NAME

       uprightdiff - examines the differences between two images

SYNOPSIS

       uprightdiff [options] <input-1> <input-2> <output>

DESCRIPTION

       uprightdiff  examines  the differences between two images. It produces a visual annotation
       and reports statistics.

       It is optimised for images which come from browser screenshots. It analyses the image  for
       vertical motion, and annotates connected regions that have the same vertical displacement.
       Then it highlights any remaining ("residual")  differences  which  are  not  explained  by
       vertical motion on a pixel-by-pixel basis.

       --help Show help message and exit

       --block-size arg
              Block size for initial search (default 16)

       --window-size arg
              Initial range for vertical motion detection (default 200)

       --brush-width arg
              Brush  width  when  heuristically  expanding  blocks. A higher value gives smoother
              motion regions. This should be an odd number. (default 9)

       --outer-hl-window arg
              The size of the  outer  square  used  for  detecting  isolated  small  features  to
              highlight.  This  size  defines  what  we  mean  by "isolated". It should be an odd
              number. (default 21)

       --inner-hl-window arg
              The size of the  inner  square  used  for  detecting  isolated  small  features  to
              highlight.  This  size defines what we mean by "small". It should be an odd number.
              (default 5)

       --intermediate-dir arg
              A directory where intermediate images should be placed. This is our  equivalent  of
              debug or trace output.

       -v [ --verbose ]
              Write progress info to stderr.

       --format arg
              The output format for statistics, may be text (the default), json or none.

       -t [ --log-timestamp ]
              Annotate progress info with elapsed time.

AUTHOR

       Tim Starling <tstarling@wikimedia.org>