LQR_CARVER_RESIZE(3)
NAME
lqr_carver_resize - liquid rescale a LqrCarver object
SYNOPSIS
#include <lqr.h> LqrRetVal lqr_carver_resize(LqrCarver* carver, gint new_width, gint new_height);
DESCRIPTION
The function lqr_carver_resize performs the liquid rescaling over the
LqrCarver object pointed to by carver. If a visibility map was loaded
through the function lqr_vmap_load, and the carver was not initialised,
the resizing operations must be limited to the direction and the sizes
included in the loaded map. If the carver was initialised through the
function lqr_carver_init, there are no limitations to the final size.
The resizing function can be called multiple times, and it will decide
automatically whether the computation of the visibility map is
necessary or not. In case it isn't, the function returns almost
immediately, otherwise operations will proceed following the order
given through the function lqr_carver_set_resize_order. Currently,
on-the-fly rescaling without computation is only possible for a single
direction at a time.
If the new size (in one direction or in both) is greater than or equal
to the original size multiplied by the enlargement step of the carver
object (as obtained through lqr_carver_get_enl_step(3)), the rescaling
will be performed in multiple steps. At each step, the original size
stored internally is reset to the new value; therefore, each step in
the process can be bigger then the previous one.
Whenever the resizing dirction changes (this may happen in a single
call of the rescaling function or through multiple calls), or if
performing a multiple steps enlargement as per the previous paragraph,
the visibility map computed during the first direction rescale is
dropped to make place for the one for the second (and the original size
of the image is reset to the current value). These visibility maps can
be saved by using the lqr_carver_set_vmap_dump function, for inspection
or future use.
RETURN VALUE
The return value follows the Liquid Rescale library signalling system.
It returns an error if trying to exceed the limitations of a loaded
visibility map, or if passed a negative or null size.
SEE ALSO
LqrRetVal(3), lqr_carver_init(3), lqr_carver_flatten(3), lqr_carver_set_enl_step(3), lqr_carver_get_enl_step(3), lqr_carver_cancel(3), lqr_vmap_load(3)
COPYRIGHT
- Copyright (C) 2007-2009 Carlo Baldassi