Section 3 Chapter 16 - Bitmapped Graphics Flashcards
Bitmap (raster)
An image that contains many pixels to make up an image. Each pixel has a colour associated with it
Equation for resolution
width * height
PPI
Pixels per inch. A value that says how many pixels are in a strip of one inch
Colour depth
The number of bits used in each pixel for the colour
Standard colour depth
32 bits 8 - red 8 - blue 8 - green 8 - alpha
Metadata
Data describing other data
Examples of metadata for an image (4)
- Dimensions
- Colour depth
- File name
- Date
Vector image
An image made up of geometric shapes and objects
Properties of a circle in a vector image
- Centre co-ordinates
- Radius
- Fill colour
- Line colour
- Line weight
Vector drawing list
The list of geometric shapes and objects stored in a vector graphics file
Advantages of vector graphics (2)
- No matter how large the image is the image will always be sharp and will never pixelate
- Smaller file size
Advantage of bitmap graphics (2)
- Can easily replicate areas of continuously changing colours such as photographs
- Individual pixels can be easily manipulated in a program like photoshop
Pixel
A small single element of a bitmap that has a single colour associated with it
Storage requirements for a bitmap
resolution * colour depth + metadata storage
Why might the actual storage of an image be different to what you would calculate
- Metadata
- Compression