Gamma DIFF: Reference Manual

interp_real

NAME
interp_real - real-valued image geometric resampling using nearest-neighbor or bicubic spline interpolation.

SYNOPSIS
interp_real <image-2> <DIFF_par> <resamp_image> [loff] [nlines] [imode]

<image2>	(input)real-valued (FLOAT) image to be resampled to geometry of reference image-1 geometry
<DIFF_par>	DIFF parameter file containing biquadratic offset polynomial coefficients
<resamp_image>	(output) resampled image in the geometry of image-1
[loff]	starting line in map (relative to start of image-1)
[nlines]	number of lines to interpolate (enter - for all lines in the file)
[imode]	interpolation mode: 0: nearest-neighbor 1: bicubic spline (default) 2: bicubic log-spline

EXAMPLE
interp_real 19960422.mli diff.par 19990422.rmli

Resamples the real-valued image 19960422.mli according to biquadratic registration function stored in DIFF_par using bicubic spline interpolation.

DESCRIPTION
interp_real reads the real-valued input data file and carries out a geometric transformation given by a bi-quadratic polynomial. The bi-quadratic registration function is obtained from range and azimuth offset data processed using offset_fitm.

The user can select the resampling interpolator to be either nearest neighbor, bicubic spline, or bicubic log-spline. For bi-cubic log-spline interpolation, the logarithm of the values are interpolated. The log-spline algorithm may be preferred for interpolation of non-negative data because it prevents negative values in the output resampled image.

OPTIONS
The starting line (relative to the reference geometry of image-1) and the number of output lines (of output image) may be selected.