Computer Graphics Techniques and Applications Chapter 1 - Graphics Fundamentals Dr Brett Stevens e-mail: Brett.Stevens@port.ac.uk phone: 023 9284 5482 address: West Wing, Eldon Building notes: http://techfaculty.port.ac.uk/cgtap 16 Hours -
Computer Graphics Techniques and Applications
Chapter 1 - Graphics Fundamentals
Dr Brett Stevens
phone: 023 9284 5482
address: West Wing, Eldon Building
Lectures to take place in Mercantile House, Room 5.02.
This will include computer graphics theory and discussion of relevant social and technical issues.
Practicals to take place in Mercantile House, Room 3.04b.
This will include access to graphics production facilities for formal tutorial sessions and continuing project work.
Exam, which will constitute 60% of your grade.
This will be an individual, open book, computer based test.
Coursework, which will constitute 40% of your grade.
There will also be an assessed, continuous practical component that will help develop practical and problem solving skills.
Unit Web Site
Red, Yellow and Blue 1921 (oil on canvas)
Relative Size (Requires Expected Size)
Shading and Shadows
Leonardo da Vinci
The Last Supper, 1498
Maurits Cornelis Escher (1898-1972)
2D - Bitmapped Graphics
Bitmapped (Raster) graphics use a 2D array of points (pixels).
Gray Weather by
George Seurat (1859-1891)
File size of a bitmap is
(Resolution x Bit depth + file overhead) / 8 = Size in Bytes
Greyscale to Black and White.
Dithering an Image.
What is the theoretical file size of the image before and after dithering?
Then create the display matrix again but with the dither matrix, 3,6,9,12 (ordered from the top left to the bottom right) and work through the exercise again. What do you notice.??
Aliased and Anti-Aliased Images.
To display a ‘continuous’ line it must be divided amongst discrete pixels. This can lead to the line looking jagged or aliased.
Perfect and Sub-Pixel Sampling
This requires enough bit depth to support the ‘extra’ colours
(Spatial resolution * Colour resolution) + file overhead) / 8 compression ratio
= File Size in Bytes (divide this by 1024 to get the size in KB).
All these factors are dictated by the file type …
2D Vector Graphics
Vector graphics use a mathematical representation.
Primitives are the basic shapes from which drawings are constructed.
The term refers to geometry, shape and position.
The primitives have attributes, which specify additional display information, such as the colour of an element, its orientation
Pieta 1498-99 Marble. Basilica of St Peter, Vatican
3D - Volume or Surface Graphics