From 68298d6fd3cbbb126fb1ae1eb4a0ff27ce224c01 Mon Sep 17 00:00:00 2001 From: Stefano Zibetti <stefano.zibetti@inaf.it> Date: Tue, 27 Jul 2021 10:19:41 +0000 Subject: [PATCH] Upload New File --- README | 156 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 156 insertions(+) create mode 100644 README diff --git a/README b/README new file mode 100644 index 0000000..b3000b3 --- /dev/null +++ b/README @@ -0,0 +1,156 @@ +Adaptsmooth V.2.7.1 15.11.2010 by Stefano Zibetti (MPIA&DARK) +Usage: adaptsmooth -p|b|l|m [-a] [-r RMS_SKY] [-G EFFECTIVE_GAIN] +[-s SN] [-L L] [-c SLCUT] input_image output_image mask + -p : noise mode: poisson+background + -b : noise mode: background-dominated + -l : noise mode: local + -m : switch to input-mask mode + -a : use arithmetic mean instead of median + -r RMS_SKY (requested in poisson+bkg and bkg-dominated noise mode) + -G EFFECTIVE_GAIN : e- per ADU (requested in poisson+bkg mode) + -s SN : minimum S/N requested (defaults to 20.0) + -L L : maximum smoothing radius (defaults to max=27) + -c SLCUT : smoothing level cut + 0: no exclusions; 1: exclude first level (1pix scale) from all others; + N<0: exclude up to the (-N)th level below current. Defaults to 0 + + + +adaptsmooth adaptively smooths images by replacing each pixel in the +input image with an average (median or mean) of the pixels in a +surrounding region of radius R, a.k.a. "smoothing level" L. L is +varied on a pixel-by-pixel base to allow the smoothed image to reach a +give S/N, or, in alternative, based on a pre-computed mask. + +I M P O R T A N T : The input image is assumed to be +*background-subtracted*. + +For general information about the algorithms and the code please refer +to the "paper". Here you can find a quick manual. + +-- Getting and installing the code + +You can get the code package adaptsmooth.tgz from this "URL" or by +requesting it directly to the author zibetti@mpia.de. + +Before installing the code check that you have the CFITSIO library +installed (http://heasarc.nasa.gov/fitsio/). + +To install the code follow these steps: +cd to your preferred installation directory +tar -zxf adaptsmooth.tgz +cd adaptsmooth_current_distr +edit the Makefile to specify: + BINDIR directory where the adaptsmooth executable will be + CFITSIO_LFLAG directory where the libcfitsio.a is located + CFITSIO_IFLAG directory where the fitsio*.h files are located +run "make adaptsmooth" +done! +Make sure that $BINDIR is in your executable PATH + +-- Note on fits file i/o +adaptsmooth assumes images are in the primary HDU of the fits files. +adaptsmooth takes as input image any numeric format (integer or float, +single or double precision) and internally converts it to +single-precision floating point. The output image is always a +single-precision float. The output mask is short-integer type. When +the mask is input, only integer types are accepted. + +All header information in the input image is propagated to the output +image (and mask if the case), with the addition of the history and all +relevant parameters of adapthsmooth-ing. + +Overwriting of output file is not allowed in the current version. + +-- Running the code +adaptsmooth runs from command line. + +Just issuing "adaptsmooth" returns a summary of the usage (reported at +the beginning of this document). + +Here is a more in-depth explanation of the usage and available +options. + +adaptsmooth always requires a mode option (p|b|l|m), an input fits +image, a name for the output image and one for the smoothing mask, +which contains the smoothing level at each position. + +Mode options p|b|l specify that the program determines the smoothing +to be applied based on different noise estimates in the input image +itself: in p mode poisson+background noise is assumed, in b +background-dominated noise, in l mode noise is given by the local +rms. At each pixel, the smoothing is iteratively increased until the +requested S/N or the maximum smoothing level is reached. In this +second case, the underflow value -1e10 is output into the image and +100 is written in the smoothing mask. + +Mode option m tells adaptsmooth to smooth according the smoothing +mask, given as input. + +p mode requires background rms noise (-r parameter) and the effective +gain, i.e. the number of photoelectrons per ADU (-G parameter) to be +specified. + +b mode requires background rms noise (-r parameter) + +l mode does not require any further option, as well as m mode + +Images are meant to be standard fits images. Pixels are always assumed +to be in the primary extension. The input image can be any numeric +type, although internal conversion to single precision float is +applied. The output image is single precision float. As for the mask, +in input-mask mode it must be any integer type, in output is +short-integer. + +--Optional parameters + +-s : specifies the minimum S/N to reach at each pixel (default is 20). +-L : specifies the maximum smoothing level that can be reached + (default is the maximum allowed by the code, i.e. 27) +-a : specifies to use the arithmetic mean instead of the median + (default) as average +-c : specifies the smoothing level cut (default is 0, i.e. no cuts) + +"Smoothing level cuts" can be useful to avoid bright localized sources +to contaminate the surroundings. See the "paper" for more details. + -c 0 (default) means no exclusions + -c 1 excludes all pixels that are individually above the S/N + threshold, that therefore do not contribute to smoothed levels + -c N (N<0) exclude all pixels that are up to -N levels below the + current. + + + +--Examples: + +a) smooth an image with background-dominated noise rms=2.4, to a +minimum S/N of 10.0, up to a max smoothing level of 10 (no pixel +exclusion): + +adaptsmooth -b -r 2.4 -s 10.0 -L 10 image.fits image_smooth.fits image_mask.fits + +b) smooth an image assuming poisson+background noise, rms=2.4 and +effective gain=5.2 e-/ADU, to a minimum S/N of 10.0, up to a max +smoothing level of 10 (no pixel exclusion): + +adaptsmooth -p -r 2.4 -G 5.2 -s 10.0 -L 10 image.fits image_smooth.fits image_mask.fits + +c) smooth an image with rms noise determined locally, to a minimum S/N of +10.0, up to a max smoothing level of 10 (no pixel exclusion): + +adaptsmooth -l -s 10.0 -L 10 image.fits image_smooth.fits image_mask.fits + +d) smooth an image according to a pre-computed mask (no pixel exclusion): + +adaptsmooth -m image.fits image_smooth.fits image_mask.fits + +e) smooth an image with rms noise determined locally, to a minimum S/N +of 10.0, up to a max smoothing level of 10, excluding pixels whose +smoothing level is lower by 2 wrt the current level: + +adaptsmooth -l -s 10.0 -L 10 -c 2 image.fits image_smooth.fits +image_mask.fits + +f) as a) but using average instead of median: + +adaptsmooth -b -a -r 2.4 -s 10.0 -L 10 image.fits image_smooth.fits image_mask.fits -- GitLab