Quality report - PIX4Dmatic

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PIX4Dmatic generates a quality report that can be used to get an overview of the project and assess its accuracy and quality.

The following is available:

  • General report is generated after running the Calibrate or Reoptimize step:
    • Click the Report Pix4Dmatic report panel.png panel.
      Pix4Dmatic quality report.png

      Report panel view.

  • Detailed quality report (.pdf). To export the detailed quality report:
    • In the Report panel, Click export Button.png
    • In the Processing options panel, check Exports - Quality report.
    • On the Menu bar > File, click Export quality report...

 
Note: Available only with PIX4Dcatch projects that contain LiDAR depth maps.
 
Important: The Quality report as .pdf is not available on macOS.

The following table describes the content of the quality report:

Quality Report Header

Header
Date The date the project was processed.
Project name The name of the project.
Version The version of the software used to process the project.
Project details
Cameras The name of the camera model(s) used to capture the images.
Average GSD The average GSD of the initial images. For more information: Ground sampling distance (GSD).
Project CRS (coordinate reference system)

The horizontal and vertical coordinate system used for processing.

When the vertical coordinate reference system is not specified, the base ellipsoid of the horizontal coordinate is used. 

Quality check
Matches

The median of matches per calibrated image.

green circle successful process Keypoints Image Scale > 1/4: More than 1'000 matches have been computed per calibrated image.
Keypoints Image Scale ≤ 1/4: More than 100 matches have been computed per calibrated image.

yellow triangle Keypoints Image Scale > 1/4: Between 100 and 1'000 matches have been computed per calibrated image.
Keypoints Image Scale ≤ 1/4: Between 50 and 100 matches have been computed per calibrated image.

error quality report red circle Keypoints Image Scale > 1/4: Less than 100 matches have been computed per calibrated image.
Keypoints Image Scale ≤ 1/4: Less than 50 matches have been computed per calibrated image.

Dataset

The percentage of images that have been calibrated as well as the number of images that have been used for the reconstruction of the model with respect to the total number of the images in the project.

green circle successful process More than 95% of enabled images are calibrated in one block.

yellow triangle Between 60% and 95% of enabled images are calibrated, or more than 95% of enabled images are calibrated in multiple block.

error_quality_report.png Less than 60% of enabled images are calibrated.

Camera optimization The percentage of the difference between initial and optimized focal length of the camera.

green circle successful process The percentage of difference between initial and optimized focal length is less than 5%.

yellow triangle The percentage of difference between initial and optimized focal length is between 5% and 20%.

error_quality_report.png The percentage of difference between initial and optimized focal length is more than 20%.

GCPs (optional) Displays the number of imported GCPs, the Mean RMS position error of the marked GCPs and their Sigma value.

green circle successful process The GCP Mean RMS position error is less than 2 times the average GSD.

yellow triangle The GCP Mean RMS position error is more than 2 times the average GSD.

error_quality_report.png The GCP Mean RMS position error is more than 4 times the average GSD.

Checkpoints (optional) Displays the number of added Checkpoints, the Mean RMS position error of the marked Checkpoints and their Sigma value.

green circle successful process The Checkpoint Mean RMS position error is less than 2 times the average GSD.

yellow triangle The Checkpoint Mean RMS position error is more than 2 times the average GSD.

error_quality_report.png The Checkpoint Mean RMS position error is more than 4 times the average GSD.

MTPs (optional) Displays the number of the added MTPs, the Mean RMS position error of the marked MTPs and their Sigma value.

green circle successful process The MTP Mean RMS reprojection error is less than 2 times the average GSD.

yellow triangle The MTP Mean RMS reprojection error is more than 2 times the average GSD.

error_quality_report.png The MTP Mean RMS reprojection error is more than 4 times the average GSD.

 

Camera Positions

Internal Camera Parameters
Camera model name + Sensor dimensions The camera model name is also displayed as well as the sensor dimensions.
Initial The initial values of the camera model.
Optimized The optimized values that are computed from the camera calibration and are used for processing.
Uncertainties (Sigma) The sigma of the uncertainties of the focal length, the Principal Point X, the Principal Point Y, the Radial Distortions R1, R2 and the Tangential Distortions T1, T2.
Focal length The focal length of the camera in pixels and in millimeters. If the sensor size is the real one, then the focal length should be the real one.
Principal point x The x image coordinate of the principal point in pixels and in millimeters. The principal point is located around the center of the image. The coordinate system has its origin as displayed here:

principal point X

Principal point y The y image coordinate of the principal point in pixels and in millimeters. The principal point is located around the center of the image. The coordinate system has its origin as displayed here:

principal_point_X.png

R1 Radial distortion of the lens R1.
R2 Radial distortion of the lens R2.
R3 Radial distortion of the lens R3.
T1 Tangential distortion of the lens T1.
T2 Tangential distortion of the lens T2.

 

Tie points

1. Ground control points (GCPs)
Label The name of the GCP.
Position error - X[m or ft] The difference between the computed and the initial position of the ground control point in the X-axis, i.e., initial position - computed position.
Position error - Y[m or ft] The difference between the computed and the initial position of the ground control point in the Y-axis, i.e., initial position - computed position.
Position error - Z[m or ft] The difference between the computed and the initial position of the ground control point in the Z-axis, i.e., initial position - computed position.
Reprojection
error [px]
The average distance in the images where the GCP has been marked and where it has been re-projected.
Accuracy - X/Y [m or ft] The Accuracy X/Y of the GCP that has been given in this project in XY direction.
Accuracy - Z [m or ft] The Accuracy Z of the GCP that has been given in this project in Z direction.
Verified/Marked Verified: The number of images on which the GCP has been marked and are taken into account for the reconstruction.
Marked: The images on which the GCP has been marked.
Mean The mean / average position error in each direction (X,Y,Z). For more information: How are the GCP Errors defined in the Quality Report?.
Min The minimum error across all GCPs in each direction (X,Y,Z) individually.
Max The maximum error across all GCPs in each direction (X,Y,Z) individually.
RMS The Root Mean Square error in each direction (X,Y,Z). For more information: How are the GCP Errors defined in the Quality Report?.
Sigma The standard deviation of the error in each direction (X,Y,Z). For more information: How are the GCP Errors defined in the Quality Report?.
2. Checkpoints (CPs)
Label The name of the checkpoint.
Position error - X[m or ft] The difference between the computed checkpoint and the original position in X direction (original position - computed position).
Position error - Y[m or ft] The difference between the computed checkpoint and the original position in Y direction (original position - computed position).
Position error - Z[m or ft] The difference between the computed checkpoint and the original position in Z direction (original position - computed position).
Reprojection
error [px]
The average distance in the images where the checkpoint has been marked and where it has been re-projected.
Accuracy - X/Y [m or ft] The Accuracy X/Y of the checkpoint that has been given in this project in XY direction.
Accuracy - Z [m or ft] The Accuracy Z of the checkpoint that has been given in this project in Z direction.
Verified/Marked Verified: The number of images on which the checkpoint has been marked and are taken into account for the reconstruction.
Marked: The images on which the checkpoint has been marked.
Mean The mean / average position error in each direction (X,Y,Z). For more information: How are the GCP Errors defined in the Quality Report?.
Min The minimum error across all checkpoints in each direction (X,Y,Z) individually.
Max The maximum error across all checkpoints in each direction (X,Y,Z) individually.
RMS The Root Mean Square error in each direction (X,Y,Z). For more information: How are the GCP Errors defined in the Quality Report?.
Sigma The standard deviation of the error in each direction (X,Y,Z). For more information: How are the GCP Errors defined in the Quality Report?.
3. Manual tie points (MTPs)
Label The name of the MTP.
Reprojection
error [px]
The average distance in the images where the MTP has been marked and where it has been re-projected.
Verified/Marked Verified: The number of images on which the MTP has been marked and are taken into account for the reconstruction.
Marked: The images on which the MTP has been marked.

 

Hardware & settings

System information
Hardware CPU, RAM, and GPU used for processing.
Operating system Operating System used for processing.
Coordinate reference systems
Image coordinate reference system(s) Coordinate system of the image geolocation.
Ground control point (GCP) coordinate reference system Coordinate system of the GCPs, if GCPs are used.
Project coordinate reference system Output coordinate system of the project.

 

Processing settings

Calibration
Pipeline

It shows the pipeline that can be selected according to the dataset used for processing:

  • Scalable standard: Sequential pipeline that enhances image calibration for large datasets and fast processing.
  • Standard: Similar to Scalable Standard, but more robust. It requires more processing time, and uses more PC resources.
  • Low texture planar: Intended for aerial nadir images with accurate geolocation and homogeneous or repetitive content of relatively flat terrain.
  • Trusted location and orientation: Intended for projects with accurate relative location and IMU data; for example, images taken with PIX4Dcatch in an indoor or outdoor setting or images from RTK or PPK drones or devices. All images must include information about the camera's initial position and orientation.

For more information see Calibrate - PIX4Dmatic.

Template

It shows the template that can be selected according to the dataset imported for processing:

  • Large scale and corridor: Utilizes the Scalable standard pipeline to generate 2D and 3D reconstructions of an area of interest.
  • Map: Utilizes the Standard pipeline to generate 2D and 3D reconstructions of a relatively large area of interest, requiring more processing time.
  • Model: Utilizes the Standard pipeline to generate 3D reconstructions of an object of interest with images captured around the object of interest.
  • Flat scene and low texture: Utilizes the Low texture planar pipeline to generate 2D and 3D reconstructions of an area of interest that contains relatively homogenous textures and relatively flat terrain, like an agricultural field.
  • PIX4Dcatch: Utilizes the Trusted location and orientation pipeline to generate reconstructions or an area or object of interest with images captured with PIX4Dcatch or images from RTK or PPK drones or devices.

For more information see Calibrate - PIX4Dmatic.

Internals confidence
  • Low: Optimizes all the internal camera parameters.
  • High: Forces the internal parameters to be close to the initial values.

For more information see Processing options - Internals confidence.

Image scale The value of the image scale used for keypoints extraction.
  • 1: Original image size.
  • 1/2: Half image size.
  • 1/4: Quarter image size.
  • 1/8: Eighth image size.

For more information, see Processing options - Image Scale.

Max extracted keypoints
  • AutomaticKeypoints parameter set to Auto.
  • Value: The value of Keypoints > Custom parameter set for processing.

For more information, see Processing options - Keypoints.

Reoptimized
  • Yes - Reoptimize cameras option was enabled.
  • No - Reoptimize cameras option was disabled.

For more information, see Processing options - Reoptimize cameras.

Use depth maps*

When enabled the depth maps generated with PIX4Dcatch are used for better calibration:

  • Enabled.
  • Disabled.

For more information, see Processing options - Use depth maps (Optional).

Duration The time needed for processing the Calibrate step.

When Reoptimize cameras option is used, the time corresponds only to the Reoptimize camera pipeline and not to the whole Calibrate step.

Depth*
Duration The time needed for processing the Depth step.
Densification
Noise filter
  • Enabled.
  • Disabled.

For more information, see Processing options - Noise filter.

Image scale
  • Image Scale defines the scale of the images at which additional 3D points are computed.
  • Disabled.

For more information, see Processing options - Image scale.

Min number of matches Minimum Number of Matches (2-6, 3 default) represents the minimum number of valid re-projections of this 3D point to the images.

For more information, see Processing options - Minumum matches.

Multiscale
  • Enabled.
  • Disabled.

For more information, see Processing options - Multiscale.

Density Defines the density of the point cloud:
  • Optimal (default): A 3D point is computed for every 8th pixel of the original image. 
  • High: A 3D point is computed for every 2nd pixel of the original image.
  • Low: A 3D point is computed for every 32rd pixel of the original image. The final point cloud is computed up to 4 times faster and uses up to 4 times less RAM than Optimal density.

For more information, see Processing options - Density.

Sky filter
  • Enabled.
  • Disabled.

For more information, see Processing options - Sky filter.

Duration The time needed for processing the Densify step.
Depth and dense*
Distance

The minimum distance [units] from a depth point to the dense point cloud for fusing it.

For more information, see Processing options - Depth and dense.

Duration The time needed for processing the Depth & dense fusion step.
Mesh
Decimation
  • Limit triangle count.
Deghosting

This option can be used for soft or aggressive outlier detection. It can be useful for complex geometries during mesh creation:

  • Weak (default)
  • Strong

For more information, see Processing options - Deghosting

Input point cloud*

It defines which point cloud is selected as the input point cloud for the Mesh generation:

  • Dense
  • Depth
  • Depth & dense fusion

For more information, see Processing options - Input point cloud

Maximum triangle count

The maximum number of triangles in the final Mesh, by default 1.000.000 triangles.

For more information, see Processing options - Decimation.

Template

It shows the template that can be selected according to the different types of datasets imported for processing:

  • Aerial: For scenes with larger extent. Typically drone flight size projects.
  • PIX4Dcatch: For projects with limited extent. Typically hand-held captures with PIX4DCatch.
  • Thin structures: For projects that include thin structures, i.e., cables, powerline tower structures, antennas.

For more information, see Processing options - Template.

Sky mask
  • Enabled.
  • Disabled.

For more information, see Processing options - Sky mask.

Texture size

Texture Size (1024x1024 - 32768x32768 pixels, default 8192x8192 pixels).

For more information, see Processing options - Texture size

Duration The time needed for processing the Mesh step.
Digital Surface Model (DSM)
Input point cloud*

This processing option defines which point cloud is used for the DSM generation:

  • Dense point cloud.
  • Depth point cloud
  • Depth & dense fusion.
Interpolation The Interpolation parameters affect the completeness of the generated DSM:
  • Enabled (default), the entire area of the DSM is filled.
  • Disabled, only areas where the dense point cloud is generated are reconstructed in the DSM model. 

For more information, see Processing options - Interpolation.

Surface smoothing The radius of the median filter used for surface smoothing of the DSM (0 - 5, 2 - default).

For more information, see Processing options - Surface smoothing.

Resolution The resolution used to generate the DSM. If the mean GSD computed at the Calibrate step is used, its value is displayed.
Duration The time needed for processing the Digital Surface Model (DSM) step.
Orthomosaic
Algorithm

It defines the orthomosaic creation algorithms:

  • Standard (default): The orthomosaic is created using the standard algorithm.
  • Hardware accelerated: The orthomosaic is created using a GPU-capable algorithm. This option contributes to reduced processing time.

For more information, see Processing options - Algorithm.

Oblique

This option improves the orthomosaic for oblique projects:

  • Disabled (default)
  • Enabled.

For more information, see Processing options - Oblique.

Deghosting

This option removes objects that move during the flight when generating the orthomosaic:

  • Disabled (default).
  • Enabled.

For more information, see Processing options - Deghosting.

Resolution The resolution used to generate the Orthomosaic. If the mean GSD computed at the Calibrate step is used, its value is displayed.
Duration The time needed for processing the Orthomosaic step.
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