Tip 86: Reusing camera positions with replaced images

When two or more cameras, affixed in un-moving positions, are used in a project, the images taken by these cameras can be replaced in the project without having to re-orient them. Doing this can save time and effort for project setups or camera rigs that are reused repeatedly.

This procedure of swapping images on fixed cameras is useful for…

• setting up repeatable measurement projects using a fixed multi-camera rig as shown at right,
• doing comparisons between data sets while minimizing variables,
• measuring movement over time from a set of fixed cameras positions (e.g. security cameras), and
• creating multiple photo textures where lighting is variable.

These projects can be oriented with SmartMatch, Coded Targets or manually marked and referenced points. The first object of interest would then be modeled, and the results analyzed. Then the photos would be replaced with new ones showing a new object/scene, or with the object/scene in a new state.

To replace the photos, the “Replace photo (retain orientation)” hyperlink on the Photo Properties dialog is clicked for each photo and the new image taken by the appropriate camera is selected.

As soon as the photos have been replaced in the project, new points can be marked and referenced (or coded targets detected) on the new photos. The points appear in 3D and can be measured.  As well, the same process can be used to generate photo textures from a new set of photos (with different lighting for example).  The first project can be considered to be a ‘template’ for re-use with different images as needed.

Watch the YouTube video for an overview: