the State of Colorado would be a single feature within a US_States feature class or shapefile) at any interval at any time. They can be moved and deleted freely, and new vertices can be added to any vector feature (a single object stored in the larger shapefile or feature class, ie. Vertices can be placed very close together or very far apart. Because we can place a vertex really anywhere we want in the software, there are no "rules" about vector data beyond the vertex minimums to create points, polylines, or polygons. We learned that vector data is data is just a graphical representation of objects using vertices connected by straight lines to outline an area (polygons), mark the location of a single instance (points), or trace along linear objects (polylines). The properties of raster data is what makes the unique compared to vector data. Notice the pixels are all squares in a grid pattern. In this image, we can see all the pixels a digital version of the Mona Lisa is made up of. Figure 3.6: A Pixelated Version of the Mona Lisa Kind of like the cliché "you can't see the forest because of the trees", meaning that you cannot see the entire forest if you are so close, you can only see the trees.
We would describe the image as pixelated, or the fact that the image pixels have become so large, that the only thing you can see is the pixel makeup of the image and not the image itself.
#GIS DIGITAL RASTER GRAPHIC FULL#
You may have seen the pixels of an image before when you try to post an picture to your social media account that was once a small sized picture and you’re trying to make it display full page.
#GIS DIGITAL RASTER GRAPHIC SERIES#
In fact, you can add a picture of your cat to the GIS, the GIS simply won't know where it should draw the raster data.Īll digital images (raster data) are comprised of a series of pixels (short for picture elements) arranged in in rows and columns to create a grid pattern.
Both a picture of your cat Mogwai and a Digital Elevation Model (DEM) are seen as raster data by the software, the only difference being that the spatial raster, the DEM, has coordinate system information attached, allowing the GIS to know where in the world to "put" when it's displayed on screen. In reality, raster data is any pixel-based picture data (JPG, PNG, TIFF for example) which is loaded into the software. Second in our list of spatial data types is raster data.
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