Coordinate Systems

Cameratransform uses three different coordinate systems.

Image

This 2D coordinate system defines a position on the image in pixel. The position X is between 0 and image_width_px and the position y is between 0 and image_height_px. (0,0) is the top left corner of the image.

See also Projections.

x=... y=... (hover over image)

image_width_px300
image_height_px200
view_x_deg72

Note: in this visualisation view_x_deg is used. The field of view can also be specified by focallength_x_px = image_width_px / (2 * tan(view_x_deg / 2)) or focallength_px = focallength_mm / sensor_width_mm * image_width_px.

Space

This 3D coordinate system defines an euclidean space in which the camera is positioned. Distances are in meter. The camera is positioned at (pos_x_m, pos_y_m, elevation_m) in this coordinate system. When heading_deg is 0, the camera faces in the positive y direction of this coordinate system.

See also Camera Orientation.

pos_x_m0
pos_y_m-1
elevation_m2

heading_deg0
tilt_deg40
roll_deg0

GPS

This is a geo-coordinate system in which the camera is positioned. The coordinates are latitude, longitude and elevation. The camera is positioned at (lat, lon). When heading_deg is 0, the camera faces north in this coordinate system.

This coordinate system shares the parameters elevation_m and the orientation angles (heading_deg, tilt_deg, roll_deg) with the Space coordinate system to keep both coordinate systems aligned.

See also Earth Position (GPS).