![]() While this seems like a straight forward approach, there are some significant down sides. We could work with the original COG file and rescale only the required section of the layer based on the user requirement.At this point, we had 2 options to move forward. They were already converted to RGB values of a tile images based on a specified legend color. In other words, the raw measurement values from the layers are no longer available in the browser. Rescaling the raster tiles colors is quite tricky since the layers that are visible to the users are already converted to image format from the original raw COG files. Users first select an area of interest, after which they can still buffer areas, scale colors or adapt the layer used, before printing the result to PDF. Screenshot of the map printing tool embedded in the interface. Once an area is drawn on the map, the user can with one-click simply download the original GIS data (TIFF file) from the browser. The Global Wind Atlas application provides users with an intuitive UI to select appropriate areas from the map. Download GIS files for custom areasĪnother great advantage of using COG-files is that it’s become way easier to let the user download clipped TIFF files for customized areas on the map. This technique is the most cost-efficient approach and allows us to satisfy both data provider (World Bank Group and DTU) and the users (Wind Energy Seekers), who get to access the data for free. We’re pre-processing raster tiles for the first 10 zoom levels and dynamically move to tiles-on-the-fly for higher zoom levels. In the Global Wind Atlas, we’re aiming for the perfect mix. Now we are able to generate raster tiles on-the-fly from our global COG files. Chris Henrick explains very well how to get started with the AWS Lambda Tiler here. Server-Free Web Map Tile Generation is using AWS Lambda to generate tiles from the COG-files. Say Hi to Server-Free Web Map Tile Generation. But we still need to generate tiles from it. ![]() Now we can access only that part of the Global Geotiff file that we’re looking at in our map view. We’re using HTTP GET range requests, that allows us to ask for only the portions of the file that we need. Said simply, COG-formated tif files allow us to request only the part of the global geotiff files we’re looking at in our map viewer. It’s a great imagery format for cloud-native geospatial processing. png’s and send them to the browser?ĬOG stands for Cloud Optimized Geotiff. We can store the global Geotiff file in the cloud, but how do we start processing a file of several GB’s to generate raster tiles, convert them to. But remember, we said we want to do it without using a map server right? Generating raster tiles on-the-fly using COG-filesĪs an alternative we coud setup a Map server (Geoserver, …) and render tiles on demand (WMS, …).
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