NAME

       lqr_carver_get_energy, lqr_carver_get_true_energy, lqr_carver_get_energy_image - get the energy map for a
       LqrCarver object

SYNOPSIS

       #include <lqr.h>

       LqrRetVal lqr_carver_get_energy(LqrCarver* carver, gfloat * buffer, gint orientation);

SYNOPSIS

       #include <lqr.h>

       LqrRetVal lqr_carver_get_true_energy(LqrCarver* carver, gfloat * buffer, gint orientation);

SYNOPSIS

       #include <lqr.h>

       LqrRetVal lqr_carver_get_energy(LqrCarver* carver, void * buffer, gint orientation,
                                       LqrColDepth col_depth, LqrImageType image_type);

DESCRIPTION

       The function lqr_carver_get_energy writes the energy map of the LqrCarver object pointed to by carver to
       the given buffer, in a format suitable for plotting: all values are in the range between 0 and 1, and the
       true values are mapped nonlinearly and stretched on this whole range, so that the differences between the
       middle values are enhanced with respect to very high or very low values.

       The orientation parameter must be either 0 to get the energy map used for horizontal scalings, or 1 to
       get the map for vertical scalings.

       The buffer must be allocated by the user before calling this function, and its size must be at least
       width * height, where width and height are the current width and height of the carver. The energy values
       are ordered by row first, then by column.

       The outcome will include the effect of the bias added to the carver, if any.

       This function can be called over non-initialised LqrCarver objects, e.g. to provide previews on the
       effect of different energy functions, but it can also be invoked at any later time. Note, however, that
       in this latter case the carver could be flattened if necessary, therefore the function invocation is
       potentially destructive of the internal visibiliy map.

       The function lqr_carvet_get_true_energy is identical to the previous one, but the resulting buffer will
       contain the true energy, not scaled nor shifted.

       The function lqr_carver_get_energy_image is very similar to the function lqr_carveR_get_energy, but it
       can be used to fill directly an image buffer of the format specified through the additional parameters
       col_depth and image_type (see LqrColDepth(3) and LqrImageType(3)). The buffer must be passed as void*,
       but it must point to a memory area with sufficient allocated space for the chosen image type and colour
       depth. The image type cannot be LQR_CUSTOM_IMAGE.

       For any choice of the parameters describing the image, the resulting buffer will hold a greyscale image,
       ranging from black (lowest energy) to white (highest energy). The opacity (alpha) will be set to 1, if
       present. All the information will be stored in the black channel in LQR_CMYK_IMAGE and LQR_CMYKA_IMAGE
       image types.

RETURN VALUES

       The return values follow the Liquid Rescale library signalling system. The function
       lqr_carver_get_energy_image will return an error if image_type is LQR_CUSTOM_IMAGE.

SEE ALSO

       lqr_carver_set_energy_function_builtin(3), lqr_carver_set_energy_function(3), lqr_carver_bias_add(3)

COPYRIGHT

       Copyright © 2007-2009 Carlo Baldassi

LqR library 0.4.1 API (3:1:3)                      10 Maj 2009                          LQR_CARVER_GET_ENERGY(3)