Some uncalibrated images - PIX4Dmapper

Issue

On the Quality Check in the Quality report, it is displayed that there are some uncalibrated cameras after performing step 1 of processing with PIX4Dmapper.

Description

When groups or individual cameras cannot calibrate, this can result in missing areas of the model and areas with lower accuracy.

Indicators:

Causes

Several causes can lead to this issue:

1. A dataset with low overlap or images not taken in a systematic way. Overlap can be assessed in figure 4 and figure 5 of the Quality Report.
2. Repetitive or complex dataset (trees, forest, fields).
3. Dataset made from multiple flights with images not similar enough (different time of capture, moving objects, different temperature, different lens).
4. Images containing reflective areas (water, windows) that cannot be calibrated.
5. Image quality is not sufficient.

Solutions

Possible solutions to the previously listed causes are proposed below.

For cause 1:

• Increase the overlap. For more information about the flight plan: Step 1. Before Starting a Project> 1. Designing the Image Acquisition Plan> a. Selecting the Image Acquisition Plan Type.

For cause 2:

• Process with lower Keypoints Image Scale: This processing option can lead to a higher number of calibrated images than the default original keypoint image scale. For more information: Menu Process> Processing Options... > 1. Initial Processing> General.
• Increase overlap ( > 80%).
• Flying at a higher altitude. This tends to improve results in forests and dense vegetation environments. For more information about the flight plan: Step 1. Before Starting a Project> 1. Designing the Image Acquisition Plan> a. Selecting the Image Acquisition Plan Type.

For cause 3:

• Process each flight individually and combine the projects together in a second step. For more information about how to merge projects: Merging projects.

For cause 4:

• Take images that contain some unreflective areas (e.g. 30% of the land minimum).

For cause 5:

• Camera parameters need to be adjusted (shutter speed, exposure time). For more information about the camera settings: Step 1. Before Starting a Project> 2. Configuring the Camera Settings.