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Trimming the DSM and Orthomosaic edges

When a project is finished the edges of the area mapped have very low overlap of images compared to average overlap of the project. This results in DSM and Orthomosaic with very bad quality and strange results around the edges. Does someone know how to trim the DSM and Orthomosaic to be able to only use areas further away from the edges where there is enough overlap of the images?

I would prefer to do this after all processing is done if that is possible.

Thanks in advance!

Hello Tryggvi,

It is possible to limit the low overlap areas that should not be included in the DSM and Orthomosaic generation, due to their low quality.
In order to do so, you can draw either a point cloud densification area or an orthomosaic area:

A point cloud densification area will exclude the low overlap areas both from step 2. Point Cloud Densification and step 3. DSM and Orthomosaic Generation.
An orthomosaic area will only exclude the low overlap areas from Step 3. DSM and orthomosaic generation.

You can draw a point cloud densification area before or after processing step 1. Intial Processing. In this case, the point cloud generated will be generated only for the area included in the point cloud densification area.
If the point cloud densification area is drawn after processing step 2. Point Cloud Desnification, then it will only affect the densified point cloud that is visualized in the 3D view of the rayCLoud, but the point cloud of the entire area will be generated and saved in the disc.

For step by step instructions on how to draw the point cloud densification area:
Before processing step 1: https://support.pix4d.com/hc/en-us/articles/202560179
After step 1 is done: https://support.pix4d.com/hc/en-us/articles/202560589

The orthomosaic area can be generated before processing or after processing step 3. DSM and Orthomosaic Generation.
If the orthomosaic area is generated before processing, then the DSM and Orthomosaic will be generated only for the area included in the orthomosaic area.
If the orthomosaic area is generated after processing, then the orthomosaic should be blended again in order to include only the area in the orthomosaic area.
For step by step instructions on how to raw the orthomosaic area: https://support.pix4d.com/hc/en-us/articles/202560209

Best regards,

Great thank you this is exactly what I was looking for!

Hello, the Link to draw the orthomosaic area doesn’t work anymore. Could you supply me with a working one please?

Hi Daniel, 

The orthomosaic area has been replaced by the Processing Area. The following article from our Knowledge Base describes how to use it: https://support.pix4d.com/hc/en-us/articles/202560179

Here is an excerpt from the article:

  • The Processing Area affects only the visualization of the Automatic Tie Points in the 3D View of the rayCloud. It does not affect the results of step 1. Initial Processing.
  • When the Processing Area is defined before step 2. Point Cloud and Mesh  is processed, it affects the Point Cloud visualized in the 3D View of the rayCloud and the results saved on disk. This Processing Area will also affect the results of step 3. DSM, Orthomosaic and Index. 
  • When the Processing Area is defined after step 2. Point Cloud and Mesh  is completed, it only affects the Point Cloud visualized in the 3D View of the rayCloud but not the results saved on disk. This Processing Area will also affect the results of step 3. DSM, Orthomosaic and Index. 
  • When the Processing Area is defined before step 3. DSM, Orthomosaic and Index is completed, only the results of step 3 will be affected.