Geospatial context fusion display

[mtiessen1175]

Display georeferenced grids as context information in the image annotation tool of BIIGLE.

ToDo:

• [ ] implement mechanism to (optionally) display georeferenced grid as background in the image-display
• [ ] linking of image coordinates to the "background map"
  • compute the position of the current image in the (potentially warped) background map
  • transform annotations affected by distortion?

[mzur]

Here are my notes concerning this feature:

• The layers uploaded on the volume edit view (see #44) can also be enabled as "annotation context layer" which will be displayed in the (image) annotation tool
• Each layer can either be a "browsing layer" (#44) or a "context layer" or both
• If there is at least one context layer, it will be added as a background layer to the image annotation tool
• Add a settings option in annotation tool to disable context layers (default: enabled)
  • Or set the context layer opacity which can also be 0? Or maybe opaticy steps (0, 25%, 50%, 75%, 100%)?

Here is the catch: Images usually have only a point geolocation. The point can be placed on the context layer but the extent is unknown. The extent could be estimated from the image area (provided by metadata or laser point detection). There should also be a new option to upload the full image extent as metadata (also from iFDO). If neither the area nor the extent is there, the context layer is hidden (with a warning in the settings tab where the layer can be enabled/disabled).