Title: Year 12 / Computer Science / Theory / 1 - Information Representation / 1.2 - Multimedia / Graphics

Q: Explain how data for a bitmapped image is encoded
A: made of pixels, each pixel has one solid colour, image is stored as array of pixels to be displayed, used for photos and complex images that would take too long to draw

Q: State what is meant by the term pixel
A: smallest unit of image, smallest addressable picture element that can be drawn

Q: State what is meant by the term file header
A: stores data about file contents, like metadata about image, file type, image resolution, type of compression, bit depth, file size, location

Q: State what is meant by the term image resolution
A: number of pixels in an image

Q: Describe what happens when image resolution is increased
A: image becomes sharper and more detailed, file size increases

Q: State what is meant by the term screen resolution
A: number of pixels that can be displayed by screen horizontally and vertically, number of pixels = width x height

Q: State what is meant by the term colour depth
A: number of bits used to represent the colour of a single pixel

Q: Describe how you would determine the colour depth of an image with n bits
A: 2^n colours per pixel

Q: Describe what happens when colour depth is increased
A: colour quality is increased, but file size is increased too

Q: Describe how you would calculate file size
A: number of pixels x colour depth

Q: State some applications of bitmapped images
A: scanned images and general computer usage

Q: State the advantages of bitmapped images
A: takes less processing power, can be compressed

Q: State what is meant by the term drawing object
A: individual shape in vector graphic defined using mathematics, can be altered without affecting other objects

Q: State what is meant by the term drawing list
A: instructions to draw vector graphic or drawing object

Q: State what is meant by the term property
A: characteristics of an object that are the basic geometric data which determine its shape and appearance

Q: State the advantage of vector graphics over bitmap graphics
A: take less storage, infinitely scalable as instructions can be executed at any scale

Q: State an application of vector graphics
A: company logos

Q: Explain how data for a vector image is encoded
A: image is drawn using mathematical equations and geometry, so is infinitely scalable, used for logo and images which have to be displayed with different sizes