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>