[Interest] Qt Location GeoServices plugin to use geo-referenced image file as map source

[Richard Lang]

Concluded that this wouldn't be the greatest idea as the implementation 
would be less than straightforward, and in practice any non-trivial map 
image would likely be large enough that an initial tiling step, followed 
by use of one of the standard tiled mapping plugins referencing a local 
tile set would be more appropriate anyway.

Refer 
https://stackoverflow.com/questions/47670504/writing-a-custom-qt-location-geoservices-plugin-to-use-geo-referenced-image-file

On 08/12/17 02:12, Paolo Angelelli wrote:
> Indeed! As answered in the bug report, the easy workaround is to cut your tif into tiles
> (like using QGis w QTiler plugin or gdal2tiles, or whatever other mean), and then you
> don't even need to serve the tiles via http, you can fetch them locally either from file
> (file:///) or qrc, depending on how it's best for you to ship them.
>
> On Thu, 7 Dec 2017 13:24:20 +0100
> Vlad Stelmahovsky <vladstelmahovsky at gmail.com> wrote:
>
>> Hi
>>
>> take a look at OSM plugin. it contains custom providers and caching
>> mechanism
>>
>> On Thu, Dec 7, 2017 at 3:19 AM, Richard Lang <richard at satco.co.nz> wrote:
>>
>>> Repost of question asked on Qt Forums and raised as a feature request on
>>> the bug tracker...
>>>
>>> https://forum.qt.io/topic/85704/qt-location-geoservices-
>>> plugin-to-use-geo-referenced-image-file-as-map-source
>>>
>>> https://bugreports.qt.io/browse/QTBUG-65018?jql=project%20%3D%20QTBUG
>>>
>>> ============================================================
>>>
>>>
>>> I'm currently working on a Qt Quick application that will provide a map
>>> viewer for a smallish area (1 square KM or so), the map details for which
>>> will be provided in a single geo-referenced image file (GeoTIFF,
>>> geo-referenced PDF, ESRI Shape file etc.), along with display of current
>>> location, operator identified points of interest etc. It's primarily
>>> responsibility is the display of custom maps (as opposed to generic maps
>>> retrieved from public map image service providers (OSM, MabBox, ESRI etc)),
>>> and it will often be used in areas with limited connectivity
>>>
>>> An extensive web search has identified others who have made similar
>>> enquiries in the past (in these forums, Stack Overflow etc), and the
>>> general suggestions for solutions are as follows:
>>>
>>>     - ArcGIS Runtime with Qt SDK *Doesn't work for me as down the track
>>>     I'm intending to target an embedded linux device using an ARM processor,
>>>     and ArcGIS doesn't make source available for cross-compilation for
>>>     arbitrary targets. They've recently produced an Android release, but
>>>     nothing for ARM linux in general)*
>>>     - QGIS developer libraries *GPL licence not compatible with my
>>>     commercial development*
>>>     - Use the Qt Location *Map* component with a local tile server or
>>>     offline tile collection,alongside a local tiling engine to create the
>>>     necessary tile set from the input image file.  *Seems a bit of a hack,
>>>     as noted I'm primarily using custom maps, as opposed to offline copies of
>>>     public map server images, and my images won't be big enough to otherwise
>>>     warrant tiling anyway*
>>>
>>> It would be feasible to develop a Qt Quick component from scratch to do
>>> this, but given that the existing Qt Location *Map* component provides a
>>> well defined pre-existing front end interface for everything my map would
>>> need to do and has an extendable plugin based architecture, writing a
>>> custom Qt Location GeoServices plugin seems the most sensible and elegant
>>> way forward.
>>>
>>> I've started examining the source code of the existing plugins, but can't
>>> shake the feeling that in a world containing 8 billion people, with
>>> "nothing new under the sun", this would have been done already if it was a
>>> good idea....
>>>
>>> Would anyone with more familiarity with the Qt Location module care to
>>> comment?
>>>
>>>
>>> thanks
>>>
>>> Richard
>>>
>>>
>>>
>>>
>>>
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>>> Interest at qt-project.org
>>> http://lists.qt-project.org/mailman/listinfo/interest
>>>
>>>   
>>