    {Mobile and Convergence Answers.pptx}
    {Convergence Markscheme.docx}

    Intercepting Communications Thurs/Fri w.2
    Read the materials on wiretapping and packet sniffing.
    (view changes)
    2:23 am

Sunday, November 6

  1. page Case Study 2011 edited ... Pegboard features and tour. Web 2.0 Marketing - Nick and Drew {ITGS-e-marketing .pdf} Us…
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    Pegboard features and tour.
    Web 2.0 Marketing - Nick and Drew
    {ITGS-e-marketing .pdf}
    Use of Twitter in marketing
    Several real life examples of e-marketing
    (view changes)
    8:20 pm
  2. 8:19 pm

Wednesday, October 26

  1. page Images, Sounds and Presentations edited ... Can you spot the forged photos? Forged or Not Photo Test Rendering Synthetic Objects into L…
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    Can you spot the forged photos?
    Forged or Not Photo Test
    Rendering Synthetic Objects into Legacy Photographs from Kevin Karsch on Vimeo
    Computer Crime: Attacks on People - Digital Forgery
    Since it is possible to easily modify digital images, what are some of the ramifications of altering images to personally attack the credibility of another person?
    (view changes)
    4:13 am

Thursday, October 13

  1. page Images, Sounds and Presentations edited ... Pentagon linked to Digital Fraud How to spot fake photos Virtual Furnishing for Real Estate…
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    Pentagon linked to Digital Fraud
    How to spot fake photos
    Virtual Furnishing for Real Estate
    editing
    Photo Sharing
    (view changes)
    3:21 am

Monday, October 10

  1. page Modeling and Simulations edited Modeling and Simulations {http://upload.wikimedia.org/wikipedia/commons/thumb/0/05/MilSim_Spectrum…
    Modeling and Simulations
    {http://upload.wikimedia.org/wikipedia/commons/thumb/0/05/MilSim_Spectrum.svg/500px-MilSim_Spectrum.svg.png} Military Simulation Spectrum
    The difference between a model and a simulation
    Pilots train without taking off
    Models' projections for Flu miss mark by wide margin
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    Move over GPS, here comes the smartphone
    GPS units with more to say

    (view changes)
    5:47 pm

Sunday, October 9

  1. page Case Study 2011 edited ... A comparison between 2 open source CMSs here (Drupal vs Joomla) An argument for commercial CM…
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    A comparison between 2 open source CMSs here (Drupal vs Joomla)
    An argument for commercial CMS - Falcon.
    Pegboard features and tour.
    Web 2.0 Marketing - Nick and Drew
    Use of Twitter in marketing
    (view changes)
    8:24 pm
  2. page Case Study 2011 edited ... Securing a Joomla site 10 Ways to secure a site from hackers E Crime Prevention - see the s…
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    Securing a Joomla site
    10 Ways to secure a site from hackers
    E Crime Prevention - see the section on 'Prevention Strategies'. This document also contains Australian statistics for credit card fraud.
    Policies - Kieren and Alasdair
    Why develop a privacy policy?
    (view changes)
    8:17 pm

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