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Leptonica 1.68
C Image Processing Library
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Leptonica 1.68
C Image Processing Library
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Boxa/Box transforms; Boxa/Boxaa sorting; Boxaa utilities. More...
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Boxa/Box transforms; Boxa/Boxaa sorting; Boxaa utilities.
Boxa/Box transform (shift, scale) and orthogonal rotation BOXA *boxaTransform() BOX *boxTransform() BOXA *boxaTransformOrdered() BOX *boxTransformOrdered() BOXA *boxaRotateOrth() BOX *boxRotateOrth() Boxa sort BOXA *boxaSort() BOXA *boxaBinSort() BOXA *boxaSortByIndex() BOXAA *boxaSort2d() BOXAA *boxaSort2dByIndex() Boxa statistics BOX *boxaGetRankSize() BOX *boxaGetMedian() Other boxaa functions l_int32 boxaaGetExtent() BOXA *boxaaFlattenToBoxa() l_int32 boxaaAlignBox()
Definition in file boxfunc2.c.
| BOXA* boxaTransform | ( | BOXA * | boxas, |
| l_int32 | shiftx, | ||
| l_int32 | shifty, | ||
| l_float32 | scalex, | ||
| l_float32 | scaley | ||
| ) |
Input: boxa shiftx, shifty scalex, scaley Return: boxad, or null on error
Notes: (1) This is a very simple function that first shifts, then scales.
Definition at line 70 of file boxfunc2.c.
References boxaAddBox(), boxaCreate(), boxaGetBox(), boxaGetCount(), boxDestroy(), boxTransform(), ERROR_PTR, L_CLONE, L_INSERT, NULL, and PROCNAME.
Referenced by main(), and pixFindBaselines().
Input: box shiftx, shifty scalex, scaley Return: boxd, or null on error
Notes: (1) This is a very simple function that first shifts, then scales.
Definition at line 111 of file boxfunc2.c.
References boxCreate(), ERROR_PTR, Box::h, L_MAX, NULL, PROCNAME, Box::w, Box::x, and Box::y.
Referenced by boxaTransform(), pixConvertToPdfDataSegmented(), and pixSplitComponentIntoBoxa().
| BOXA* boxaTransformOrdered | ( | BOXA * | boxas, |
| l_int32 | shiftx, | ||
| l_int32 | shifty, | ||
| l_float32 | scalex, | ||
| l_float32 | scaley, | ||
| l_int32 | xcen, | ||
| l_int32 | ycen, | ||
| l_float32 | angle, | ||
| l_int32 | order | ||
| ) |
Input: boxa shiftx, shifty scalex, scaley xcen, ycen (center of rotation) angle (in radians; clockwise is positive) order (one of 6 combinations: L_TR_SC_RO, ...) Return: boxd, or null on error
Notes: (1) This allows a sequence of linear transforms on each box. the transforms are from the affine set, composed of shift, scaling and rotation, and the order of the transforms is specified. (2) Although these operations appear to be on an infinite 2D plane, in practice the region of interest is clipped to a finite image. The center of rotation is usually taken with respect to the image (either the UL corner or the center). A translation can have two very different effects: (a) Moves the boxes across the fixed image region. (b) Moves the image origin, causing a change in the image region and an opposite effective translation of the boxes. This function should only be used for (a), where the image region is fixed on translation. If the image region is changed by the translation, use instead the functions in affinecompose.c, where the image region and rotation center can be computed from the actual clipping due to translation of the image origin. (3) See boxTransformOrdered() for usage and implementation details.
Definition at line 161 of file boxfunc2.c.
References boxaAddBox(), boxaCreate(), boxaGetBox(), boxaGetCount(), boxDestroy(), boxTransformOrdered(), ERROR_PTR, L_CLONE, L_INSERT, NULL, and PROCNAME.
Referenced by main().
| BOX* boxTransformOrdered | ( | BOX * | boxs, |
| l_int32 | shiftx, | ||
| l_int32 | shifty, | ||
| l_float32 | scalex, | ||
| l_float32 | scaley, | ||
| l_int32 | xcen, | ||
| l_int32 | ycen, | ||
| l_float32 | angle, | ||
| l_int32 | order | ||
| ) |
Input: boxs shiftx, shifty scalex, scaley xcen, ycen (center of rotation) angle (in radians; clockwise is positive) order (one of 6 combinations: L_TR_SC_RO, ...) Return: boxd, or null on error
Notes: (1) This allows a sequence of linear transforms, composed of shift, scaling and rotation, where the order of the transforms is specified. (2) The rotation is taken about a point specified by (xcen, ycen). Let the components of the vector from the center of rotation to the box center be (xdif, ydif): xdif = (bx + 0.5 * bw) - xcen ydif = (by + 0.5 * bh) - ycen Then the box center after rotation has new components: bxcen = xcen + xdif * cosa + ydif * sina bycen = ycen + ydif * cosa - xdif * sina where cosa and sina are the cos and sin of the angle, and the enclosing box for the rotated box has size: rw = |bw * cosa| + |bh * sina| rh = |bh * cosa| + |bw * sina| where bw and bh are the unrotated width and height. Then the box UL corner (rx, ry) is rx = bxcen - 0.5 * rw ry = bycen - 0.5 * rh (3) The center of rotation specified by args and is the point BEFORE any translation or scaling. If the rotation is not the first operation, this function finds the actual center at the time of rotation. It does this by making the following assumptions: (1) Any scaling is with respect to the UL corner, so that the center location scales accordingly. (2) A translation does not affect the center of the image; it just moves the boxes. We always use assumption (1). However, assumption (2) will be incorrect if the apparent translation is due to a clipping operation that, in effect, moves the origin of the image. In that case, you should NOT use these simple functions. Instead, use the functions in affinecompose.c, where the rotation center can be computed from the actual clipping due to translation of the image origin.
Definition at line 245 of file boxfunc2.c.
References boxCreate(), boxGetGeometry(), ERROR_PTR, L_ABS, L_MAX, L_RO_SC_TR, L_RO_TR_SC, L_SC_RO_TR, L_SC_TR_RO, L_TR_RO_SC, L_TR_SC_RO, NULL, and PROCNAME.
Referenced by boxaTransformOrdered().
Input: boxa w, h (of image in which the boxa is embedded) rotation (0 = noop, 1 = 90 deg, 2 = 180 deg, 3 = 270 deg; all rotations are clockwise) Return: boxad, or null on error
Notes: (1) See boxRotateOrth() for details.
Definition at line 424 of file boxfunc2.c.
References boxaAddBox(), boxaCopy(), boxaCreate(), boxaGetBox(), boxaGetCount(), boxDestroy(), boxRotateOrth(), ERROR_PTR, L_CLONE, L_COPY, L_INSERT, NULL, and PROCNAME.
Input: box w, h (of image in which the box is embedded) rotation (0 = noop, 1 = 90 deg, 2 = 180 deg, 3 = 270 deg; all rotations are clockwise) Return: boxd, or null on error
Notes: (1) Rotate the image with the embedded box by the specified amount. (2) After rotation, the rotated box is always measured with respect to the UL corner of the image.
Definition at line 472 of file boxfunc2.c.
References boxCopy(), boxCreate(), boxGetGeometry(), ERROR_PTR, NULL, and PROCNAME.
Referenced by boxaRotateOrth().
Input: boxa sorttype (L_SORT_BY_X, L_SORT_BY_Y, L_SORT_BY_WIDTH, L_SORT_BY_HEIGHT, L_SORT_BY_MIN_DIMENSION, L_SORT_BY_MAX_DIMENSION, L_SORT_BY_PERIMETER, L_SORT_BY_AREA, L_SORT_BY_ASPECT_RATIO) sortorder (L_SORT_INCREASING, L_SORT_DECREASING) &naindex (<optional return>=""> index of sorted order into original array) Return: boxad (sorted version of boxas), or null on error
Definition at line 516 of file boxfunc2.c.
References boxaBinSort(), boxaGetBoxGeometry(), boxaGetCount(), boxaSortByIndex(), ERROR_PTR, L_MAX, L_MIN, L_SORT_BY_AREA, L_SORT_BY_ASPECT_RATIO, L_SORT_BY_HEIGHT, L_SORT_BY_MAX_DIMENSION, L_SORT_BY_MIN_DIMENSION, L_SORT_BY_PERIMETER, L_SORT_BY_WIDTH, L_SORT_BY_X, L_SORT_BY_Y, L_SORT_DECREASING, L_SORT_INCREASING, L_WARNING, MIN_COMPS_FOR_BIN_SORT, NULL, numaAddNumber(), numaCreate(), numaDestroy(), numaGetSortIndex(), PROCNAME, and size.
Referenced by boxaSort2d(), BoxaSortTest(), main(), pixaGenerateFont(), pixDeskewBarcode(), and pixFindBaselines().
Input: boxa sorttype (L_SORT_BY_X, L_SORT_BY_Y, L_SORT_BY_WIDTH, L_SORT_BY_HEIGHT, L_SORT_BY_PERIMETER) sortorder (L_SORT_INCREASING, L_SORT_DECREASING) &naindex (<optional return>=""> index of sorted order into original array) Return: boxad (sorted version of boxas), or null on error
Notes: (1) For a large number of boxes (say, greater than 1000), this O(n) binsort is much faster than the O(nlogn) shellsort. For 5000 components, this is over 20x faster than boxaSort(). (2) Consequently, boxaSort() calls this function if it will likely go much faster.
Definition at line 627 of file boxfunc2.c.
References boxaGetBoxGeometry(), boxaGetCount(), boxaSortByIndex(), ERROR_PTR, L_SORT_BY_HEIGHT, L_SORT_BY_PERIMETER, L_SORT_BY_WIDTH, L_SORT_BY_X, L_SORT_BY_Y, L_SORT_DECREASING, L_SORT_INCREASING, L_WARNING, NULL, numaAddNumber(), numaCreate(), numaDestroy(), numaGetBinSortIndex(), and PROCNAME.
Referenced by boxaSort(), and BoxaSortTest().
Input: boxas naindex (na that maps from the new boxa to the input boxa) Return: boxad (sorted), or null on error
Definition at line 700 of file boxfunc2.c.
References boxaAddBox(), boxaCreate(), boxaGetBox(), boxaGetCount(), ERROR_PTR, L_COPY, L_INSERT, NULL, numaGetIValue(), and PROCNAME.
Referenced by boxaBinSort(), boxaPermutePseudorandom(), and boxaSort().
Input: boxas &naa (<optional return>=""> numaa with sorted indices whose values are the indices of the input array) delta1 (min overlap that permits aggregation of a box onto a boxa of horizontally-aligned boxes; pass 1) delta2 (min overlap that permits aggregation of a box onto a boxa of horizontally-aligned boxes; pass 2) minh1 (components less than this height either join an existing boxa or are set aside for pass 2) Return: boxaa (2d sorted version of boxa), or null on error
Notes: (1) The final result is a sort where the 'fast scan' direction is left to right, and the 'slow scan' direction is from top to bottom. Each boxa in the boxaa represents a sorted set of boxes from left to right. (2) Two passes are used to aggregate the boxas, which can corresond to characters or words in a line of text. In pass 1, only taller components, which correspond to xheight or larger, are permitted to start a new boxa, whereas in pass 2, the remaining vertically-challenged components are allowed to join an existing boxa or start a new one. (3) If delta1 < 0, the first pass allows aggregation when boxes in the same boxa do not overlap vertically. The distance by which they can miss and still be aggregated is the absolute value |delta1|. Similar for delta2 on the second pass. (4) On the first pass, any component of height less than minh1 cannot start a new boxa; it's put aside for later insertion. (5) On the second pass, any small component that doesn't align with an existing boxa can start a new one. (6) This can be used to identify lines of text from character or word bounding boxes.
Definition at line 764 of file boxfunc2.c.
References boxaaAddBox(), boxaaAddBoxa(), boxaaAlignBox(), boxaaCreate(), boxaAddBox(), boxaaDestroy(), boxaaGetBoxa(), boxaaGetCount(), boxaaReplaceBoxa(), boxaCreate(), boxaDestroy(), boxaGetBox(), boxaGetCount(), boxaSort(), boxGetGeometry(), ERROR_PTR, L_CLONE, L_INSERT, L_SORT_BY_X, L_SORT_BY_Y, L_SORT_INCREASING, NULL, numaaAddNuma(), numaaAddNumber(), numaaCreate(), numaAddNumber(), numaaDestroy(), numaaGetNuma(), numaaReplaceNuma(), numaCreate(), numaDestroy(), numaGetIValue(), numaSortByIndex(), and PROCNAME.
Referenced by pixGetWordBoxesInTextlines(), and pixGetWordsInTextlines().
Input: boxas naa (numaa that maps from the new baa to the input boxa) Return: baa (sorted boxaa), or null on error
Definition at line 904 of file boxfunc2.c.
References boxaaAddBoxa(), boxaaCreate(), boxaAddBox(), boxaCreate(), boxaGetBox(), boxaGetCount(), ERROR_PTR, L_CLONE, L_COPY, L_INSERT, NULL, numaaGetCount(), numaaGetNuma(), numaaGetNumberCount(), numaDestroy(), numaGetCount(), numaGetIValue(), and PROCNAME.
Input: boxa fract (use 0.0 for smallest, 1.0 for largest) Return: box (with rank values for x, y, w, h), or null on error or if the boxa is empty (has no valid boxes)
Notes: (1) This function does not assume that all boxes in the boxa are valid (2) The four box parameters are sorted independently. To assure that the resulting box size is sorted in increasing order:
Definition at line 964 of file boxfunc2.c.
References boxaGetBoxGeometry(), boxaGetCount(), boxCreate(), ERROR_PTR, NULL, numaAddNumber(), numaCreate(), numaDestroy(), numaGetRankValue(), and PROCNAME.
Referenced by boxaGetMedian().
Input: boxa Return: box (with median values for x, y, w, h), or null on error or if the boxa is empty.
Notes: (1) See boxaGetRankSize()
Definition at line 1018 of file boxfunc2.c.
References boxaGetCount(), boxaGetRankSize(), ERROR_PTR, NULL, and PROCNAME.
Input: boxaa &w (<optional return>=""> width) &h (<optional return>=""> height) &box (<optional return>="">, minimum box containing all boxa in boxaa) Return: 0 if OK, 1 on error
Notes: (1) The returned w and h are the minimum size image that would contain all boxes untranslated.
Definition at line 1049 of file boxfunc2.c.
References boxaaGetBoxa(), boxaaGetCount(), boxaGetBoxGeometry(), boxaGetCount(), boxCreate(), ERROR_INT, L_CLONE, L_MAX, L_MIN, NULL, and PROCNAME.
Referenced by boxaaDisplay().
Input: boxaa &naindex (<optional return>=""> the boxa index in the boxaa) copyflag (L_COPY or L_CLONE) Return: boxa, or null on error
Notes: (1) This 'flattens' the boxaa to a boxa, taking the boxes in order in the first boxa, then the second, etc. (2) If &naindex is defined, we generate a Numa that gives, for each box in the boxaa, the index of the boxa to which it belongs.
Definition at line 1108 of file boxfunc2.c.
References boxaAddBox(), boxaaGetBoxa(), boxaaGetCount(), boxaCreate(), boxaDestroy(), boxaGetBox(), boxaGetCount(), ERROR_PTR, L_CLONE, L_COPY, L_INSERT, NULL, numaAddNumber(), numaCreate(), and PROCNAME.
Referenced by pixGetWordBoxesInTextlines().
Input: boxaa box (to be aligned with the last of one of the boxa in boxaa, if possible) delta (amount by which consecutive components can miss in overlap and still be included in the array) &index (of boxa with best overlap, or if none match, this is the index of the next boxa to be generated) Return: 0 if OK, 1 on error
Notes: (1) This is not greedy; it finds the boxa whose last box has the biggest overlap with the input box.
Definition at line 1164 of file boxfunc2.c.
References boxaaGetBoxa(), boxaaGetCount(), boxaDestroy(), boxaGetBoxGeometry(), boxaGetCount(), boxGetGeometry(), ERROR_INT, L_CLONE, L_WARNING, NULL, and PROCNAME.
Referenced by boxaSort2d().
const l_int32 MIN_COMPS_FOR_BIN_SORT = 500 [static] |
Definition at line 52 of file boxfunc2.c.
Referenced by boxaSort().
1.7.3 
