Defining Collection Properties with collectionProperties.xml

You can define collection properties and override those included in the metadata (e.g., Exif) encoded in photo files by creating a file named collectionProperties.xml with the required collection properties. This saves you the trouble of creating a full Excel or XML file that contains a list of all the photos. The collectionProperties.xml file is commonly used to add band information, focal length, or other collection level properties. Each collectionProperties.xml file can only contain data for a single collection, so a separate file must be created for each collection for which you want to provide supplementary information and placed in the corresponding collection folder.

There are several mandatory properties in the collectionProperties.xml file. If you want to use the values in the metadata encoded in the photo files, for these properties, set the required property in the collectionProperties.xml file equal to 0, e.g., "Width = 0".

A sample collectionProperties.xml follows below. Property descriptions are in the comments <! ….>.

<?xml version="1.0" encoding="UTF-8"?>

<!—Coordinate system definition à

<SpatialReferenceSystems>
    <SRS>
      <Id>0</Id>
      <Name>WGS 84</Name>
      <Definition>GEOGCS["WGS 84",
    DATUM["WGS_1984",
        SPHEROID["WGS 84",6378137,298.257223563,
            AUTHORITY["EPSG","7030"]],
        AUTHORITY["EPSG","6326"]],
    PRIMEM["Greenwich",0,
        AUTHORITY["EPSG","8901"]],
    UNIT["degree",0.0174532925199433,
        AUTHORITY["EPSG","9122"]],
    AUTHORITY["EPSG","4326"]]</Definition>
    </SRS>
</SpatialReferenceSystems>

<!–Block definition à

<Block>

<Photogroups>–-- A photogroup is a homogeneous group of photographs, all taken by the same physical camera with identical focal length and principal point.-->

<Photogroup>–-- Name of the photogroup -->

–-- (Mandatory) Width and height of the photos, in pixels. If you do not want the collectionProperties.xml to override the width or height information in the metadata encoded in the photo files, set their values equal to 0. -->

</ImageDimensions>

–-- (Optional) Weight to assign to the photos' provided accuracy values. See "Collection Property Sheet" in the "Photo Management" chapter for information.-->

–-- (Optional) Weight to assign to the photos’ provided XY coordinates in determining the calculated XY values. This ranges from 0-100, where 100 is Very High - External AT and 0 is Unreliable.-->

–-- (Optional) Weight to assign to the photos’ provided altitude in determining the calculated altitude value. This ranges from 0-100, where 100 is Very High - External AT and 0 is Unreliable.-->

–-- (Optional) A percentage that indicates the allowable deviation from the provided focal length value when calculating the AT. This represents the accuracy of the provided focal length. This ranges from 0-100, where 0 is Use Input Value and 100 is Unreliable.->

–-- (Optional) A percentage that indicates the allowable deviation from the provided principal point when calculating the AT. This represents the accuracy of the provided principal point. This ranges from 0-100, where 0 is Use Input Value and 100 is Unreliable.-->

–-- (Optional) Radial accuracy. It is generally recommended to enter a value of 1 for the "Standard" option. If your data was captured with a professional camera that automatically applied a radial distortion correction (i.e., the original distortion value is extremely accurate), enter 0 for "Use input value". -->

–-- (Optional) Tangential accuracy. It is generally recommended to enter a value of 1 for the "Standard" option. If your data was captured with a professional camera that automatically applied a radial distortion correction (i.e., the original distortion value is extremely accurate), enter 0 for "Use input value". -->

–-- (Optional) Enter a value of 1 to ignore the provided orientation value. -->

</Accuracy>

–-- Optional Parameters. Don’t include if you do not want the collectionProperties.xml to override the information in the metadata encoded in the photo files. -->

–-- (Optional) Bands in comma delimited string format, e.g., (Red,Green,Blue,NIR). Possible values are: Grayscale, Red, Green, Blue, NIR, InfraRed, RedEdge, Alpha, Pan, SWIR_1, SWIR_2, TIR_1, TIR_2, Costal, Custom_0, Custom_1, Custom_2, Custom_3, Custom_4, Custom_5, Custom_6, Custom_7, Custom_8, Custom_9, Exclude (This band will be ignored.) -->

<Bands>Red,Green,Custom_1</Bands>

–-- (Optional) Focal length in millimeters. -->

–-- (Optional) Size of a physical pixel on the camera sensor in millimeters. -->

<!— (Mandatory) Origin and units of the principal point. The possible values are: topleftpixels topleftmm centerpixels centermm. Use "centermm" if you don't have this information. -->

<PrincipalPointReferenceMethod>centerpixels</PrincipalPointReferenceMethod>

<!— (Optional) PrincipalPoint x and y values, in the units set by PrincipalPointReferenceMethod. -->

</PrincipalPoint>

<!—Use yaw, pitch, roll values for orientation -->

</UseYPR>

–-- (Optional) Offset along the Phi axis in degrees.-->

–-- (Optional) Offset along the Kappa axis in degrees.-->

–-- (Optional) Offset along the Omega axis in degrees. -->

–-- (Optional) Offset from the current altitude value in the coordinate system units. If Lat-Long, use meters. -->

–-- (Optional) Flips the Phi axis.-->

<FlipPhi>false</FlipPhi>

–-- (Optional) Flips the Kappa axis.-->

<FlipKappa>false</FlipKappa>

–-- (Optional) Flips the Omega axis.-->

<FlipOmega>false</FlipOmega>

–-- (Optional) Boolean that determines whether to include this collection in the point cloud.-->

<UseInDpc>false</UseInDpc>

–-- (Optional) Boolean that determines whether to include this collection in the textured model.-->

–-- (Optional) Boolean that determines whether to include this collection in the orthophoto. -->

–-- (Optional) Radial and tangential distortion coefficients calculated using the Brown-Conrady model. See here for more information. -->

–-- (Optional) Defines the 1^st radial distortion coefficient. -->

–-- (Optional) Defines the 2nd radial distortion coefficient. -->

–-- (Optional) Defines the 3rd radial distortion coefficient. -->

–-- (Optional) Defines the 1st tangential distortion coefficient. -->

–-- (Optional) Defines the 2nd tangential distortion coefficient. -->

</Distortion>

</Photogroup>

</Photogroups>

</Block>

</BlocksExchange>

To define collection properties using a collectionProperties.xml file:

1. Place the collectionProperties.xml file in the corresponding collection folder.

2. Load the collection folder. See "Loading Photo Files from Disk" in this chapter for information.