sfs_orig_lr ( Image : Height : Slant, Tilt, Albedo, Ambient : )
Reconstruct a surface from a gray value image.
sfs_orig_lr reconstructs a surface (i.e., the relative
height of each image point) using the original algorithm of Lee and
Rosenfeld. The surface is reconstructed from the input image
Image, and the light source given by the parameters
Slant, Tilt, Albedo and
Ambient, and is assumed to lie infinitely far away in the
direction given by Slant and Tilt. The
parameter Albedo determines the albedo of the surface,
i.e., the percentage of light reflected in all directions.
Ambient 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
time the image was taken.
Attention
sfs_orig_lr 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 by the step width after the
call to sfs_orig_lr. A Cartesian coordinate system with
the origin in the lower left corner of the image is used internally.
Because the operator is based on the Fast Fourier Transform, only
square images with the edge length being a power of 2 are accepted.
sfs_orig_lr can only handle byte-images.
Parameters
Image (input_object)
|
image(-array) -> object
|
Shaded input image. |
Height (output_object)
|
image(-array) -> object
|
Reconstructed height field. |
Slant (input_control)
|
angle.deg -> real / integer
|
Angle of 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 |
Range of values: 0.0 <= Slant <= 180.0 (lin) |
Minimum increment: 0.01
|
Recommended increment: 10.0
|
Tilt (input_control)
|
angle.deg -> real / integer
|
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 |
Range of values: 0.0 <= Tilt <= 360.0 (lin) |
Minimum increment: 0.01
|
Recommended increment: 10.0
|
Albedo (input_control)
|
number -> real / integer
|
Amount of light reflected by the surface. |
Default value: 1.0 |
Suggested values: 0.1, 0.5, 1.0, 5.0 |
Range of values: 0.0 <= Albedo <= 5.0 (lin) |
Minimum increment: 0.01
|
Recommended increment: 0.1
|
Restriction: Albedo >= 0.0 |
Ambient (input_control)
|
number -> real / integer
|
Amount of ambient light. |
Default value: 0.0 |
Suggested values: 0.1, 0.5, 1.0 |
Range of values: 0.0 <= Ambient <= 1.0 (lin) |
Minimum increment: 0.01
|
Recommended increment: 0.1
|
Restriction: Ambient >= 0.0 |
Result
If all parameters are correct sfs_orig_lr returns the
value TRUE. Otherwise, an exception is raised.
Possible Predecessors
estimate_al_am,
estimate_sl_al_lr,
estimate_sl_al_zc,
estimate_tilt_lr,
estimate_tilt_zc
Possible Successors
shade_height_field
Copyright © 1996-1997 MVTec Software GmbH