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% @(#)citterwave.hlq 19.1 (ESO-IPG) 02/25/03 13:34:18
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%++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
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%.COPYRIGHT (c) 1993 European Southern Observatory
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%.AUTHOR 18-MAY-93, IPG/ESO
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%.KEYWORDS MIDAS, help files,
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%.PURPOSE On-line help file for the command: CITTERT/WAVE
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%.VERSION 1.0 JS : Creation, 18-MAY-93
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%----------------------------------------------------------------
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CITTERT/WAVE JS 18-MAY-93
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CITTERT/WAVE Image_In Psf Imag_Out [residual] [Nb_Scales, Max_Iter]
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[N_Sigma, Noise] [Epsilon] [Fwmh]
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Deconvolution by Van Cittert's algorithm with a regularization
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in the wavelet space. The deconvolution equation is:\\
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where I is the data, P is the PSF, B is the nopise and O is the
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CITTERT/WAVE Image_In Psf Imag_Out [residual] [Nb_Scales, Max_Iter]
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[N_Sigma, Noise] [Epsilon] [Fwhm]
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Image_In = Name of the image I
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Psf = Name of the Point Spread Function P
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Imag_Out = Name of the deconvolved image O
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residual = Name of the file wich will contain the residual
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residual = I - P * O\\
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default value is "residual.bdf"
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Nbr_Scale = Number of scales of the wavelet transform; default 4.
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Max_Iter = maximum number of iterations; The default value is 100
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N_Sigma = threshold parameter
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The threshold level_j at a scale j of the wavelet
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Level_j = N_Sigma * Noise_Standard_Deviation_Scale_j
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The standard deviation of the noise at the scale j is
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estimated from the noise standard deviation of the image
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N_Sigma = 4 is the default value.
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Sigma_Noise = Standard deviation of the noise. If Sigma_Noise = 0.
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then the standard deviation of the noise is estimated in
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the program. The default value is 0.
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Epsilon = Convergence parameter; default value is 0.001
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Fwhm = Full Width at Half Maximum. This parameter allows us to
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reduce the resolution in the deconvolved image. If
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Fwhm is greater than 0. then the resolution is limited
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the image of a star will be Gaussian with a a full width
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at half maximum equal to Fwmh.
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TRANSF/WAVE, FILTER/WAVE, LUCY/WAVE, GRAD/WAVE
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CITTERT/WAVE data psf result
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deconvolves the frame data by the psf and stores the
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deconvolved image in result.
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CITTERT/WAVE data psf result ? 4,300 3.5,50
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the standard deviation of the noise is 50, and the threshold
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level at the scale j is: 3.5 * Standard_deviation_Scale_j
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the maximum number of iterations is 300. But the program can
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stop before, due to the convergence parameter. 4 scales are
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used in the wavelet transform.
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CITTERT/WAVE data psf result ? 4,50 ? 0. 3.
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set the convergence paramater to zero, and the number of
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iterations to 50. In this case, 50 fifty iterations will be
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done. The Full Width at Half Maximum is equal to 3.