3) What does “RGB” have to do with graphic files?

RGB = Red-Green-Blue. Computer monitors use RGB to define the colours that appear on screen. Each color in the RGB combination is measured from 0 - 255. An example would be the colour blue, the RGB combination for this colour would be 0-0-255.

4) What is an alpha channel?

An alpha channel is basically a mask that specifies how the pixel's of one image should be merged with another pixel from another image when the two are overlaid, one on top of the other, allowing transparency

How can this be useful in your coursework project?

Alpha channels can be helpful and useful in my coursework as it allows me to merge two or more images together to create a realistic image, e.g. placing a tram system from Germany into the Guildhall, by making certain parts of the tram system transparent and placing it in another image with the guildhall as the background.

5) What are the characteristics of the following graphics file formats?

Bitmap: A pixel based image which is of low quality but are also easy to use and manipulate
GIF: A 256 colour or 8 bit image format with a 72dpi resolution. Supports transparent backgrounds.
PNG: Two versions are availabe, Flattened PNG or Fireworks PNG, Flattened PNG does not support layers or transparent backgrounds whereas Fireworks PNG does. Fireworks PNG shows up incorrectly in Internet Explorer 6.0 and older although a javascript fix is possible for versions 5.5 and 6.0. Internet Explorer 7.0 supports this file format much better and Windows Vista uses this file formats compression to allow zoomable icons while still using reasonably low file sizes.
JPEG: JPEG maintains a higher resolution/standard of color. When uncompressed, JPEG can be used for high-quality printing,storing and reproducing images on the internet. Widely used in digital cameras.
XCF: A GIMP image file format that is unsupported by web browsers. It can save layer information and other information that you may want to use again, e.g. text layer.
PSD: A bitmap file format used for Adobe Photoshop. PSD stands for PhotoShop Data. Widely used on both Macintosh and Windows Operating Systems. Supports layers with masks, color spaces, ICC profiles, transparency, text, alpha channels and spot colors, clipping paths and doutone settings.
SVG: An XML markup language for describing two-dimensional vector graphics, both static and animated. Can be used both by Web browsers and desktop publishing to produce vector graphics which are very fast and easily transmittable files.