Recall that colour is represented in a computer by a triplet of values (R,G,B)representing relative intensities of red, green and blue at a…
Recall that colour is represented in a computer by a triplet of values (R,G,B)representing relative intensities of red, green and blue at a particular position (“pixel”) in an image. (Usually R, G and B lie between 0 and 255, but some other maximum value may be appropriate when more or less intensity resolution is
desired.) Part a. What is a “colour lookup table,” and why is it useful? (It might be a good idea to read part b before answering this part.)
Part b. Explain the two most important differences between an image stored in gif format and an image stored in jpeg format. Give an example of a situation in
which each format would be preferable to the other.
Part c. Why is it a general rule of web page design to minimize the size of graphic images to the greatest extent possible?
Describe the basic idea of additive colour, where it is used in computers, and why.
Part b Briefly describe subtractive colour and how it relates to additive colour. When is subtractive colour used, and why?
Part a What are the two most important differences between the gif image format and the jpeg image format? Explain the practical implications of each
difference you list.(Your answers to parts b and c of this question are not appropriate here.)
Part b What kind of image would you normally store as a gif file, and why?
Part c What kind of image would you normally store as a jpeg file, and why?
part a Why is it that with vector graphics, you can easily manipulate individual objects (for example, changing their shape)? Does this differ from the situation in
pixel graphics? If so, what is the fundamental difference?
Part b [2 marks] What are Bézier curves, and why are they such an important topic?
Part c Is it easy to convert pixel graphics to vector graphics, and vector graphics to pixel graphics? Why or why not?
part a Give an example of a situation in which you would want to decrease your monitor’s spatial resolution.
Part b What’s the difference between pixel graphics and vector graphics? Give an example of a situation in which you would use each of them.
Part c What’s the difference between lossy compression and loss-less compression? Name a graphics file format that uses each type of compression.
In the context of Adobe Photoshop or Photoshop Elements… What is “feathering?” What does feathering have to do with selections and masks?It should be clear from your answer what selections and masks are.
Part a Explain the fundamental difference between pixel graphics (as in Adobe Photoshop) and geometric graphics (as in Adobe Illustrator).
Part b What is an “object” in Adobe Photoshop Elements (i.e., what is our model of a Photoshop “object”), and what is the most important advantage of having objects in Photoshop Elements?
Part c What is an “adjustment layer” in Adobe Photoshop Elements (i.e., what is our model of a Photoshop “adjustment layer”), and what is the most important advantage of having adjustment layers in Photoshop?
Part d As you can see from the screen snapshot on the right, Adobe Illustrator’s “Layers” palette lists the “layers” in a Adobe Illustrator document. What is an Adobe Illustrator “layer”(i.e., what is our model of a “layer” in Adobe Illustrator)?
List five important things you can do with layers via Adobe Illustrator’s Layers Palette.
What is a Photoshop (or Photoshop Elements) “djustment layer”,?and why is it
a significant feature? Your answer should make clear
what the major components of an adjustment layer are,
what the purpose of each component is, and
what difficulty would arise if Photoshop (or PSE) lacked adjustment layers. You should also provide an illustrative example.
Part a What is the standard representation of colour in a computer, and what connection does it have to how the human eye works?
Part b Adobe Photoshop Elements has a tool specifically for the purpose of altering the overall “colour” or “balance” of an image. How does that tool
work, and how does its design reflect how the human eye works?