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Raster and Vector Data - What's the Difference?

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Vector Data

A representation of the world using points, lines, and polygons. These data are created by digitizing the base data. They store information in x, y coordinates. Vectors models are used to store data, which have discrete boundaries like country borders, land parcels and roads. Vector models are useful for storing data that has discrete boundaries, such as country borders, land parcels, and streets.


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Points                                                          Lines                                                           Polygons


Characteristic of Points:
  • Represented as a single ‘dot ‘on the map.
  • Points are used to indicate discrete locations.
  • They usually have a single X, Y coordinate.
  • Used to represent a feature that is too small to be displayed as a line or area.
Characteristic of Polylines:
  • Ordered sets of points that have the look of a straight line or a curved arc depending upon the feature it describes
  • They have a length but no width
  • They are used to represent a geographical feature that is too narrow to have area, such as a stream or a road.
Characteristic of a Polygon:
  • Closed features whose boundary encloses a homogenous area
  • Have an area that is given by the arcs/lines that make the boundary
  • Are used to represent features that have area

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Raster Data
Raster data stores information of features in cell-based manner. Satellite images, photogrammetry and scanned maps are all raster-based data. Raster models are used to store data, which varies continuously as in aerial photography, a satellite image or elevation values (DEM- Digital Elevation Model).

A raster consists of a matrix of cells (or pixels) organized into rows and columns. A raster image can take many forms, such as .bmp, .tif, .jpg etc. If you examine a raster image closely, you will notice that they are made up of many (usually) square cells. A raster data set is a regular grid of cells divided into rows and columns. In a raster data set, data values for a given parameter are stored in each cell. These values may represent an elevation in meters above sea level, a land use class. The spatial resolution of the raster data set is determined by the size of the cell, these cells are used to represent geographic data. Every cell contained in the raster map has either numeric or character attribute information associated with it. A raster based GIS can portray continuously varying data more effectively and can analyze multiple layers of data easily. Raster GIS is relatively fast and you can perform a wide range of visualization and analysis that are not possible in a vector based system.

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Multi-Resolution Raster (MRR) - A New Raster File Format

While raster based data allows for richer insight, files can often be very large and difficult to manage. MapInfo Advanced solves for this by using a specifically-designed data format called Multi-Resolution Raster (MRR). 

MRR is a completely new raster data format that reimagines how raster data is stored and what data can be stored as a raster. It is a unifying and enabling technology. It unifies the storage of multiple raster data types, including satellite imagery, gridded data (e.g. digital terrain models) and vector-based thematic data. MRR removes the barriers to working with large and complex raster files, and enables the highest quality visualization and processing of raster data at any scale and for rasters of any size.

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Advantage and disadvantage of using raster and vector data
  • Raster data model record value of all the points of the area covered which required more data storage than model represented by the vector model.
  • Raster data is less expensive to create computationally compare to vector graphics.
  • Raster data has issue while overlaying multiple images.
  • Vector data are easily overlaid, for example overlaying roads, rivers, land use are easier than raster data.
  • Vector data are easier to scale, re-project or register.
  • Vector data are more compatible with the relational database management system.
  • Vector file sizes are much smaller than raster image file.
  • Vector data are easier to update like adding river stream but has to be recreated for the raster image.
Raster formats
  • ADRG – ARC Digitized Raster Graphics
  • RPF – Raster Product Format, military
  • DRG – Digital raster graphic
  • ECRG – Enhanced Compressed ARC Raster Graphics
  • ECW – Enhanced Compressed Wavelet (from ERDAS
  • Esri grid –ASCII raster formats used by ESRI
  • GeoTIFF – TIFF variant enriched with GIS relevant metadata
  • IMG – image file format used by ERDAS
  • JPEG2000 – Open-source raster format
  • MRR- Multi-Resolution Raster
  • MrSID – Multi-Resolution Seamless Image Database
Vector Formats
  • AutoCAD DXF –AutoCAD DXF format by Autodesk
  • Cartesian coordinate system (XYZ) – simple point cloud
  • DLG – Digital Line Graph (USGS format)
  • GML – Geography Markup Language – Open GIS format used for exchanging GIS data
  • GeoJSON – a lightweight format based on JSON, used by many open source GIS packages
  • GeoMedia – Intergraph’s Microsoft Access based format for spatial vector storage
  • ISFC – Intergraph’s MicroStation based CAD solution
  • Keyhole Markup Language KML – Keyhole Markup Language a XML based
  • MapInfo TAB format – MapInfo’s vector data format
  • NTF – National Transfer Format
  • Spatialite – is a spatial extension to SQLite,
  • Shapefile – Most popular vector data developed by Esri
  • Simple Features – specification for vector data
  • SOSI – a spatial data format used for all public exchange of spatial data in Norway
  • Spatial Data File – Autodesk’s high-performance geodatabase format
  • TIGER – Topologically Integrated Geographic Encoding and Referencing
  • (VPF) – Vector Product Format
References
  • http://geokov.com
  • http://grindgis.com/
  • https://en.wikipedia.org/wiki/Map_projection
  • https://www.gislounge.com/map-projection/
  • http://www.kidsgeo.com/geography-for-kids/0029-large-and-small-scale-maps.php
  • http://study.com/academy/lesson/what-is-a-map-scale-definition-types-examples.html
  • https://www.ordnancesurvey.co.uk/support/understanding-gis/
Interested to know more, please read these related articles on raster:
A functionality comparison between Discover Surfaces (32-bit) and MapInfo Pro Advanced Raster (64-bit)
Get on the Grid: An Overview of Raster GIS Concepts
Multi Resolution Raster (MRR) - Revolutionizing Raster Performance and usage

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UPDATED:  July 16, 2018