Leptonica  1.54
Файл src/boxfunc1.c
#include "allheaders.h"

Функции

l_int32 boxContains (BOX *box1, BOX *box2, l_int32 *presult)
l_int32 boxIntersects (BOX *box1, BOX *box2, l_int32 *presult)
BOXAboxaContainedInBox (BOXA *boxas, BOX *box)
BOXAboxaIntersectsBox (BOXA *boxas, BOX *box)
BOXAboxaClipToBox (BOXA *boxas, BOX *box)
BOXAboxaCombineOverlaps (BOXA *boxas)
BOXboxOverlapRegion (BOX *box1, BOX *box2)
BOXboxBoundingRegion (BOX *box1, BOX *box2)
l_int32 boxOverlapFraction (BOX *box1, BOX *box2, l_float32 *pfract)
l_int32 boxContainsPt (BOX *box, l_float32 x, l_float32 y, l_int32 *pcontains)
BOXboxaGetNearestToPt (BOXA *boxa, l_int32 x, l_int32 y)
l_int32 boxGetCenter (BOX *box, l_float32 *pcx, l_float32 *pcy)
l_int32 boxIntersectByLine (BOX *box, l_int32 x, l_int32 y, l_float32 slope, l_int32 *px1, l_int32 *py1, l_int32 *px2, l_int32 *py2, l_int32 *pn)
BOXboxClipToRectangle (BOX *box, l_int32 wi, l_int32 hi)
BOXboxRelocateOneSide (BOX *boxd, BOX *boxs, l_int32 loc, l_int32 sideflag)
BOXboxAdjustSides (BOX *boxd, BOX *boxs, l_int32 delleft, l_int32 delright, l_int32 deltop, l_int32 delbot)
l_int32 boxEqual (BOX *box1, BOX *box2, l_int32 *psame)
l_int32 boxaEqual (BOXA *boxa1, BOXA *boxa2, l_int32 maxdist, NUMA **pnaindex, l_int32 *psame)
l_int32 boxaJoin (BOXA *boxad, BOXA *boxas, l_int32 istart, l_int32 iend)
l_int32 boxaSplitEvenOdd (BOXA *boxa, BOXA **pboxae, BOXA **pboxao)
BOXAboxaMergeEvenOdd (BOXA *boxae, BOXA *boxao)

Функции

BOXA* boxaClipToBox ( BOXA boxas,
BOX box 
)

boxaClipToBox()

Input: boxas box (for clipping) Return boxad (boxa with boxes in boxas clipped to box), or null on error

Notes: (1) All boxes in boxa not intersecting with box are removed, and the remaining boxes are clipped to box.

BOXA* boxaCombineOverlaps ( BOXA boxas)

boxaCombineOverlaps()

Input: boxas Return: boxad (where each set of boxes in boxas that overlap are combined into a single bounding box in boxad), or null on error.

Notes: (1) If there are no overlapping boxes, it simply returns a copy of . (2) The alternative method of painting each rectanle and finding the 4-connected components gives the wrong result, because two non-overlapping rectangles, when rendered, can still be 4-connected, and hence they will be joined. (3) A bad case is to have n boxes, none of which overlap. Then you have one iteration with O(n^2) compares. This is still faster than painting each rectangle and finding the connected components, even for thousands of rectangles.

BOXA* boxaContainedInBox ( BOXA boxas,
BOX box 
)

boxaContainedInBox()

Input: boxas box (for containment) Return: boxad (boxa with all boxes in boxas that are entirely contained in box), or null on error

Notes: (1) All boxes in boxa that are entirely outside box are removed.

BOX* boxAdjustSides ( BOX boxd,
BOX boxs,
l_int32  delleft,
l_int32  delright,
l_int32  deltop,
l_int32  delbot 
)

boxAdjustSides()

Input: boxd (<optional>; this can be null, equal to boxs, or different from boxs) boxs (starting box; to have sides adjusted) delleft, delright, deltop, delbot (changes in location of each side) Return: boxd, or null on error or if the computed boxd has width or height <= 0.

Notes: (1) Set boxd == NULL to get new box; boxd == boxs for in-place; or otherwise to resize existing boxd. (2) For usage, suggest one of these: boxd = boxAdjustSides(NULL, boxs, ...); // new boxAdjustSides(boxs, boxs, ...); // in-place boxAdjustSides(boxd, boxs, ...); // other (1) New box dimensions are cropped at left and top to x >= 0 and y >= 0. (2) For example, to expand in-place by 20 pixels on each side, use boxAdjustSides(box, box, -20, 20, -20, 20);

l_int32 boxaEqual ( BOXA boxa1,
BOXA boxa2,
l_int32  maxdist,
NUMA **  pnaindex,
l_int32 psame 
)

boxaEqual()

Input: boxa1 boxa2 maxdist &naindex (<optional return>=""> index array of correspondences &same (<return> 1 if equal; 0 otherwise) Return 0 if OK, 1 on error

Notes: (1) The two boxa are the "same" if they contain the same boxes and each box is within of its counterpart in their positions within the boxa. This allows for small rearrangements. Use 0 for maxdist if the boxa must be identical. (2) This applies only to geometry and ordering; refcounts are not considered. (3) allows some latitude in the ordering of the boxes. For the boxa to be the "same", corresponding boxes must be within of each other. Note that for large , we should use a hash function for efficiency. (4) naindex[i] gives the position of the box in boxa2 that corresponds to box i in boxa1. It is only returned if the boxa are equal.

BOX* boxaGetNearestToPt ( BOXA boxa,
l_int32  x,
l_int32  y 
)

boxaGetNearestToPt()

Input: boxa x, y (point) Return box (box with centroid closest to the given point [x,y]), or NULL if no boxes in boxa)

Notes: (1) Uses euclidean distance between centroid and point.

BOXA* boxaIntersectsBox ( BOXA boxas,
BOX box 
)

boxaIntersectsBox()

Input: boxas box (for intersecting) Return boxad (boxa with all boxes in boxas that intersect box), or null on error

Notes: (1) All boxes in boxa that intersect with box (i.e., are completely or partially contained in box) are retained.

l_int32 boxaJoin ( BOXA boxad,
BOXA boxas,
l_int32  istart,
l_int32  iend 
)

boxaJoin()

Input: boxad (dest boxa; add to this one) boxas (source boxa; add from this one) istart (starting index in nas) iend (ending index in nas; use 0 to cat all) Return: 0 if OK, 1 on error

Notes: (1) This appends a clone of each indicated box in boxas to boxad (2) istart < 0 is taken to mean 'read from the start' (istart = 0) (3) iend <= 0 means 'read to the end'

BOXA* boxaMergeEvenOdd ( BOXA boxae,
BOXA boxao 
)

boxaMergeEvenOdd()

Input: boxae (boxes to go in even positions in merged boxa) boxao (boxes to go in odd positions in merged boxa) Return: boxad (merged), or null on error

Notes: (1) Boxes are alternatingly selected from boxae and boxao. Both boxae and boxao are of the same size.

l_int32 boxaSplitEvenOdd ( BOXA boxa,
BOXA **  pboxae,
BOXA **  pboxao 
)

boxaSplitEvenOdd()

Input: boxa &boxae, &boxao (<return> save even and odd boxes in their separate boxa, setting the other type to invalid boxes.) Return: 0 if OK, 1 on error

Notes: (1) For example, boxae copies of the even boxes, in their original location, that are in boxa. Invalid boxes are placed in the odd array locations.

BOX* boxBoundingRegion ( BOX box1,
BOX box2 
)

boxBoundingRegion()

Input: box1, box2 (two boxes) Return: box (of bounding region containing the input boxes), or null on error

BOX* boxClipToRectangle ( BOX box,
l_int32  wi,
l_int32  hi 
)

boxClipToRectangle()

Input: box wi, hi (rectangle representing image) Return: part of box within given rectangle, or NULL on error or if box is entirely outside the rectangle

Notes: (1) This can be used to clip a rectangle to an image. The clipping rectangle is assumed to have a UL corner at (0, 0), and a LR corner at (wi - 1, hi - 1).

l_int32 boxContains ( BOX box1,
BOX box2,
l_int32 presult 
)

boxContains()

Input: box1, box2 &result (<return> 1 if box2 is entirely contained within box1, and 0 otherwise) Return: 0 if OK, 1 on error

l_int32 boxContainsPt ( BOX box,
l_float32  x,
l_float32  y,
l_int32 pcontains 
)

boxContainsPt()

Input: box x, y (a point) &contains (<return> 1 if box contains point; 0 otherwise) Return: 0 if OK, 1 on error.

l_int32 boxEqual ( BOX box1,
BOX box2,
l_int32 psame 
)

boxEqual()

Input: box1 box2 &same (<return> 1 if equal; 0 otherwise) Return 0 if OK, 1 on error

l_int32 boxGetCenter ( BOX box,
l_float32 pcx,
l_float32 pcy 
)

boxGetCenter()

Input: box &cx, &cy (<return> location of center of box) Return 0 if OK, 1 on error

l_int32 boxIntersectByLine ( BOX box,
l_int32  x,
l_int32  y,
l_float32  slope,
l_int32 px1,
l_int32 py1,
l_int32 px2,
l_int32 py2,
l_int32 pn 
)

boxIntersectByLine()

Input: box x, y (point that line goes through) slope (of line) (&x1, &y1) (<return> 1st point of intersection with box) (&x2, &y2) (<return> 2nd point of intersection with box) &n (<return> number of points of intersection) Return: 0 if OK, 1 on error

Notes: (1) If the intersection is at only one point (a corner), the coordinates are returned in (x1, y1). (2) Represent a vertical line by one with a large but finite slope.

l_int32 boxIntersects ( BOX box1,
BOX box2,
l_int32 presult 
)

boxIntersects()

Input: box1, box2 &result (<return> 1 if any part of box2 is contained in box1, and 0 otherwise) Return: 0 if OK, 1 on error

l_int32 boxOverlapFraction ( BOX box1,
BOX box2,
l_float32 pfract 
)

boxOverlapFraction()

Input: box1, box2 (two boxes) &fract (<return> the fraction of box2 overlapped by box1) Return: 0 if OK, 1 on error.

Notes: (1) The result depends on the order of the input boxes, because the overlap is taken as a fraction of box2.

BOX* boxOverlapRegion ( BOX box1,
BOX box2 
)

boxOverlapRegion()

Input: box1, box2 (two boxes) Return: box (of overlap region between input boxes), or null if no overlap or on error

BOX* boxRelocateOneSide ( BOX boxd,
BOX boxs,
l_int32  loc,
l_int32  sideflag 
)

boxRelocateOneSide()

Input: boxd (<optional>; this can be null, equal to boxs, or different from boxs); boxs (starting box; to have one side relocated) loc (new location of the side that is changing) sideflag (L_FROM_LEFT, etc., indicating the side that moves) Return: boxd, or null on error or if the computed boxd has width or height <= 0.

Notes: (1) Set boxd == NULL to get new box; boxd == boxs for in-place; or otherwise to resize existing boxd. (2) For usage, suggest one of these: boxd = boxRelocateOneSide(NULL, boxs, ...); // new boxRelocateOneSide(boxs, boxs, ...); // in-place boxRelocateOneSide(boxd, boxs, ...); // other