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I managed to load a rectified Mapwarper layer off Marble's cache in JOSM, but it has a very significant offset (500-ish km) and apparently it was heavily distorted. If it is seen through Marble, it looks fine without a problem.

Is there any way to correct this?

(quesion converted from a comment to how to configure offline imagery for josm)

asked 09 Mar '16, 03:50

AkuAnakTimur's gravatar image

accept rate: 6%

converted 10 Mar '16, 22:30

Vincent%20de%20Phily's gravatar image

Vincent de P... ♦

Can you give more details about your setup ? What is the url of the mapwarper layer ? Are you using the same url in Marble and JOSM ? Is the mapwarper layer fully rectified ? Is it using mercator projection ?

(10 Mar '16, 22:36) Vincent de P... ♦

Setup details: JOSM 9900 and Marble 1.9.1 on Windows 7.

I am using this layer that I composed myself. Then, I used the WMS link to display it through Marble (File > Create new map).

The Mapwarper layer has been fully rectified, because it appears fine when the layer is viewed through Marble. Also, no problems if I used it as a WMS layer in JOSM.

I have checked the projection being used in both Marble and JOSM. Making sure both are using the same Mercator projection.

I also have attempted to delete and reload the Mapwarper layer in Marble, but it seems that I cannot rule out the offset problem.

(11 Mar '16, 01:28) AkuAnakTimur

I can see the same offset as you do when using the WMS link in Marble. This is because this WMS url serves tiles in Equirectangular projection (see the *.dgml file in the marble directory).

Create the marble map using the tms url and you'll have tiles in the mercator projection mandated by tms. You'll also get png tiles, which have the advantage of being transparent where mapwarper has no data.

Maybe you could achieve the same results using WMS parameters, but I don't know what those would be.

permanent link

answered 11 Mar '16, 17:36

Vincent%20de%20Phily's gravatar image

Vincent de P... ♦
accept rate: 19%

Thank you very much! It worked! A bit late to respond to your solution due to a metered internet connection. I think I'll stick to your method, better keep it simple.

PS: Is this the correct way to fully download the Mapwarper layer on Marble? Select the Mapwarper layer and then File and then Download region?

(13 Mar '16, 17:46) AkuAnakTimur

Yes it is the correct way to do this in marble. Also check marble's cache size settings.

On the other hand, watch out for tile usage policies, as bulk download of thousands of tiles are often frowned upon. Not sure what/where mapwarper's tile usage policy is.

(13 Mar '16, 19:50) Vincent de P... ♦

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question asked: 09 Mar '16, 03:50

question was seen: 3,148 times

last updated: 13 Mar '16, 19:50

NOTICE: is no longer in use from 1st March 2024. Please use the OpenStreetMap Community Forum