HALCON Reference Manual 10.0.2

Table of Contents / Filters / Wiener Filter

gen_psf_motiongen_psf_motiongen_psf_motionGenPsfMotionGenPsfMotion (Operator)

Name

gen_psf_motiongen_psf_motiongen_psf_motionGenPsfMotionGenPsfMotion — Generate an impulse response of a (linearly) motion blurring.

Signature

gen_psf_motion( : Psf : PSFwidth, PSFheight, Blurring, Angle, Type : )

gen_psf_motiongen_psf_motiongen_psf_motionGenPsfMotionGenPsfMotion generates an impulse response (spatial domain) of a blurring caused by a relative motion between the object and the camera during exposure. The generated impulse response is output into an image of HALCON image type 'real'. PSFwidthPSFwidthPSFwidthPSFwidthPSFwidth and PSFheightPSFheightPSFheightPSFheightPSFheight define the width and height of the output image. The blurring motion moves along an even. AngleAngleAngleAngleangle fixes its direction by specifying the angle between the motion direction and the x-axis (anticlockwise, measured in degrees). To specify different velocity behaviour five PSF prototypes can be generated. TypeTypeTypeTypetype switches between the following prototypes:

reverse ramp (crude model for acceleration)

reverse trapezoid (crude model for high acceleration)

square pulse (exact model for constant velocity), this is default

forward trapezoid (crude model for deceleration)

forward ramp (crude model for high deceleration)

(default value is 3.)

The blurring affects all part of the image uniformly. BlurringBlurringBlurringBlurringblurring controls the extent of blurring. It specifies the number of pixels (lying one after another) that are affetcetd by the blurring. This number is determined by velocity of the motion and exposure time. If BlurringBlurringBlurringBlurringblurring is a negative number, an adequate blurring in reverse direction is simulated. If AngleAngleAngleAngleangle is a negative number, it is interpreted clockwise. If AngleAngleAngleAngleangle exceeds 360 or falls below -360, it is transformed modulo(360) in an adequate number between [0..360] resp. [-360..0]. The result image of gen_psf_motiongen_psf_motiongen_psf_motionGenPsfMotionGenPsfMotion encloses an spatial domain impulse response of the specified blurring. Its representation presumes the origin in the upper left corner. This results in the following disposition of an NxM sized image:

first rectangle (“upper left”): (image coordinates xb = 0..(N/2)-1, yb = 0..(M/2)-1)

- conforms to the fourth quadrant of the Cartesian coordinate system, encloses values of the impulse response at position x = 0..N/2 and y = 0..-M/2

second rectangle (“upper right”): (image coordinates xb = N/2..N-1, yb = 0..(M/2)-1)

- conforms to the third quadrant of the Cartesian coordinate system, encloses values of the impulse response at position x = -N/2..-1 and y = -1..-M/2

third rectangle (“lower left”): (image coordinates xb = 0..(N/2)-1, yb = M/2..M-1)

- conforms to the first quadrant of the Cartesian coordinate system, encloses values of the impulse response at position x = 1..N/2 and y = M/2..0

fourth rectangle (“lower right”): (image coordinates xb = N/2..N-1, yb = M/2..M-1)

- conforms to the second quadrant of the Cartesian coordinate system, encloses values of the impulse response at position x = -N/2..-1 and y = M/2..1

This representation conforms to that of the impulse response parameter of the HALCON-operator wiener_filterwiener_filterwiener_filterWienerFilterWienerFilter. So one can use gen_psf_motiongen_psf_motiongen_psf_motionGenPsfMotionGenPsfMotion to generate an impulse response for Wiener filtering a motion blurred image.

Parallelization

Multithreading type: reentrant (runs in parallel with non-exclusive operators).
Multithreading scope: global (may be called from any thread).
Processed without parallelization.

Parameters

PsfPsfPsfPsfpsf (output_object) image → object (real)

Impulse response of motion-blur.

PSFwidthPSFwidthPSFwidthPSFwidthPSFwidth (input_control) integer → (integer)

Width of impulse response image.

Default value: 256

Suggested values: 128, 256, 512, 1024

Typical range of values: 1 ≤ PSFwidth PSFwidth PSFwidth PSFwidth PSFwidth

PSFheightPSFheightPSFheightPSFheightPSFheight (input_control) integer → (integer)

Height of impulse response image.

Default value: 256

Suggested values: 128, 256, 512, 1024

Typical range of values: 1 ≤ PSFheight PSFheight PSFheight PSFheight PSFheight

BlurringBlurringBlurringBlurringblurring (input_control) real → (real)

Degree of motion-blur.

Default value: 20.0

Suggested values: 5.0, 10.0, 20.0, 30.0, 40.0

AngleAngleAngleAngleangle (input_control) integer → (integer)

Angle between direction of motion and x-axis (anticlockwise).

Default value: 0

Suggested values: 0, 45, 90, 180, 270

TypeTypeTypeTypetype (input_control) integer → (integer)

PSF prototype resp. type of motion.

Default value: 3

List of values: 1, 2, 3, 4, 5

Result

gen_psf_motiongen_psf_motiongen_psf_motionGenPsfMotionGenPsfMotion returns 2 (H_MSG_TRUE) if all parameters are correct.

Possible Predecessors

gen_psf_motiongen_psf_motiongen_psf_motionGenPsfMotionGenPsfMotion, simulate_defocussimulate_defocussimulate_defocusSimulateDefocusSimulateDefocus, gen_psf_defocusgen_psf_defocusgen_psf_defocusGenPsfDefocusGenPsfDefocus

Possible Successors

simulate_motionsimulate_motionsimulate_motionSimulateMotionSimulateMotion, wiener_filterwiener_filterwiener_filterWienerFilterWienerFilter, wiener_filter_niwiener_filter_niwiener_filter_niWienerFilterNiWienerFilterNi

References

Anil K. Jain:Fundamentals of Digital Image Processing, Prentice-Hall International Inc., Englewood Cliffs, New Jersey, 1989
M. Lückenhaus:“Grundlagen des Wiener-Filters und seine Anwendung in der Bildanalyse”; Diplomarbeit; Technische Universität München, Institut für Informatik; Lehrstuhl Prof. Radig; 1995.
Kha-Chye Tan, Hock Lim, B. T. G. Tan:“Restoration of Real-World Motion-Blurred Images”;S. 291-299 in: CVGIP Graphical Models and Image Processing, Vol. 53, No. 3, May 1991

Module

Foundation