Vectors & Bitmaps
- Computers represent all data in binary, including images that are seen on a screen, TV or other output device
- Images can be stored in binary as Bitmap or Vector
What is a bitmap?
- A bitmap image is made up of squares called pixels
- A pixel is the smallest element of a bitmap image
- Each pixel is stored as a binary code
- Binary codes are unique to the colour in each pixel
- A typical example of a bitmap image is a photograph
- The more colours and more detail in the image, the higher the quality of the image and the more binary that needs to be stored
What is a vector?
- A vector image is created from mathematical equations and points
- Only the mathematics used to create the image are stored
- For example, to create a circle the data stored would be:
- Centre point (x, y coordinates)
- Radius
- Typical examples of vector images are logos and clipart
- Vector images are infinitely scalable
- Ideal for situations where the same image will be made bigger and smaller and a loss of quality is unacceptable. For example, the same logo used on both a pencil and a billboard
Exam Tip
In the exam, the focus will be on bitmap images. You need to know the basics of a vector but after that all questions will relate to bitmaps only!