GIS File Formats - Advantages and Disadvantages

Advantages and Disadvantages

There are some important advantages and disadvantages to using a raster or vector data model to represent reality:

• Raster datasets record a value for all points in the area covered which may require more storage space than representing data in a vector format that can store data only where needed.
• Raster data is computationally less expensive to render than vector graphics
• There are transparency and aliasing problems when overlaying multiple stacked pieces of raster images
• Vector data allows for visually smooth and easy implementation of overlay operations, especially in terms of graphics and shape-driven information like maps, routes and custom fonts, which are more difficult with raster data.
• Vector data can be displayed as vector graphics used on traditional maps, whereas raster data will appear as an image that may have a blocky appearance for object boundaries. (depending on the resolution of the raster file)
• Vector data can be easier to register, scale, and re-project, which can simplify combining vector layers from different sources.
• Vector data is more compatible with relational database environments, where they can be part of a relational table as a normal column and processed using a multitude of operators.
• Vector file sizes are usually smaller than raster data, which can be tens, hundreds or more times larger than vector data (depending on resolution).
• Vector data is simpler to update and maintain, whereas a raster image will have to be completely reproduced. (Example: a new road is added).
• Vector data allows much more analysis capability, especially for "networks" such as roads, power, rail, telecommunications, etc. (Examples: Best route, largest port, airfields connected to two-lane highways). Raster data will not have all the characteristics of the features it displays.