InternalParams

Internal (intrinsic) parameters of a camera or projector system
Represent the internal parameters of a camera or projector system, e.g.
sensor and lens characteristics of a pinhole camera model.

Category: Calibration

Base class: _BlipValue

Constructors

__init__(self)

Constructor using default values for 1080p HD, 1/2” sensor, f=15mm
Create a set of internal parameters of an optical system, e.g. a camera
or projector.

__init__(self, imgSize: Int2, focal: float, pixSize: Vec2, ppShift: Vec2)

Constructor for specifying most important parameters

Create a set of internal parameters of an optical system, e.g. a camera
or projector.
Note: The focal length, pixel size and focus distance must be specified in the
same unit (e.g. [m])!

Parameters:

• imgSize image width and height in [pixel]
• focal focal length of lens in [m]
• pixSize physical size of a single pixel on the sensor in [m] (implicitly pixel aspect ratio)
• ppShift horizontal and vertical shift of principal point on image plane in [pixel]

Methods

getAspectRatio(self) -> float

Get image aspect ratio

getFocalLengthPixels(self) -> Vec2

Get focal length in pixels

getFovX(self, bAdjustForFocus: bool) -> float

Calculate the horizontal field of view in [rad]

getFovY(self, bAdjustForFocus: bool) -> float

Calculate the vertical field of view in [rad]

getMatrix(self, verbose: int) -> Mat

Get the internal transformation matrix resulting in pixel coordinates

NOTE: This matrix does not contain perspective elements to divide by Z!

getPixelAspectRatio(self) -> float

Get pixel image aspect ratio

getPrincipalPoint(self) -> Vec2

Calculate the principal point position in [pixels]

getSensorAspectRatio(self) -> float

Get image sensor aspect ratio

getSensorSize(self) -> Vec2

Get full image sensor size in [m]

getThrowRatio(self) -> float

Calculate the throw ratio using focal length and sensor size: D/W = f/s_x

setIntrinsicMatrix(self, K: Mat, verbose: int) -> bool

Extract individual parameters from specified intrinsic matrix and set them

• Use the specified intrinsic matrix to extract individual parameters and then
  set this objects parameter values to those derived from the matrix.
  The following parameters are affected:

• focal length
• principal point shift
  If the value extraction from the matrix failed, then no parameters are changed.
  NOTE: This method uses getIntrinsicParameters() and assumes that the current
  image size and sensor size stay the same!

Parameters:

• K 3x3 intrinsic matrix with new parameters
  Returns returns ‘false’ if extraction from matrix K failed (not a valid intrinsic matrix)

setPrincipalPoint(self, ppointX: float, ppointY: float)

Set the position of the principal point in [pixels]

The principal point shift is modified according to the specified position
and the current image size.