(XMP) Camera

(XMP) Radiometric correction

(XMP) Radiometric calibration target

(XMP) Position and orientation

(XMP) Sun irradiance position and orientation

(XMP) Bit-depth reduction

(XMP) Miscellaneous

**Projects which require radiometric calculations** (e.g. agriculture applications): Refer to the camera XMP section as well as this page which gives the specifications for the different corrections to be applied: Camera radiometric correction specifications.

## (XMP) Camera

Key | Value example | Type | Meaning |
---|---|---|---|

Xmp.Camera.ModelType | "fisheye" | Ascii | Camera model type: one of "perspective" or "fisheye". |

Xmp.Camera.PrincipalPoint | 2.42299,1.850154 | Ascii | c_{x}, c_{y} in millimetres separated by comma. |

Xmp.Camera.PerspectiveFocalLength | 4.569165 | double | For perspective camera: focal length in millimetres. |

Xmp.Camera.PerspectiveDistortion |
0.201690322,-0.358534038, 0.256185599, 0.004208643,0.000268361 |
Ascii | For perspective camera: R1, R2, R3, T1, T2 separated by comma: How are the Internal and External Camera Parameters defined?. |

Xmp.Camera.FisheyeAffineMatrix |
1583.319083002,0,0, 1583.319083002 |
Ascii | For fisheye camera: Affine matrix C, D, E, F separated by comma: How are the Internal and External Camera Parameters defined?. |

Xmp.Camera.FisheyeAffineSymmetric | 1 | Boolean | For fisheye camera: If symmetric affine matrix should be used (default false). |

Xmp.Camera.FisheyePolynomial |
0,1,-0.025178575, 0.167834214 |
Ascii | For fisheye camera: Polynomial separated by comma: How are the Internal and External Camera Parameters defined?. |

Xmp.Camera.RigName | Airinov multiSPEC4C 1.1 | XmpText | Name of the rig model this image belongs to. |

Xmp.Camera.RigCameraIndex | 0 | Short | Corresponding camera index within the rig model. |

Xmp.Camera.RigRelatives | 0.3836, -1.27665, -0.1156 | XmpText | Rotation angles with respect to the reference camera. For angle convention in Pix4D: How are defined omega, phi, kappa?. |

## (XMP) Radiometric correction

Key | Value example | Type | Meaning |
---|---|---|---|

Xmp.Camera.BandName | {"Red", "NIR"} | XmpSeq |
Name of each band (sequence). The band name must not start with the following characters: 0-9, ',', '(' or ')'. |

Xmp.Camera.CentralWavelength | {660, 800} | XmpSeq | Central wavelength of each band in nm. Similar to band names. If band names are not defined, default band names are generated. |

Xmp.Camera.WavelengthFWHM | {10, 10} | XmpSeq | Full-width half maximum of the wavelength distribution in nm. |

Xmp.Camera.BlackCurrent |
{10, 7} |
XmpSeq | Dark current for each band/page: Camera radiometric correction specifications. |

Xmp.Camera.BandSensitivity | {0.78, 0.043} | XmpSeq | The sensitivity of each band (pixel intensity value per irradiance). |

Xmp.Camera.SunSensor | {12.87, 9.72} | XmpSeq | Sun irradiance sensor (upwards looking sensor) raw value for each band. |

Xmp.Camera.SunSensorExposureTime | {0.1, 0.1} | XmpSeq | Sun irradiance sensor exposure time in seconds. |

Xmp.Camera.SunSensorSensitivity | {16.45, 14.08} | XmpSeq | Sun irradiance sensor sensitivity. |

Xmp.Camera.InvalidPixel | {"40,593,981,291"} | XmpSeq | List of bad pixels as comma-separated x,y coordinate list, one sequence for each band. |

Xmp.Camera.VignettingPolynomial | {"0.00325, 1.983e-6, 5.0983e-9"} | XmpSeq | Vignetting correction by radial polynomial: 1D polynomial coefficients (one string of comma-separated values per page, 1 string for RGB images): Camera radiometric correction specifications. |

Xmp.Camera.VignettingCenter | {"542,912"} | XmpSeq | Vignetting correction by radial polynomial: Center point cx, cy in pixel (one string of comma-separated values per page): Camera radiometric correction specifications. |

Xmp.Camera.VignettingPolynomial2DName | {"0,0,1,0, ..., 2,2,3,1"} | XmpSeq | Vignetting correction by 2D polynomial: name of coefficients: n,m for c_{n,m} separated by commas (one string of comma-separated values per page): Camera radiometric correction specifications. |

Xmp.Camera.VignettingPolynomial2D | {"0.633287676149, 1.47936368033, ..., -1.58329242609, 0.130259802058"} | XmpSeq | Vignetting correction by 2D polynomial: coefficients c_{n,m} for names given by Xmp.Camera.VignettingPolynomial2DName separated by commas (one string of comma-separated values per page): Camera radiometric correction specifications. |

Xmp.Camera.ColorTransform |
{1, -0.114886,-0.0456918, -0.176716, 1, 0, -0.0715561, 0, 1} |
XmpSeq | Sequence of double, color conversion matrix (for RGB: R2R, G2R, B2R, R2G, G2G, B2G, R2B, G2B, B2B). Considering the information as a 3x3 matrix M, (R,G,B)<sub>new</sub>= M * (R,G,B). |

Xmp.Camera.IsNormalized | 1 | Bool | Defines whether the radiometric correction is required (value 0) or the data has already been corrected (value 1) and therefore should not be corrected. |

## (XMP) Radiometric calibration target

Key | Value example | Type | Meaning |
---|---|---|---|

Xmp.Camera.Albedo | {0.22, 0.19 , 0.37} | XmpSeq | For radiometric calibration target images: Albedo of the disk for each band/page. |

Xmp.Camera.ReflectArea | {"X1,Y1,X2,Y2,X3,Y3,X4,Y4", "X1,Y1,...", ...} | XmpSeq | For radiometric calibration target images: polygon defining the target area for each page. |

Xmp.Camera.CalibrationPicture | 2 | Short |
Specifies if this image is a radiometric calibration target: 0 = no, 1 = yes but invalid, 2 = yes and valid. For Sequoia cameras: 0 = no, 1 and 2 = yes. |

## (XMP) Position and orientation

Key | Value example | Type | Meaning |
---|---|---|---|

Xmp.Camera.Yaw | 72.7942 | Rational or Double | Orientation data in degrees. For more information on the definition of yaw, pitch, roll: How are defined yaw, pitch, roll?. |

Xmp.Camera.Pitch | 1.7943 | Rational or Double | Orientation data in degrees. For more information on the definition of yaw, pitch, roll: How are defined yaw, pitch, roll?. |

Xmp.Camera.Roll | 2.8909 | Rational or Double | Orientation data in degrees. For more information on the definition of yaw, pitch, roll: How are defined yaw, pitch, roll?. |

Xmp.Camera.GPSXYAccuracy | 5 | Rational | Horizontal GPS Accuracy in meters. |

Xmp.Camera.GPSZAccuracy | 10 | Rational | Vertical GPS Accuracy in meters. |

Xmp.Camera.GyroRate | 0.0487 | Rational | Gyro rate during image acquisition, lower = better quality. |

Xmp.Camera.IMUPitchAccuracy | 0.113 | Rational | The value in degrees of 1-sigma of the Gaussian noise of the IMU Pitch measurement. |

Xmp.Camera.IMURollAccuracy | 0.087 | Rational | The value in degrees of 1-sigma of the Gaussian noise of the IMU Roll measurement. |

Xmp.Camera.IMUYawAccuracy | 1.250 | Rational | The value in degrees of 1-sigma of the Gaussian noise of the IMU Yaw measurement. |

Xmp.Camera.NominalCameraDistance | 25.87 | Rational | Nominal GPS distance between calibrated cameras in meters in order to have a decent overlap. Use to dynamically remove the cameras with worst quality as determined by the GyroRate such the target distance is as specified. |

Xmp.Camera.AboveGroundAltitude | 25.3 | Rational or Double | Altitude above ground/take-off location in meters (from the altimeter of the drone). |

## (XMP) Sun irradiance position and orientation

Key | Value example | Type | Meaning |
---|---|---|---|

Xmp.Camera.SunSensorYaw | 72.7942 | Rational or Double | Sun irradiance sensor orientation data in degrees. For more information on the definition of yaw, pitch, roll: How are defined yaw, pitch, roll?. |

Xmp.Camera.SunSensorPitch |
1.7943 | Rational or Double | Sun irradiance sensor orientation data in degrees. For more information on the definition of yaw, pitch, roll: How are defined yaw, pitch, roll?. |

Xmp.Camera.SunSensorRoll | 2.8909 | Rational or Double | Sun irradiance sensor orientation data in degrees. For more information on the definition of yaw, pitch, roll: How are defined yaw, pitch, roll?. |

Xmp.Camera.SunSensorRelativeRotation | 175, 0, 0 | XmpSeq | Relative angle between camera and sunshine sensor in the omega, phi, kappa system (same as rig relatives). |

## (XMP) Bit-depth reduction

Key | Value example | Type | Meaning |
---|---|---|---|

Xmp.Camera.TransformAlpha | {55684.1, 58672.8, 58889.1} | XmpSeq |
Sequence of double, alpha parameter for each band. where pixel_normalized is the pixel value stored in the JPG image scaled to the [0,1] interval. |

Xmp.Camera.TransformBeta | {9850.9, 6862.2, 6645.91} | XmpSeq | Sequence of double, beta parameter for each band. |

Xmp.Camera.TransformGamma | {2.12109, 2.6243, 2.33549} | XmpSeq | Sequence of double, gamma parameter for each band. |

## (XMP) Miscellaneous

Key | Value example | Type | Meaning |
---|---|---|---|

Xmp.Camera.SensorBitDepth | 14 | Short | Bit depth of the original sensor. |

Xmp.Camera.SensorTemperature | 43.4 | Double | Temperature of the sensor [degree Celsius]. |

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