1. Commonalities and Differences between Computer Graphics, Digital Image Processing, and Pattern Recognition
are three branches of the development of computer applications
Common: Processing information with computers
Differences: Image processing is the image processing of the original object, reproducing the image, pattern recognition is the identification and description of graphic information, extraction of data models, computer graphics is the description of a given graphic to generate graphic images.
2. Contents of computer graphics research, list the application areas of computer graphics:
Research content: basic graphic element generation algorithm, graphic transformation, modeling technology, photorealistic graphic generation, human-computer interaction technology.
Application areas: computer-aided manufacturing, computer graphics, scientific computing visualization, computer simulation and simulation, process control, office automation, computer-aided teaching, computer animation, computer art.
3. The figure consists of two elements?
The elements that make up the figure are divided into two categories: one is the geometric elements such as points, lines, surfaces, and volumes that describe the shape. The other is to reflect the inherent properties of the object itself, such as surface properties or non-geometric elements such as light and shade, grayscale, and color of materials.
4. What is the structure of the raster scanner?
frame buffer memory, display controller, display processor
5. Graphic scan conversion, why does aliasing occur?
Use discrete quantities to represent distortion caused by continuous quantities
Use finite discrete quantities with area to model infinite continuous area without area
6. What is the principle of raster scanner?
Draw a point device, control the characteristics of the point.
Raster scanning is to control the electron beam to scan sequentially according to a certain raster shape, while characters and images are formed by controlling the brightness of the Z-axis signal.
7. What is human-computer interaction technology? Human-computer interaction techniques commonly used in computer graphics?
Human-computer interaction technology: The technology of realizing human-computer dialogue in an effective way through computer input and output devices.
Four human-computer interaction technologies: construction technology, command technology, selection technology, and direct manipulation technology
8. Calculate video memory size
2^N times aligned color types
1024*1024, 15 bits, frame buffer: 1024*1025*15/8=2M
9. What are the components of a computer graphics system?
It consists of hardware and software. The basic physical equipment of a computer graphics system is called hardware, including the host computer and large-capacity external memory, display processor, graphics input and graphics output devices.
Graphics software: graphic application data structure, graphic application software, graphic support software
Graphics Hardware: Graphics Computer Platform, Graphics Device
10. What coordinate systems are commonly used in computer systems?
User Coordinate System: Building the Model
Observation coordinate system: display area, select the observation area, for cutting
Normalizing Device Coordinate Systems: An Abstraction for Devices
Equipment coordinate system: specific equipment, origin, etc. are fixed
11. Anti-aliasing technology?
Oversampling: Calculated with point sampling at a higher resolution than the display resolution, and then averages the properties of several pixels to obtain the pixel properties at the lower resolution
Area Sampling: Sampling within the entire pixel area, this technique is called area sampling. Since the brightness of a pixel is determined as a whole and does not need to be divided into sub-pixels, it is also called pre-value filtering.
12. Perspective projection and its characteristics
The distance between the projection center of the perspective projection and the projection surface is limited
Perspective reduction effect: The size of the perspective projection of an object is inversely proportional to the Z distance from the object to the center of the projection.
Perspective projection has a stronger sense of depth and is more realistic, but perspective projection cannot accurately reflect the size and shape of objects.
The size of the perspective projection is related to the distance of the object from the center of the projection.
When a set of parallel lines is parallel to the projection surface, the angle on the surface can be preserved in perspective projection.
The vanishing point formed by the parallel lines not parallel to the projection on the projection plane is regarded as the main vanishing point.
A perspective has a main vanishing point, that is, the projection plane is orthogonal to one coordinate axis and parallel to the other two coordinate axes.
Two-point perspective has two main vanishing points, that is, the projection plane intersects two coordinate axes and is parallel to the other coordinate axis.
Three-point perspective has three main vanishing points, that is, the projection plane intersects all three coordinate axes.