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How to process Images with different Spectral Signature (RGB, NIRGB, etc) - PIX4Dmapper

Processing images with different spectral signature (RGB, NIRGB, etc) in one project can be useful, for example, in the following cases:

  • Generating different orthomosaics (one orthomosaic per dataset) that are perfectly overlaid because they are generated from the same DSM.
  • When processing different types of imagery together, all input bands contribute with a specific weight to the keypoint extraction. Thus more 3D points can be extracted than when processing each dataset separately. This leads to a more precise DSM, in turn leading to better orthomosaics.

Warning:

To process images with different band configurations (RGB, NIRGB, etc) verify that:

If the resolutions of the two cameras are significantly different:

  • Calibration of the images in Step 1. Initial Processing will be improved if the processing options are adapted to each set of images. For this the following merging procedure is recommended: Merging projects.

Band configuration - Grouped Images

Pix4Dmapper reads the EXIF data from the images in order to retrieve an EXIF ID that is used to associate each image to a camera model from Pix4Dmapper's database. The following cases can be encountered:

Note: If you don't know which case corresponds to your project:

1. Create a new project.
2. In the New Project Wizard, add all the images.
3. In the New Project Wizard, in the Image Properties window, verify how many camera models are detected.
4. In the New Project Wizard, in the Image Properties window, examine the band configuration for each camera model: it is written next to the camera model under the section Selected Camera Model (for example: CanonPowerShotG12_6.1_3648x2736 (RGB)).

For step by step instructions about how to create a new project: Step 2. Creating a Project.

Images with different EXIF ID detected with correct band information

1. Create a new project. For step by step instructions about how to create a new project: Step 2. Creating a Project.
2. In the New Project Wizard, add all the images. Images with different EXIF ID that are associated to different camera models with the correct band information are already grouped correctly.
3. Process the project. For more information about how to process a project: Step 4. Processing.

Example: 2 datasets, one RGB and one NIRGB, taken by 2 cameras whose EXIF IDs exist in Pix4Dmapper's camera model database. The first camera model exists in the database as a camera model with RGB band configuration, and the second camera model as a camera model with NIRGB band configuration.

Images with different EXIF ID detected with incorrect band information

1. In this case, in order to group the images correctly and to set the correct band configuration, follow: How to merge Images with different Spectral Signatures (RGB, NIRGB, etc).

Example: 2 datasets, one RGB and one NIRGB, taken by 2 cameras whose EXIF IDs exist in Pix4Dmapper's camera model database. Both camera models exist in the database as camera models with an RGB band configuration. This can happen when modifying an RGB camera by changing filters so that it can capture NIRGB instead of RGB.

Images with the same EXIF ID detected with incorrect band information

1. In this case, in order to group the images correctly and to set the correct band configuration, follow: How to merge Images with different Spectral Signatures (RGB, NIRGB, etc).

Example: 2 datasets, one RGB and one NIRGB dataset, taken by the same camera whose EXIF ID exists in Pix4Dmapper's camera model database. The camera model exists in the database as a camera model with RGB band configuration. This can happen when modifying an RGB camera by changing filters so that it can capture NIRGB instead of RGB.