![]() Here is where I am lost! I am looking at this interative map of where Thanksgiving dinner ingredients are produced, for example ( link), and it is a basic map of the united states with circles in each county, and the size of the circles represent how much of the ingredient is farmed in that county.Īttributes associated with each circle would be county name, # of acres of ingredient farmed there, and # of farms.īut for whatever reason, something is just not clicking for me to understand if this is raster or vector data - I want to guess raster because it seems like simpler data? but truly I have no idea. This all makes sense when thinking about very basic maps, but for an assignment this week I am supposed to take examples of maps and discuss weather the data presented is showing a vector or raster model of data. I have grasped that in theory, the difference between vector data and raster data is that vector data uses a series of lines and points to show where features are, where raster data is made up of pixels. Boca Raton, FL: CRC Press.Hello! I'm taking an online GIS course and we are covering spatial data models. A computational introduction to digital image processing (2nd ed.). In general, vector images require less memory to store necessary data compared to raster images. A vector image can be converted into a bitmap image of the required resolution, but it is rather difficult to convert the bitmap image into a vector without loss of quality. It is noteworthy that vector graphics can be easily transferred to raster format. Thus, vector images are based on geometrical formulas, while raster pictures have pattern dots. The Adobe Illustrator and CorelDraw programs are more appropriate for working with vector images. ![]() Although Adobe Photoshop allows working with vector images, it is still a raster editor. For example, various logos, business cards, and banners for websites need vector images in terms of design. Vector images are especially useful when there is a need to increase a photo or any other picture without losing its quality. In other words, a vector image includes information in the form of formulas and mathematical calculations, having a small size regardless of the actual scale of the depicted canvas (McAndrew, 2015). A vector image contains information about the positions of points as well as data about the line passing through the reference points. Vector images do not consist of dots containing color information, but reference points and vector lines connecting them. As a result, the image is distorted, and its small details become illegible. To reduce the raster pattern, one has to transform several neighboring points into one or throw away extra points. To enlarge an image, it is necessary to increase the size of the squares, and then it becomes stepped. According to McAndrew (2015), the mentioned images are also difficult to scale and even harder to edit. The computer remembers the colors of all the squares in a row in a certain order, which explains why bitmaps require more memory to store information. ![]() A raster image, unlike a vector image, is capable of transmitting a realistic image with a lot of small details. ![]() For example, any digital photo consists of these multicolored dots. Looking at the screen with thousands of dots of different colors and shades, people identify objects and images composed from them (McAndrew, 2015). The more points on the plane and the smaller they are, the more one sees the image. In bitmap images, each square called raster has its color and brightness, composing a mosaic. ![]()
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