HALCON 18.05 / HALCON Operator Reference / 3D Reconstruction / Photometric Stereo
ClassesClasses | | Operators

sfs_pentlandsfs_pentlandSfsPentlandSfsPentland (Operator)

Name

sfs_pentlandsfs_pentlandSfsPentlandSfsPentland — Reconstruct a surface from a gray value image.

Signature

sfs_pentland(Image : Height : Slant, Tilt, Albedo, Ambient : )

Herror sfs_pentland(const Hobject Image, Hobject* Height, double Slant, double Tilt, double Albedo, double Ambient)

Herror T_sfs_pentland(const Hobject Image, Hobject* Height, const Htuple Slant, const Htuple Tilt, const Htuple Albedo, const Htuple Ambient)

void SfsPentland(const HObject& Image, HObject* Height, const HTuple& Slant, const HTuple& Tilt, const HTuple& Albedo, const HTuple& Ambient)

HImage HImage::SfsPentland(const HTuple& Slant, const HTuple& Tilt, const HTuple& Albedo, const HTuple& Ambient) const

HImage HImage::SfsPentland(double Slant, double Tilt, double Albedo, double Ambient) const

static void HOperatorSet.SfsPentland(HObject image, out HObject height, HTuple slant, HTuple tilt, HTuple albedo, HTuple ambient)

HImage HImage.SfsPentland(HTuple slant, HTuple tilt, HTuple albedo, HTuple ambient)

HImage HImage.SfsPentland(double slant, double tilt, double albedo, double ambient)

Description

sfs_pentlandsfs_pentlandSfsPentlandSfsPentlandSfsPentland reconstructs a surface (i.e. the relative height of each image point) using the algorithm of Pentland. The surface is reconstructed from the input image ImageImageImageImageimage. The light source must be given by the parameters SlantSlantSlantSlantslant, TiltTiltTiltTilttilt, AlbedoAlbedoAlbedoAlbedoalbedo and AmbientAmbientAmbientAmbientambient, and is assumed to lie infinitely far away in the direction given by SlantSlantSlantSlantslant and TiltTiltTiltTilttilt. The parameter AlbedoAlbedoAlbedoAlbedoalbedo determines the albedo of the surface, i.e. the percentage of light reflected in all directions. AmbientAmbientAmbientAmbientambient determines the amount of ambient light falling onto the surface. It can be set to values greater than zero if, for example, the white balance of the camera was badly adjusted at the moment the image was taken.

Attention

sfs_pentlandsfs_pentlandSfsPentlandSfsPentlandSfsPentland assumes that the heights are to be extracted on a lattice with step width 1. If this is not the case, the calculated heights must be multiplied with the step width after the call to sfs_pentlandsfs_pentlandSfsPentlandSfsPentlandSfsPentland. A Cartesian coordinate system with the origin in the lower left corner of the image is used internally. sfs_pentlandsfs_pentlandSfsPentlandSfsPentlandSfsPentland can only handle byte-images.

Execution Information

Parameters

ImageImageImageImageimage (input_object)  singlechannelimage(-array) → objectHImageHImageHobject (byte)

Shaded input image.

HeightHeightHeightHeightheight (output_object)  image(-array) → objectHImageHImageHobject * (real)

Reconstructed height field.

SlantSlantSlantSlantslant (input_control)  angle.deg → HTupleHTupleHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong)

Angle between the light source and the positive z-axis (in degrees).

Default value: 45.0

Suggested values: 1.0, 5.0, 10.0, 20.0, 40.0, 60.0, 90.0

Typical range of values: 0.0 ≤ Slant Slant Slant Slant slant ≤ 180.0 (lin)

Minimum increment: 1.0

Recommended increment: 10.0

TiltTiltTiltTilttilt (input_control)  angle.deg → HTupleHTupleHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong)

Angle between the light source and the x-axis after projection into the xy-plane (in degrees).

Default value: 45.0

Suggested values: 1.0, 5.0, 10.0, 20.0, 40.0, 60.0, 90.0

Typical range of values: 0.0 ≤ Tilt Tilt Tilt Tilt tilt ≤ 360.0 (lin)

Minimum increment: 1.0

Recommended increment: 10.0

AlbedoAlbedoAlbedoAlbedoalbedo (input_control)  number → HTupleHTupleHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong)

Amount of light reflected by the surface.

Default value: 1.0

Suggested values: 0.1, 0.5, 1.0, 5.0

Typical range of values: 0.0 ≤ Albedo Albedo Albedo Albedo albedo ≤ 5.0 (lin)

Minimum increment: 0.01

Recommended increment: 0.1

Restriction: Albedo >= 0.0

AmbientAmbientAmbientAmbientambient (input_control)  number → HTupleHTupleHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong)

Amount of ambient light.

Default value: 0.0

Suggested values: 0.1, 0.5, 1.0

Typical range of values: 0.0 ≤ Ambient Ambient Ambient Ambient ambient ≤ 1.0 (lin)

Minimum increment: 0.01

Recommended increment: 0.1

Restriction: Ambient >= 0.0

Result

If all parameters are correct sfs_pentlandsfs_pentlandSfsPentlandSfsPentlandSfsPentland returns the value 2 (H_MSG_TRUE). Otherwise, an exception is raised.

Possible Predecessors

estimate_al_amestimate_al_amEstimateAlAmEstimateAlAmEstimateAlAm, estimate_sl_al_lrestimate_sl_al_lrEstimateSlAlLrEstimateSlAlLrEstimateSlAlLr, estimate_sl_al_zcestimate_sl_al_zcEstimateSlAlZcEstimateSlAlZcEstimateSlAlZc, estimate_tilt_lrestimate_tilt_lrEstimateTiltLrEstimateTiltLrEstimateTiltLr, estimate_tilt_zcestimate_tilt_zcEstimateTiltZcEstimateTiltZcEstimateTiltZc, optimize_fft_speedoptimize_fft_speedOptimizeFftSpeedOptimizeFftSpeedOptimizeFftSpeed

Possible Successors

shade_height_fieldshade_height_fieldShadeHeightFieldShadeHeightFieldShadeHeightField

Module

3D Metrology

ClassesClasses | | Operators
HALCON Operator Reference 18.05 Copyright © 1996-2018 MVTec Software GmbH