debian man page for invert_raw_image

INVERT_RAW_IMAGE(1)					      General Commands Manual					       INVERT_RAW_IMAGE(1)

NAME
       invert_raw_image - invert 2D image along either or both axes

SYNOPSIS
       invert_raw_image xsize xsize [bytesperpixel]

DESCRIPTION
       invert_raw_image  reads	an image from standard input and copies it to standard output, inverting along either or both dimensions according
       to the arguments.

       The parameter xsize specifies the number of pixels in the x-direction.  Use a negative number to flip the image along this axis.  Ditto for
       ysize.  The number of bytes per pixel defaults to 1 if not specified.

															       INVERT_RAW_IMAGE(1)