ObitImageUtil.c File Reference

ObitImageUtil module function definitions for ObitImage class. More...

#include <sys/types.h>
#include <time.h>
#include "ObitImageUtil.h"
#include "ObitUVWeight.h"
#include "ObitSkyGeom.h"
#include "ObitFInterpolate.h"
#include "ObitPBUtil.h"
#include "ObitIOImageFITS.h"
#include "ObitFArrayUtil.h"

Functions
ObitImage *	ObitImageUtilCreateImage (ObitUV *inUV, glong fieldNo, gboolean doBeam, ObitErr *err)
	Public: Create an ObitImage from uv data.
void	ObitImageUtilMakeImage (ObitUV *inUV, ObitImage *outImage, glong channel, gboolean doBeam, gboolean doWeight, ObitErr *err)
	Public: Fill an image with an image made from from uv data.
void	ObitImageUtilInterpolateImage (ObitImage *inImage, ObitImage *outImage, gint *inPlane, gint *outPlane, glong hwidth, ObitErr *err)
	Public: Interpolate pixels in one image to another.
void	ObitImageUtilInterpolateImageZern (ObitImage *inImage, ObitImage *outImage, gint *inPlane, gint *outPlane, glong hwidth, gint nZern, gfloat *ZCoef, ObitErr *err)
	Public: Interpolate pixels in one image to another with Zernike corrections.
void	ObitImageUtilInterpolateWeight (ObitImage *inImage, ObitImage *outImage, ObitImage *outWeight, gboolean memOnly, gint radius, gint *inPlane, gint *outPlane, glong hwidth, ObitErr *err)
	Public: Interpolate pixels in one image to another giving output weighting.
void	ObitImageUtilPBCorr (ObitImage *inImage, ObitImage *pntImage, ObitImage *outImage, gint *inPlane, gint *outPlane, gfloat antSize, ObitErr *err)
	Public: Correct (divide) an image by the primary beam pattern of another.
void	ObitImageUtilPBApply (ObitImage *inImage, ObitImage *pntImage, ObitImage *outImage, gint *inPlane, gint *outPlane, gfloat antSize, ObitErr *err)
	Public: Multiply an image by the primary beam pattern of another.
void	ObitImageUtilPBImage (ObitImage *pntImage, ObitImage *outImage, gint *outPlane, gfloat antSize, gfloat minGain, ObitErr *err)
	Public: Fill image with the primary beam pattern.
void	ObitImageUtilImagParm (gfloat MaxBL, gfloat MaxW, gfloat *Cells, gfloat *Radius)
	Public: determine imaging parameters from UVW Extrema.
ObitImage *	ObitImageUtilArray2Image (gchar *fileName, gint disk, ObitFArray *inArray, ObitErr *err)
	Public: Create a FITS image from an ObitFArray.
ObitImage *	ObitImageUtilQuanFITS (ObitImage *inImage, gchar *fileName, gint disk, ObitErr *err)
	Public: Quantize an ObitImage and write to a FITS image.
void	ObitImageUtilMakeCube (ObitImageDesc *inDesc, ObitUVDesc *UVDesc, ObitImageDesc *outDesc, gchar *Stokes, gint bchan, gint echan, gint incr, ObitErr *err)
	Public: Define an Image freq cube descriptor from a single plane and uv Descriptors.
void	ObitImageUtilInsertPlane (ObitImage *in, ObitImage *out, glong *plane, ObitErr *err)
	Public: Insert a plane from an image into a cube.
void	ObitImageUtilUV2ImageDesc (ObitUVDesc *UVDesc, ObitImageDesc *imageDesc, gint nchavg)
	Public: Convert an ObitUVDesc to an ObitImageDesc.
void	ObitImageUtilVel (ObitImage *inImage, ObitImage *outImage, ObitErr *err)
	Public: Flux weighted velocity image from Cube.
void	ObitImageUtilSelCopy (ObitImage *inImage, ObitImage *outImage, ObitErr *err)
	Public: Copy with selection by pixel increment.

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Detailed Description

ObitImageUtil module function definitions for ObitImage class.

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Function Documentation

ObitImage* ObitImageUtilArray2Image (  gchar *  fileName, gint  disk, ObitFArray *  inArray, ObitErr *  err )

Public: Create a FITS image from an ObitFArray. Currently only does two to four dimensions. Parameters: fileName  output FITS image file name disk  output FITS disk number inArray  Data array to be written err  Error stack, returns if not empty. Returns: pointer to the new object.

ObitImage* ObitImageUtilCreateImage (  ObitUV *  inUV, glong  fieldNo, gboolean  doBeam, ObitErr *  err )

Public: Create an ObitImage from uv data. Imaging parameters are on the inUV info member as arrays for a number of fields. "nChAvg" OBIT_int (1,1,1) number of channels to average. This is for spectral line observations and is ignored if the IF axis on the uv data has more than one IF. Default is continuum = average all freq/IFs. 0=> all. "rotate" OBIT_float (?,1,1) Desired rotation on sky (from N thru E) in deg. [0] "nx" OBIT_int (?,1,1) Dimension of image in RA [no default]. This and the following are arrays with one entry per field. "nxBeam" OBIT_int (?,1,1) Dimension of beam in RA, [def. nx] "ny" OBIT_int (?,1,1) Dimension of image in declination[no default] "nyBeam" OBIT_int (?,1,1) Dimension of beam in declination, [def. ny] "xCells" OBIT_float (?,1,1) X (=RA) cell spacing in asec [no default] "yCells" OBIT_float (?,1,1) Y (=dec) cell spacing in asec [no default] "xShift" OBIT_float (?,1,1) Desired shift in X (=RA) in degrees. [0] "yShift" OBIT_float (?,1,1) Desired shift in Y (=dec) in degrees. [0] Parameters: inUV  Input uv data. fieldNo  Which field (1-rel) in imaging parameter arrays. doBeam  if TRUE also create beam as the myBeam member of returned image. err  Error stack, returns if not empty. Returns: Pointer to the newly created ObitImage.

void ObitImageUtilImagParm (  gfloat  MaxBL, gfloat  MaxW, gfloat *  Cells, gfloat *  Radius )

Public: determine imaging parameters from UVW Extrema. Otherwise, maximum field size from Lecture 2 (A. R. Thompson) in "Synthesis Imaging in Radio Astronomy II", PASP, vol. 180, 1999, p. 24 is used. A correction is applied for the actual range in W. Parameters: MaxBL  maximum baseline length (sqrt(u*u+v*v)) MaxW  Max abs(w) in data. Cells  Cell spacing in asec. If zero on input the value is set based on MaxBL (1/4 min fringe spacing) Radius  Maximum undistorted Field of view in cells (Cells). If zero on input, the value is set from MaxW.

void ObitImageUtilInsertPlane (  ObitImage *  in, ObitImage *  out, glong *  plane, ObitErr *  err )

Public: Insert a plane from an image into a cube. Parameters: in  Input image with plane to copy out  Output cube to accept plane plane  (1-rel) pixel indices for planes 3-7 in out.

void ObitImageUtilInterpolateImage (  ObitImage *  inImage, ObitImage *  outImage, gint *  inPlane, gint *  outPlane, glong  hwidth, ObitErr *  err )

Public: Interpolate pixels in one image to another. There is no interpolation between planes Parameters: inImage  Image to be interpolated. outImage  Image to be written. Must be previously instantiated. inPlane  desired plane in inImage, 1-rel pixel numbers on planes 3-7 outPlane  desired plane in outImage hwidth  interpolation halfwidth (1 or 2 usually OK, 4 max) err  Error stack, returns if not empty.

void ObitImageUtilInterpolateImageZern (  ObitImage *  inImage, ObitImage *  outImage, gint *  inPlane, gint *  outPlane, glong  hwidth, gint  nZern, gfloat *  ZCoef, ObitErr *  err )

Public: Interpolate pixels in one image to another with Zernike corrections. There is no interpolation between planes Parameters: inImage  Image to be interpolated. outImage  Image to be written. Must be previously instantiated. inPlane  desired plane in inImage, 1-rel pixel numbers on planes 3-7 outPlane  desired plane in outImage hwidth  interpolation halfwidth (1 or 2 usually OK, 4 max) nZern  Number of Zernike terms, can handle up to 17 ZCoef  Array of Zernike coefficients (piston ignored) err  Error stack, returns if not empty.

void ObitImageUtilInterpolateWeight (  ObitImage *  inImage, ObitImage *  outImage, ObitImage *  outWeight, gboolean  memOnly, gint  radius, gint *  inPlane, gint *  outPlane, glong  hwidth, ObitErr *  err )

Public: Interpolate pixels in one image to another giving output weighting. Also calculates a weight based on a circle defined by radius; this is 1.0 in the center and tapers with distance^2 to 0.0 outside. If memOnly then the input image plane is assumed in inImage and only memory resident parts of outImage and outWeight are modified. There is no interpolation between planes Parameters: inImage  Image to be interpolated. outImage  Image to be written. Must be previously instantiated. outWeight  Weight image to be written. Must be previously instantiated and have same geometry as outImage. memOnly  if TRUE then work only in memory radius  Radius in pixels of weighting circle inPlane  Desired plane in inImage, 1-rel pixel numbers on planes 3-7; ignored if memOnly outPlane  Desired plane in outImage; ignored if memOnly hwidth  Interpolation halfwidth (1 or 2 usually OK, 4 max) err  Error stack, returns if not empty.

void ObitImageUtilMakeCube (  ObitImageDesc *  inDesc, ObitUVDesc *  UVDesc, ObitImageDesc *  outDesc, gchar *  Stokes, gint  bchan, gint  echan, gint  incr, ObitErr *  err )

Public: Define an Image freq cube descriptor from a single plane and uv Descriptors. This should be called before the image is Opened or instantiated. Parameters: inDesc  Input Image Descriptor. UVDesc  Input UV Descriptor. outDesc  Output Image Descriptor Stokes  Stokes parameter of image ' '=>'I', (I, Q, U, V, R, L) bchan  first (1-rel) channel in UVDesc echan  highest (1-rel) channel in UVDesc incr  channel increment in input nchavg  How many uv channels to average per image channel. Ignored if uv data has multiple IFs.

void ObitImageUtilMakeImage (  ObitUV *  inUV, ObitImage *  outImage, glong  channel, gboolean  doBeam, gboolean  doWeight, ObitErr *  err )

Public: Fill an image with an image made from from uv data. Uses (creating if necessary) the myGrid member of out. Parameters: inUV  Input uv data. Should be in form of stokes to be imaged will all calibration and selection applied and any weighting applied. outImage  Image to be written. Must be previously instantiated. Beam normalization factor is written to output Beam infoList as SUMWTS doBeam  if TRUE also make beam. Will make the myBeam member of outImage. If FALSE, and myGrid->BeamNorm 0.0 then reads SUMWTS value from beam infolist doWeight  if TRUE Apply uniform weighting corrections to uvdata before imaging. Weighting parameters on inUV: "nuGrid" OBIT_int scalar = Number of "U" pixels in weighting grid. [defaults to "nx"] "nvGrid" OBIT_int scalar = Number of "V" pixels in weighting grid. "WtBox" OBIT_int scalar = Size of weighting box in cells [def 1] "WtFunc" OBIT_int scalar = Weighting convolution function [def. 1] 1=Pill box, 2=linear, 3=exponential, 4=Gaussian if positive, function is of radius, negative in u and v. "xCells" OBIT_float scalar = Image cell spacing in X in asec. "yCells" OBIT_float scalar = Image cell spacing in Y in asec. "UVTaper" OBIT_float scalar = UV taper width in kilowavelengths. [def. no taper]. NB: If the taper is applied her is should not also be applied in the imaging step as the taper will be applied to the output data. "Robust" OBIT_float scalar = Briggs robust parameter. [def. 0.0] < -7 -> Pure Uniform weight, >7 -> Pure natural weight. Uses AIPS rather than Briggs definition of Robust. "WtPower" OBIT_float scalar = Power to raise weights to. [def = 1.0] Note: a power of 0.0 sets all the output weights to 1 as modified by uniform/Tapering weighting. Applied in determinng weights as well as after. channel  Which frequency channel to image, 0->all. err  Error stack, returns if not empty.

void ObitImageUtilPBApply (  ObitImage *  inImage, ObitImage *  pntImage, ObitImage *  outImage, gint *  inPlane, gint *  outPlane, gfloat  antSize, ObitErr *  err )

Public: Multiply an image by the primary beam pattern of another. For frequencies < 1 GHz uses the VLA polynomial gain curves, for higher frequencies, it uses a jinc function based on the antenna size. Parameters: inImage  Image to be corrected pntImage  Image with pointing position outImage  Image to be written. Must be previously instantiated. inPlane  Desired plane in inImage, 1-rel pixel numbers on planes 3-7; ignored if memOnly outPlane  Desired plane in outImage; ignored if memOnly antSize  Antenna size err  Error stack, returns if not empty.

void ObitImageUtilPBCorr (  ObitImage *  inImage, ObitImage *  pntImage, ObitImage *  outImage, gint *  inPlane, gint *  outPlane, gfloat  antSize, ObitErr *  err )

Public: Correct (divide) an image by the primary beam pattern of another. For frequencies < 1 GHz uses the VLA polynomial gain curves, for higher frequencies, it uses a jinc function based on the antenna size. Parameters: inImage  Image to be corrected pntImage  Image with pointing position outImage  Image to be written. Must be previously instantiated. inPlane  Desired plane in inImage, 1-rel pixel numbers on planes 3-7; ignored if memOnly outPlane  Desired plane in outImage; ignored if memOnly antSize  Antenna size, used to correct beam for freq>1 GHz, def. 25m. err  Error stack, returns if not empty.

void ObitImageUtilPBImage (  ObitImage *  pntImage, ObitImage *  outImage, gint *  outPlane, gfloat  antSize, gfloat  minGain, ObitErr *  err )

Public: Fill image with the primary beam pattern. For frequencies < 1 GHz uses the VLA polynomial gain curves, for higher frequencies, it uses a jinc function based on the antenna size. Parameters: pntImage  Image with pointing position outImage  Image to be written. Must be previously instantiated. outPlane  Desired plane in outImage on planes 3-5; ignored if memOnly antSize  Antenna size minGain  Min. allowed antenna gain, lower values are blanked err  Error stack, returns if not empty.

ObitImage* ObitImageUtilQuanFITS (  ObitImage *  inImage, gchar *  fileName, gint  disk, ObitErr *  err )

Public: Quantize an ObitImage and write to a FITS image. Image RMS derived from histogram fitting and should be a reasonable estimate of the "noise". Selection by blc, trc in inImage is honored. Parameters: inImage  Image to quantize, parameters in info: "factor" OBIT_float (1,1,1) quantize at factor*RMS [def 0.2] RMS is the minimum rms in any selected plane. "quant" OBIT_float (1,1,1) quantization level, has presidence over factor, def.(or <=0) use factor fileName  output FITS image file name disk  output FITS directory number err  Error stack, returns if not empty. Returns: pointer to the new object, may be NULL on failure.

void ObitImageUtilSelCopy (  ObitImage *  inImage, ObitImage *  outImage, ObitErr *  err )

Public: Copy with selection by pixel increment. Parameters: inImage  Input image Parameters in info: "BLC" OBIT_int (7) Lowest x,y,v pixel number selected [def 1,1,1] "TRC" OBIT_int (7) Highest x,y,v pixel number selected [def all] "inc" OBIT_int (7) Pixel increment on each axis [def all 1] outImage  Image to be written. Must be previously instantiated. err  Error stack, returns if not empty.

void ObitImageUtilUV2ImageDesc (  ObitUVDesc *  UVDesc, ObitImageDesc *  imageDesc, gint  nchavg )

Public: Convert an ObitUVDesc to an ObitImageDesc. Needs any xshift an y shift filled into the image prior to call. Information about the first two axes other than the type an coordinate value need to be set separately. to get the final position correct. Parameters: UVDesc  Input UV Descriptor. imageDesc  Output image Descriptor nchavg  How many uv channels to average per image channel. Ignored if uv data has multiple IFs.

void ObitImageUtilVel (  ObitImage *  inImage, ObitImage *  outImage, ObitErr *  err )

Public: Flux weighted velocity image from Cube. Input image is clipped to only significant pixels. Convolution of each plane by Parms[3] cells used to mask image Parameters: inImage  Input velocity cube image Parameters in info: "BLC" OBIT_int (7) Lowest x,y,v pixel number selected [def 1,1,1] "TRC" OBIT_int (7) Highest x,y,v pixel number selected [def all] Note: the first two output axes will have an even number of pixels. "Parms" OBIT_float (4) Parameters [0] min. RMS (convolved image) [1] min. fraction of peak [2] <0.5 => blank fill, else zero fill [3] Convolution size (0->5) outImage  Image to be written. Must be previously instantiated. err  Error stack, returns if not empty.

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