This is gta.info, produced by makeinfo version 6.6 from gta.texi.

This manual was last updated 13 June 2018 for version 2.4.0 of GTA Tool.

   Copyright (C) 2010, 2011, 2012, 2013, 2014 Martin Lambers
<marlam@marlam.de>

     Copying and distribution of this file, with or without
     modification, are permitted in any medium without royalty provided
     the copyright notice and this notice are preserved.  This file is
     offered as-is, without any warranty.
INFO-DIR-SECTION Individual utilities
START-INFO-DIR-ENTRY
* Gtatool: (gta).                           Manipulate Generic Tagged Array (GTA) files.
END-INFO-DIR-ENTRY


File: gta.info,  Node: Top,  Next: Overview,  Up: (dir)

GTA Tool
********

This manual was last updated 13 June 2018 for version 2.4.0 of GTA Tool.

   Copyright (C) 2010, 2011, 2012, 2013, 2014 Martin Lambers
<marlam@marlam.de>

     Copying and distribution of this file, with or without
     modification, are permitted in any medium without royalty provided
     the copyright notice and this notice are preserved.  This file is
     offered as-is, without any warranty.

* Menu:

* Overview::
* Examples::


File: gta.info,  Node: Overview,  Next: Examples,  Prev: Top,  Up: Top

1 Overview
**********

Gtatool (‘gta’) manipulates Generic Tagged Arrays (GTAs).

   A GTA is an n-dimensional _array_ with metadata in the form of _tags_
(key-value pairs).

   A GTA file or _stream_ contains a sequence of such arrays.

   Each array has n _dimensions_.  For example, images have 2
dimensions, and volume data sets have 3.

   Each array element consists of m _components_.  These components can
have different types.  For example, image data is commonly stored using
3 components of type ‘uint8’.

   The ‘gta’ tool provides commands to manipulate GTAs.  These commands
are organized in the following categories:
   • Commands that operate on element component level.
     For example, these commands add or remove components, or change
     their types.
   • Commands that operate on dimension level.
     For example, these commands add or remove dimensions, or change
     their sizes.
   • Commands that operate on array level.
     For example, these commands create or compare arrays, or modify
     array tags.
   • Commands that operate on stream level.
     For example, these commands add or remove arrays.
   • Commands to convert from/to other file formats.
     These commands import and export GTAs from/to many different file
     formats.

   Use ‘gta help’ to get a list of available commands, and ‘gta help
cmd’ to get help for command ‘cmd’.

   (Alternatively, you can use ‘gta --help’ and ‘gta cmd --help’.)


File: gta.info,  Node: Examples,  Prev: Overview,  Up: Top

2 Examples
**********

2.1 Average of Arrays
=====================

Say you recorded 100 camera frames in a file called ‘frames.gta’, and
you want to compute the average of these 100 frames.

   First, produce separate files ‘000.gta’, ..., ‘099.gta’:
     $ gta stream-split %3N.gta frames.gta

   Then add them all up and store the result in ‘sum.gta’:
     $ gta combine -m add ???.gta > sum.gta

   Then divide by the number of frames to get the average:
     $ gta component-compute -e 'c0 = c0 / 100' sum.gta > avg.gta

   This works fine with floating point values.  If your array uses
integer component types, e.g.  uint8 for RGB, you may need to convert to
floating point first (using ‘component-convert’) so that the sum does
not overflow.



Tag Table:
Node: Top635
Node: Overview1150
Node: Examples2715

End Tag Table


Local Variables:
coding: utf-8
End:
