It is possible to process step 3. DSM, Orthomosaic and Index without processing step 2. Point Cloud and Mesh but it is not recommended as lower quality DSM and orthomosaic will be generated.
The orthomosaic is generated using the 2.5D DSM. The DSM is generated using the densified 3D point cloud generated from step 2. If step 2 is skipped, the DSM will be based on the automatic tie points generated at step 1. Initial Processing. The automatic tie points have much less information than the densified point cloud. The densified point cloud has more points and therefore produces more accurate and complete results.
Step 2 can be skipped in the following cases:
- Lower accuracy results are acceptable.
- The area to be mapped is totally flat. Even in this case, lower accuracy results should be expected.
Important: Pix4D uses Orthorectification for generating the orthomosaic instead of Photo Stitching: Photo stitching vs orthomosaic generation. The orthomosaic is generated using the:
- 2.5D DSM.
- Original images.
Note: The orthomosaic corrects the:
- Perspective of the camera.
- Different scale based on the distance that each point of the object / ground has from the camera.
Very important information. I thought there wasn't any difference,
Thanks for this.