Lecture 1 Flashcards
What is Computer Graphics?
The production of images computers for use in any medium
What is Image Processing?
Electronic analysis or manipulation of an image
What are the two types of computer graphics?
Raster Graphics (bitmaps) and Vector Graphs
Define Raster Graphics
One type of computer graphics. It uses a grid of individual pixels where each pixel can be a different colour or shade. Used to create Digital Images.
Define Vector Graphics
Uses Mathematical relationships between points and the paths connecting them to describe the image. Generally produces a clearer image than when raster graphics are used.
What is a pixel?
A display element on a screen. There are two main types of Pixels: RGB and CMYK
What are RGB Pixels
A RBG pixel is composed of three values: Red, Green and Blue.
It tries to match the functionality of the human eye
The pixel values are stored in a 3D array with a dimension for each colour usually ranging from 0 - 255
What are CMYK Pixels?
A CMYK pixel is composed of 4 values: Cyan, Magenta, Yellow and Black. Less common than RGB pixels.
What is resolution?
Resolution is the number of pixels in an image
What is a megapixel?
1 megapixel = 1 million pixels
What is a Grey-Scale Image / Monochrome Image?
An image containing grey-level information and no colour info.
Typically contains 8 bits per pixel data, allowing for 256 different grey-levels.
Grey-level resolution?
L = 2^k
k = the number of bits used to represent grey-levels of the digital image
e.g. if L = 2^8, then this is an 8-bit image with a greyscale of 256.
For an 8-bit image of size 512 x 512, then the storage size for this image is 512 x 512 x 8 = 2,097,152 bits
How are histograms used to analyse light values of an image?
It plots how often each intensity value in an image occurs. Used to visualise the light values in the image and to test some of the heuristics for better image quality.
