; IMEAN ;--------------------------------------------------------------- ;! displays the mean & extrema and plots histogram of an image ;# Task Plot ANALYSIS ;----------------------------------------------------------------------- ;; Copyright (C) 1995, 1999, 2002-2004, 2006-2009, 2011-2012, 2014 ;; Associated Universities, Inc. Washington DC, USA. ;; ;; This program is free software; you can redistribute it and/or ;; modify it under the terms of the GNU General Public License as ;; published by the Free Software Foundation; either version 2 of ;; the License, or (at your option) any later version. ;; ;; This program is distributed in the hope that it will be useful, ;; but WITHOUT ANY WARRANTY; without even the implied warranty of ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;; GNU General Public License for more details. ;; ;; You should have received a copy of the GNU General Public ;; License along with this program; if not, write to the Free ;; Software Foundation, Inc., 675 Massachusetts Ave, Cambridge, ;; MA 02139, USA. ;; ;; Correspondence concerning AIPS should be addressed as follows: ;; Internet email: aipsmail@nrao.edu. ;; Postal address: AIPS Project Office ;; National Radio Astronomy Observatory ;; 520 Edgemont Road ;; Charlottesville, VA 22903-2475 USA ;----------------------------------------------------------------------- IMEAN LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC IMEAN: Task to print the mean, rms and extrema in an image DOHIST -3.0 2.01 True (1.0) do histogram plot. = 2 => flux on x axis USERID -32000.0 32000.0 User ID. ignored INNAME Image name (name) INCLASS Image name (class) INSEQ 0.0 9999.0 Image name (seq. #) INDISK 0.0 9.0 Disk drive # BLC -1.0 4096.0 Bottom left corner of image 0=>entire image TRC 0.0 4096.0 Top right corner of image 0=>entire image DOINVERS -1.0 1.0 > 0 => histogram outside <=0 => inside BLC/TRC NBOXES 0.0 1024.0 No. of ranges for histogram. PIXRANGE Min and max range for hist. FUNCTYPE 'LG' => do log10 plot of # samples, else linear DOMODEL -1.0 1.0 > 0 fit, plot Gaussian DOCAT -1.0 3.0 Put true RMS in header >= 2 even for amall subimg. LTYPE -410.0 410.0 Type of labeling: 1 border, 2 no ticks, 3 - 6 standard, 7 - 10 only tick labels <0 -> no date/time DOPRINT 0 - no print, -3 brief OUTTEXT Name of output log file, No output to file if blank DOTV -1.0 1.0 > 0 Do plot on the TV, else make a plot file GRCHAN 0.0 8.0 Graphics channel 0 => 1. PIXAVG @ Mean noise value PIXSTD @ True noise rms TRIANGLE @ Brightness at the top 1%, 2%, @ 3%, ,,,50% of full histogram ---------------------------------------------------------------- IMEAN Type: Task Use: IMEAN will read a portion of an image and print the mean and rms brightnesses found. It also prints the location and value of the max and min brightnesses in that portion. For clean maps, the mean is converted into a total flux. An option to generate a histogram plot and/or print file is available. It also computes the peak and rms of the histogram of the image in an attempt to determine the mean and rms of the noise part of the signal. It determines the initial values for this from the header (ACTNOISE, ACTMEAN) or from a robust fit from the first plane of the image. Note that pixel values which are exactly zero are not used in the fit for the rms. This allows blanked pixels to be REMAGed to zero without affecting these computations. Three adverbs are returned by the task. This allows the fit mean and noise to be used in other computations or tasks. It also returns in TRIANGLE(i) the brightness level exceeded by i% of the pixels. The aperture for the computation may be either rectangular or circular. The histogram is computed even if it will not be plotted since it may be printed. Thus, BLC, TRC, DOINVERS, NBOXES, PIXRANGE are used even of DOHIST <= 0. A special one-line print option is available when DOPRINT=-3. Adverbs: DOHIST......True (>0) means plot the histogram determined with NBOXES and PIXRANGE. A second histogram is always computed, ignoring these adverbs, in an attempt to fit a Gaussian to the peak. If that is succesful, the fit is plotted on any plotted histogram. If 0 < DOHIST <= 1, then the flux is plotted on the Y axis and the counts on the X axis. If DOHIST > 1, the axes are reversed - which is a more common form. USERID......User ID of owner of image. Ignored. INNAME......Image name(name). Standard defaults. INCLASS.....Image name(class). Standard defaults. INSEQ.......Image name(seq. #). 0 => highest. INDISK......Disk drive # of image. 0 => any. BLC.........The Bottom Left-hand pixel of the subarray of the image to be analysed. The value (0,0) means (1,1). If BLC(1) = -1, then BLC(2) is taken as the radius of a circular aperture centered in TRC(1),TRC(2) which must be specified, not defaulted. TRC.........The Top Right-hand pixel of the subarray of the image to be analysed. The value (0,0) means the top right hand corner of the entire image. See note about circular aperture under BLC above. DOINVERS....> 0 Do the histogram OUTSIDE the rectangular or circular area defined by BLC/TRC <= 0 Do the histogram INSIDE (including borders) the rectangular or circular area defined by BLC/TRC NBOXES......Number of boxes used in computing histogram for plotting. The number of boxes used to compute the apparent noise rms is controlled by the task. <= 1 => 101 boxes, > 1024 => 512 PIXRANGE....Intensity range min/max over which plotted histogram is computed. Max <= min (i.e. 0) => full range. This is used to set the range between the center of box 1 and the center of box NBOXES. FUNCTYPE....Type of axis plot for number of samples in each box. 'LG' => log base 10, else linear. DOMODEL.....> 0 => fit a Gaussian to the histogram and plot it along with the histogram. DOCAT.......> 0 => write the new actual noise estimate as keyword ACTNOISE and the estimate zero level as ACTMEAN in the image header. If BLC/TRC occupies less than 20% of a plane or less than 10% of a cube, this function will be done only if DOCAT >= 2. LTYPE.......Labelling type, see HELP LTYPE for details: 1 = border, 2 = no ticks, 3 or 7 = standard, 4 or 8 = relative to ref. pixel, 5 or 9 = relative to subimage (BLC, TRC) center, 6 or 10 = pixels. 7-10 all labels other than tick numbers and axis type are omitted. Less than 0 is the same except that the plot file version number and create time are omitted. Add n * 100 to alter the metric scaling. DOPRINT.....Additional print control when OUTTEXT is not blank. = 0 => no printing, = -3 => print a single line giving BLC(3-7), TRC(3-7), minimum, maximum, flux, and rms all in one line. For plots note that task RSPEC will compute rmses and plot the spectra (and print it too). OUTTEXT.....Output file to log measurements for later user processing. File created if it does not exist and appended to if it already exists. Nothing is written to a file if the name is blank. File name should contain directory and file parts, i.e, "LOCAL:IMEAN.OUT" or "RUNFIL:IMPORTANT.POINTS". The histogram is printed into the file even if DOHIST <= 0. DOTV........> 0 => plot directly on the TV device, otherwise make a plot file for later display on one or more devices (including the TV if desired). GRCHAN......Graphics channel (1 - 7) to use for line drawing. 0 => 1 Output adverbs PIXAVG......Mean value of the noise part of the image. The final fit to the noise portion is returned. PIXSTD......RMS of the noise portion of the image. The final fit is returned. TRIANGLE....TRIANGLE(i) returns the brightness which is exceeded by only i% of the pixels. Values for 1 to 50% are returned. Note that the histoigram used to compute this is computed over the full intensity range of the image, not just PIXRANGE. ----------------------------------------------------------------