Computer Graphics Review Guide
Ø Glossary
Computer Graphics Standard: An interface standard between computer graphics systems and their associated application interfaces and data transmission.
The concept of geometric transformation: the new graphics generated by the transformation of the geometric information of the graphics through translation, scale, rotation, etc., is the transformation of the graphics in terms of direction, size and shape.
Cropping and cropping window: In two-dimensional observation, the window needs to be cropped under the observation coordinates, only the part of the image in the window is retained, and the graphics outside the window are removed.
Anti-aliasing: The reduction or elimination of distortion caused by discrete quantities.
Projection transformation: The process of projecting a three-dimensional stereo onto a projection surface to obtain a two-dimensional plan.
Graphics: objective impressions capable of forming visual impressions in the human visual system
Image: Refers to the actual scene image captured by the input device or any image stored in digital form
Photoelectric: generally refers to the minimum light-emitting point that the display can display when the electron beam hits the screen of the display.
Pixel point: refers to the minimum element point that can be provided by the current graphic display resolution when the graphic is displayed on the screen.
Cropping window: In computer graphics, a coordinate area that needs to be observed and processed in the user coordinate system. In two-dimensional observation, the window needs to be cropped in the observation coordinate system, and only the part of the graphics in the window is retained. Remove graphics outside the window.
View: Maps the window to the coordinate area on the display device.
Dot matrix method: use points with grayscale or color to represent graphics, and represent graphics by enumerating all points in the graphics, emphasizing which points constitute the graphics and what colors these points have
Parametric method: use the shape parameters and attribute parameters of the graphics to represent the graphics. Shape parameters refer to the coefficients of the equations or analytical expressions describing the graph, the coordinates of the endpoints of line segments and polygons, etc. Attribute parameters include color line type, etc.
Display resolution: The display mode resolution that can be controlled by the computer display, which is referred to as the display mode in practical applications. For the way text is displayed, the display resolution is expressed as the product of the total number of characters that can be achieved in the horizontal and vertical directions.
Screen Resolution: Determines the maximum possible resolution of the system. No display resolution can exceed this physical resolution.
Four-connected region: Starting from a point on the region, by visiting the 4-adjacent points of the known points, without going beyond the region, traverse all the pixels in the region.
Eight-connected region: Starting from a point on the region, by visiting the 8-adjacent points of the known points, without going beyond the region, traverse all the pixels in the region.
Display Processor: Graphics controller, scan-convert graphics to be displayed and some additional operations.
Display controller: According to the set display working mode, it can independently and repeatedly read the graphic dot matrix data in the frame buffer, convert them into RGB three-color signals and send them to the display together with the synchronization signal, then the screen can be refreshed .
Combined pixel method: All information of a graphic pixel is encoded into a data byte, which is stored in the frame buffer in a certain way. The length of the encoded byte is related to the attribute of the point.
Color bit plane method: The frame buffer is divided into several independent storage areas, each area is called a bit plane, each bit plane controls a color or grayscale, and each graphic pixel occupies one bit in each bit plane , a pixel is composed of the same bit in several bit planes.
Parallel projection: The distance from the projection center to the projection surface is infinite, which can accurately reflect the actual size of the object.
Perspective projection: The distance between the projection center and the projection surface is limited.