Colorisation (PC)
- Author: HfT Stuttgart (c) 2013
- Menu: Imagery | Photogrammetry
Description
This tool 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
| | Name | Type | Identifier | Description | Constraints |
|---|
| Input | RGB Image | grid, input | rgbImage | RGB Image | - |
| Points to be Colorised | point cloud, input | PC_IN | Points to be Colorised | - |
| Output | Colorised Point Cloud | point cloud, output | PC_OUT | Colorised Point Cloud | - |
| Options | Grid system | grid system | rgbImage_GRIDSYSTEM | - | - |
| Provide Time stamp of Image? | boolean | GIVE_TIME | Do you wish to provide the time stamp of Image? | Default: 0 |
| Time stamp of Image | floating point number | IMG_TIME | Time stamp of Image | Default: 0.000000 |
| Time Difference between Image & Points | floating point number | TIME_DIFF | Acceptable Time Difference between Image and Laser Points | Default: 0.000000 |
| Focal Length (mm) | floating point number | F | Focal Length in mm | Default: 0.000000 |
| Pixel Width (um) | floating point number | W | Pixel Width in micro meters | Default: 0.000000 |
| Principal Point Offset in X (pixles) | floating point number | ppX | Principal Point Offset in X | Default: 0.000000 |
| Principal Point Offset in Y (pixels) | floating point number | ppY | Principal Point Offset in Y | Default: 0.000000 |
| Provide Radial Distortion Parameters? | boolean | GIVE_DISTORTIONS | Do you wish to provide the Radial Distortion Parameters? | Default: 0 |
| K1 | floating point number | K1 | K1 | Default: 0.000000 |
| K2 | floating point number | K2 | K2 | Default: 0.000000 |
| K3 | floating point number | K3 | K3 | Default: 0.000000 |
| Projection Centre - X | floating point number | Xc | Projection Centre | Default: 0.000000 |
| Projection Centre - Y | floating point number | Yc | Projection Centre | Default: 0.000000 |
| Projection Centre - Z | floating point number | Zc | Projection Centre | Default: 0.000000 |
| Omega | floating point number | omega | Rotation Angle | Default: 0.000000 |
| Kappa | floating point number | kappa | Rotation Angle | Default: 0.000000 |
| Alpha | floating point number | alpha | Rotation Angle | Default: 0.000000 |
Command Line
Usage: saga_cmd imagery_photogrammetry 1 [-rgbImage ] [-PC_IN ] [-GIVE_TIME ] [-IMG_TIME ] [-TIME_DIFF ] [-F ] [-W ] [-ppX ] [-ppY ] [-GIVE_DISTORTIONS ] [-K1 ] [-K2 ] [-K3 ] [-Xc ] [-Yc ] [-Zc ] [-omega ] [-kappa ] [-alpha ] [-PC_OUT ]
-rgbImage: RGB Image
grid, input
-PC_IN: Points to be Colorised
point cloud, input
-GIVE_TIME: Provide Time stamp of Image?
boolean
Default: 0
-IMG_TIME: Time stamp of Image
floating point number
Default: 0.000000
-TIME_DIFF: Time Difference between Image & Points
floating point number
Default: 0.000000
-F: Focal Length (mm)
floating point number
Default: 0.000000
-W: Pixel Width (um)
floating point number
Default: 0.000000
-ppX: Principal Point Offset in X (pixles)
floating point number
Default: 0.000000
-ppY: Principal Point Offset in Y (pixels)
floating point number
Default: 0.000000
-GIVE_DISTORTIONS: Provide Radial Distortion Parameters?
boolean
Default: 0
-K1: K1
floating point number
Default: 0.000000
-K2: K2
floating point number
Default: 0.000000
-K3: K3
floating point number
Default: 0.000000
-Xc: Projection Centre - X
floating point number
Default: 0.000000
-Yc: Projection Centre - Y
floating point number
Default: 0.000000
-Zc: Projection Centre - Z
floating point number
Default: 0.000000
-omega: Omega
floating point number
Default: 0.000000
-kappa: Kappa
floating point number
Default: 0.000000
-alpha: Alpha
floating point number
Default: 0.000000
-PC_OUT: Colorised Point Cloud
point cloud, output