opencv 序列

1.杂项标志位

 CvSeq 结构中有一杂项标志位flags，这个标志里面某些标志可能要依赖其它位，才能确定最终意思。查看源代码，其值如下：

/****************************************************************************************\
*                                    Sequence types                                      *
\****************************************************************************************/

#define CV_SEQ_MAGIC_VAL             0x42990000

#define CV_IS_SEQ(seq) \
    ((seq) != NULL && (((CvSeq*)(seq))->flags & CV_MAGIC_MASK) == CV_SEQ_MAGIC_VAL)

#define CV_SET_MAGIC_VAL             0x42980000
#define CV_IS_SET(set) \
    ((set) != NULL && (((CvSeq*)(set))->flags & CV_MAGIC_MASK) == CV_SET_MAGIC_VAL)

#define CV_SEQ_ELTYPE_BITS           12
#define CV_SEQ_ELTYPE_MASK           ((1 << CV_SEQ_ELTYPE_BITS) - 1)

#define CV_SEQ_ELTYPE_POINT          CV_32SC2  /* (x,y) */
#define CV_SEQ_ELTYPE_CODE           CV_8UC1   /* freeman code: 0..7 */
#define CV_SEQ_ELTYPE_GENERIC        0
#define CV_SEQ_ELTYPE_PTR            CV_USRTYPE1
#define CV_SEQ_ELTYPE_PPOINT         CV_SEQ_ELTYPE_PTR  /* &(x,y) */
#define CV_SEQ_ELTYPE_INDEX          CV_32SC1  /* #(x,y) */
#define CV_SEQ_ELTYPE_GRAPH_EDGE     0  /* &next_o, &next_d, &vtx_o, &vtx_d */
#define CV_SEQ_ELTYPE_GRAPH_VERTEX   0  /* first_edge, &(x,y) */
#define CV_SEQ_ELTYPE_TRIAN_ATR      0  /* vertex of the binary tree   */
#define CV_SEQ_ELTYPE_CONNECTED_COMP 0  /* connected component  */
#define CV_SEQ_ELTYPE_POINT3D        CV_32FC3  /* (x,y,z)  */

#define CV_SEQ_KIND_BITS        2
#define CV_SEQ_KIND_MASK        (((1 << CV_SEQ_KIND_BITS) - 1)<<CV_SEQ_ELTYPE_BITS)

/* types of sequences */ //序列类型
#define CV_SEQ_KIND_GENERIC     (0 << CV_SEQ_ELTYPE_BITS)
#define CV_SEQ_KIND_CURVE       (1 << CV_SEQ_ELTYPE_BITS)
#define CV_SEQ_KIND_BIN_TREE    (2 << CV_SEQ_ELTYPE_BITS)

/* types of sparse sequences (sets) *///稀疏序列的类型(sets)
#define CV_SEQ_KIND_GRAPH       (1 << CV_SEQ_ELTYPE_BITS)
#define CV_SEQ_KIND_SUBDIV2D    (2 << CV_SEQ_ELTYPE_BITS)

#define CV_SEQ_FLAG_SHIFT       (CV_SEQ_KIND_BITS + CV_SEQ_ELTYPE_BITS)

/* flags for curves */

//曲线标志
#define CV_SEQ_FLAG_CLOSED     (1 << CV_SEQ_FLAG_SHIFT)
#define CV_SEQ_FLAG_SIMPLE     (0 << CV_SEQ_FLAG_SHIFT)
#define CV_SEQ_FLAG_CONVEX     (0 << CV_SEQ_FLAG_SHIFT)
#define CV_SEQ_FLAG_HOLE       (2 << CV_SEQ_FLAG_SHIFT)

/* flags for graphs */ //图像标志
#define CV_GRAPH_FLAG_ORIENTED (1 << CV_SEQ_FLAG_SHIFT)

#define CV_GRAPH               CV_SEQ_KIND_GRAPH
#define CV_ORIENTED_GRAPH      (CV_SEQ_KIND_GRAPH|CV_GRAPH_FLAG_ORIENTED)

/* point sets *///点设置
#define CV_SEQ_POINT_SET       (CV_SEQ_KIND_GENERIC| CV_SEQ_ELTYPE_POINT)
#define CV_SEQ_POINT3D_SET     (CV_SEQ_KIND_GENERIC| CV_SEQ_ELTYPE_POINT3D)
#define CV_SEQ_POLYLINE        (CV_SEQ_KIND_CURVE  | CV_SEQ_ELTYPE_POINT)
#define CV_SEQ_POLYGON         (CV_SEQ_FLAG_CLOSED | CV_SEQ_POLYLINE )
#define CV_SEQ_CONTOUR         CV_SEQ_POLYGON
#define CV_SEQ_SIMPLE_POLYGON  (CV_SEQ_FLAG_SIMPLE | CV_SEQ_POLYGON  )

/* chain-coded curves */ //曲线链编码
#define CV_SEQ_CHAIN           (CV_SEQ_KIND_CURVE  | CV_SEQ_ELTYPE_CODE)
#define CV_SEQ_CHAIN_CONTOUR   (CV_SEQ_FLAG_CLOSED | CV_SEQ_CHAIN)

/* binary tree for the contour */ //二叉树的轮廓
#define CV_SEQ_POLYGON_TREE    (CV_SEQ_KIND_BIN_TREE  | CV_SEQ_ELTYPE_TRIAN_ATR)

/* sequence of the connected components *///序列的连接组件
#define CV_SEQ_CONNECTED_COMP  (CV_SEQ_KIND_GENERIC  | CV_SEQ_ELTYPE_CONNECTED_COMP)

/* sequence of the integer numbers */
#define CV_SEQ_INDEX           (CV_SEQ_KIND_GENERIC  | CV_SEQ_ELTYPE_INDEX)

#define CV_SEQ_ELTYPE( seq )   ((seq)->flags & CV_SEQ_ELTYPE_MASK)
#define CV_SEQ_KIND( seq )     ((seq)->flags & CV_SEQ_KIND_MASK )

/* flag checking *///标志检查

//索引标志
#define CV_IS_SEQ_INDEX( seq )      ((CV_SEQ_ELTYPE(seq) == CV_SEQ_ELTYPE_INDEX) && \
                                     (CV_SEQ_KIND(seq) == CV_SEQ_KIND_GENERIC))
//是否是曲线
#define CV_IS_SEQ_CURVE( seq )      (CV_SEQ_KIND(seq) == CV_SEQ_KIND_CURVE)

//闭合性
#define CV_IS_SEQ_CLOSED( seq )     (((seq)->flags & CV_SEQ_FLAG_CLOSED) != 0)   

//是否是凸包

#define CV_IS_SEQ_CONVEX( seq )     0

//是否是洞
#define CV_IS_SEQ_HOLE( seq )       (((seq)->flags & CV_SEQ_FLAG_HOLE) != 0)
#define CV_IS_SEQ_SIMPLE( seq )     1

/* type checking macros */ //类型检查宏
#define CV_IS_SEQ_POINT_SET( seq ) \
    ((CV_SEQ_ELTYPE(seq) == CV_32SC2 || CV_SEQ_ELTYPE(seq) == CV_32FC2))

#define CV_IS_SEQ_POINT_SUBSET( seq ) \
    (CV_IS_SEQ_INDEX( seq ) || CV_SEQ_ELTYPE(seq) == CV_SEQ_ELTYPE_PPOINT)

#define CV_IS_SEQ_POLYLINE( seq )   \
    (CV_SEQ_KIND(seq) == CV_SEQ_KIND_CURVE && CV_IS_SEQ_POINT_SET(seq))

#define CV_IS_SEQ_POLYGON( seq )   \
    (CV_IS_SEQ_POLYLINE(seq) && CV_IS_SEQ_CLOSED(seq))

#define CV_IS_SEQ_CHAIN( seq )   \
    (CV_SEQ_KIND(seq) == CV_SEQ_KIND_CURVE && (seq)->elem_size == 1)

#define CV_IS_SEQ_CONTOUR( seq )   \
    (CV_IS_SEQ_CLOSED(seq) && (CV_IS_SEQ_POLYLINE(seq) || CV_IS_SEQ_CHAIN(seq)))

#define CV_IS_SEQ_CHAIN_CONTOUR( seq ) \
    (CV_IS_SEQ_CHAIN( seq ) && CV_IS_SEQ_CLOSED( seq ))

#define CV_IS_SEQ_POLYGON_TREE( seq ) \
    (CV_SEQ_ELTYPE (seq) ==  CV_SEQ_ELTYPE_TRIAN_ATR &&    \
    CV_SEQ_KIND( seq ) ==  CV_SEQ_KIND_BIN_TREE )

#define CV_IS_GRAPH( seq )    \
    (CV_IS_SET(seq) && CV_SEQ_KIND((CvSet*)(seq)) == CV_SEQ_KIND_GRAPH)

#define CV_IS_GRAPH_ORIENTED( seq )   \
    (((seq)->flags & CV_GRAPH_FLAG_ORIENTED) != 0)

#define CV_IS_SUBDIV2D( seq )  \
    (CV_IS_SET(seq) && CV_SEQ_KIND((CvSet*)(seq)) == CV_SEQ_KIND_SUBDIV2D)

参考： gavin710 的 CvSeq 文章   http://blog.youkuaiyun.com/gavin710/article/details/7405437