Raster Scan Displays in Computer Graphics
Raster scan displays are a fundamental concept in computer graphics. They are widely used in monitors and screens to render images, text, and graphics. Here, we'll delve into the details of raster scan displays and how they function.
What is a Raster Scan Display?
A raster scan display, also known as a bitmap display, operates by scanning the image from left to right and from top to bottom. It consists of a grid of pixels, with each pixel being a small, discrete unit that can display different colors or shades. The entire image is built up by illuminating appropriate pixels in the grid.
How does it work?
When an image is displayed on a raster scan display, it is first converted into a raster format. This means that the image is represented as a grid of pixels, with each pixel assigned a color value. The display then scans across each row of the grid, illuminating the pixels according to their color values. This process is repeated for each row, from top to bottom, until the entire image is displayed.
Advantages of Raster Scan Displays:
- Simple and efficient method for displaying images.
- Can display complex images with varying colors and shades.
- Widely used in various applications, from computer monitors to television screens.
Disadvantages of Raster Scan Displays:
- Resolution limitations: The quality of the image is limited by the number of pixels in the display.
- Fixed refresh rate: Raster scan displays have a fixed refresh rate, which can lead to motion blur in fast-moving images.
- Not suitable for vector graphics: Raster scan displays are not well-suited for displaying vector graphics, which require precise rendering of lines and curves.
Example:
Consider a simple example of displaying the letter "A" on a raster scan display. The letter "A" is represented as a grid of pixels, with each pixel assigned a color value. The display scans across each row of the grid, illuminating the pixels according to their color values, until the entire letter "A" is displayed on the screen.
Conclusion:
Raster scan displays play a crucial role in computer graphics, providing a simple and efficient method for displaying images and graphics. Despite their limitations, they remain widely used in various applications due to their versatility and effectiveness.