MultiLayer map with different tile sizes on different layers

Hey Orux,


First off: great app! I love it!

I'm writing here since I have a large Map (1.5 GB+) and OruxDesktop can not convert it. I guess it tries to load the complete image into memory instead of using a stream based approach. 8 GB are not enough, I guess...

So my idea was to create the tile database myself and just use OruxDesktop to get the XML file for calibration.

Works pretty well so far, except I ran into an issue when generating multi-layer maps. For every layer there is an img_width and img_height attribute in the XML.
What I wanted to do is to use 512x512 tiles for all layers except level 12. Here I use 256x256 tiles.

The problem:
OruxMaps now uses 256x256 for ALL layers, not only for the last one in the file (level 12). Messes up the map pretty good on all other level, except level 12.

Is that a bug or a feature?

---

side note: Which tile size would you suggest? 128, 256 or 512?

janek_schumann wrote:Hey Orux,


First off: great app! I love it!

I'm writing here since I have a large Map (1.5 GB+) and OruxDesktop can not convert it. I guess it tries to load the complete image into memory instead of using a stream based approach. 8 GB are not enough, I guess...

So my idea was to create the tile database myself and just use OruxDesktop to get the XML file for calibration.

Works pretty well so far, except I ran into an issue when generating multi-layer maps. For every layer there is an img_width and img_height attribute in the XML.
What I wanted to do is to use 512x512 tiles for all layers except level 12. Here I use 256x256 tiles.

The problem:
OruxMaps now uses 256x256 for ALL layers, not only for the last one in the file (level 12). Messes up the map pretty good on all other level, except level 12.

Is that a bug or a feature?

---

side note: Which tile size would you suggest? 128, 256 or 512?

Hello,

OMD tries to read the images in strips, but the java support for image processing is not very good, I have to search other libraries.

Sorry, but you can not mix different tile sizes in the same map.

256 or 512 give a good result.

orux

Here is what I did to get my final solution:

• exported every level / layer with OziMapTrans to one single png file + map file for calibration
  
• calibration:
  
  
  
  • converted each map file to ortk2
    
  • copied the content of every ortk2 file into one single file
    
  • modified tile size and tiles count
    
  
  
• tiles
  
  
  
  • used PngCs (C# port of PngJ) to read and write PNGs line by line
    
  • used tile size of 128x128
    
  • processed every level / layer separately (created a SQLite database for each)
    
  • merged all databases together in the end
    
  
  

as a result I got a ~2 GB database with level 9-16 for the complete alps. Works wonders. Tested it yesterday in the field and I can't see any performance issues with it. (old smartphone with only 600Mhz and 150MB RAM! ) Calibration is also very impressive. (lets say 2-5 "pixels" around the real position on the map is waaayyyy within the noise level of the built-in GPS receiver! so absolutely no complaints here. )

Next step:
writing a program to create maps directly from canadian geodata services (they have really good and free material which is very easy to process).
After that, I'm all set for my next expedition to the rockies! hurray!


My wishlist for the future:
Layers, layers, layers and more layers. (e.g. layer for altitude lines, roads, POIs, summits, huts, ...)


BTW: I *love* the photo-waypoint-function!