How to use the Editing Camera Model Options - PIX4Dmapper

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This article describes how to edit the camera model in the PIX4Dmapper database.

Image Properties Editor

To edit the camera model first go to the Image Properties Editor. This can be accessed by either:

  • On the main menu, Project > Image Properties Editor…
  • Clicking on the camera icon on the main menu.

    image_properties_editor.png

    Camera icon.

  • From the New Project wizard when creating a new project, the Image Properties window appears after loading the images.

After opening the Image Properties Editor click on Edit...

Image Properties Editor.

Methods to edit a camera model:

 
Note: If a different camera model than the one that was first assigned to the camera is chosen, a pop-up appears asking if you want to assign by default the currently selected camera model to the cameras with the same EXIF ID.

Edit Camera Model.

 
Important: The Camera Model field displays the EXIF ID for which the camera model will be edited.
 
Warning: When changing the camera parameters in Edit Camera Model, the focal length and sensor size ratio should be correct. Use the real focal length and sensor size of the camera. To find the real sensor size, ask the camera manufacturer or search here.

Selecting another camera model

In order to change the camera model to another existing camera model:

1. On the section Camera Model, click the Camera Model Name drop-down list.
2. Use the right scroll bar to navigate among the different camera models available and click the desired camera model.

Drop down menu.

3. On the section Camera Model Parameters, check the camera internal parameters set up for the selected camera. If the internal camera parameters do not match the camera used, edit the camera model following the instructions below.

 
Note: Only the camera models with the same resolution as the one detected for the camera are available.
 
Note:

database.png Refers to camera models existing in the software internal camera model database.

user.png Refers to a camera model existing in the user camera model database.

pencil.png Refers to a camera model existing in the software internal camera model database that has been edited by the user.

camera.png Refers to a camera model whose parameters have been retrieved from the EXIF data.

document.png Refers to a camera model taken from a project file.

Editing an existing camera model

 
Warning: If the camera model exists in the software database or was manually created, it is recommended to edit the camera model ONLY when:
  • A project has been processed and if the quality report displays under the Quality Check section, on Camera Optimization, a relative difference between initial and final focal length that is higher than 5%. This is indicated with a yellow check mark. In this event, change the camera initial values to the optimized values. For more information: How to change the Camera Initial Values to the Optimized Values
  • Or, when no project has been processed using this camera model but the values of the camera model differ considerably from the known values.

In order to modify an existing camera model:

1. Select the Camera Model to be edited following the instructions above.
2. On the section Camera Model, click Edit.
3. Select the lens type between Perspective Lens or Fisheye Lens.

Perspective or Fisheye lens option.

4. Edit the parameters by changing their values. The parameters can be reset by clicking Clear. If the images have sufficient information about the camera model in the EXIF data, the parameters can be estimated from the EXIF data by clicking Estimate from EXIF.
5. There are two options to save the edited information:

    • The camera model can be saved to the camera database by clicking Save to DB (the icon user.png will be displayed with the camera model name) and click OK.
    • Or the camera model can be used just for the project and not saved to the database. Simply click OK (the icon document.png will be displayed with the camera model name).
 
Note: If the radial and tangential distortion parameters for a perspective lens are not known, it is recommended to set them to 0.
Camera Model Name Field used to type the camera model name. It is recommended to type the name as follow: 

camera_name_focal_length_sensor_widthxsensor_height

Image Width [pixel] Image width in pixels.
Image Height [pixel] Image height in pixels.
Focal Length [pixel] Focal length in pixels (if defined in pixels, the mm value is automatically computed and added to the corresponding field).
Principal Point x [pixel] Principal point x coordinate in pixels (if defined in pixels, the mm value is automatically computed and added to the corresponding field).
Principal Point y [pixel] Principal point y coordinate in pixels (if defined in pixels, the mm value is automatically computed and added to the corresponding field).
Sensor Width [mm] Sensor width in mm.
Sensor Height [mm] Sensor height in mm.
Pixel Size [μm] Pixel size in μm.
Focal Length [mm] Focal length in mm (if defined in mm, the pixel value is automatically computed and added to the corresponding field).
Principal Point x [mm] Principal point x coordinate in mm (if defined in mm, the pixel value is automatically computed and added to the corresponding field).
Principal Point y [mm] Principal point y coordinate in mm (if defined in mm, the pixel value is automatically computed and added to the corresponding field).
Radial Distortion R1 Radial distortion R1 parameter of the lens (optional, it is recommended to leave the distortion parameters to 0).
Radial Distortion R2 Radial distortion R2 parameter of the lens (optional, it is recommended to leave the distortion parameters to 0).
Radial Distortion R3 Radial distortion R3 parameter of the lens (optional, it is recommended to leave the distortion parameters to 0).
Tangential Distortion T1 Tangential distortion T1 parameter of the lens (optional, it is recommended to leave the distortion parameters to 0).
Tangential Distortion T2 Tangential distortion T2 parameter of the lens (optional, it is recommended to leave the distortion parameters to 0).
 
Note: For detailed information about the internal Camera Model Parameters: How are the Internal and External Camera Parameters defined?.

Creating a new camera model

If the camera model has not been detected or the actual camera model does not meet the specifications of the camera, it is possible to create a new camera model following:

1. On the section Camera Model, click New.
2. Select the lens type between Persepective Lens or Fisheye Lens.
3. Edit the parameters by changing their values. The parameters can be reset by clicking Clear. If the images have enough information about the camera model in the EXIF data, the parameters can be estimated from the EXIF data clicking Estimate from EXIF.
4. There are two options to save the new camera:

    • The camera model can be saved to the camera database by clicking Save to DB (the icon user.png will be displayed with the camera model name) and click OK.
    • Or, the camera model can be used just for the project and not saved to the database. Simply click OK (the icon document.png will be displayed with the camera model name).
 
Note: If the radial and tangential distortion parameters for a perspective lens are not known, it is recommended to set them to 0.

 

Camera Model Name Field used to type the camera model name. It is recommended to type the name as following: 

camera_name_focal_length_sensor_widthxsensor_height

Image Width [pixel] Image width in pixels.
Image Height [pixel] Image height in pixels.
Focal Length [pixel] Focal length in pixels (if defined in pixels , the mm value is automatically computed and added to the corresponding field).
Principal Point x [pixel] Principal point x coordinate in pixels (if defined in pixels , the mm value is automatically computed and added to the corresponding field).
Principal Point y [pixel] Principal point y coordinate in pixels (if defined in pixels , the mm value is automatically computed and added to the corresponding field).
Sensor Width [mm] Sensor width in mm.
Sensor Height [mm] Sensor height in mm.
Pixel Size [μm] Pixel size in μm.
Focal Length [mm] Focal length in mm (if defined in mm, the pixel value is automatically computed and added to the corresponding field).
Principal Point x [mm] Principal point x coordinate in mm (if defined in mm, the pixel value is automatically computed and added to the corresponding field).
Principal Point y [mm] Principal point y coordinate in mm (if defined in mm, the pixel value is automatically computed and added to the corresponding field).
Radial Distortion R1 Radial distortion R1 parameter of the lens (optional, it is recommended to leave the distortion parameters to 0).
Radial Distortion R2 Radial distortion R2 parameter of the lens (optional, it is recommended to leave the distortion parameters to 0).
Radial Distortion R3 Radial distortion R3 parameter of the lens (optional, it is recommended to leave the distortion parameters to 0).
Tangential Distortion T1 Tangential distortion T1 parameter of the lens (optional, it is recommended to leave the distortion parameters to 0).
Tangential Distortion T2 Tangential distortion T2 parameter of the lens (optional, it is recommended to leave the distortion parameters to 0).
 
Note: For detailed information about the internal Camera Model Parameters: How are the Internal and External Camera Parameters defined?.

Resetting pencil.png an edited Camera model to database.pnga database Camera mode

If a camera model taken from the internal camera model database was modified , the change can be reverted following:

1. On the section Camera Model, click the Camera Model Name drop-down list.
2. Select the camera model that needs to be reset.
3. Click Restore.
4. Click OK.

 

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4 comments

  • Tess Trethewey

    my camera is Zenmuse xt 9mm 640x512. Pix4d recognizes it as FLIr_9.0_720x480. How can I force it to use the Exif ID FLIR_9.0_640x512. I've tried to keep this exif id but change the values in sensor width, pixel size, etc. But the results are off. also the camera model bands are set to RGB and when I try to edit to only have thermal I can't click OK. My results always form a 'banana shape', as Marc puts it, and the data is not aligned with RGB images I take at the same time. 

  • Ina (Pix4D)

    Hi Tess,

     

    To select the camera from the exif of the under the section  Selecting another camera model from a list of existing camera models among the camera model listed you will have the one that is associated with the EXIF. You can recognize it by the icon:  
    Otherwise under Camera Model Parameters >> Estimate from EXIF will populate the internal parameters fields with the values from the EXIF of your imagery.

    The bands are always read from the EXIF of your images. Most probably you are processing the jpeg imagery and not the r-jpeg or tiff grayscale. The following article may be useful: Processing thermal images.

    For the rest of the request, please submit a ticket via our request page so that we can further investigate. To fasten the investigation, please include the requested files: p4d file, log file, and quality report. 

    Thank you for your feedback on our article.

     

    Best,

    Ina

  • Hamza Hamza

    I am using videos from  GoPro Hero 7 black and can't extract the EXIF data. Can I use camera parameters extracted from images acquired using  the GoPro Hero 7 instead?

    Thank you. 

     

  • Holden (Pix4D)

    Hi Hamza. This will depend on whether the camera internals are the same. I'm not sure as to that point. If they are then the model should be acceptable. You can also generate a custom camera model by following the article linked below. 

    https://support.pix4d.com/hc/en-us/articles/202557009-How-to-calibrate-a-Fisheye-Lens-Camera

    I hope this helps. 

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