ex::Lattice

Encapsulates a lattice defined by two lattice vectors P and Q, an origin O, a barrel distortion Kb and a spiral distortion Ks. The vector L of a lattice point at index (h,k) is given by the following formula:

For zero distortion constants, this simplifies to L = O + h P + k Q. All values are dimensionless, but since a lattice is usually determined and/or used for an image, it's units should be considered to be pixels.

Interface

Construction

Lattice()

Default ctor, will set P to {1,0}, Q to {0,1}, and O to {0,0}

Lattice(Vec2 P, Vec2 Q, Vec2 O=Vec2(0.0,0.0))

Initialization with P and Q, the origin defaults to {0,0} if not explicitly given

Parameter Getter/Setter

These should be self-explanatory, P is the first and Q the second vector

SetFirst(Vec2 P)

Vec2 GetFirst()

SetSecond(Vec2 Q)

Vec2 GetSecond()

SetOffset(Vec2 O)

Vec2 GetOffset()

SetBarrelDistortion(double)

double GetBarrelDistortion()

SetSpiralDistortion(double)

double GetSpiralDistortion()

Operators

Lattice objects may be compared for equality and inequality, i.e. with == and !=.

Others

Vec2 CalcPosition(Point hk)

Calculates L based on the given integer (h,k) index

Vec2 CalcPosition(Vec2 hk)

Calculates L based on the given fractional (h,k) index

Vec2 CalcComponents(Point xy)

Determines the (fractional) (h,k) index at the given pixel position

Vec2 CalcComponents(Vec2 xy)

Determines the (fractional) (h,k) index at the given (fractional) pixel position

Functions

Lattice InvertLattice(Lattice l)

Returns the inverted form of the given lattice, which is defined by

Examples

import ex
lat=ex.Lattice(Vec2(10,0), Vec2(0,15), Vec2(50,50))
print lat.CalcPosition(Point(10,10))
lat.SetBarrelDistortion(1e-6)
print lat.CalcPosition(Point(10,10))

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