GXFFT2 class

class GXFFT2(handle=0)[source]

GXFFT2 class.

2-D Fast Fourier Transforms These methods now work with an GXIMG object, instead of creating their own GXFFT2 object.

__init__(handle=0)[source]
classmethod cross_correlation_pg(pg1, pg2, normalise, pgo)[source]

Calculate the cross-correlation of two transform pagers: The complex conjugate of (r, i) items in the first pager are multiplied by the second pager (r, i) values.

Parameters:

  • pg1 (GXPG) – Input pager 1

  • pg2 (GXPG) – Input pager 2

  • normalise (int) – 0 - do not normalise, 1 - result is normalised by max value

  • pgo (GXPG) – Output pager

New in version 2023.2.

License: Geosoft Extended End-User License

classmethod fft2_in(im_gi, trn_fil, spc_fil)[source]

GXFFT2 transform

Parameters:

  • im_gi (GXIMG) – Input image

  • trn_fil (str) – Output Transform file name string

  • spc_fil (str) – Output Power Spectrum file name string

New in version 5.0.

License: Geosoft Extended End-User License

classmethod filter_pg(pg, con_fil, tr, dx, dy, rot)[source]

Apply 2D FFT filters to data in pager

Parameters:

  • pg (GXPG) – Pager obj

  • con_fil (str) – FFT filter control file

  • tr (GXTR) – GXTR obj

  • dx (float) – rDx - X increment

  • dy (float) – rDy - Y increment

  • rot (float) – rRot- Rotation degree

New in version 5.0.

License: Geosoft Extended End-User License

classmethod filter_response(con_fil, start, increment, input_vv, output_vv, profile_vv)[source]

Calculates response for filter(s) defined in control file. Not specific to 2D.

Parameters:

  • con_fil (str) – FFT filter control file

  • start (float) – Wavenumber start

  • increment (float) – Wavenumber increment

  • input_vv (GXVV) – Input spectrum

  • output_vv (GXVV) – Output spectrum

  • profile_vv (GXVV) – Output filter profile

New in version 9.9.

License: Geosoft Open License

classmethod flt(im_gi, out_fil, con_fil)[source]

GXFFT2 filter

Parameters:

  • im_gi (GXIMG) – Input image (Transform grid)

  • out_fil (str) – Output file (Transform grid)

  • con_fil (str) – Control file

New in version 5.0.

License: Geosoft Extended End-User License

classmethod flt_inv(im_gi, out_fil, con_fil)[source]

GXFFT2 filter and inverse

Parameters:

  • im_gi (GXIMG) – Input image (Transform grid)

  • out_fil (str) – Output file

  • con_fil (str) – Control file

New in version 5.0.

License: Geosoft Extended End-User License

is_null()[source]

Check if this is a null (undefined) instance

Returns:

True if this is a null (undefined) instance, False otherwise.

Return type:

bool

classmethod null()[source]

A null (undefined) instance of GXFFT2

Returns:

A null GXFFT2

Return type:

GXFFT2

classmethod pow_spc(im_gi, spc_fil)[source]

GXFFT2 transform power spectrum

Parameters:

  • im_gi (GXIMG) – Input image (Transform grid)

  • spc_fil (str) – Output Power Spectrum file name string

New in version 5.0.

License: Geosoft Extended End-User License

classmethod rad_spc(im_gi, spc_fil)[source]

GXFFT2 transform Radially averaged power spectrum

Parameters:

  • im_gi (GXIMG) – Input image (Transform grid)

  • spc_fil (str) – Output Radial Spectrum file name string

New in version 5.0.

License: Geosoft Extended End-User License

classmethod rad_spc1(img, vv)[source]

GXFFT2 transform Radially averaged power spectrum for one GXIMG

Parameters:

  • img (GXIMG) – Input image (Transform grid)

  • vv (GXVV) – Output Radial Spectrum GXVV

New in version 7.2.

License: Geosoft Open License

classmethod rad_spc2(img1, img2, vv, v_vst, opt)[source]

GXFFT2 transform Radially averaged power spectrum for two IMGs

Parameters:

  • img1 (GXIMG) – Input image1 (Transform grid1 - G)

  • img2 (GXIMG) – Input image2 (Transform grid2 - H)

  • vv (GXVV) – Output Radial Spectrum GXVV

  • v_vst (GXVV) – Output Radial Spectrum Standard deviation VVst (Null: no calc)

  • opt (int) – lOpt - 1: <Re(GH*/HH*)> GXVV; 0: <Re(GH*)> GXVV

New in version 7.2.

License: Geosoft Open License

classmethod rad_spc_alt(im_gi, spc_fil)[source]

GXFFT2 transform Radially averaged power spectrum - log before average and no normalization

Parameters:

  • im_gi (GXIMG) – Input image (Transform grid)

  • spc_fil (str) – Output Radial Spectrum file name string

New in version 9.4.

License: Geosoft Extended End-User License

classmethod td_xd_y(img_tx, img_ty, out_fil, inv_flg)[source]

GXFFT2 filter (calculate T from the derivatives Tx and Ty)

Parameters:

  • img_tx (GXIMG) – Input dX image (Transform grid)

  • img_ty (GXIMG) – Input dY image (Transform grid)

  • out_fil (str) – Output T file name

  • inv_flg (int) – 0 - no invers, 1 - invers FFT applied

New in version 5.0.1.

License: Geosoft Extended End-User License

classmethod trans_pg(pg, opt)[source]

Apply 2D FFT transform to data in pager

Parameters:

New in version 5.0.

License: Geosoft Extended End-User License

FFT2_PG constants

Pager Direction

FFT2_PG_FORWARD

Forward

gxapi.FFT2_PG_FORWARD = 0
FFT2_PG_INVERSE

Inverse

gxapi.FFT2_PG_INVERSE = 1