gwy_NIELD_splash_water()

void
gwy_NIELD_splash_water (GwyField *field,
                        GwyNield *water,
                        GwyField *markbuf,
                        gint locate_steps,
                        gdouble locate_dropsize);

Performs a few location steps of watershed marking.

If a non-NULL markbuf is passed, it must have the same dimensions as field and water .

gwy_NIELD_watershed_init()

GwyComputationState *
gwy_NIELD_watershed_init (GwyField *field,
                          GwyNield *grains,
                          gint locate_steps,
                          gint locate_thresh,
                          gdouble locate_dropsize,
                          gint wshed_steps,
                          gdouble wshed_dropsize,
                          gboolean prefilter,
                          gboolean below);

Initializes the watershed algorithm.

This iterator reports its state as GwyWatershedStateType.

gwy_NIELD_watershed_iteration()

void
gwy_NIELD_watershed_iteration (GwyComputationState *state);

Performs one iteration of the watershed algorithm.

Fields state and progress fraction of watershed state are updated (fraction is calculated for each phase individually). Once state becomes GWY_WATERSHED_STATE_FINISHED, the calculation is finised.

A watershed iterator can be created with gwy_field_watershed_init(). When iteration ends, either by finishing or being aborted, gwy_field_watershed_finalize() must be called to release allocated resources.

gwy_NIELD_watershed_finalize()

void
gwy_NIELD_watershed_finalize (GwyComputationState *state);

Destroys a watershed iterator, freeing all resources.

gwy_NIELD_waterpour()

gint
gwy_NIELD_waterpour (GwyField *field,
                     GwyNield *grains);

Performs the classical Vincent watershed segmentation of a data field.

The segmentation always results in the entire field being masked with the exception of thin (8-connectivity) lines separating the segments (grains). The grains are already numbered in the same manner as gwy_nield_number_contiguous() as a side-effect.

Compared to gwy_field_mark_watershed(), this algorithm is very fast. However, when used alone, it typically results in a serious oversegmentation as each local minimum gives raise to a grain. Furthermore, the full segmentation means that also pixels which would be considered outside any grain in the topographical sense will be assigned to some catchment basin. Therefore, pre- and/or postprocessing is usually necessary, using the gradient image or a more sophisticated method.

The function does not assign pixels with value HUGE_VAL or larger to any segment. This can be used to pre-mark certain areas explicitly as boundaries.

gwy_NIELD_mark_extrema()

void
gwy_NIELD_mark_extrema (GwyField *field,
                        GwyNield *extrema,
                        gboolean maxima);

gwy_NIELD_mark_watershed()

void
gwy_NIELD_mark_watershed (GwyField *field,
                          GwyNield *grains,
                          gint locate_steps,
                          gint locate_thresh,
                          gdouble locate_dropsize,
                          gint wshed_steps,
                          gdouble wshed_dropsize,
                          gboolean prefilter,
                          gboolean below);

enum GwyWatershedStateType