found::Camera Class Reference

A Camera is a mutable object that represents a pinhole camera. More...

#include <camera.hpp>

Public Member Functions
	Camera (const Camera &)=default
	Copy Constructor for Camera.
	Camera (decimal focalLength, int xResolution, int yResolution, decimal xCenter, decimal yCenter, decimal xPixelPitch, decimal yPixelPitch)
	Creates a Camera object off of real Camera parameters.
	Camera (decimal focalLength, decimal pixelSize, int xResolution, int yResolution)
	Creates a Camera object off of ideal Camera parameters.
Vec2	CameraToPixelCoordinates (const Vec3 &) const
	Uses the pinhole camera model to map a 3D vector in the camera frame to a 2D point in pixel coordinates (row and column index of image matrix).
Vec3	PixelToImageCoordinates (const Vec2 &) const
	Maps a 2D point in pixel coordinates (row and column index of image matrix) to a point on the image plane.
bool	InSensor (const Vec2 &vector) const
	Evaluates whether a vector can be seen in the camera.
const Mat3 &	GetCalibrationMatrix () const
	Expose camera calibration matrix (intrinsic matrix)
const Mat3 &	GetInverseCalibrationMatrix () const
	Expose inverse camera calibration matrix (intrinsic matrix)

Private Member Functions
Mat3	initCalibrationMatrix ()
	Computes and initializes the calibration matrix and the inverse calibration matrix from camera parameters.

Private Attributes
decimal	focalLength_
	The focal length (m)
int	xResolution_
	The x resolution (pixels)
int	yResolution_
	The y resolution (pixels)
decimal	xCenter_
	The x center (pixels)
decimal	yCenter_
	The y center (pixels)
decimal	xPixelPitch_
	The x pixel pitch (m)
decimal	yPixelPitch_
	The y pixel pitch (m)
Mat3	calibrationMatrix_
	The camera calibration matrix.
Mat3	inverseCalibrationMatrix_
	The inverse camera calibration matrix.

Detailed Description

A Camera is a mutable object that represents a pinhole camera.

Precondition

Camera dimensions are in SI

Note

Follows the convention as laid out in Fundamentals of Space OpNav (Christian, 2026)

• The optical center (hole in pinhole camera model) is located at the origin (0, 0, 0)
• The x-axis points to the right
• The y-axis points down
• The z-axis points along the camera's optical axis (depth)
• The virtual image plane is located at z = 1
• The detector plane is located at z = -focalLength

Constructor & Destructor Documentation

Camera() [1/2]

found::Camera::Camera	(	decimal	focalLength,
		int	xResolution,
		int	yResolution,
		decimal	xCenter,
		decimal	yCenter,
		decimal	xPixelPitch,
		decimal	yPixelPitch
	)

Creates a Camera object off of real Camera parameters.

Parameters

focalLength	The focal length of the camera
xResolution	The resolution of the camera in the x-direction
yResolution	The resolution of the camera in the y-direction
xCenter,yCenter	The "principal point" of the camera.
xPixelPitch	The physical size of a pixel in the x-direction (in meters)
yPixelPitch	The physical size of a pixel in the y-direction (in meters)

Camera() [2/2]

found::Camera::Camera	(	decimal	focalLength,
		decimal	pixelSize,
		int	xResolution,
		int	yResolution
	)

Creates a Camera object off of ideal Camera parameters.

Parameters

focalLength	The focal length of the camera
pixelSize	The physical size of a pixel (in meters)
xResolution	The resolution of the camera in the x-direction
yResolution	The resolution of the camera in the y-direction

Note

In an ideal camera, the x and y centers are just half the resolution, but physical cameras often have a bit of offset.

Member Function Documentation

CameraToPixelCoordinates()

Vec2 found::Camera::CameraToPixelCoordinates

(

const Vec3 &

vector

)

const

Uses the pinhole camera model to map a 3D vector in the camera frame to a 2D point in pixel coordinates (row and column index of image matrix).

Parameters

vector

A 3D vector to convert to a vector on the camera

Returns

The 2D Vector that represents the 3D vector on the camera

Note

Any vector (x, 0, 0), x > 0, will be projected onto the principal point of the sensor.

GetCalibrationMatrix()

const Mat3 & found::Camera::GetCalibrationMatrix ( ) const

inline

Expose camera calibration matrix (intrinsic matrix)

Returns

The camera calibration matrix

GetInverseCalibrationMatrix()

const Mat3 & found::Camera::GetInverseCalibrationMatrix ( ) const

inline

Expose inverse camera calibration matrix (intrinsic matrix)

Returns

The inverse camera calibration matrix

initCalibrationMatrix()

Mat3 found::Camera::initCalibrationMatrix ( )

private

Computes and initializes the calibration matrix and the inverse calibration matrix from camera parameters.

Returns

The camera calibration matrix

InSensor()

bool found::Camera::InSensor

(

const Vec2 &

vector

)

const

Evaluates whether a vector can be seen in the camera.

Parameters

vector

The vector to evaluate

Returns

true iff vector could be seen in this camera

PixelToImageCoordinates()

Vec3 found::Camera::PixelToImageCoordinates

(

const Vec2 &

vector

)

const

Maps a 2D point in pixel coordinates (row and column index of image matrix) to a point on the image plane.

This is techinally a mapping from a 2D homogenous vector to another 2D homogenous vector, but the returned vector can be interpreted as a 3D vector where the x-componet, optical axis direction, is equal to 1.

Parameters

vector

The vector on the camera to convert to a 3D vector

Returns

A vector in 3D space corresponding to the given vector, with x-component equal to 1

Note

Not all vectors returned by this function will necessarily have the same magnitude. Assumes that X is the depth direction and that it points normal to the camera sensor in the direction of the scene. Coordinate system: X=out, Y=left, Z=up. This coordinate frame has the distinct advantage that there is an identity rotation into equatorial coordinates when right-ascension, declination, and roll are all zero.

Warning

Other functions rely on the fact that returned vectors are placed one unit away (x-component equal to 1). Don't change this behavior!

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The documentation for this class was generated from the following files:

• src/common/spatial/camera.hpp
• src/common/spatial/camera.cpp