view release on metacpan or  search on metacpan

lib/Image/Leptonica/Func/boxfunc1.pm  view on Meta::CPAN

      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.

=head2 boxIntersects

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

=head2 boxOverlapArea

l_int32 boxOverlapArea ( BOX *box1, BOX *box2, l_int32 *parea )

  boxOverlapArea()

      Input:  box1, box2 (two boxes)
              &area (<return> the number of pixels in the overlap)
      Return: 0 if OK, 1 on error.

=head2 boxOverlapFraction

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.

=head2 boxOverlapRegion

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

=head2 boxRelocateOneSide

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

=head2 boxSeparationDistance

l_int32 boxSeparationDistance ( BOX *box1, BOX *box2, l_int32 *ph_sep, l_int32 *pv_sep )

  boxSeparationDistance()

      Input:  box1, box2 (two boxes, in any order)
              &h_sep (<optional return> horizontal separation)
              &v_sep (<optional return> vertical separation)
      Return: 0 if OK, 1 on error

  Notes:
      (1) This measures horizontal and vertical separation of the
          two boxes.  If the boxes are touching but have no pixels
          in common, the separation is 0.  If the boxes overlap by
          a distance d, the returned separation is -d.

=head2 boxSimilar

l_int32 boxSimilar ( BOX *box1, BOX *box2, l_int32 leftdiff, l_int32 rightdiff, l_int32 topdiff, l_int32 botdiff, l_int32 *psimilar )

  boxSimilar()

      Input:  box1
              box2
              leftdiff, rightdiff, topdiff, botdiff
              &similar (<return> 1 if similar; 0 otherwise)
      Return  0 if OK, 1 on error

  Notes:
      (1) The values of leftdiff (etc) are the maximum allowed deviations
          between the locations of the left (etc) sides.  If any side
          pairs differ by more than this amount, the boxes are not similar.

=head2 boxaAdjustHeightToTarget

BOXA * boxaAdjustHeightToTarget ( BOXA *boxad, BOXA *boxas, l_int32 sides, l_int32 target, l_int32 thresh )

  boxaAdjustHeightToTarget()

      Input:  boxad (use null to get a new one)
              boxas
              sides (L_ADJUST_TOP, L_ADJUST_BOT, L_ADJUST_TOP_AND_BOT)
              target (target height if differs by more than thresh)
              thresh (min abs difference in height to cause adjustment)
      Return: boxad, or null on error