eCapture eyesmap, User Manual

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7 Practical cases
User Manual 168
7.4. Orthophoto
To generate a true orthophoto of a scene, you should choose the orthophoto module
from the main EyesMap menu. This module uses different images of the object / scan
to create, with photogrammetric methods, a true orthophoto. It is important to take into
account the considerations which are explained in the manual before trying to create
an orthophoto of any object. In general terms, it is important to note that not all objects
are good for making an orthophoto and the success of said action depends on:
In order to create an orthophoto, you must go through the following steps:
7.4.1.1. Photograph Capture and Management
In all photogrammetric captures, the following considerations should be taken into
account:

Take clear photos, try not to move while you are capturing. Avoid the sun facing
you. Capture the entire object to be measured, try to place said object in the
centre of the image.

Take different shots from the left to the right of the object, from the right to the
left, from the top to the bottom or from the bottom to the top. Try to have
displacement between the shots (never take two shots from the same position).

The overlapping area between the two images should be 80%. If this
overlapping can get to be almost 100%, it would be better for improved
orientation.

Not all objects are good for photogrammetry: for example, areas with a very
homogeneous texture like walls painted a single colour, plastic or glass objects
or water are not good for photogrammetry as the system has trouble finding
common points in the images due to reflection.
Whenever possible, we recommend taking photographs as perpendicularly to the
object as possible.
Incorrect Correct