Interactive vs Passive Graphics
The term computer graphics refers to all that is not sound and text on the monitor of the computer. Development of graphics on computers has made it easier for common people to interact and understand information that has no sound or text. Computer graphics have had a significant impact in the sense that they allow for effective communication between people and computers. There are basically two types of computer graphics namely interactive computer graphics (IGU) and passive computer graphics. The major difference over the two types is that while in interactive computer graphics user can interact with the graphics and can make changes in them, he cannot do so in passive computer graphics i.e. he has no control over the images.
There are many advantages of interactive graphics over passive graphics
• Higher quality of images
• Low cost
• Higher productivity
• Low analysis
There are three main components of interactive computer graphics namely, digital memory, monitor, and display controller. The display is stored in the digital memory in the form of binary numbers that represent individual pixels. When it is B&W graphics, the information is in the form of 1’s and 0’s in the digital memory. An array of 16 x 16 pixels can be represented using 32 bytes stored in the digital memory. It is the display controller that reads this information in the form of binary numbers and converts them into video signals. These signals are fed on to the monitor that produces black and white images. Display controller repeats this information 30 times a second to keep a steady graphics on the monitor. You as a user can modify the image by making suitable changes in the information stored in the digital memory.