[josm-dev] Image extraction from TMS cache

[Wiktor Niesiobedzki]

Hi Holger,

If you use josm code, there is a directory locking code, that prevents
from accessing cache simultaneously from different processes, as they
do not share memory structures that store current disk file layout and
may lead to corrupted reads/writes. So you should have JOSM shut down
first, before extracting the PNG.

There is no information stored about original file format. But you can
try to extract CacheEntry objects, which getContent() should return
original file content. But you will need to do file format
identification by your self using "magic" (like file), as uses this
magic to identify file format.

Cheers,

Wiktor

2015-12-20 18:33 GMT+01:00 Holger Mappt <holgerosm at gmx.net>:
> Hi,
>
> I re-package josm-latest.jar into my cachextractor.jar to have a self
> contained archive. I missed to copy data/preferences.xsd, which killed my
> JOSM preferences. Now I copy directory data in addition to **/*.java and the
> cache read works.
>
> What do I need to do to shut down JOSM if it was started with the functions
> in JOSMFixture.init() (no GUI mode)? Looks like there is a background
> process. I call System.exit(0), but I would like to stop all running
> processes first.
>
> The other thing that caused me some headache was the export disk file
> format. The old cache that wrote tile files to disk wrote *.png files. I
> tried different PNG writers, but my files were always about 8 times bigger.
> It took me some time to figure out that even JPEG files were written with
> the .png file name extension. Now I save the tiles as JPEG and everything is
> fine. Does the current cache have information about the original tile file
> (format, data)?
>
> Regards,
> Holger
>
>
> Am 12.12.2015 um 20:09 schrieb Wiktor Niesiobedzki:
>>
>> As for your problem - this is kind of the problem we face also writing
>> the unit tests. It is solved by calling:
>> org.openstreetmap.josm.JOSMFixture.createUnitTestFixture().init();
>>
>> Though keep in mind, that this is part of the testing code, so it's
>> located here:
>>
>> http://josm.openstreetmap.de/browser/josm/trunk/test/unit/org/openstreetmap/josm/JOSMFixture.java
>>
>> This should give you a hint, how to initiate "headless" mode.
>>
>> Cheers,
>> Wiktor
>>
>> 2015-12-12 18:52 GMT+01:00 Holger Mappt:
>>>
>>> My idea was to write a small program that calls TMSLayer.getCache() to
>>> get
>>> the TMS cache. But to do that I need to initialize JOSM (preferences, TMS
>>> layer, and tile cache). How would I do that? Is there something like a
>>> headless mode where I can hook into? I tried to call some of the
>>> initialization methods, but there are too many dependencies and I would
>>> need
>>> a running JOSM to make that work.