Gamma DIFF: Reference Manual

phase_sum

ANSI-C program: ave_image.c

NAME
phase_sum - Calculate sum of input 2-D (float) phase files such as a stack of unwrapped interferograms (a-b, b-c, c-d...)

SYNOPSIS
phase_sum <im_list> <width> [start] [nlines] [pixav_x] [pixav_y] [zero_flag]

im_list	(input) text file containing list of names of co-registered data sets in column 1 (float)
<width>	number of samples/line
<sum>	(output) sum of input data files (float)
[start]	starting line (default: 1)
[nlines]	number of lines to process (enter - for default: entire file))
[pixav_x]	number of pixels to average in width (default: 1)
[pixav_y]	number of pixels to average in height (default:1)
[zero_flag]	zero flag: 0: interpret 0.0 as missing data value (default) NOTE: output pixels are set to 0.0 if any of the corresponding input pixels has 0.0 1: interpret 0.0 as valid data
[nmin]	minimum number of images required to calculate the average (enter - for default: all) (default: 3*nfiles/4)

EXAMPLE
phase_sum im_list sum 1750 1

sums images in float format listed in the data_tab file. Each line of these files is 1750 pixels wide

DESCRIPTIONphase_sum is used to sum a stack of 2D data files in float format (32-bit floating point). It also has the capability to sum the data sets in x and y dimensions as specified by the pixave_x and pixav_y parameters on the command line. A subset of the input image can be specified by the start and nlines parameters. Finally, input data values that are 0.0 can either be interpreted as missing data or as a valid value using the zero_flag parameter. If any data in the input stack are missing, the output pixel is set to 0.0 by default. If zero_flag is set to 1, then 0.0 is interpreted as a valid data value.

The files (including path) are listed in the im_list text file, one line entry for each file. Lines containing a # in column 1 and blank lines are ignored. This program is useful for computing the phase sum of a sequence of unwrapped interferograms.

SEE ALSO