TransDEM Forum

I just wondered if any functionality could be added to Transdem to improve the contrast and sharpness of mapping taken from sources such as Google or Open Street? This seems to translate into very blurry textures on the terrain, for example it can be hard to see minor roads where these are virtually the same colour as the general background and the edge is almost invisible. I know it is possible to use UTM, but I would prefer not to do that. Even at fairly zoomed in levels the lovely sharp map in the Transdem window or indeed even in an IE window becomes a bit of a blurry mess, can't even see place or street names clearly.

This doesn't happen with the Ordnance Survey maps either from the Sabre site or via Windows Live but I suspect that is because Transdem is reading the contrast better.

The only workround I can see is to assemble clippings from Open Street et al into a separate geo-referenced image, but that kind of defeats having the Map Tile function in the first place!

Vern,

are you talking about contrast/clarity in TransDEM or in Trainz?

In TransDEM you can increase a bit of sharpness when acquiring/georeferncing maps by activating the bicubic filter. Map images against DEM background can be made clearer by increasing DEM transparency in the settings.

In Trainz, it's the TransDEM texture set. This has been created as a "best fit" for a selection of topographic maps from various countries and map agencies. It's not the optimum for every kind of map. The bicubic filter will accentuate edges and this may survive when exporting to Trainz.

What you could do for the Trainz route, of course, is to create a modified custom ground texture set to be used by TransDEM. In TransDEM 2.2 handling of custom texture sets has been made a bit more user friendly. And I added an explanatory note in the documentation on the role of RGB/KUID pairs in the texture set text file, see page 23 in the TransDEM Trainz manual.

Contrast in Trainz, Roland. Even using the 5m grid the results from Google and Open Street are often just too blurry. Reading the maps in Transdem is fine.

However now you've mentioned the bicubic filter I will give that a shot next time I set up a route using those types of map.

G'day BigVern,

I have had some success with 'better' reproduction of 'standard' Topographic maps by using the Web Safe Colours Texture Set created by ModellerMJ (see elsewhere in these pages for further details), although they are by no means 'perfect' for this purpose (they were 'developed' for use with aerial imagery) the larger number of colours does make a difference. Don't forget to tell all your 'clients' of the need to download and install the new colour set if you upload any routes using it to the DLS...

Jerker {:)}

I couldn't get bicubic filter to work (it was greyed out as an option after acquiring the map imagery). So I just ran each PNG file through PSP7, -50 brilliance +50 contrast and that made the colours more distinguishable. Took a few minutes to do 25 - 30 clippings but made a difference. Only thing I couldn't do was sharpen the images as that was greyed out in PSP. At least they are clearer in Surveyor.

It must be set before acquiring the data because it is applied when converting the downloaded images to UTM. It will be sensitive when the WMS or the Map Tile dialog is open (or manual georeferencing is to be started).

Free IrfanView has a batch mode which can probably do the same job, applying it to an entire folder.