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TRANSPOSE(9.1)                                                  TRANSPOSE(9.1)



NAME
       rotate, transpose - re-orient an image

SYNOPSIS
       fb/rotate angle [ input ]

       fb/transpose [ -vhadrlui ] [ -ox y ] [ input ]

DESCRIPTION
       Rotate  rotates  the  image in its input picture file (default standard
       input) clockwise by angle degrees, writing the resulting  picture  file
       on standard output.

       Transpose  turns  its  input  picture  file  on  its side by reflection
       through its major (descending from left to right) diagonal, writing the
       resulting  picture  file on standard output.  If no file name is given,
       the picture is read from standard input.  Options  yield  all  possible
       symmetries of the square grid:

       -d     reflects   the   image  through  its  descending  diagonal  (the
              default).

       -a     reflects the image through its ascending diagonal.

       -v     reflects the image left-to-right  through  its  vertical  center
              line.

       -h     inverts  the  image  top-to-bottom through its horizontal center
              line.

       -r     rotates the image to the right (clockwise) 90 degrees.

       -l     rotates the image to the left (counterclockwise) 90 degrees.

       -u     rotates the image upside down (180 degrees).

       -i     identity transformation (for completeness only.)

       -o x y translates by (x,y).  Without -o, the  input  and  output  files
              have the same upper-left corner.

       Transpose  is particularly useful to convince programs that work on the
       rows of a picture file to operate on columns.  For example

              fb/transpose big |
                   fb/resample 48 |
                   fb/transpose |
                   fb/resample 48 >tiny

       makes a tiny 4848 version of a big picture.

SOURCE
       /sys/src/fb/rotate.c
       /sys/src/fb/transpose.c

SEE ALSO
       picfile(9.6), resample(9.1)

BUGS
       Very large images may not fit in memory.  The result of rotate  is  not
       anti-aliased.



                                                                TRANSPOSE(9.1)