[Qgis-developer] Render miniature rasters?

[Martin Dobias]

Hi Magnus

On Wed, Jul 21, 2010 at 1:14 PM, Magnus Homann <magnus at homann.se> wrote:
> What does it take development-wise to accomplish what one can do in google
> maps, i.e showing as symbol a miniature of a raster (different per point).
>
> Like so:
>
> http://img7.imageshack.us/img7/1498/geosettergogle.jpg

You could achieve this by creating a custom renderer which would draw
thumbnails. The images would be rendered directly to the map.

Another option is to implement a custom map canvas item that will show
thumbnails on top of the map.

Each approach is better suited for a different scenario. If you want
to print such map, implement a renderer - map canvas items are not a
part of the print output. If you want just browse the images, map
canvas items are probably a better solution - for example, they could
be loaded and scaled in a worker thread, thus achieving a better user
experience.

You can check out the player plugin [1] from my former qgis-mapper
project - it uses canvas items to show thumbnails of geotagged images
along the track. It also supports grouping of images when there are
more of them close to each other.

[1] http://code.google.com/p/qgismapper/wiki/PlayerPlugin

Regards
Martin