Why does my Orthomosaic have holes?

Problem:

When previewing my orthomosaic in the color points mode, or looking at the final orthomosaic there are holes.

Probable Resolution #1:

Holes can occur if one or more sides of the triangles formed from the triangulation of the loaded points exceeds the Max ground triangle setting. Increase the value to allow the triangulation to stretch across the voids. In preview mode this is done on the Color Point Settings dialog when starting Color Points.

TPhoto – Color Point Settings

For the final orthomosaic, modify the TerraPhoto -> Settings -> Laser Points -> Ground Model Triangles -> Max Length before rectifying the mosaic.

Probable Resolution #2:

Terrain with steep relief, such as mountainous terrain, can cause the edges of the imagery to move inward by great distances thereby creating holes between images due to not enough overlap of the images that cover the area.

Probable Resolution #3:

For final orthomosaics, ensure the Ground Model -> Search Points setting in the Rectify Mosaic dialog is large enough to span voids, such as waterbodies, in a dataset such that ground points on the other side of the void may be found and a TIN formed to cover the hole. No ground model in a location means a hole in your resulting orthomosaic.

Share

GeoCue Group Support

GeoCue Group Support has written 804 articles

3 thoughts on “Why does my Orthomosaic have holes?

  1. Avatar Saxon says:

    I have large lake areas which have provided no lidar returns. I have used Photo settings > laser points>ground model triangles set to 50000m which should be about 4 times the maximum length of the triangle but there are still holes in the ortho. When changing settings in photo settings do I need to
    a) close and reload terraphoto for the changes to take place
    b) also change the max triangle in Colour Points window even though I am not using colour points in this job.
    Thanks

    1. Settings for the Terrasolid products are saved when the settings dialog is closed. No need to close or reload the module for them to take effect. The settings for the color points window only affect the display when in Color Points mode.The max triangle size affects the triangles that are formed form the ground points. We’ve updated the post above with probable resolution #3, which may be the reason behind your holes.

Leave a Reply