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Export unwrapped interferogram with voids as bmp file

Added by Julia Neelmeijer over 8 years ago

Hi folks,

I am using rasrmg to export an unwrapped interferogram with voids (due to masking, etc) as bmp file. If I leave the default values, the void areas in the indexed colour space appear in a green colour, which unfortunately is also used within the colour ramp of the interferogram. I'd like to change the color of the void areas to black to better highlight the remaining valid data.

However, if I do this in a postprocessing step in Photoshop, I run into the problem that I cannot select the void areas by colour, as I would then also select valid areas as they both contain the same indexed colour. This means, I cannot differentiate between voids and valid areas.

The question for you is: is there a possibility in GAMMA to save such an bmp image in a way that the voids have an unique colour value that can be selected in Photoshop?

Thanks for your help.


Replies (3)

RE: Export unwrapped interferogram with voids as bmp file - Added by Redmine Admin over 8 years ago

Hello Julie,­

There is a way. Consider using the program thres_data:

  • Data are set to 0 where t_data < t_min or t_data > t_max (FLOAT,
    FCOMPLEX, or SUN/BMP­/TIFF raster format)*­**
  • Copyright 2016, ­Gamma Remote Sensing,­ v1.2 14-Jun-2016 clw­ ***

usage: thres_data <data_in> <width> <data­_out> <t_data> <t_min­> <t_max>
[dtype]­

input parameters:­
data_in (input) data file (FLOAT, FCOM­PLEX, or SUN/BMP/TIFF­ raster
format)­
width width of input data file and threshold data file
data_out (output)­data file, same data­format as input data
all points in data_in are­set to 0.0 where thres_data <
tmin or thres_data >­ t_max
t_data (input) data used for threshold­ test (FLOAT format)
t_min minimum threshold data value (FL­OAT)
t_max maximum threshold data value (FL­OAT)
dtype data type:­
0: ­FLOAT (default)
1: ­FCOMPLEX
2: ­SUN/BMP/TIFF raster image

The input data file ­(data_in) (a float, f­complex, or raster image) can
be masked (values set to 0_
depending on the values in another image file (t_data) with the same
width and height.­
So for example if you have a correlation file, you can mask data_in
based on the correlation vales
in the t_data file. ­You can set the range­of values that are ­ccepted
with the t_min and t_max
thresholds. The masked output data is written to data_out.

I would convert your­8 bit raster image with the indexed color­space to
24-bit color with the program ras_ras in the LAT. Then the program
thres_data will do I think what you want.

Charles­

Links:­
------­
[1] ­http://dep1doc.gfz-potsdam.de/boards/23/to­pics/167

RE: Export unwrapped interferogram with voids as bmp file - Added by Julia Neelmeijer over 8 years ago

Hi Charles,

thank you very much for your input!
I think, I have an easier solution (that was suggested per mail to me - thanks!)

If one adds a correlation file to the rasrmg process and set the threshold to 0, than all voids appear as greyscale within the bitmap image. An example would look like:

rasrmg unwfile.unw - xxxx - - - - - - - - - - image.bmp - correlationfile.cc - 0

Export unwrapped interferogram with voids as bmp file - Added by Charles Werner over 8 years ago

Hello Julie,

There is a way. Consider using the program thres_data:

  • Data are set to 0 where t_data < t_min or t_data > t_max (FLOAT,
    FCOMPLEX, or SUN/BMP/TIFF raster format)***
  • Copyright 2016, Gamma Remote Sensing, v1.2 14-Jun-2016 clw ***

usage: thres_data <data_in> <width> <data_out> <t_data> <t_min> <t_max>
[dtype]

input parameters:
data_in (input) data file (FLOAT, FCOMPLEX, or SUN/BMP/TIFF raster
format)
width width of input data file and threshold data file
data_out (output) data file, same data format as input data
all points in data_in are set to 0.0 where thres_data <
tmin or thres_data > t_max
t_data (input) data used for threshold test (FLOAT format)
t_min minimum threshold data value (FLOAT)
t_max maximum threshold data value (FLOAT)
dtype data type:
0: FLOAT (default)
1: FCOMPLEX
2: SUN/BMP/TIFF raster image

The input data file (data_in) (a float, fcomplex, or raster image) can
be masked (values set to 0_
depending on the values in another image file (t_data) with the same
width and height.
So for example if you have a correlation file, you can mask data_in
based on the correlation vales
in the t_data file. You can set the range of values that are accepted
with the t_min and t_max
thresholds. The masked output data is written to data_out.

I would convert your 8 bit raster image with the indexed color space to
24-bit color with the program ras_ras in the LAT. Then the program
thres_data will do I think what you want.

Charles

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