gen_sin_bandpass

Herror ::gen_sin_bandpass ( Hobject *ImageFilter, const HTuple &Frequency, const HTuple &Size ) HImage HImage::GenSinBandpass ( const HTuple &Frequency, const HTuple &Size ) HImageArray HImageArray::GenSinBandpass ( const HTuple &Frequency, const HTuple &Size )

Generate a bandpass filter with sinusoidal shape.

::gen_sin_bandpass generates a rotationally invariant bandpass filter with the response being a sinusoidal function in the frequency domain. The maximum of the sine (255) is determined by Frequency (distance from the DC term in pixels). The filter is always zero for the DC term, rises with the sine function up to Frequency, and drops for higher frequencies accordingly. The range of the sine used is from 0 to pi. All other points are set to zero.

Parameters

`ImageFilter` (output_object)	image(-array) `->` Hobject : HImage(Array)* ( byte )
Bandpass filter as image in the frequency domain.

`Frequency` (input_control)	real `->` HTuple.double
Distance of the filter's maximum from the DC term.
Default value: 20
Suggested values: 0.0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 80, 100, 150, 200
Typical range of values: `0.0 <= Frequency <= 1000`
Minimum increment: 1
Recommended increment: 2

`Size` (input_control)	integer `->` HTuple.long
Size (dimension) of the image (filter).
Default value: 512
List of values: 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192

Result

::gen_sin_bandpass returns H_MSG_TRUE if all parameters are correct. If necessary, an exception handling is raised.

Possible Predecessors

::fft_image, ::fft_generic

Possible Successors

::convol_fft

Alternatives

::gen_std_bandpass, ::gen_bandpass, ::gen_bandfilter, ::gen_highpass, ::gen_lowpass

See also

::fft_image_inv

Module

Image filters