PLEASE NOTE : This is the documentation for the avs module executable transform1D, which contains the following modules: dfft1d dfht dhart1d difft1d dihart1d dmpp Any mention of xvimage is actually a "field 2D". Also, the INPUTs and OUTPUTs, which are mapped to avs parameters, inputs, and outputs, are for the khoros library routine. ********************************************************************************* Documentation for avs module dfft1d INPUT image pointer to VIFF structure containing image data to be processed. center_opt centering choice: 0 for centered, 1 for not centered. scale_opt scaling choice: 0 for no scaling, 1 for mul- tiplying by 1/n, 2 for multiplying by 1/sqrt(n), where n is the number of data points. procdir process direction: 0 indicated vector oriented processing, 1 indicates band oriented processing. OUTPUT image pointer to VIFF structure containing image data after processing. Return Value: 1 on success, 0 on failure. DESCRIPTION performs the 1D Fourier transform on a set of data sequences. It can operate on Real and Complex data. NOTE: complex data is expected to be in rectangular (not polar) form. The output data type is VFF_TYP_COMPLEX. The transform can be centered about its N/2 term by setting the -c option to 1. If -c is set to 0, the transform will not be centered (This is the default setting.). The output data can be scaled by 1/N or by 1/sqrt(N) if desired by using the -s option. The default setting is to leave the output data unscaled (-s = 0). If -s is set to 1, the output data is scaled by 1/N, where N in the number of points in the data sequence. The output can be scaled by 1/sqrt(N) by setting -s to 2. The default data processing direction for dfft1d is in the vector direction. This means that data stored in multiband format will be processed as a set of data sequences, where each sequence corresponds to a pixel location, and the points of each sequence are defined by the bands correspond- ing to that pixel location. The direction of processing can be changed so that each band is processed as a signal (instead of each vector being a signal) by setting the -d option to 1. SEE ALSO dfft1d(1), intro(3), vipl(3), verror(3), vutils(3) AUTHOR Ramiro Jordan and Donna Koechner COPYRIGHT Copyright 1992, University of New Mexico. All rights reserved. ********************************************************************************* Documentation for avs module dfht INPUT 1. img - a pointer to an xvimage structure containing the signal to be transformed 2. scale_flag - an integer which specifies whether the output from the transform should be left unscaled(0), scaled by 1/N(1), or scaled by 1/sqrt(N)(2). 3. dir_flag - an integer which specifies whether the transform should be taken down vectors(0) or across bands(1). OUTPUT 1. img - the input image is overwritten and the output is returned in its place. Be careful not to overwrite important data. dfht returns 1 upon success and 0 on failure. DESCRIPTION dfht performs a 1-D Fast Hadamard Transform on a signal. The Hadamard Transform uses a series of pulses as its basis functions. This program uses the successive doubling algor- ithim to implement a Fast Transform. The output coeffi- cients are, by definition, in sequency order. The output data may be scaled by 1/N, 1/sqrt(N), or not scaled at all. The default is to not scale the data at all. The only difference between a forward and a reverse Hadamard Transform is the scaling factor, so this routine functions as both a forward and reverse transform provided that one of the transforms (forward OR reverse) is set to scale by 1/N and the other performs no scaling. Signals may be processed either across bands or in the vec- tor direction. The default data processing direction is across bands. The Following references were used in creating this program : 1. "Digital Image Processing, Second Edition" Rafael C. Gonzale Paul Wintz Addison-Wesley Publishing Company, Reading Mas- sachusetts, 1987 2. "The C User's Journal", July 1989, "The Fast Walsh Transform", p101 Ian AshDown SEE ALSO dfht(1), intro(3), vipl(3), verror(3), vutils(3) lvfwt2d(3) RESTRICTIONS dfht only operates on data of type VFF_TYP_FLOAT. Images using maps are not accepted and neither is data with expli- cit locations included. AUTHOR Per Lysne COPYRIGHT Copyright 1992, University of New Mexico. All rights reserved. ********************************************************************************* Documentation for avs module dhart1d INPUT image contains the signal data to be transformed. trans_dir specifies the transform direction. 0 indi- cates the inverse transform, 1 indicates the forward transform. This is only useful when center_opt is set to 1 (center). center_opt centering choice: 1 for centered, 0 for not centered. scale_opt scaling choice: 0 for no scaling, 1 for mul- tiplying by 1/n, 2 for multiplying by 1/sqrt(n), where n is the number of data points. process_dir processing direction: 0 for vector processing or 1 for band oriented processing. OUTPUT image holds the result of the transform. Return Value: 1 on success, 0 on failure. DESCRIPTION 1D Forward Hartley Transform. Performs the 1D forward Hart- ley transform of a sequence. It can operate on Real data. The transform can be centered about its N/2 term by setting the -c option to 1. (This is the default setting.) If -c is set to 0, the transform will not be centered. The output data can be scaled by 1/N or by 1/sqrt(N) if desired by using the -s option. The default setting is to leave the output data unscaled (-s = 0). If -s is set to 1, the output data is scaled by 1/N, where N in the number of points in the data sequence. The output can be scaled by 1/sqrt(N) by setting -s to 2. The default data processing direction for dfft1d is in the vector direction. This means that data stored in multiband format will be processed as a set of data sequences, where each sequence corresponds to a pixel location, and the points of each sequence are defined by the bands correspond- ing to that pixel location. The direction of processing can be changed so that each band is processed as a signal (instead of each vector being a signal) by setting the -d option to 1. SEE ALSO dhart1d(1), intro(3), vipl(3), verror(3), vutils(3) AUTHOR Jeremy Worley COPYRIGHT Copyright 1992, University of New Mexico. All rights reserved. ********************************************************************************* Documentation for avs module difft1d INPUT image pointer to VIFF structure containing image data to be processed. center_opt centering choice: 0 for not centered, 1 for centered. scale_opt scaling choice: 0 for no scaling, 1 for mul- tiplying by 1/n, 2 for multiplying by 1/sqrt(n), where n is the number of data points. procdir process direction: 0 indicated vector oriented processing, 1 indicates band oriented processing. OUTPUT image pointer to VIFF structure containing image data after processing. Return Value: 1 on success, 0 on failure. DESCRIPTION performs the 1D inverse Fourier transform on a set of data sequences. It can operate on Real and Complex data. NOTE: complex data is expected to be in rectangular (not polar) form. The output data type is VFF_TYP_COMPLEX. The transform can be centered about its N/2 term by setting the -c option to 1. If -c is set to 0, the transform will not be centered (This is the default setting.). The output data can be scaled by 1/N or by 1/sqrt(N) if desired by using the -s option. The default setting is to leave the output data unscaled (-s = 0). If -s is set to 1, the output data is scaled by 1/N, where N in the number of points in the data sequence. The output can be scaled by 1/sqrt(N) by setting -s to 2. The default data processing direction for difft1d is in the vector direction. This means that data stored in multiband format will be processed as a set of data sequences, where each sequence corresponds to a pixel location, and the points of each sequence are defined by the bands correspond- ing to that pixel location. The direction of processing can be changed so that each band is processed as a signal (instead of each vector being a signal) by setting the -d option to 1. SEE ALSO difft1d(1), intro(3), vipl(3), verror(3), vutils(3) AUTHOR Ramiro Jordan and Donna Koechner COPYRIGHT Copyright 1992, University of New Mexico. All rights reserved. ********************************************************************************* Documentation for avs module dihart1d INPUT -i input data file (xviff file) -o resulting output file (xviff file) [-c] select to center (1) or not to center (0) the transform [-d] data processing direction (0 = down vectors, 1 = across bands) [-s] scale fft by 1, 1/N or 1/sqrt(N) [-V] Gives the version for dihart1d [-U] Gives the usage for dihart1d [-P] prompts for command line options [-A[file1]] creates the answer file called dihart1d.ans [-a[file1]] uses dihart1d.ans as answer file DESCRIPTION 1D Inverse Hartley Transform. Performs the 1D inverse Hartley transform of a sequence. It can operate on Real data. The transform can be centered about its N/2 term by setting the -c option to 0. (This is the default setting.) If -c is set to 1, the transform will not be centered. The output data can be scaled by 1/N or by 1/sqrt(N) if desired by using the -s option. The default setting is to leave the output data unscaled (-s = 0). If -s is set to 1, the output data is scaled by 1/N, where N is the number of points in the data sequence. The output can be scaled by 1/sqrt(N) by setting -s to 2.N The default data processing direction for dfft1d is in the vector direction. This means that data stored in multiband format will be processed as a set of data sequences, where each sequence corresponds to a pixel location, and the points of each sequence are defined by the bands corresponding to that pixel location. The direction of processing can be changed so that each band is processed as a signal (instead of each vector being a signal) by setting the -d option to 1. SEE ALSO intro(1), verror(3), vgparms(3), vutils(3), ldihart1d(3) COPYRIGHT Copyright 1991, University of New Mexico. All rights reserved. Documentation for avs module dmpp INPUT image pointer to VIFF structure containing image data to be processed. mode determines type of data desired (0 = magni- tude, 1 = power, 2 = phase). output magnitude or power output option: 0 = magni- tude or power; 1 = log(magnitude or power); 2 = log(magnitude or power +1); 3 = ln(magnitude or power); 4 = ln(magnitude or power +1). phase phase output option: 0 = radians; 1 = degrees. direction process direction: 0 indicated vector oriented processing, 1 indicates band oriented processing. OUTPUT image pointer to VIFF structure containing image data after processing. Return Value: 1 on success, 0 on failure. DESCRIPTION determines the magnitude, power, or phase of each 1-D data point in the input data file. dmpp will find the 1-D magnitude, power, or phase of each data point. If magnitude or power is selected, it can gen- erate the log or natural log of the result, or the log or natural log of the result +1. If phase is selected, then dmpp can generate either the radian or degree result. dmpp does not work on explicit location data and will return an error when such a file is encountered. No output file will be created. dmpp works only on VFF_TYP_FLOAT or VFF_TYP_COMPLEX data files. Input/Output Files The input file must be of type VFF_TYP_FLOAT or VFF_TYP_COMPLEX. The output file returned will be the same size of the input file and the type will be VFF_TYP_FLOAT. Process direction Data can be processed with either band or vector orientation (-d option). The default data processing direction is in the vector direction (-d = 0). This means that data stored in multiband format will be processed as a set of data sequences, where each sequence corresponds to a pixel loca- tion, and the points of each sequence are defined by the bands corresponding to that pixel location. The direction of processing can be changed so that each band is processed as a signal (instead of each vector being a signal) by set- ting the -d option to 1. SEE ALSO dmpp(1), intro(3), vipl(3), verror(3), vutils(3) RESTRICTIONS dmpp works only on VFF_TYP_COMPLEX and VFF_TYP_FLOAT. dmpp does not work on explicit location data and will return an error when such a data file is encountered. - bugs_end AUTHOR Ramiro Jordan, Jeremy Worley COPYRIGHT Copyright 1992, University of New Mexico. All rights reserved. *********************************************************************************