ref: a901d5647d30cf20fc0a096a612c58b2f99b8551
dir: /h/thresh.h/
typedef struct {
int init;
SPFLOAT prev, thresh, mode;
} sp_thresh;
int sp_thresh_create(sp_thresh **p);
int sp_thresh_destroy(sp_thresh **p);
int sp_thresh_init(sp_data *sp, sp_thresh *p);
int sp_thresh_compute(sp_data *sp, sp_thresh *p, SPFLOAT *in, SPFLOAT *out);