Operator Reference

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

sfs_pentlandsfs_pentlandSfsPentlandSfsPentlandsfs_pentland (Operator)

sfs_pentlandsfs_pentlandSfsPentlandSfsPentlandsfs_pentland — 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)

def sfs_pentland(image: HObject, slant: Union[float, int], tilt: Union[float, int], albedo: Union[float, int], ambient: Union[float, int]) -> HObject

Description

sfs_pentlandsfs_pentlandSfsPentlandSfsPentlandsfs_pentland 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_pentlandSfsPentlandSfsPentlandsfs_pentland 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_pentlandSfsPentlandSfsPentlandsfs_pentland. A Cartesian coordinate system with the origin in the lower left corner of the image is used internally. sfs_pentlandsfs_pentlandSfsPentlandSfsPentlandsfs_pentland can only handle byte-images.

Execution Information

  • Multithreading type: reentrant (runs in parallel with non-exclusive operators).
  • Multithreading scope: global (may be called from any thread).
  • Automatically parallelized on tuple level.

Parameters

ImageImageImageimageimage (input_object)  singlechannelimage(-array) → objectHImageHObjectHObjectHobject (byte)

Shaded input image.

HeightHeightHeightheightheight (output_object)  image(-array) → objectHImageHObjectHObjectHobject * (real)

Reconstructed height field.

SlantSlantSlantslantslant (input_control)  angle.deg → HTupleUnion[float, int]HTupleHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong)

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

Default: 45.0

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

Value range: 0.0 ≤ Slant Slant Slant slant slant ≤ 180.0 (lin)

Minimum increment: 1.0

Recommended increment: 10.0

TiltTiltTilttilttilt (input_control)  angle.deg → HTupleUnion[float, int]HTupleHtuple (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: 45.0

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

Value range: 0.0 ≤ Tilt Tilt Tilt tilt tilt ≤ 360.0 (lin)

Minimum increment: 1.0

Recommended increment: 10.0

AlbedoAlbedoAlbedoalbedoalbedo (input_control)  number → HTupleUnion[float, int]HTupleHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong)

Amount of light reflected by the surface.

Default: 1.0

Suggested values: 0.1, 0.5, 1.0, 5.0

Value range: 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 → HTupleUnion[float, int]HTupleHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong)

Amount of ambient light.

Default: 0.0

Suggested values: 0.1, 0.5, 1.0

Value range: 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_pentlandSfsPentlandSfsPentlandsfs_pentland returns the value 2 ( H_MSG_TRUE) . Otherwise, an exception is raised.

Possible Predecessors

estimate_al_amestimate_al_amEstimateAlAmEstimateAlAmestimate_al_am, estimate_sl_al_lrestimate_sl_al_lrEstimateSlAlLrEstimateSlAlLrestimate_sl_al_lr, estimate_sl_al_zcestimate_sl_al_zcEstimateSlAlZcEstimateSlAlZcestimate_sl_al_zc, estimate_tilt_lrestimate_tilt_lrEstimateTiltLrEstimateTiltLrestimate_tilt_lr, estimate_tilt_zcestimate_tilt_zcEstimateTiltZcEstimateTiltZcestimate_tilt_zc, optimize_fft_speedoptimize_fft_speedOptimizeFftSpeedOptimizeFftSpeedoptimize_fft_speed

Possible Successors

shade_height_fieldshade_height_fieldShadeHeightFieldShadeHeightFieldshade_height_field

Module

3D Metrology

ClassesClasses | | Operators