Terminology


Term Definition
Computer Graphics Is the methodology of the creation of images using a computer (Computer graphics does synthesis: from models to images)
Image Synthesis is the subfield of computer graphics that attempts to produce realistic pictures
Image Processing Is the manipulation of an image to produce another image which is in some way different from the input image (Image processing does analysis: from images to images)
Computer Vision (Sometimes called Image Understanding) is the extraction of information from an image (from images to models)
Graphics System is any collection of hardware and software designed to make it easier to use graphics input and output in computer programs
Graphic Primitive Is something we know how to draw directly into a bitmap, such as a line, a point, and some polygons
Primitives Basic geometric elements from which complex objects can be built

Terminology


Term Definition
Bitmap (raster) (Also known as a pixel image) An image is stored as a collection of pixels. May be any resolution or color depth. Simply, it is a rectangular array of points or dots
Pixels An acronym that stands for Picture Element. It is the smallest component which makes up the display on a computer monitor. Each dot on the screen is a pixel. Many images displayed on the screen are likewise stored in a pixel form that is mapped to the screen pixels for viewing. Simply it is one dot or picture element of the raster
Physical Pixels Physical Pixels are the actual dots displayed on an output device. Each one takes up a small amount of space on the surface of the device.
Logical Pixels Logical Pixels are like mathematical points: they specify a location, but are assumed to occupy no area.
Cut Scene Set scenes of action which the player cannot control. Usually cut scenes are used to develop the plot orstory of a game, or to give the player information such as introducing them to a character or telling themwhere to find something
Resolution The number of pixels per unit. The higher the number of pixels, the higher the resolution, and the greater the capability to display details.

Terminology


Term Definition
Color Depth The number of bits required to define the color of each pixel in an image. Black and white images use one bit. Grayscale images use eight bits (256 shades of gray). Eight-bit color images provide 256 colors. Images with 24-bits provide millions of colors (eight bits for each color: red, green, and blue). Images with 32 bits provide an additional eight bits for alpha data.
RGB A method of representing all colors as the combination of red, green, and blue light.
Point It is just a dot. In CG the smallest thing we can draw directly is a pixel. A point is often drawn as one pixel, but we might also use a small clump of pixels
Polygon Is a bunch of line segments connected end to end in a closed loop
Polyline Is just a bunch of vectors drawn end to end
Vector A computer graphics vector primitive is just a line segment
Image Is a 2D array of pixels
2D Stands for two-dimensional. Two-dimensional objects are always flat because they have only two dimensions: width and height

Terminology


Term Definition
3D Stands for three-dimensional. Three-dimensional objects are exist in a volume and have dimensions of width, height, and depth. For example, a rectangle drawn on a piece of paper is 2D, whereas a cardboard box is 3D
Video Monitor is a display device that converts electrical signals into visible images
Color CRT Displays color pictures by using a combination of phosphors that emit different colored light
Scan line Is a row of pixels
Scan (or refresh) rate Refers to how fast the electron beams are swept across the screen. There are two scan rates: horizontal and vertical. The horizontal scan rate is the rate at which individual scan lines are drawn; this rate is of little interest to end users. Users are more concerned with how many scan lines there are and how often the whole screen is refreshed. The vertical scan rate indicates how often the entire image is the refreshed
Aspect Ratio The width and height of the frame dimensions of an image.
Alpha Channel An eight-bit channel in the 32-bit color image which is used to store transparency data.

Terminology



Terminology