Source code for soma.wip.aimsalgo.transform.taperingtransform

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#########################################################################
#
# Project : Pyaimsalgo
# Module : aimsalgo.transform
# Create date : 2007-07-19
#
# Description :
# 	This file contains TaperingTransform class
#
#########################################################################
from __future__ import absolute_import
import sys
import math

from soma import aims


class TaperingTransform(object):

    def __init__(self, coefficients):
        self._coefficients = coefficients

    def transform(self, point):

        x = point[0]
        y = point[1]
        z = point[2]

        zlimit = self._coefficients[0]
        k1 = self._coefficients[1]
        k2 = self._coefficients[2]
        k3 = self._coefficients[3]

        if (zlimit != 0):

            # Apply the tapering transformation
            X = ((k1 * z + k3) / zlimit + 1) * x
            Y = ((k2 * z + k3) / zlimit + 1) * y
            Z = z

        else:
            X = x
            Y = y
            Z = z

        return aims.Point3df(X, Y, Z)

    def inverseTransform(self, point):

        X = point[0]
        Y = point[1]
        Z = point[2]

        zlimit = self._coefficients[0]
        k1 = self._coefficients[1]
        k2 = self._coefficients[2]
        k3 = self._coefficients[3]

        coef1 = ((k1 * Z + k3) / zlimit + 1)
        coef2 = ((k2 * Z + k3) / zlimit + 1)

        if ((coef1 != 0) and (coef2 != 0)):

            # Apply inverse of the tapering transformation
            x = X / coef1
            y = Y / coef2
            z = Z

        else:
            x = X
            y = Y
            z = Z

        return aims.Point3df(x, y, z)