new skull image and additional alternative text

geo_app.md

@@ -32,7 +32,9 @@ Our research into digital geometry and appearance is method oriented and applica
 [![3D Modelling in VR](images/VR_modelling.png)](video/VR_modelling.mp4) [![From microgeometry to optical properties describing appearance](images/optprops.svg)](https://people.compute.dtu.dk/jerf/cg-opt-props.html)
 
 ## Digital Twins
-![Oak tree reconstructed from LiDAR scan using skeletonization. Scan courtesy of Ebba Dellwik, DTU Wind](images/oak_27_4_2020_small.png) [![3D Scanned seal skull](images/seal_skull_small.png)](https://doi.org/10.2312/visgap.20211088) [![Comparing an object with its digital twin: photo, rendering](images/bunny_compare_small.png)](https://eco3d.compute.dtu.dk/pages/appearance#ao2020) 
+![A point cloud of the tree was acquired using LiDAR by Ebba Dellwik and colleagues from the Department of Wind and Energy Systems at DTU.
+The reconstruction is performed using our Local Separator method https://people.compute.dtu.dk/janba/LS_notebook/LS_project_page.html
+For the full procedure, please see upcoming chapter in https://link.springer.com/book/9789819907755](images/oak_27_4_2020_small.png) [![3D Scanned seal skull](images/seal_skull_colored.png)](https://doi.org/10.2312/visgap.20211088) [![Comparing an object with its digital twin: photo, rendering](images/bunny_compare_small.png)](https://eco3d.compute.dtu.dk/pages/appearance#ao2020) 
 
 - Acquisition of geometry and optical properties that describe object appearance.
 - Additive manufacturing and control of shape and appearance.