Hi,
I have questions about the speed of the display of the raster.
I use the class MultiGeoRasterLayer for display the raster (cf. wiki).
The configuration of the overlay is :
ovLy.TileHeight = 1024;
ovLy.TileWidth = 1024;
ovLy.TileType = TileType.HybridTile;
For our customer, the display of the raster is slow ;-(.
Question 1 : this option "ovLy.DrawingQuality = DrawingQuality.HighSpeed;" can accelerate the display of the raster ?
Question 2 : Is there other option which can the speed of the display ?
Question 3 : Is it possible to have the same fluidity of navigation as in google map ?
Thanks a lot for your help.
Regards.
Steph.
Rendering raster
Hi Steph,
For the question 1: yes, this property is designed to improve the rendering speed but will make the map quality not the best.
question 2: Currently, I think there are two ways would help to speed up the map. One is replace the GdiPlusRasterLayer with some specified raster layer like EcwRasterLayer, GeoTiffRasterLayer etc in DrawCore method of the MultiGeoRasterLayer class (I guess you have done this from the other post I can see). The second one is using the cache system on the layeroverlay level. But I am not sure if the cache is fit for your requirement.
Question 3: Sorry I am not very clear on this question, would you mind to provide more details?
Also, I will do some tests on the tile size to see if there is a big performance behavior with difference tile size.
Regards,
Johnny
Hi Johnny,
Thanks for your help.
For the question 2, yes I use raster like ecwrasterlayer, geotiffrasterlayer.
Currently, I use a cache system and the parameters of this cache are :
ovLy.TileCache = new FileBitmapTileCache(OutilsOvLyr.PathCacheRaster, "ManualCache");
ovLy.TileHeight = 1024;
ovLy.TileWidth = 1024;
ovLy.TileType = TileType.HybridTile;
And I do not specify drawingquality so far …
Is it good ?
you say "I am not sure if the cache is fit for your requirement".
What is the rules to respect to have a "good cache system" ?
For the question 3, sorry for not being more explicit.
What I meant is when you use google map with zoom + , zoom -, pan, the navigation is fluid, the tiles appear very quickly.
What are the tricks to have the same ease of use when you zoom, un-zooms, pan ?
Thanks again for your help
Regards.
Steph
Hi Steph,
It’s Ok to keep the default setting of the drawingquality. As for “are there some rules for cache system?”, there is no any special limitations or differences in caching system. So you can simply use it if you want.
For the last question, I think we did a lot of enhancements before and I am not sure you are using it in a proper way such as keeping the tile size as default should be recommended.
If there is any question, please feel free to let us know.
Regards,
Johnny
Hi Johnny,
Thanks for your help.
I have few more questions about this subject.
1)
About the Drawingquality, when you say “but will make the map quality not the best.”.
I do not see much difference in quality compared to the default option
In which case, we can detect this lower quality?
2)
Following your comment "I am not sure you are using it in a proper way such as keeping the tile size as default should be recommended. "
I changed the TileHeight and TileWidth to 256.
And I added TileBuffer = 2. This last propertie improves user experience while panning but not for zooming ?
is there other things to change to improve the rendering raster ?
I still use HybridTile because I did few tests with singletile and it’s slower.
Thanks again for your help.
Regards.
Stéphanie.
Hi Steph,
I think in the below cased we can use DrawingQuality.HighSpeed(lower quality):
1. When we focus on the label rendering with a small font size (font size < 10px). In this case, if we use “HighQuality”, the label text will be blur.
2. When we are doing the test or debug.
3. When we don’t care the image linear and gamma corrected.
For the second question, set the tile size as 256*256 should be the recommend value. And yes, set the TileBuffer does help on the user experience when paning as more tiles are loaded around the boundary. But not help on the zooming.
Currently, I think you have done enough enhancements on the rendering raster.
Hope it helps.
Regards,
Johnny