SAGA-GIS Module Library Documentation (v2.1.3)

Module Colorisation (PC)

This module attaches the color information from a RGB image to Laser Points.
The RGB Image and the Point Cloud to be colorised are the inputs along with the interior and exterior orientation parameters of the camera. The necessary interior orientation parameters are Focal Length (mm), Pixel Size (um), Principal Point Offsets (pixels) and optionally the Radial Distortion Parameters. The distortion model being used is as follows:
x_d = x_u (1 - dR)
y_d = y_u (1 - dR)
where, dR = K1 * r_u ^ 2 + K2 * r_u ^ 4 + K3 * r_u ^ 6,
r_u ^ 2 = x_u ^ 2 + y_u ^ 2,
x_u, y_u are the undistorted (corrected) image coordinates in mm,
x_d, y_d are the distorted (observed) image coordinates in mm,
K1 is in [mm ^ -2], K2 is in [mm ^ -4], K3 is in [mm ^ -6].
The necessary exterior orientation parameters are the coordinates of the Projection Center and the Cardan angles Omega, Kappa and Alpha. The Cardan angles refer to the following transformation between image coordinates (x_image) and global coordinates (X_Global):
x_image = R_1(omega) * R_2(kappa) * R_3(alpha) * X_Global

[Optional] If the Time Stamp of the RGB Image is given, an acceptable time difference between the points and the image must provided in order to colorise only those points falling that range. If no time is given all points are colorised.
The result is a colorised point cloud.

Parameters

 NameTypeIdentifierDescriptionConstraints
InputRGB ImageGrid (input)rgbImageRGB Image-
Points to be ColorisedPoint Cloud (input)PC_INPoints to be Colorised-
OutputColorised Point CloudPoint Cloud (output)PC_OUTColorised Point Cloud-
OptionsProvide Time stamp of Image?BooleanGIVE_TIMEDo you wish to provide the time stamp of Image?Default: 0
Time stamp of ImageFloating pointIMG_TIMETime stamp of ImageDefault: 0.000000
Time Difference between Image & PointsFloating pointTIME_DIFFAcceptable Time Difference between Image and Laser PointsDefault: 0.000000
Focal Length (mm)Floating pointFFocal Length in mmDefault: 0.000000
Pixel Width (um)Floating pointWPixel Width in micro metersDefault: 0.000000
Principal Point Offset in X (pixles)Floating pointppXPrincipal Point Offset in XDefault: 0.000000
Principal Point Offset in Y (pixels)Floating pointppYPrincipal Point Offset in YDefault: 0.000000
Provide Radial Distortion Parameters?BooleanGIVE_DISTORTIONSDo you wish to provide the Radial Distortion Parameters?Default: 0
K1Floating pointK1K1Default: 0.000000
K2Floating pointK2K2Default: 0.000000
K3Floating pointK3K3Default: 0.000000
Projection Centre - XFloating pointXcProjection CentreDefault: 0.000000
Projection Centre - YFloating pointYcProjection CentreDefault: 0.000000
Projection Centre - ZFloating pointZcProjection CentreDefault: 0.000000
OmegaFloating pointomegaRotation AngleDefault: 0.000000
KappaFloating pointkappaRotation AngleDefault: 0.000000
AlphaFloating pointalphaRotation AngleDefault: 0.000000

Command-line

Usage: saga_cmd imagery_photogrammetry 1 -rgbImage <str> -PC_IN <str> [-GIVE_TIME <str>] [-IMG_TIME <str>] [-TIME_DIFF <str>] [-F <str>] [-W <str>] [-ppX <str>] [-ppY <str>] [-GIVE_DISTORTIONS <str>] [-K1 <str>] [-K2 <str>] [-K3 <str>] [-Xc <str>] [-Yc <str>] [-Zc <str>] [-omega <str>] [-kappa <str>] [-alpha <str>] [-PC_OUT <str>]
  -rgbImage:<str>        	RGB Image
	Grid (input)
  -PC_IN:<str>           	Points to be Colorised
	Point Cloud (input)
  -GIVE_TIME:<str>       	Provide Time stamp of Image?
	Boolean
	Default: 0
  -IMG_TIME:<str>        	Time stamp of Image
	Floating point
	Default: 0.000000
  -TIME_DIFF:<str>       	Time Difference between Image & Points
	Floating point
	Default: 0.000000
  -F:<str>               	Focal Length (mm)
	Floating point
	Default: 0.000000
  -W:<str>               	Pixel Width (um)
	Floating point
	Default: 0.000000
  -ppX:<str>             	Principal Point Offset in X (pixles)
	Floating point
	Default: 0.000000
  -ppY:<str>             	Principal Point Offset in Y (pixels)
	Floating point
	Default: 0.000000
  -GIVE_DISTORTIONS:<str>	Provide Radial Distortion Parameters?
	Boolean
	Default: 0
  -K1:<str>              	K1
	Floating point
	Default: 0.000000
  -K2:<str>              	K2
	Floating point
	Default: 0.000000
  -K3:<str>              	K3
	Floating point
	Default: 0.000000
  -Xc:<str>              	Projection Centre - X
	Floating point
	Default: 0.000000
  -Yc:<str>              	Projection Centre - Y
	Floating point
	Default: 0.000000
  -Zc:<str>              	Projection Centre - Z
	Floating point
	Default: 0.000000
  -omega:<str>           	Omega
	Floating point
	Default: 0.000000
  -kappa:<str>           	Kappa
	Floating point
	Default: 0.000000
  -alpha:<str>           	Alpha
	Floating point
	Default: 0.000000
  -PC_OUT:<str>          	Colorised Point Cloud
	Point Cloud (output)