Reusable Learning Objects for Multimedia

subglobal1 link | subglobal1 link | subglobal1 link | subglobal1 link | subglobal1 link | subglobal1 link | subglobal1 link
subglobal2 link | subglobal2 link | subglobal2 link | subglobal2 link | subglobal2 link | subglobal2 link | subglobal2 link
subglobal3 link | subglobal3 link | subglobal3 link | subglobal3 link | subglobal3 link | subglobal3 link | subglobal3 link

Bitmaps and Vectors

Bitmaps and Vectors

Bitmapped images are fundamentally different from vector graphics. Experiment with the two examples above: the simple sketches are identical, except the one on the left is a vector graphic, and the one on the right is a bitmap.

First, drag on the different elements in each of them - the circles and other shapes - to reposition them. Notice the difference between the vector and the bitmap?

Second, shift-drag on them to make them bigger or smaller. Again, what do you notice about the different ways the vector and bitmap images behave?

Structural information

Vectors contain structural information that bitmap images do not. In the examples above, the components of the vector image can be manipulated separately - while those of the bitmap image cannot. Each point, line and shape in a vector image is specified precisely in mathematical terms. It follows that such elements can be moved and resized separately - and without loss in resolution. On the other hand, a bitmap is simply a flat pixel grid, with no structural information. The only information a bitmap image contains is the colour for each pixel. When it is enlarged, there is no information available about the new pixels created by the enlargement, and a jagged 'staircasing' effect is produced. With a vector, the resizing factor is simply fed into the equation, and the quality of the larger image is identical to that of the original.

Next page: bits

About | Site Map | Main Page | Contact | ©2005-2006 MMU/Higher Education Academy