I am using open layers with a tile server. I want to load maps while panning and destroy the loaded region when out of screen (Alternative to unloadinvisibletiles of leaflet.js)
How am i suppose to achieve this?
ol3 maintains a tile cache and will automatically expire unused tiles when the cache is full (that is if it contains more than 2048 tiles).
Related
I'm trying to extract some a data (a map image) from a PNG file which is tiled somehow. The file itself is only 256x256 pixels (according to 'get info' on the mac) but is is 23MB. It is from an iPad app called Mud Map and it contains a map that I purchased but I've lost the original that I converted to this format. When I view this file (renamed to a .PNG) I see one section of the map - 256x256px.
I'm asking this question on StackOverflow because I want to know more about these tiled images. How does one create a tiled PNG and what is the software that will open and or create these things. I'm interested in what metadata is required too. I'm loving the outdoors and mapping!!
The answer to this question, is that it cannot be done in manner I have described.
The images in the PNG are not tiled, the the files are just merged together which is no doubt an individual feature of the program as is it does not appear to be any kind of standard.
I have no access to application you mentioned in IPad. Just share some thought about possible situation here.
1) Map tiles are commonly used in GIS web application such as Google maps and so on. It is used to improve the performance especially when user pan very often. A map displayed typical map window is divided into for instance 4*4 separate calls. So maybe only 4 call will be made when user just pan a little bit instead of get the whole map for the 16 tiles.
The source image for this tiles can be in pre-generated tiles or just one static map.
2) Assemble separate images to one in GIS is called image mosaic function. GIS server can read a collection of images and mosaiced them into one with the overlapping part handle based on a certain rule. And the images are in pre defined grid format which are seamless and no overlapping, then it is called tiled images. We could pre-generated the tiles from one mosaiced image, or we can server it on the fly. Some GIS server/library/application does have the tile server function built in.
I want to generate different raster according to scale like Google Maps with gdal tool GDAL2TILES for my WEB GIS who run with OL3. For example,
scale 1 :
and the same place Scale 2 :
What you are looking for is a tile server to seeding the tiles for your openlayers application to consume. And the different image output at different zoom level in the same location is called raster pyramid.
http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?TopicName=Raster_pyramids
Back to your question, if you want to generate tiles, there are multiple solutions out there, many free open sourced ones are build based on GDAL as you mentioned such as GeoWebCache, MapProxy, etc.
You can seed/replace tile image at different zoom level to generate your own raster pyramids. And then you can either consume the Tile map service, or directly access the tiles via OpenLayers.
DeepZoom is creating 12 levels of images. Here my problem is when i click the zoom in ,it works only 3 times. I cannot go depth of zooming. starting Level 10 to Level 12. Is it possible create more DeepZoom images or create custom code for more zooming to add ?
There is no direct relationship between the levels of tiles created versus how many times you can click to zoom in. It all depends on how big your viewer is and how big your image is. If you want to be able to zoom further into your image, perhaps you need a bigger image. You can also use the maxZoomPixelRatio option when creating the viewer to allow zooming further (though the image will get blurry when you zoom past full resolution); for instance, try maxZoomPixelRatio: 2 (the default is 1.1).
I am using mapbox for showing map in my app, I need to include offline map feature also. Since there is a limit in tile size download, so can anyone tell me what is the size of single tile of mapbox map? Thanks in advance!
This is equivalent to asking "what is the size of an image": tiles range from 5kb to 40kb, depending on a range of factors from the complexity of the image to the compression chosen.
I want to be able to load a list or an array of tiles and displayed them on a map.
Cocos2D offers a possibility to load tiles on a map. But for my case, I have to load just a specific part/range of tiles (which I define) and this changes dynamically during the run time. I never want to load the whole map at once. Is this possibile? Maybe an alternative to Cocos2D on iOS? The map details come from a server. It should be done in a quite large multiplayer environment, that's why each player/client should only load his relevant parts of the map.
You can definitely do this, and there are many different ways. For example, swapping scenes or layers during run time, with different tile maps on them, or by creating tile maps your own way with a custom set of methods using CCSprite (for example, it is common to create your own parallax scene instead of using the built-in Parallax scene methods in Cocos2d, and you could do the same with tile maps, if desired). The options are really limited only by creativity.