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twain3.0/3rdparty/hgOCR/leptonica/boxfunc5.c

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/*====================================================================*
- Copyright (C) 2001 Leptonica. All rights reserved.
-
- Redistribution and use in source and binary forms, with or without
- modification, are permitted provided that the following conditions
- are met:
- 1. Redistributions of source code must retain the above copyright
- notice, this list of conditions and the following disclaimer.
- 2. Redistributions in binary form must reproduce the above
- copyright notice, this list of conditions and the following
- disclaimer in the documentation and/or other materials
- provided with the distribution.
-
- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL ANY
- CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
- OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
- NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
- SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*====================================================================*/
/*!
* \file boxfunc5.c
* <pre>
*
* Boxa sequence fitting
* BOXA *boxaSmoothSequenceLS()
* BOXA *boxaSmoothSequenceMedian()
* BOXA *boxaLinearFit()
* BOXA *boxaWindowedMedian()
* BOXA *boxaModifyWithBoxa()
* BOXA *boxaConstrainSize()
* BOXA *boxaReconcileEvenOddHeight()
* static l_int32 boxaTestEvenOddHeight()
* BOXA *boxaReconcilePairWidth()
* l_int32 boxaSizeConsistency1()
* l_int32 boxaSizeConsistency2()
* BOXA *boxaReconcileSizeByMedian()
* l_int32 boxaPlotSides() [for debugging]
* l_int32 boxaPlotSizes() [for debugging]
* BOXA *boxaFillSequence()
* static l_int32 boxaFillAll()
* l_int32 boxaSizeVariation()
* l_int32 boxaMedianDimensions()
* </pre>
*/
#include <math.h>
#include "allheaders.h"
static l_int32 boxaTestEvenOddHeight(BOXA *boxa1, BOXA *boxa2, l_int32 start,
l_float32 *pdel1, l_float32 *pdel2);
static l_int32 boxaFillAll(BOXA *boxa);
/*---------------------------------------------------------------------*
* Boxa sequence fitting *
*---------------------------------------------------------------------*/
/*!
* \brief boxaSmoothSequenceLS()
*
* \param[in] boxas source boxa
* \param[in] factor reject outliers with widths and heights deviating
* from the median by more than %factor times
* the median variation from the median; typically ~3
* \param[in] subflag L_USE_MINSIZE, L_USE_MAXSIZE,
* L_SUB_ON_LOC_DIFF, L_SUB_ON_SIZE_DIFF,
* L_USE_CAPPED_MIN, L_USE_CAPPED_MAX
* \param[in] maxdiff parameter used with L_SUB_ON_LOC_DIFF,
* L_SUB_ON_SIZE_DIFF, L_USE_CAPPED_MIN,
* L_USE_CAPPED_MAX
* \param[in] extrapixels pixels added on all sides (or subtracted
* if %extrapixels < 0) when using
* L_SUB_ON_LOC_DIFF and L_SUB_ON_SIZE_DIFF
* \param[in] debug 1 for debug output
* \return boxad fitted boxa, or NULL on error
*
* <pre>
* Notes:
* (1) This returns a modified version of %boxas by constructing
* for each input box a box that has been linear least square fit
* (LSF) to the entire set. The linear fitting is done to each of
* the box sides independently, after outliers are rejected,
* and it is computed separately for sequences of even and
* odd boxes. Once the linear LSF box is found, the output box
* (in %boxad) is constructed from the input box and the LSF
* box, depending on %subflag. See boxaModifyWithBoxa() for
* details on the use of %subflag and %maxdiff.
* (2) This is useful if, in both the even and odd sets, the box
* edges vary roughly linearly with its index in the set.
* </pre>
*/
BOXA *
boxaSmoothSequenceLS(BOXA *boxas,
l_float32 factor,
l_int32 subflag,
l_int32 maxdiff,
l_int32 extrapixels,
l_int32 debug)
{
l_int32 n;
BOXA *boxae, *boxao, *boxalfe, *boxalfo, *boxame, *boxamo, *boxad;
PROCNAME("boxaSmoothSequenceLS");
if (!boxas)
return (BOXA *)ERROR_PTR("boxas not defined", procName, NULL);
if (factor <= 0.0) {
L_WARNING("factor must be > 0.0; returning copy\n", procName);
return boxaCopy(boxas, L_COPY);
}
if (maxdiff < 0) {
L_WARNING("maxdiff must be >= 0; returning copy\n", procName);
return boxaCopy(boxas, L_COPY);
}
if (subflag != L_USE_MINSIZE && subflag != L_USE_MAXSIZE &&
subflag != L_SUB_ON_LOC_DIFF && subflag != L_SUB_ON_SIZE_DIFF &&
subflag != L_USE_CAPPED_MIN && subflag != L_USE_CAPPED_MAX) {
L_WARNING("invalid subflag; returning copy\n", procName);
return boxaCopy(boxas, L_COPY);
}
if ((n = boxaGetCount(boxas)) < 4) {
L_WARNING("need at least 4 boxes; returning copy\n", procName);
return boxaCopy(boxas, L_COPY);
}
boxaSplitEvenOdd(boxas, 1, &boxae, &boxao);
if (debug) {
lept_mkdir("lept/smooth");
boxaWriteDebug("/tmp/lept/smooth/boxae.ba", boxae);
boxaWriteDebug("/tmp/lept/smooth/boxao.ba", boxao);
}
boxalfe = boxaLinearFit(boxae, factor, debug);
boxalfo = boxaLinearFit(boxao, factor, debug);
if (debug) {
boxaWriteDebug("/tmp/lept/smooth/boxalfe.ba", boxalfe);
boxaWriteDebug("/tmp/lept/smooth/boxalfo.ba", boxalfo);
}
boxame = boxaModifyWithBoxa(boxae, boxalfe, subflag, maxdiff, extrapixels);
boxamo = boxaModifyWithBoxa(boxao, boxalfo, subflag, maxdiff, extrapixels);
if (debug) {
boxaWriteDebug("/tmp/lept/smooth/boxame.ba", boxame);
boxaWriteDebug("/tmp/lept/smooth/boxamo.ba", boxamo);
}
boxad = boxaMergeEvenOdd(boxame, boxamo, 1);
boxaDestroy(&boxae);
boxaDestroy(&boxao);
boxaDestroy(&boxalfe);
boxaDestroy(&boxalfo);
boxaDestroy(&boxame);
boxaDestroy(&boxamo);
return boxad;
}
/*!
* \brief boxaSmoothSequenceMedian()
*
* \param[in] boxas source boxa
* \param[in] halfwin half-width of sliding window; used to find median
* \param[in] subflag L_USE_MINSIZE, L_USE_MAXSIZE,
* L_SUB_ON_LOC_DIFF, L_SUB_ON_SIZE_DIFF,
* L_USE_CAPPED_MIN, L_USE_CAPPED_MAX
* \param[in] maxdiff parameter used with L_SUB_ON_LOC_DIFF,
* L_SUB_ON_SIZE_DIFF, L_USE_CAPPED_MIN,
* L_USE_CAPPED_MAX
* \param[in] extrapixels pixels added on all sides (or subtracted
* if %extrapixels < 0) when using
* L_SUB_ON_LOC_DIFF and L_SUB_ON_SIZE_DIFF
* \param[in] debug 1 for debug output
* \return boxad fitted boxa, or NULL on error
*
* <pre>
* Notes:
* (1) The target width of the sliding window is 2 * %halfwin + 1.
* If necessary, this will be reduced by boxaWindowedMedian().
* (2) This returns a modified version of %boxas by constructing
* for each input box a box that has been smoothed with windowed
* median filtering. The filtering is done to each of the
* box sides independently, and it is computed separately for
* sequences of even and odd boxes. The output %boxad is
* constructed from the input boxa and the filtered boxa,
* depending on %subflag. See boxaModifyWithBoxa() for
* details on the use of %subflag, %maxdiff and %extrapixels.
* (3) This is useful for removing noise separately in the even
* and odd sets, where the box edge locations can have
* discontinuities but otherwise vary roughly linearly within
* intervals of size %halfwin or larger.
* (4) If you don't need to handle even and odd sets separately,
* just do this:
* boxam = boxaWindowedMedian(boxas, halfwin, debug);
* boxad = boxaModifyWithBoxa(boxas, boxam, subflag, maxdiff,
* extrapixels);
* boxaDestroy(&boxam);
* </pre>
*/
BOXA *
boxaSmoothSequenceMedian(BOXA *boxas,
l_int32 halfwin,
l_int32 subflag,
l_int32 maxdiff,
l_int32 extrapixels,
l_int32 debug)
{
l_int32 n;
BOXA *boxae, *boxao, *boxamede, *boxamedo, *boxame, *boxamo, *boxad;
PROCNAME("boxaSmoothSequenceMedian");
if (!boxas)
return (BOXA *)ERROR_PTR("boxas not defined", procName, NULL);
if (halfwin <= 0) {
L_WARNING("halfwin must be > 0; returning copy\n", procName);
return boxaCopy(boxas, L_COPY);
}
if (maxdiff < 0) {
L_WARNING("maxdiff must be >= 0; returning copy\n", procName);
return boxaCopy(boxas, L_COPY);
}
if (subflag != L_USE_MINSIZE && subflag != L_USE_MAXSIZE &&
subflag != L_SUB_ON_LOC_DIFF && subflag != L_SUB_ON_SIZE_DIFF &&
subflag != L_USE_CAPPED_MIN && subflag != L_USE_CAPPED_MAX) {
L_WARNING("invalid subflag; returning copy\n", procName);
return boxaCopy(boxas, L_COPY);
}
if ((n = boxaGetCount(boxas)) < 6) {
L_WARNING("need at least 6 boxes; returning copy\n", procName);
return boxaCopy(boxas, L_COPY);
}
boxaSplitEvenOdd(boxas, 0, &boxae, &boxao);
if (debug) {
lept_mkdir("lept/smooth");
boxaWriteDebug("/tmp/lept/smooth/boxae.ba", boxae);
boxaWriteDebug("/tmp/lept/smooth/boxao.ba", boxao);
}
boxamede = boxaWindowedMedian(boxae, halfwin, debug);
boxamedo = boxaWindowedMedian(boxao, halfwin, debug);
if (debug) {
boxaWriteDebug("/tmp/lept/smooth/boxamede.ba", boxamede);
boxaWriteDebug("/tmp/lept/smooth/boxamedo.ba", boxamedo);
}
boxame = boxaModifyWithBoxa(boxae, boxamede, subflag, maxdiff, extrapixels);
boxamo = boxaModifyWithBoxa(boxao, boxamedo, subflag, maxdiff, extrapixels);
if (debug) {
boxaWriteDebug("/tmp/lept/smooth/boxame.ba", boxame);
boxaWriteDebug("/tmp/lept/smooth/boxamo.ba", boxamo);
}
boxad = boxaMergeEvenOdd(boxame, boxamo, 0);
if (debug) {
boxaPlotSides(boxas, NULL, NULL, NULL, NULL, NULL, NULL);
boxaPlotSides(boxad, NULL, NULL, NULL, NULL, NULL, NULL);
boxaPlotSizes(boxas, NULL, NULL, NULL, NULL);
boxaPlotSizes(boxad, NULL, NULL, NULL, NULL);
}
boxaDestroy(&boxae);
boxaDestroy(&boxao);
boxaDestroy(&boxamede);
boxaDestroy(&boxamedo);
boxaDestroy(&boxame);
boxaDestroy(&boxamo);
return boxad;
}
/*!
* \brief boxaLinearFit()
*
* \param[in] boxas source boxa
* \param[in] factor reject outliers with widths and heights deviating
* from the median by more than %factor times
* the median deviation from the median; typically ~3
* \param[in] debug 1 for debug output
* \return boxad fitted boxa, or NULL on error
*
* <pre>
* Notes:
* (1) This finds a set of boxes (boxad) where each edge of each box is
* a linear least square fit (LSF) to the edges of the
* input set of boxes (boxas). Before fitting, outliers in
* the boxes in boxas are removed (see below).
* (2) This is useful when each of the box edges in boxas are expected
* to vary linearly with box index in the set. These could
* be, for example, noisy measurements of similar regions
* on successive scanned pages.
* (3) Method: there are 2 steps:
* (a) Find and remove outliers, separately based on the deviation
* from the median of the width and height of the box.
* Use %factor to specify tolerance to outliers; use a very
* large value of %factor to avoid rejecting any box sides
* in the linear LSF.
* (b) On the remaining boxes, do a linear LSF independently
* for each of the four sides.
* (4) Invalid input boxes are not used in computation of the LSF.
* (5) The returned boxad can then be used in boxaModifyWithBoxa()
* to selectively change the boxes in boxas.
* </pre>
*/
BOXA *
boxaLinearFit(BOXA *boxas,
l_float32 factor,
l_int32 debug)
{
l_int32 n, i, w, h, lval, tval, rval, bval, rejectlr, rejecttb;
l_float32 al, bl, at, bt, ar, br, ab, bb; /* LSF coefficients */
l_float32 medw, medh, medvarw, medvarh;
BOX *box, *boxempty;
BOXA *boxalr, *boxatb, *boxad;
NUMA *naw, *nah;
PTA *ptal, *ptat, *ptar, *ptab;
PROCNAME("boxaLinearFit");
if (!boxas)
return (BOXA *)ERROR_PTR("boxas not defined", procName, NULL);
if ((n = boxaGetCount(boxas)) < 2)
return (BOXA *)ERROR_PTR("need at least 2 boxes", procName, NULL);
/* Remove outliers based on width and height.
* First find the median width and the median deviation from
* the median width. Ditto for the height. */
boxaExtractAsNuma(boxas, NULL, NULL, NULL, NULL, &naw, &nah, 0);
numaGetMedianDevFromMedian(naw, &medw, &medvarw);
numaGetMedianDevFromMedian(nah, &medh, &medvarh);
numaDestroy(&naw);
numaDestroy(&nah);
if (debug) {
fprintf(stderr, "medw = %7.3f, medvarw = %7.3f\n", medw, medvarw);
fprintf(stderr, "medh = %7.3f, medvarh = %7.3f\n", medh, medvarh);
}
/* To fit the left and right sides, only use boxes whose
* width is within (factor * medvarw) of the median width.
* Ditto for the top and bottom sides. Add empty boxes
* in as placeholders so that the index remains the same
* as in boxas. */
boxalr = boxaCreate(n);
boxatb = boxaCreate(n);
boxempty = boxCreate(0, 0, 0, 0); /* placeholders */
rejectlr = rejecttb = 0;
for (i = 0; i < n; i++) {
if ((box = boxaGetValidBox(boxas, i, L_CLONE)) == NULL) {
boxaAddBox(boxalr, boxempty, L_COPY);
boxaAddBox(boxatb, boxempty, L_COPY);
continue;
}
boxGetGeometry(box, NULL, NULL, &w, &h);
if (L_ABS(w - medw) <= factor * medvarw) {
boxaAddBox(boxalr, box, L_COPY);
} else {
rejectlr++;
boxaAddBox(boxalr, boxempty, L_COPY);
}
if (L_ABS(h - medh) <= factor * medvarh) {
boxaAddBox(boxatb, box, L_COPY);
} else {
rejecttb++;
boxaAddBox(boxatb, boxempty, L_COPY);
}
boxDestroy(&box);
}
boxDestroy(&boxempty);
if (boxaGetCount(boxalr) < 2 || boxaGetCount(boxatb) < 2) {
boxaDestroy(&boxalr);
boxaDestroy(&boxatb);
return (BOXA *)ERROR_PTR("need at least 2 valid boxes", procName, NULL);
}
if (debug) {
L_INFO("# lr reject = %d, # tb reject = %d\n", procName,
rejectlr, rejecttb);
lept_mkdir("linfit");
boxaWriteDebug("/tmp/linfit/boxalr.ba", boxalr);
boxaWriteDebug("/tmp/linfit/boxatb.ba", boxatb);
}
/* Extract the valid left and right box sides, along with the box
* index, from boxalr. This only extracts pts corresponding to
* valid boxes. Ditto: top and bottom sides from boxatb. */
boxaExtractAsPta(boxalr, &ptal, NULL, &ptar, NULL, NULL, NULL, 0);
boxaExtractAsPta(boxatb, NULL, &ptat, NULL, &ptab, NULL, NULL, 0);
boxaDestroy(&boxalr);
boxaDestroy(&boxatb);
if (debug) {
ptaWriteDebug("/tmp/linfit/ptal.pta", ptal, 1);
ptaWriteDebug("/tmp/linfit/ptar.pta", ptar, 1);
ptaWriteDebug("/tmp/linfit/ptat.pta", ptat, 1);
ptaWriteDebug("/tmp/linfit/ptab.pta", ptab, 1);
}
/* Do a linear LSF fit to the points that are width and height
* validated. Because we've eliminated the outliers, there is no
* need to use ptaNoisyLinearLSF(ptal, factor, NULL, &al, &bl, ...) */
ptaGetLinearLSF(ptal, &al, &bl, NULL);
ptaGetLinearLSF(ptat, &at, &bt, NULL);
ptaGetLinearLSF(ptar, &ar, &br, NULL);
ptaGetLinearLSF(ptab, &ab, &bb, NULL);
/* Return the LSF smoothed values, interleaved with invalid
* boxes when the corresponding box in boxas is invalid. */
boxad = boxaCreate(n);
boxempty = boxCreate(0, 0, 0, 0); /* use for placeholders */
for (i = 0; i < n; i++) {
lval = (l_int32)(al * i + bl + 0.5);
tval = (l_int32)(at * i + bt + 0.5);
rval = (l_int32)(ar * i + br + 0.5);
bval = (l_int32)(ab * i + bb + 0.5);
if ((box = boxaGetValidBox(boxas, i, L_CLONE)) == NULL) {
boxaAddBox(boxad, boxempty, L_COPY);
} else {
boxDestroy(&box);
box = boxCreate(lval, tval, rval - lval + 1, bval - tval + 1);
boxaAddBox(boxad, box, L_INSERT);
}
}
boxDestroy(&boxempty);
if (debug) {
boxaPlotSides(boxad, NULL, NULL, NULL, NULL, NULL, NULL);
boxaPlotSizes(boxad, NULL, NULL, NULL, NULL);
}
ptaDestroy(&ptal);
ptaDestroy(&ptat);
ptaDestroy(&ptar);
ptaDestroy(&ptab);
return boxad;
}
/*!
* \brief boxaWindowedMedian()
*
* \param[in] boxas source boxa
* \param[in] halfwin half width of window over which the median is found
* \param[in] debug 1 for debug output
* \return boxad smoothed boxa, or NULL on error
*
* <pre>
* Notes:
* (1) This finds a set of boxes (boxad) where each edge of each box is
* a windowed median smoothed value to the edges of the
* input set of boxes (boxas).
* (2) Invalid input boxes are filled from nearby ones.
* (3) The returned boxad can then be used in boxaModifyWithBoxa()
* to selectively change the boxes in the source boxa.
* </pre>
*/
BOXA *
boxaWindowedMedian(BOXA *boxas,
l_int32 halfwin,
l_int32 debug)
{
l_int32 n, i, left, top, right, bot;
BOX *box;
BOXA *boxaf, *boxad;
NUMA *nal, *nat, *nar, *nab, *naml, *namt, *namr, *namb;
PROCNAME("boxaWindowedMedian");
if (!boxas)
return (BOXA *)ERROR_PTR("boxas not defined", procName, NULL);
if ((n = boxaGetCount(boxas)) < 3) {
L_WARNING("less than 3 boxes; returning a copy\n", procName);
return boxaCopy(boxas, L_COPY);
}
if (halfwin <= 0) {
L_WARNING("halfwin must be > 0; returning copy\n", procName);
return boxaCopy(boxas, L_COPY);
}
/* Fill invalid boxes in the input sequence */
if ((boxaf = boxaFillSequence(boxas, L_USE_ALL_BOXES, debug)) == NULL)
return (BOXA *)ERROR_PTR("filled boxa not made", procName, NULL);
/* Get the windowed median output from each of the sides */
boxaExtractAsNuma(boxaf, &nal, &nat, &nar, &nab, NULL, NULL, 0);
naml = numaWindowedMedian(nal, halfwin);
namt = numaWindowedMedian(nat, halfwin);
namr = numaWindowedMedian(nar, halfwin);
namb = numaWindowedMedian(nab, halfwin);
n = boxaGetCount(boxaf);
boxad = boxaCreate(n);
for (i = 0; i < n; i++) {
numaGetIValue(naml, i, &left);
numaGetIValue(namt, i, &top);
numaGetIValue(namr, i, &right);
numaGetIValue(namb, i, &bot);
box = boxCreate(left, top, right - left + 1, bot - top + 1);
boxaAddBox(boxad, box, L_INSERT);
}
if (debug) {
boxaPlotSides(boxaf, NULL, NULL, NULL, NULL, NULL, NULL);
boxaPlotSides(boxad, NULL, NULL, NULL, NULL, NULL, NULL);
boxaPlotSizes(boxaf, NULL, NULL, NULL, NULL);
boxaPlotSizes(boxad, NULL, NULL, NULL, NULL);
}
boxaDestroy(&boxaf);
numaDestroy(&nal);
numaDestroy(&nat);
numaDestroy(&nar);
numaDestroy(&nab);
numaDestroy(&naml);
numaDestroy(&namt);
numaDestroy(&namr);
numaDestroy(&namb);
return boxad;
}
/*!
* \brief boxaModifyWithBoxa()
*
* \param[in] boxas
* \param[in] boxam boxa with boxes used to modify those in boxas
* \param[in] subflag L_USE_MINSIZE, L_USE_MAXSIZE,
* L_SUB_ON_LOC_DIFF, L_SUB_ON_SIZE_DIFF,
* L_USE_CAPPED_MIN, L_USE_CAPPED_MAX
* \param[in] maxdiff parameter used with L_SUB_ON_LOC_DIFF,
* L_SUB_ON_SIZE_DIFF, L_USE_CAPPED_MIN,
* L_USE_CAPPED_MAX
* \param[in] extrapixels pixels added on all sides (or subtracted
* if %extrapixels < 0) when using
* L_SUB_ON_LOC_DIFF and L_SUB_ON_SIZE_DIFF
* \return boxad result after adjusting boxes in boxas, or NULL on error.
*
* <pre>
* Notes:
* (1) This takes two input boxa (boxas, boxam) and constructs boxad,
* where each box in boxad is generated from the corresponding
* boxes in boxas and boxam. The rule for constructing each
* output box depends on %subflag and %maxdiff. Let boxs be
* a box from %boxas and boxm be a box from %boxam.
* * If %subflag == L_USE_MINSIZE: the output box is the intersection
* of the two input boxes.
* * If %subflag == L_USE_MAXSIZE: the output box is the union of the
* two input boxes; i.e., the minimum bounding rectangle for the
* two input boxes.
* * If %subflag == L_SUB_ON_LOC_DIFF: each side of the output box
* is found separately from the corresponding side of boxs and boxm.
* Use the boxm side, expanded by %extrapixels, if greater than
* %maxdiff pixels from the boxs side.
* * If %subflag == L_SUB_ON_SIZE_DIFF: the sides of the output box
* are determined in pairs from the width and height of boxs
* and boxm. If the boxm width differs by more than %maxdiff
* pixels from boxs, use the boxm left and right sides,
* expanded by %extrapixels. Ditto for the height difference.
* For the last two flags, each side of the output box is found
* separately from the corresponding side of boxs and boxm,
* according to these rules, where "smaller"("bigger") mean in a
* direction that decreases(increases) the size of the output box:
* * If %subflag == L_USE_CAPPED_MIN: use the Min of boxm
* with the Max of (boxs, boxm +- %maxdiff), where the sign
* is adjusted to make the box smaller (e.g., use "+" on left side).
* * If %subflag == L_USE_CAPPED_MAX: use the Max of boxm
* with the Min of (boxs, boxm +- %maxdiff), where the sign
* is adjusted to make the box bigger (e.g., use "-" on left side).
* Use of the last 2 flags is further explained in (3) and (4).
* (2) boxas and boxam must be the same size. If boxam == NULL,
* this returns a copy of boxas with a warning.
* (3) If %subflag == L_SUB_ON_LOC_DIFF, use boxm for each side
* where the corresponding sides differ by more than %maxdiff.
* Two extreme cases:
* (a) set %maxdiff == 0 to use only values from boxam in boxad.
* (b) set %maxdiff == 10000 to ignore all values from boxam;
* then boxad will be the same as boxas.
* (4) If %subflag == L_USE_CAPPED_MAX: use boxm if boxs is smaller;
* use boxs if boxs is bigger than boxm by an amount up to %maxdiff;
* and use boxm +- %maxdiff (the 'capped' value) if boxs is
* bigger than boxm by an amount larger than %maxdiff.
* Similarly, with interchange of Min/Max and sign of %maxdiff,
* for %subflag == L_USE_CAPPED_MIN.
* (5) If either of corresponding boxes in boxas and boxam is invalid,
* an invalid box is copied to the result.
* (6) Typical input for boxam may be the output of boxaLinearFit().
* where outliers have been removed and each side is LS fit to a line.
* (7) Unlike boxaAdjustWidthToTarget() and boxaAdjustHeightToTarget(),
* this uses two boxes and does not specify target dimensions.
* Additional constraints on the size of each box can be enforced
* by following this operation with boxaConstrainSize(), taking
* boxad as input.
* </pre>
*/
BOXA *
boxaModifyWithBoxa(BOXA *boxas,
BOXA *boxam,
l_int32 subflag,
l_int32 maxdiff,
l_int32 extrapixels)
{
l_int32 n, i, ls, ts, rs, bs, ws, hs, lm, tm, rm, bm, wm, hm, ld, td, rd, bd;
BOX *boxs, *boxm, *boxd, *boxempty;
BOXA *boxad;
PROCNAME("boxaModifyWithBoxa");
if (!boxas)
return (BOXA *)ERROR_PTR("boxas not defined", procName, NULL);
if (!boxam) {
L_WARNING("boxam not defined; returning copy", procName);
return boxaCopy(boxas, L_COPY);
}
if (subflag != L_USE_MINSIZE && subflag != L_USE_MAXSIZE &&
subflag != L_SUB_ON_LOC_DIFF && subflag != L_SUB_ON_SIZE_DIFF &&
subflag != L_USE_CAPPED_MIN && subflag != L_USE_CAPPED_MAX) {
L_WARNING("invalid subflag; returning copy", procName);
return boxaCopy(boxas, L_COPY);
}
n = boxaGetCount(boxas);
if (n != boxaGetCount(boxam)) {
L_WARNING("boxas and boxam sizes differ; returning copy", procName);
return boxaCopy(boxas, L_COPY);
}
boxad = boxaCreate(n);
boxempty = boxCreate(0, 0, 0, 0); /* placeholders */
for (i = 0; i < n; i++) {
boxs = boxaGetValidBox(boxas, i, L_CLONE);
boxm = boxaGetValidBox(boxam, i, L_CLONE);
if (!boxs || !boxm) {
boxaAddBox(boxad, boxempty, L_COPY);
} else {
boxGetGeometry(boxs, &ls, &ts, &ws, &hs);
boxGetGeometry(boxm, &lm, &tm, &wm, &hm);
rs = ls + ws - 1;
bs = ts + hs - 1;
rm = lm + wm - 1;
bm = tm + hm - 1;
if (subflag == L_USE_MINSIZE) {
ld = L_MAX(ls, lm);
rd = L_MIN(rs, rm);
td = L_MAX(ts, tm);
bd = L_MIN(bs, bm);
} else if (subflag == L_USE_MAXSIZE) {
ld = L_MIN(ls, lm);
rd = L_MAX(rs, rm);
td = L_MIN(ts, tm);
bd = L_MAX(bs, bm);
} else if (subflag == L_SUB_ON_LOC_DIFF) {
ld = (L_ABS(lm - ls) <= maxdiff) ? ls : lm - extrapixels;
td = (L_ABS(tm - ts) <= maxdiff) ? ts : tm - extrapixels;
rd = (L_ABS(rm - rs) <= maxdiff) ? rs : rm + extrapixels;
bd = (L_ABS(bm - bs) <= maxdiff) ? bs : bm + extrapixels;
} else if (subflag == L_SUB_ON_SIZE_DIFF) {
ld = (L_ABS(wm - ws) <= maxdiff) ? ls : lm - extrapixels;
td = (L_ABS(hm - hs) <= maxdiff) ? ts : tm - extrapixels;
rd = (L_ABS(wm - ws) <= maxdiff) ? rs : rm + extrapixels;
bd = (L_ABS(hm - hs) <= maxdiff) ? bs : bm + extrapixels;
} else if (subflag == L_USE_CAPPED_MIN) {
ld = L_MAX(lm, L_MIN(ls, lm + maxdiff));
td = L_MAX(tm, L_MIN(ts, tm + maxdiff));
rd = L_MIN(rm, L_MAX(rs, rm - maxdiff));
bd = L_MIN(bm, L_MAX(bs, bm - maxdiff));
} else { /* subflag == L_USE_CAPPED_MAX */
ld = L_MIN(lm, L_MAX(ls, lm - maxdiff));
td = L_MIN(tm, L_MAX(ts, tm - maxdiff));
rd = L_MAX(rm, L_MIN(rs, rm + maxdiff));
bd = L_MAX(bm, L_MIN(bs, bm + maxdiff));
}
boxd = boxCreate(ld, td, rd - ld + 1, bd - td + 1);
boxaAddBox(boxad, boxd, L_INSERT);
}
boxDestroy(&boxs);
boxDestroy(&boxm);
}
boxDestroy(&boxempty);
return boxad;
}
/*!
* \brief boxaConstrainSize()
*
* \param[in] boxas
* \param[in] width force width of all boxes to this size;
* input 0 to use the median width
* \param[in] widthflag L_ADJUST_SKIP, L_ADJUST_LEFT, L_ADJUST_RIGHT,
* or L_ADJUST_LEFT_AND_RIGHT
* \param[in] height force height of all boxes to this size;
* input 0 to use the median height
* \param[in] heightflag L_ADJUST_SKIP, L_ADJUST_TOP, L_ADJUST_BOT,
* or L_ADJUST_TOP_AND_BOT
* \return boxad adjusted so all boxes are the same size
*
* <pre>
* Notes:
* (1) Forces either width or height (or both) of every box in
* the boxa to a specified size, by moving the indicated sides.
* (2) Not all input boxes need to be valid. Median values will be
* used with invalid boxes.
* (3) Typical input might be the output of boxaLinearFit(),
* where each side has been fit.
* (4) Unlike boxaAdjustWidthToTarget() and boxaAdjustHeightToTarget(),
* this is not dependent on a difference threshold to change the size.
* (5) On error, a message is issued and a copy of the input boxa
* is returned.
* </pre>
*/
BOXA *
boxaConstrainSize(BOXA *boxas,
l_int32 width,
l_int32 widthflag,
l_int32 height,
l_int32 heightflag)
{
l_int32 n, i, x, y, w, h, invalid;
l_int32 delw, delh, del_left, del_right, del_top, del_bot;
BOX *medbox, *boxs, *boxd;
BOXA *boxad;
PROCNAME("boxaConstrainSize");
if (!boxas)
return (BOXA *)ERROR_PTR("boxas not defined", procName, NULL);
/* Need median values if requested or if there are invalid boxes */
invalid = boxaGetCount(boxas) - boxaGetValidCount(boxas);
medbox = NULL;
if (width == 0 || height == 0 || invalid > 0) {
if (boxaGetMedianVals(boxas, &x, &y, NULL, NULL, &w, &h)) {
L_ERROR("median vals not returned", procName);
return boxaCopy(boxas, L_COPY);
}
medbox = boxCreate(x, y, w, h);
if (width == 0) width = w;
if (height == 0) height = h;
}
n = boxaGetCount(boxas);
boxad = boxaCreate(n);
for (i = 0; i < n; i++) {
if ((boxs = boxaGetValidBox(boxas, i, L_COPY)) == NULL)
boxs = boxCopy(medbox);
boxGetGeometry(boxs, NULL, NULL, &w, &h);
delw = width - w;
delh = height - h;
del_left = del_right = del_top = del_bot = 0;
if (widthflag == L_ADJUST_LEFT) {
del_left = -delw;
} else if (widthflag == L_ADJUST_RIGHT) {
del_right = delw;
} else {
del_left = -delw / 2;
del_right = delw / 2 + L_SIGN(delw) * (delw & 1);
}
if (heightflag == L_ADJUST_TOP) {
del_top = -delh;
} else if (heightflag == L_ADJUST_BOT) {
del_bot = delh;
} else {
del_top = -delh / 2;
del_bot = delh / 2 + L_SIGN(delh) * (delh & 1);
}
boxd = boxAdjustSides(NULL, boxs, del_left, del_right,
del_top, del_bot);
boxaAddBox(boxad, boxd, L_INSERT);
boxDestroy(&boxs);
}
boxDestroy(&medbox);
return boxad;
}
/*!
* \brief boxaReconcileEvenOddHeight()
*
* \param[in] boxas containing at least 3 valid boxes in even and odd
* \param[in] sides L_ADJUST_TOP, L_ADJUST_BOT, L_ADJUST_TOP_AND_BOT
* \param[in] delh threshold on median height difference
* \param[in] op L_ADJUST_CHOOSE_MIN, L_ADJUST_CHOOSE_MAX
* \param[in] factor > 0.0, typically near 1.0
* \param[in] start 0 if pairing (0,1), etc; 1 if pairing (1,2), etc
* \return boxad adjusted, or a copy of boxas on error
*
* <pre>
* Notes:
* (1) The basic idea is to reconcile differences in box height
* in the even and odd boxes, by moving the top and/or bottom
* edges in the even and odd boxes. Choose the edge or edges
* to be moved, whether to adjust the boxes with the min
* or the max of the medians, and the threshold on the median
* difference between even and odd box heights for the operations
* to take place. The same threshold is also used to
* determine if each individual box edge is to be adjusted.
* (2) Boxes are conditionally reset with either the same top (y)
* value or the same bottom value, or both. The value is
* determined by the greater or lesser of the medians of the
* even and odd boxes, with the choice depending on the value
* of %op, which selects for either min or max median height.
* If the median difference between even and odd boxes is
* greater than %dely, then any individual box edge that differs
* from the selected median by more than %dely is set to
* the selected median times a factor typically near 1.0.
* (3) Note that if selecting for minimum height, you will choose
* the largest y-value for the top and the smallest y-value for
* the bottom of the box.
* (4) Typical input might be the output of boxaSmoothSequence(),
* where even and odd boxa have been independently regulated.
* (5) Require at least 3 valid even boxes and 3 valid odd boxes.
* Median values will be used for invalid boxes.
* (6) If the median height is not representative of the boxes
* in %boxas, this can make things much worse. In that case,
* ignore the value of %op, and force pairwise equality of the
* heights, with pairwise maximal vertical extension.
* </pre>
*/
BOXA *
boxaReconcileEvenOddHeight(BOXA *boxas,
l_int32 sides,
l_int32 delh,
l_int32 op,
l_float32 factor,
l_int32 start)
{
l_int32 n, he, ho, hmed, doeven;
l_float32 del1, del2;
BOXA *boxae, *boxao, *boxa1e, *boxa1o, *boxad;
PROCNAME("boxaReconcileEvenOddHeight");
if (!boxas)
return (BOXA *)ERROR_PTR("boxas not defined", procName, NULL);
if (sides != L_ADJUST_TOP && sides != L_ADJUST_BOT &&
sides != L_ADJUST_TOP_AND_BOT) {
L_WARNING("no action requested; returning copy\n", procName);
return boxaCopy(boxas, L_COPY);
}
if ((n = boxaGetValidCount(boxas)) < 6) {
L_WARNING("need at least 6 valid boxes; returning copy\n", procName);
return boxaCopy(boxas, L_COPY);
}
if (factor <= 0.0) {
L_WARNING("invalid factor; setting to 1.0\n", procName);
factor = 1.0;
}
/* Require at least 3 valid boxes of both types */
boxaSplitEvenOdd(boxas, 0, &boxae, &boxao);
if (boxaGetValidCount(boxae) < 3 || boxaGetValidCount(boxao) < 3) {
boxaDestroy(&boxae);
boxaDestroy(&boxao);
return boxaCopy(boxas, L_COPY);
}
/* Get the median heights for each set */
boxaGetMedianVals(boxae, NULL, NULL, NULL, NULL, NULL, &he);
boxaGetMedianVals(boxao, NULL, NULL, NULL, NULL, NULL, &ho);
L_INFO("median he = %d, median ho = %d\n", procName, he, ho);
/* If the difference in median height reaches the threshold %delh,
* only adjust the side(s) of one of the sets. If we choose
* the minimum median height as the target, allow the target
* to be scaled by a factor, typically near 1.0, of the
* minimum median height. And similarly if the target is
* the maximum median height. */
if (L_ABS(he - ho) > delh) {
if (op == L_ADJUST_CHOOSE_MIN) {
doeven = (ho < he) ? TRUE : FALSE;
hmed = (l_int32)(factor * L_MIN(he, ho));
hmed = L_MIN(hmed, L_MAX(he, ho)); /* don't make it bigger! */
} else { /* max height */
doeven = (ho > he) ? TRUE : FALSE;
hmed = (l_int32)(factor * L_MAX(he, ho));
hmed = L_MAX(hmed, L_MIN(he, ho)); /* don't make it smaller! */
}
if (doeven) {
boxa1e = boxaAdjustHeightToTarget(NULL, boxae, sides, hmed, delh);
boxa1o = boxaCopy(boxao, L_COPY);
} else { /* !doeven */
boxa1e = boxaCopy(boxae, L_COPY);
boxa1o = boxaAdjustHeightToTarget(NULL, boxao, sides, hmed, delh);
}
} else {
boxa1e = boxaCopy(boxae, L_CLONE);
boxa1o = boxaCopy(boxao, L_CLONE);
}
boxaDestroy(&boxae);
boxaDestroy(&boxao);
/* It can happen that the median is not a good measure for an
* entire book. In that case, the reconciliation above can do
* more harm than good. Sanity check by comparing height and y
* differences of adjacent even/odd boxes, before and after
* reconciliation. */
boxad = boxaMergeEvenOdd(boxa1e, boxa1o, 0);
boxaTestEvenOddHeight(boxas, boxad, start, &del1, &del2);
boxaDestroy(&boxa1e);
boxaDestroy(&boxa1o);
if (del2 < del1 + 10.)
return boxad;
/* Using the median made it worse. Skip reconciliation:
* forcing all pairs of top and bottom values to have
* maximum extent does not improve the situation either. */
L_INFO("Got worse: del2 = %f > del1 = %f\n", procName, del2, del1);
boxaDestroy(&boxad);
return boxaCopy(boxas, L_COPY);
}
/*!
* \brief boxaTestEvenOddHeight()
*
* \param[in] boxa1 input boxa 1
* \param[in] boxa2 input boxa 2
* \param[in] start 0 if pairing (0,1), etc; 1 if pairing (1,2), etc
* \param[out] pdel1 root mean of (dely^2 + delh^2 for boxa1
* \param[out] pdel2 root mean of (dely^2 + delh^2 for boxa2
* \return 0 if OK, 1 on error
*
* <pre>
* Notes:
* (1) This compares differences in the y location and height of
* adjacent boxes, in each of the input boxa.
* </pre>
*/
static l_int32
boxaTestEvenOddHeight(BOXA *boxa1,
BOXA *boxa2,
l_int32 start,
l_float32 *pdel1,
l_float32 *pdel2)
{
l_int32 i, n, npairs, y1a, y1b, y2a, y2b, h1a, h1b, h2a, h2b;
l_float32 del1, del2;
PROCNAME("boxaTestEvenOddHeight");
if (pdel1) *pdel1 = 0.0;
if (pdel2) *pdel2 = 0.0;
if (!pdel1 || !pdel2)
return ERROR_INT("&del1 and &del2 not both defined", procName, 1);
if (!boxa1 || !boxa2)
return ERROR_INT("boxa1 and boxa2 not both defined", procName, 1);
n = L_MIN(boxaGetCount(boxa1), boxaGetCount(boxa2));
/* For boxa1 and boxa2 separately, we expect the y and h values
* to be similar for adjacent boxes. Get a measure of similarity
* by finding the sum of squares of differences between
* y values and between h values, and adding them. */
del1 = del2 = 0.0;
npairs = (n - start) / 2;
for (i = start; i < 2 * npairs; i += 2) {
boxaGetBoxGeometry(boxa1, i, NULL, &y1a, NULL, &h1a);
boxaGetBoxGeometry(boxa1, i + 1, NULL, &y1b, NULL, &h1b);
del1 += (l_float32)(y1a - y1b) * (y1a - y1b)
+ (h1a - h1b) * (h1a - h1b);
boxaGetBoxGeometry(boxa2, i, NULL, &y2a, NULL, &h2a);
boxaGetBoxGeometry(boxa2, i + 1, NULL, &y2b, NULL, &h2b);
del2 += (l_float32)(y2a - y2b) * (y2a - y2b)
+ (h2a - h2b) * (h2a - h2b);
}
/* Get the root of the average of the sum of square differences */
*pdel1 = (l_float32)sqrt((l_float64)del1 / (0.5 * n));
*pdel2 = (l_float32)sqrt((l_float64)del2 / (0.5 * n));
return 0;
}
/*!
* \brief boxaReconcilePairWidth()
*
* \param[in] boxas
* \param[in] delw threshold on adjacent width difference
* \param[in] op L_ADJUST_CHOOSE_MIN, L_ADJUST_CHOOSE_MAX
* \param[in] factor > 0.0, typically near 1.0
* \param[in] na [optional] indicator array allowing change
* \return boxad adjusted, or a copy of boxas on error
*
* <pre>
* Notes:
* (1) This reconciles differences in the width of adjacent boxes,
* by moving one side of one of the boxes in each pair.
* If the widths in the pair differ by more than some
* threshold, move either the left side for even boxes or
* the right side for odd boxes, depending on if we're choosing
* the min or max. If choosing min, the width of the max is
* set to factor * (width of min). If choosing max, the width
* of the min is set to factor * (width of max).
* (2) If %na exists, it is an indicator array corresponding to the
* boxes in %boxas. If %na != NULL, only boxes with an
* indicator value of 1 are allowed to adjust; otherwise,
* all boxes can adjust.
* (3) Typical input might be the output of boxaSmoothSequence(),
* where even and odd boxa have been independently regulated.
* </pre>
*/
BOXA *
boxaReconcilePairWidth(BOXA *boxas,
l_int32 delw,
l_int32 op,
l_float32 factor,
NUMA *na)
{
l_int32 i, ne, no, nmin, xe, we, xo, wo, inde, indo, x, w;
BOX *boxe, *boxo;
BOXA *boxae, *boxao, *boxad;
PROCNAME("boxaReconcilePairWidth");
if (!boxas)
return (BOXA *)ERROR_PTR("boxas not defined", procName, NULL);
if (factor <= 0.0) {
L_WARNING("invalid factor; setting to 1.0\n", procName);
factor = 1.0;
}
/* Taking the boxes in pairs, if the difference in width reaches
* the threshold %delw, adjust the left or right side of one
* of the pair. */
boxaSplitEvenOdd(boxas, 0, &boxae, &boxao);
ne = boxaGetCount(boxae);
no = boxaGetCount(boxao);
nmin = L_MIN(ne, no);
for (i = 0; i < nmin; i++) {
/* Set indicator values */
if (na) {
numaGetIValue(na, 2 * i, &inde);
numaGetIValue(na, 2 * i + 1, &indo);
} else {
inde = indo = 1;
}
if (inde == 0 && indo == 0) continue;
boxe = boxaGetBox(boxae, i, L_CLONE);
boxo = boxaGetBox(boxao, i, L_CLONE);
boxGetGeometry(boxe, &xe, NULL, &we, NULL);
boxGetGeometry(boxo, &xo, NULL, &wo, NULL);
if (we == 0 || wo == 0) { /* if either is invalid; skip */
boxDestroy(&boxe);
boxDestroy(&boxo);
continue;
} else if (L_ABS(we - wo) > delw) {
if (op == L_ADJUST_CHOOSE_MIN) {
if (we > wo && inde == 1) {
/* move left side of even to the right */
w = factor * wo;
x = xe + (we - w);
boxSetGeometry(boxe, x, -1, w, -1);
} else if (we < wo && indo == 1) {
/* move right side of odd to the left */
w = factor * we;
boxSetGeometry(boxo, -1, -1, w, -1);
}
} else { /* maximize width */
if (we < wo && inde == 1) {
/* move left side of even to the left */
w = factor * wo;
x = L_MAX(0, xe + (we - w));
w = we + (xe - x); /* covers both cases for the max */
boxSetGeometry(boxe, x, -1, w, -1);
} else if (we > wo && indo == 1) {
/* move right side of odd to the right */
w = factor * we;
boxSetGeometry(boxo, -1, -1, w, -1);
}
}
}
boxDestroy(&boxe);
boxDestroy(&boxo);
}
boxad = boxaMergeEvenOdd(boxae, boxao, 0);
boxaDestroy(&boxae);
boxaDestroy(&boxao);
return boxad;
}
/*!
* \brief boxaSizeConsistency1()
*
* \param[in] boxas of size >= 10
* \param[in] type L_CHECK_WIDTH, L_CHECK_HEIGHT
* \param[in] threshp threshold for pairwise fractional variation
* \param[in] threshm threshold for fractional variation from median
* \param[out] pfvarp [optional] average fractional pairwise variation
* \param[out] pfvarm [optional] average fractional median variation
* \param[out] psame decision for uniformity of page size (1, 0, -1)
*
* <pre>
* Notes:
* (1) This evaluates a boxa for particular types of dimensional
* variation. Select either width or height variation. Then
* it returns two numbers: one is based on pairwise (even/odd)
* variation; the other is based on the average variation
* from the boxa median.
* (2) For the pairwise variation, get the fraction of the absolute
* difference in dimension of each pair of boxes, and take
* the average value. The median variation is simply the
* the average of the fractional deviation from the median
* of all the boxes.
* (3) Use 0 for default values of %threshp and %threshm. They are
* threshp: 0.02
* threshm: 0.015
* (4) The intended application is that the boxes are a sequence of
* page regions in a book scan, and we calculate two numbers
* that can give an indication if the pages are approximately
* the same size. The pairwise variation should be small if
* the boxes are correctly calculated. If there are a
* significant number of random or systematic outliers, the
* pairwise variation will be large, and no decision will be made
* (i.e., return same == -1). Here are the possible outcomes:
* Pairwise Var Median Var Decision
* ------------ ---------- --------
* small small same size (1)
* small large different size (0)
* large small/large unknown (-1)
* </pre>
*/
l_ok
boxaSizeConsistency1(BOXA *boxas,
l_int32 type,
l_float32 threshp,
l_float32 threshm,
l_float32 *pfvarp,
l_float32 *pfvarm,
l_int32 *psame)
{
l_int32 i, n, bw1, bh1, bw2, bh2, npairs;
l_float32 ave, fdiff, sumdiff, med, fvarp, fvarm;
NUMA *na1;
PROCNAME("boxaSizeConsistency1");
if (pfvarp) *pfvarp = 0.0;
if (pfvarm) *pfvarm = 0.0;
if (!psame)
return ERROR_INT("&same not defined", procName, 1);
*psame = -1;
if (!boxas)
return ERROR_INT("boxas not defined", procName, 1);
if (boxaGetValidCount(boxas) < 6)
return ERROR_INT("need a least 6 valid boxes", procName, 1);
if (type != L_CHECK_WIDTH && type != L_CHECK_HEIGHT)
return ERROR_INT("invalid type", procName, 1);
if (threshp < 0.0 || threshp >= 0.5)
return ERROR_INT("invalid threshp", procName, 1);
if (threshm < 0.0 || threshm >= 0.5)
return ERROR_INT("invalid threshm", procName, 1);
if (threshp == 0.0) threshp = 0.02;
if (threshm == 0.0) threshm = 0.015;
/* Evaluate pairwise variation */
n = boxaGetCount(boxas);
na1 = numaCreate(0);
for (i = 0, npairs = 0, sumdiff = 0; i < n - 1; i += 2) {
boxaGetBoxGeometry(boxas, i, NULL, NULL, &bw1, &bh1);
boxaGetBoxGeometry(boxas, i + 1, NULL, NULL, &bw2, &bh2);
if (bw1 == 0 || bh1 == 0 || bw2 == 0 || bh2 == 0)
continue;
npairs++;
if (type == L_CHECK_WIDTH) {
ave = (bw1 + bw2) / 2.0;
fdiff = L_ABS(bw1 - bw2) / ave;
numaAddNumber(na1, bw1);
numaAddNumber(na1, bw2);
} else { /* type == L_CHECK_HEIGHT) */
ave = (bh1 + bh2) / 2.0;
fdiff = L_ABS(bh1 - bh2) / ave;
numaAddNumber(na1, bh1);
numaAddNumber(na1, bh2);
}
sumdiff += fdiff;
}
fvarp = sumdiff / npairs;
if (pfvarp) *pfvarp = fvarp;
/* Evaluate the average abs fractional deviation from the median */
numaGetMedian(na1, &med);
if (med == 0.0) {
L_WARNING("median value is 0\n", procName);
} else {
numaGetMeanDevFromMedian(na1, med, &fvarm);
fvarm /= med;
if (pfvarm) *pfvarm = fvarm;
}
numaDestroy(&na1);
/* Make decision */
if (fvarp < threshp && fvarm < threshm)
*psame = 1;
else if (fvarp < threshp && fvarm > threshm)
*psame = 0;
else
*psame = -1; /* unknown */
return 0;
}
/*!
* \brief boxaSizeConsistency2()
*
* \param[in] boxas of size >= 10
* \param[out] pfdevw average fractional deviation from median width
* \param[out] pfdevh average fractional deviation from median height
* \param[in] debug 1 for debug plot output of input and regularized
* width and height
*
* <pre>
* Notes:
* (1) This evaluates a boxa for consistency of the box sizes.
* The intended application is that the boxes are a sequence of
* page regions in a book scan, and the output is a decision
* about whether the pages should be approximately the same size.
* The determination should be robust to outliers, both random
* and (for many cases) systematic.
* (2) This differs from boxaSizeConsistency1() in that it attempts
* to correct for box dimensional errors before doing the
* evaluation. For this reason, it may be less robust.
* (3) Adjacent even and odd boxes are expected to be the same size.
* Take them pairwise, and assume the minimum height, hmin,
* is correct. Then for (the usual case) wmin/hmin > 0.5, assume
* the minimum width is correct. If wmin/hmin <= 0.5, assume
* the maximum width is correct.
* (4) After correcting each pair so that they are the same size,
* compute the average fractional deviation, from median width and
* height. A deviation of width or height by more than about
* 0.02 is evidence that the boxes may be from a non-homogeneous
* source, such as a book with significantly different page sizes.
* </pre>
*/
l_ok
boxaSizeConsistency2(BOXA *boxas,
l_float32 *pfdevw,
l_float32 *pfdevh,
l_int32 debug)
{
l_int32 i, n, bw1, bh1, bw2, bh2, npairs;
l_float32 medw, medh, devw, devh, minw, maxw, minh, w;
BOX *box;
BOXA *boxa1;
NUMA *naw, *nah;
PIX *pix1, *pix2, *pix3;
PIXA *pixa;
PROCNAME("boxaSizeConsistency2");
if (pfdevw) *pfdevw = 0.0;
if (pfdevh) *pfdevh = 0.0;
if (!boxas)
return ERROR_INT("boxas not defined", procName, 1);
if (!pfdevw || !pfdevh)
return ERROR_INT("&fdevw and &fdevh not both defined", procName, 1);
n = boxaGetCount(boxas);
if (n < 10) {
L_WARNING("small boxa; assuming OK", procName);
return 0;
}
/* Regularize w and h in pairs; skip last box if n is odd */
boxa1 = (debug) ? boxaCreate(n) : NULL;
naw = numaCreate(0);
nah = numaCreate(0);
for (i = 0, npairs = 0; i < n - 1; i += 2) {
boxaGetBoxGeometry(boxas, i, NULL, NULL, &bw1, &bh1);
boxaGetBoxGeometry(boxas, i + 1, NULL, NULL, &bw2, &bh2);
if (bw1 == 0 || bh1 == 0 || bw2 == 0 || bh2 == 0)
continue;
npairs++;
minw = (l_float32)L_MIN(bw1, bw2);
maxw = (l_float32)L_MAX(bw1, bw2);
minh = (l_float32)L_MIN(bh1, bh2);
w = (minw / minh > 0.5) ? minw : maxw;
numaAddNumber(naw, w);
numaAddNumber(nah, minh);
if (debug) {
box = boxCreate(0, 0, w, minh);
boxaAddBox(boxa1, box, L_COPY);
boxaAddBox(boxa1, box, L_INSERT);
}
}
if (npairs == 0) {
L_WARNING("no valid box pairs\n", procName);
numaDestroy(&naw);
numaDestroy(&nah);
boxaDestroy(&boxa1);
}
/* Get the median value of the regularized sizes, and find
* the average absolute fractional deviation from the median. */
numaGetMedian(naw, &medw);
numaGetMedian(nah, &medh);
numaGetMeanDevFromMedian(naw, medw, &devw);
numaGetMeanDevFromMedian(nah, medh, &devh);
*pfdevw = devw / medw;
*pfdevh = devh / medh;
if (debug) {
fprintf(stderr, "medw = %5.1f, medh = %5.1f\n", medw, medh);
fprintf(stderr, "fdevw = %6.3f, fdevh = %6.3f\n", *pfdevw, *pfdevh);
boxaPlotSizes(boxas, "input_boxa", NULL, NULL, &pix1);
boxaPlotSizes(boxa1, "regularized_boxa", NULL, NULL, &pix2);
pixDisplay(pix1, 500, 0);
pixDisplay(pix2, 500, 1000);
pixa = pixaCreate(2);
pixaAddPix(pixa, pix1, L_INSERT);
pixaAddPix(pixa, pix2, L_INSERT);
pix3 = pixaDisplayTiledInColumns(pixa, 2, 1.0, 3, 2);
lept_mkdir("lept/boxa");
pixWrite("/tmp/lept/boxa/eval.png", pix3, IFF_PNG);
pixDisplay(pix3, 100, 100);
pixDestroy(&pix3);
pixaDestroy(&pixa);
boxaDestroy(&boxa1);
}
numaDestroy(&naw);
numaDestroy(&nah);
return 0;
}
/*!
* \brief boxaReconcileSizeByMedian()
*
* \param[in] boxas containing at least 6 valid boxes
* \param[in] type L_CHECK_WIDTH, L_CHECK_HEIGHT, L_CHECK_BOTH
* \param[in] dfract threshold fraction of dimensional variation from
* median; in range (0 ... 1); typ. about 0.05.
* \param[in] sfract threshold fraction of side variation from median;
* in range (0 ... 1); typ. about 0.04.
* \param[in] factor expansion for fixed box beyond median width;
* should be near 1.0.
* \param[out] pnadelw [optional] diff from median width for boxes
* above threshold
* \param[out] pnadelh [optional] diff from median height for boxes
* above threshold
* \param[out] ratiowh [optional] ratio of median width/height of boxas
* \return boxad possibly adjusted from boxas; a copy of boxas on error
*
* <pre>
* Notes:
* (1) The basic idea is to identify significant differences in box
* dimension (either width or height) and modify the outlier boxes.
* (2) %type specifies if we are reconciling the width, height or both.
* (3) %dfract specifies the tolerance for different dimensions. Any
* box with a fractional difference from the median size that
* exceeds %dfract will be altered.
* (4) %sfract specifies the tolerance for different side locations.
* If a box has been marked by (3) for alteration, any side
* location that differs from the median side location by
* more than %sfract of the median dimension (medw or medh)
* will be moved.
* (5) Median width and height are found for all valid boxes (i.e.,
* for all boxes with width and height > 0.
* Median side locations are found separately for even and odd boxes,
* using only boxes that are "inliers"; i.e., that have been
* found by (3) to be within tolerance for width or height.
* (6) If all box dimensions are within threshold of the median size,
* just return a copy. Otherwise, box sides of the outliers
* will be adjusted.
* (7) Using %sfract, sides that are sufficiently far from the median
* are first moved to the median value. Then they are moved
* together (in or out) so that the final box dimension
* is %factor times the median dimension.
* (8) The arrays that are the initial deviation from median size
* (width and height) are optionally returned. Also optionally
* returned is the median w/h asperity ratio of the input %boxas.
* </pre>
*/
BOXA *
boxaReconcileSizeByMedian(BOXA *boxas,
l_int32 type,
l_float32 dfract,
l_float32 sfract,
l_float32 factor,
NUMA **pnadelw,
NUMA **pnadelh,
l_float32 *pratiowh)
{
l_int32 i, n, ne, no, outfound, isvalid, ind, del, maxdel;
l_int32 medw, medh, bw, bh, left, right, top, bot;
l_int32 medleft, medlefte, medlefto, medright, medrighte, medrighto;
l_int32 medtop, medtope, medtopo, medbot, medbote, medboto;
l_float32 brat;
BOX *box;
BOXA *boxa1, *boxae, *boxao, *boxad;
NUMA *naind, *nadelw, *nadelh;
PROCNAME("boxaReconcileSizeByMedian");
if (pnadelw) *pnadelw = NULL;
if (pnadelh) *pnadelh = NULL;
if (pratiowh) *pratiowh = 0.0;
if (!boxas)
return (BOXA *)ERROR_PTR("boxas not defined", procName, NULL);
if (type != L_CHECK_WIDTH && type != L_CHECK_HEIGHT &&
type != L_CHECK_BOTH) {
L_WARNING("invalid type; returning copy\n", procName);
return boxaCopy(boxas, L_COPY);
}
if (dfract <= 0.0 || dfract >= 0.5) {
L_WARNING("invalid dimensional fract; returning copy\n", procName);
return boxaCopy(boxas, L_COPY);
}
if (sfract <= 0.0 || sfract >= 0.5) {
L_WARNING("invalid side fract; returning copy\n", procName);
return boxaCopy(boxas, L_COPY);
}
if (factor < 0.8 || factor > 1.25)
L_WARNING("factor %5.3f is typ. closer to 1.0\n", procName, factor);
if (boxaGetValidCount(boxas) < 6) {
L_WARNING("need at least 6 valid boxes; returning copy\n", procName);
return boxaCopy(boxas, L_COPY);
}
/* If reconciling both width and height, optionally return array of
* median deviations and even/odd ratio for width measurements */
if (type == L_CHECK_BOTH) {
boxa1 = boxaReconcileSizeByMedian(boxas, L_CHECK_WIDTH, dfract, sfract,
factor, pnadelw, NULL, pratiowh);
boxad = boxaReconcileSizeByMedian(boxa1, L_CHECK_HEIGHT, dfract, sfract,
factor, NULL, pnadelh, NULL);
boxaDestroy(&boxa1);
return boxad;
}
n = boxaGetCount(boxas);
naind = numaCreate(n); /* outlier indicator array */
boxae = boxaCreate(0); /* even inliers */
boxao = boxaCreate(0); /* odd inliers */
outfound = FALSE;
if (type == L_CHECK_WIDTH) {
boxaMedianDimensions(boxas, &medw, &medh, NULL, NULL, NULL, NULL,
&nadelw, NULL);
if (pratiowh) {
*pratiowh = (l_float32)medw / (l_float32)medh;
L_INFO("median ratio w/h = %5.3f\n", procName, *pratiowh);
}
if (pnadelw)
*pnadelw = nadelw;
else
numaDestroy(&nadelw);
/* Check for outliers; assemble inliers */
for (i = 0; i < n; i++) {
if ((box = boxaGetValidBox(boxas, i, L_COPY)) == NULL) {
numaAddNumber(naind, 0);
continue;
}
boxGetGeometry(box, NULL, NULL, &bw, NULL);
brat = (l_float32)bw / (l_float32)medw;
if (brat < 1.0 - dfract || brat > 1.0 + dfract) {
outfound = TRUE;
numaAddNumber(naind, 1);
boxDestroy(&box);
} else { /* add to inliers */
numaAddNumber(naind, 0);
if (i % 2 == 0)
boxaAddBox(boxae, box, L_INSERT);
else
boxaAddBox(boxao, box, L_INSERT);
}
}
if (!outfound) { /* nothing to do */
numaDestroy(&naind);
boxaDestroy(&boxae);
boxaDestroy(&boxao);
L_INFO("no width outlier boxes found\n", procName);
return boxaCopy(boxas, L_COPY);
}
/* Get left/right parameters from inliers. Handle the case
* where there are no inliers for one of the sets. For example,
* when all the even boxes have a different dimension from
* the odd boxes, and the median arbitrarily gets assigned
* to the even boxes, there are no odd inliers; in that case,
* use the even inliers sides to decide whether to adjust
* the left or the right sides of individual outliers. */
L_INFO("fixing width of outlier boxes\n", procName);
medlefte = medrighte = medlefto = medrighto = 0;
if ((ne = boxaGetValidCount(boxae)) > 0)
boxaGetMedianVals(boxae, &medlefte, NULL, &medrighte, NULL,
NULL, NULL);
if ((no = boxaGetValidCount(boxao)) > 0)
boxaGetMedianVals(boxao, &medlefto, NULL, &medrighto, NULL,
NULL, NULL);
if (ne == 0) { /* use odd inliers values for both */
medlefte = medlefto;
medrighte = medrighto;
} else if (no == 0) { /* use even inliers values for both */
medlefto = medlefte;
medrighto = medrighte;
}
/* Adjust the left and/or right sides of outliers.
* For each box that is a dimensional outlier, consider each side.
* Any side that differs fractionally from the median value
* by more than %sfract times the median width (medw) is set to
* the median value for that side. Then both sides are moved
* an equal distance in or out to make w = %factor * medw. */
boxad = boxaCreate(n);
maxdel = (l_int32)(sfract * medw + 0.5);
for (i = 0; i < n; i++) {
box = boxaGetBox(boxas, i, L_COPY);
boxIsValid(box, &isvalid);
numaGetIValue(naind, i, &ind);
medleft = (i % 2 == 0) ? medlefte : medlefto;
medright = (i % 2 == 0) ? medrighte : medrighto;
if (ind == 1 && isvalid) { /* adjust sides */
boxGetSideLocations(box, &left, &right, NULL, NULL);
if (L_ABS(left - medleft) > maxdel) left = medleft;
if (L_ABS(right - medright) > maxdel) right = medright;
del = (l_int32)(factor * medw - (right - left)) / 2;
boxSetSide(box, L_SET_LEFT, left - del, 0);
boxSetSide(box, L_SET_RIGHT, right + del, 0);
}
boxaAddBox(boxad, box, L_INSERT);
}
} else { /* L_CHECK_HEIGHT */
boxaMedianDimensions(boxas, &medw, &medh, NULL, NULL, NULL, NULL,
NULL, &nadelh);
if (pratiowh) {
*pratiowh = (l_float32)medw / (l_float32)medh;
L_INFO("median ratio w/h = %5.3f\n", procName, *pratiowh);
}
if (pnadelh)
*pnadelh = nadelh;
else
numaDestroy(&nadelh);
/* Check for outliers; assemble inliers */
for (i = 0; i < n; i++) {
if ((box = boxaGetValidBox(boxas, i, L_COPY)) == NULL) {
numaAddNumber(naind, 0);
continue;
}
boxGetGeometry(box, NULL, NULL, NULL, &bh);
brat = (l_float32)bh / (l_float32)medh;
if (brat < 1.0 - dfract || brat > 1.0 + dfract) {
outfound = TRUE;
numaAddNumber(naind, 1);
boxDestroy(&box);
} else { /* add to inliers */
numaAddNumber(naind, 0);
if (i % 2 == 0)
boxaAddBox(boxae, box, L_INSERT);
else
boxaAddBox(boxao, box, L_INSERT);
}
}
if (!outfound) { /* nothing to do */
numaDestroy(&naind);
boxaDestroy(&boxae);
boxaDestroy(&boxao);
L_INFO("no height outlier boxes found\n", procName);
return boxaCopy(boxas, L_COPY);
}
/* Get top/bot parameters from inliers. Handle the case
* where there are no inliers for one of the sets. For example,
* when all the even boxes have a different dimension from
* the odd boxes, and the median arbitrarily gets assigned
* to the even boxes, there are no odd inliers; in that case,
* use the even inlier sides to decide whether to adjust
* the top or the bottom sides of individual outliers. */
L_INFO("fixing height of outlier boxes\n", procName);
medlefte = medtope = medbote = medtopo = medboto = 0;
if ((ne = boxaGetValidCount(boxae)) > 0)
boxaGetMedianVals(boxae, NULL, &medtope, NULL, &medbote,
NULL, NULL);
if ((no = boxaGetValidCount(boxao)) > 0)
boxaGetMedianVals(boxao, NULL, &medtopo, NULL, &medboto,
NULL, NULL);
if (ne == 0) { /* use odd inliers values for both */
medtope = medtopo;
medbote = medboto;
} else if (no == 0) { /* use even inliers values for both */
medtopo = medtope;
medboto = medbote;
}
/* Adjust the top and/or bottom sides of outliers.
* For each box that is a dimensional outlier, consider each side.
* Any side that differs fractionally from the median value
* by more than %sfract times the median height (medh) is
* set to the median value for that that side. Then both
* sides are moved an equal distance in or out to make
* h = %factor * medh). */
boxad = boxaCreate(n);
maxdel = (l_int32)(sfract * medh + 0.5);
for (i = 0; i < n; i++) {
box = boxaGetBox(boxas, i, L_COPY);
boxIsValid(box, &isvalid);
numaGetIValue(naind, i, &ind);
medtop = (i % 2 == 0) ? medtope : medtopo;
medbot = (i % 2 == 0) ? medbote : medboto;
if (ind == 1 && isvalid) { /* adjust sides */
boxGetSideLocations(box, NULL, NULL, &top, &bot);
if (L_ABS(top - medtop) > maxdel) top = medtop;
if (L_ABS(bot - medbot) > maxdel) bot = medbot;
del = (l_int32)(factor * medh - (bot - top)) / 2; /* typ > 0 */
boxSetSide(box, L_SET_TOP, L_MAX(0, top - del), 0);
boxSetSide(box, L_SET_BOT, bot + del, 0);
}
boxaAddBox(boxad, box, L_INSERT);
}
}
numaDestroy(&naind);
boxaDestroy(&boxae);
boxaDestroy(&boxao);
return boxad;
}
/*!
* \brief boxaPlotSides()
*
* \param[in] boxa source boxa
* \param[in] plotname [optional], can be NULL
* \param[out] pnal [optional] na of left sides
* \param[out] pnat [optional] na of top sides
* \param[out] pnar [optional] na of right sides
* \param[out] pnab [optional] na of bottom sides
* \param[out] ppixd [optional] pix of the output plot
* \return 0 if OK, 1 on error
*
* <pre>
* Notes:
* (1) This debugging function shows the progression of the four
* sides in the boxa. There must be at least 2 boxes.
* (2) If there are invalid boxes (e.g., if only even or odd
* indices have valid boxes), this will fill them with the
* nearest valid box before plotting.
* (3) The plotfiles are put in /tmp/lept/plots/, and are named
* either with %plotname or, if NULL, a default name. If
* %plotname is used, make sure is has no whitespace characters.
* </pre>
*/
l_ok
boxaPlotSides(BOXA *boxa,
const char *plotname,
NUMA **pnal,
NUMA **pnat,
NUMA **pnar,
NUMA **pnab,
PIX **ppixd)
{
char buf[128], titlebuf[128];
char *dataname;
static l_int32 plotid = 0;
l_int32 n, i, w, h, left, top, right, bot;
l_float32 med, dev;
BOXA *boxat;
GPLOT *gplot;
NUMA *nal, *nat, *nar, *nab;
PROCNAME("boxaPlotSides");
if (pnal) *pnal = NULL;
if (pnat) *pnat = NULL;
if (pnar) *pnar = NULL;
if (pnab) *pnab = NULL;
if (ppixd) *ppixd = NULL;
if (!boxa)
return ERROR_INT("boxa not defined", procName, 1);
if ((n = boxaGetCount(boxa)) < 2)
return ERROR_INT("less than 2 boxes", procName, 1);
boxat = boxaFillSequence(boxa, L_USE_ALL_BOXES, 0);
/* Build the numas for each side */
nal = numaCreate(n);
nat = numaCreate(n);
nar = numaCreate(n);
nab = numaCreate(n);
for (i = 0; i < n; i++) {
boxaGetBoxGeometry(boxat, i, &left, &top, &w, &h);
right = left + w - 1;
bot = top + h - 1;
numaAddNumber(nal, left);
numaAddNumber(nat, top);
numaAddNumber(nar, right);
numaAddNumber(nab, bot);
}
boxaDestroy(&boxat);
lept_mkdir("lept/plots");
if (plotname) {
snprintf(buf, sizeof(buf), "/tmp/lept/plots/sides.%s", plotname);
snprintf(titlebuf, sizeof(titlebuf), "%s: Box sides vs. box index",
plotname);
} else {
snprintf(buf, sizeof(buf), "/tmp/lept/plots/sides.%d", plotid++);
snprintf(titlebuf, sizeof(titlebuf), "Box sides vs. box index");
}
gplot = gplotCreate(buf, GPLOT_PNG, titlebuf,
"box index", "side location");
gplotAddPlot(gplot, NULL, nal, GPLOT_LINES, "left side");
gplotAddPlot(gplot, NULL, nat, GPLOT_LINES, "top side");
gplotAddPlot(gplot, NULL, nar, GPLOT_LINES, "right side");
gplotAddPlot(gplot, NULL, nab, GPLOT_LINES, "bottom side");
gplotMakeOutput(gplot);
gplotDestroy(&gplot);
if (ppixd) {
stringCat(buf, sizeof(buf), ".png");
*ppixd = pixRead(buf);
dataname = (plotname) ? stringNew(plotname) : stringNew("no_name");
numaGetMedian(nal, &med);
numaGetMeanDevFromMedian(nal, med, &dev);
fprintf(stderr, "%s left: med = %7.3f, meandev = %7.3f\n",
dataname, med, dev);
numaGetMedian(nat, &med);
numaGetMeanDevFromMedian(nat, med, &dev);
fprintf(stderr, "%s top: med = %7.3f, meandev = %7.3f\n",
dataname, med, dev);
numaGetMedian(nar, &med);
numaGetMeanDevFromMedian(nar, med, &dev);
fprintf(stderr, "%s right: med = %7.3f, meandev = %7.3f\n",
dataname, med, dev);
numaGetMedian(nab, &med);
numaGetMeanDevFromMedian(nab, med, &dev);
fprintf(stderr, "%s bot: med = %7.3f, meandev = %7.3f\n",
dataname, med, dev);
LEPT_FREE(dataname);
}
if (pnal)
*pnal = nal;
else
numaDestroy(&nal);
if (pnat)
*pnat = nat;
else
numaDestroy(&nat);
if (pnar)
*pnar = nar;
else
numaDestroy(&nar);
if (pnab)
*pnab = nab;
else
numaDestroy(&nab);
return 0;
}
/*!
* \brief boxaPlotSizes()
*
* \param[in] boxa source boxa
* \param[in] plotname [optional], can be NULL
* \param[out] pnaw [optional] na of widths
* \param[out] pnah [optional] na of heights
* \param[out] ppixd [optional] pix of the output plot
* \return 0 if OK, 1 on error
*
* <pre>
* Notes:
* (1) This debugging function shows the progression of box width
* and height in the boxa. There must be at least 2 boxes.
* (2) If there are invalid boxes (e.g., if only even or odd
* indices have valid boxes), this will fill them with the
* nearest valid box before plotting.
* (3) The plotfiles are put in /tmp/lept/plots/, and are named
* either with %plotname or, if NULL, a default name. If
* %plotname is used, make sure is has no whitespace characters.
* </pre>
*/
l_ok
boxaPlotSizes(BOXA *boxa,
const char *plotname,
NUMA **pnaw,
NUMA **pnah,
PIX **ppixd)
{
char buf[128], titlebuf[128];
static l_int32 plotid = 0;
l_int32 n, i, w, h;
BOXA *boxat;
GPLOT *gplot;
NUMA *naw, *nah;
PROCNAME("boxaPlotSizes");
if (pnaw) *pnaw = NULL;
if (pnah) *pnah = NULL;
if (ppixd) *ppixd = NULL;
if (!boxa)
return ERROR_INT("boxa not defined", procName, 1);
if ((n = boxaGetCount(boxa)) < 2)
return ERROR_INT("less than 2 boxes", procName, 1);
boxat = boxaFillSequence(boxa, L_USE_ALL_BOXES, 0);
/* Build the numas for the width and height */
naw = numaCreate(n);
nah = numaCreate(n);
for (i = 0; i < n; i++) {
boxaGetBoxGeometry(boxat, i, NULL, NULL, &w, &h);
numaAddNumber(naw, w);
numaAddNumber(nah, h);
}
boxaDestroy(&boxat);
lept_mkdir("lept/plots");
if (plotname) {
snprintf(buf, sizeof(buf), "/tmp/lept/plots/size.%s", plotname);
snprintf(titlebuf, sizeof(titlebuf), "%s: Box size vs. box index",
plotname);
} else {
snprintf(buf, sizeof(buf), "/tmp/lept/plots/size.%d", plotid++);
snprintf(titlebuf, sizeof(titlebuf), "Box size vs. box index");
}
gplot = gplotCreate(buf, GPLOT_PNG, titlebuf,
"box index", "box dimension");
gplotAddPlot(gplot, NULL, naw, GPLOT_LINES, "width");
gplotAddPlot(gplot, NULL, nah, GPLOT_LINES, "height");
gplotMakeOutput(gplot);
gplotDestroy(&gplot);
if (ppixd) {
stringCat(buf, sizeof(buf), ".png");
*ppixd = pixRead(buf);
}
if (pnaw)
*pnaw = naw;
else
numaDestroy(&naw);
if (pnah)
*pnah = nah;
else
numaDestroy(&nah);
return 0;
}
/*!
* \brief boxaFillSequence()
*
* \param[in] boxas with at least 3 boxes
* \param[in] useflag L_USE_ALL_BOXES, L_USE_SAME_PARITY_BOXES
* \param[in] debug 1 for debug output
* \return boxad filled boxa, or NULL on error
*
* <pre>
* Notes:
* (1) This simple function replaces invalid boxes with a copy of
* the nearest valid box, selected from either the entire
* sequence (L_USE_ALL_BOXES) or from the boxes with the
* same parity (L_USE_SAME_PARITY_BOXES). It returns a new boxa.
* (2) This is useful if you expect boxes in the sequence to
* vary slowly with index.
* </pre>
*/
BOXA *
boxaFillSequence(BOXA *boxas,
l_int32 useflag,
l_int32 debug)
{
l_int32 n, nv;
BOXA *boxae, *boxao, *boxad;
PROCNAME("boxaFillSequence");
if (!boxas)
return (BOXA *)ERROR_PTR("boxas not defined", procName, NULL);
if (useflag != L_USE_ALL_BOXES && useflag != L_USE_SAME_PARITY_BOXES)
return (BOXA *)ERROR_PTR("invalid useflag", procName, NULL);
n = boxaGetCount(boxas);
nv = boxaGetValidCount(boxas);
if (n == nv)
return boxaCopy(boxas, L_COPY); /* all valid */
if (debug)
L_INFO("%d valid boxes, %d invalid boxes\n", procName, nv, n - nv);
if (useflag == L_USE_SAME_PARITY_BOXES && n < 3) {
L_WARNING("n < 3; some invalid\n", procName);
return boxaCopy(boxas, L_COPY);
}
if (useflag == L_USE_ALL_BOXES) {
boxad = boxaCopy(boxas, L_COPY);
boxaFillAll(boxad);
} else {
boxaSplitEvenOdd(boxas, 0, &boxae, &boxao);
boxaFillAll(boxae);
boxaFillAll(boxao);
boxad = boxaMergeEvenOdd(boxae, boxao, 0);
boxaDestroy(&boxae);
boxaDestroy(&boxao);
}
nv = boxaGetValidCount(boxad);
if (n != nv)
L_WARNING("there are still %d invalid boxes\n", procName, n - nv);
return boxad;
}
/*!
* \brief boxaFillAll()
*
* \param[in] boxa
* \return 0 if OK, 1 on error
*
* <pre>
* Notes:
* (1) This static function replaces every invalid box with the
* nearest valid box. If there are no valid boxes, it
* issues a warning.
* </pre>
*/
static l_int32
boxaFillAll(BOXA *boxa)
{
l_int32 n, nv, i, j, spandown, spanup;
l_int32 *indic;
BOX *box, *boxt;
PROCNAME("boxaFillAll");
if (!boxa)
return ERROR_INT("boxa not defined", procName, 1);
n = boxaGetCount(boxa);
nv = boxaGetValidCount(boxa);
if (n == nv) return 0;
if (nv == 0) {
L_WARNING("no valid boxes out of %d boxes\n", procName, n);
return 0;
}
/* Make indicator array for valid boxes */
if ((indic = (l_int32 *)LEPT_CALLOC(n, sizeof(l_int32))) == NULL)
return ERROR_INT("indic not made", procName, 1);
for (i = 0; i < n; i++) {
box = boxaGetValidBox(boxa, i, L_CLONE);
if (box)
indic[i] = 1;
boxDestroy(&box);
}
/* Replace invalid boxes with the nearest valid one */
for (i = 0; i < n; i++) {
box = boxaGetValidBox(boxa, i, L_CLONE);
if (!box) {
spandown = spanup = 10000000;
for (j = i - 1; j >= 0; j--) {
if (indic[j] == 1) {
spandown = i - j;
break;
}
}
for (j = i + 1; j < n; j++) {
if (indic[j] == 1) {
spanup = j - i;
break;
}
}
if (spandown < spanup)
boxt = boxaGetBox(boxa, i - spandown, L_COPY);
else
boxt = boxaGetBox(boxa, i + spanup, L_COPY);
boxaReplaceBox(boxa, i, boxt);
}
boxDestroy(&box);
}
LEPT_FREE(indic);
return 0;
}
/*!
* \brief boxaSizeVariation()
*
* \param[in] boxa at least 4 boxes
* \param[in] type L_SELECT_WIDTH, L_SELECT_HEIGHT
* \param[out] pdel_evenodd [optional] average absolute value of
* (even - odd) size pairs
* \param[out] prms_even [optional] rms deviation of even boxes
* \param[out] prms_odd [optional] rms deviation of odd boxes
* \param[out] prms_all [optional] rms deviation of all boxes
* \return 0 if OK, 1 on error
*
* <pre>
* Notes:
* (1) This gives several measures of the smoothness of either the
* width or height of a sequence of boxes.
* See boxaMedianDimensions() for some other measures.
* (2) Statistics can be found separately for even and odd boxes.
* Additionally, the average pair-wise difference between
* adjacent even and odd boxes can be returned.
* (3) The use case is bounding boxes for scanned page images,
* where ideally the sizes should have little variance.
* </pre>
*/
l_ok
boxaSizeVariation(BOXA *boxa,
l_int32 type,
l_float32 *pdel_evenodd,
l_float32 *prms_even,
l_float32 *prms_odd,
l_float32 *prms_all)
{
l_int32 n, ne, no, nmin, vale, valo, i;
l_float32 sum;
BOXA *boxae, *boxao;
NUMA *nae, *nao, *na_all;
PROCNAME("boxaSizeVariation");
if (pdel_evenodd) *pdel_evenodd = 0.0;
if (prms_even) *prms_even = 0.0;
if (prms_odd) *prms_odd = 0.0;
if (prms_all) *prms_all = 0.0;
if (!boxa)
return ERROR_INT("boxa not defined", procName, 1);
if (type != L_SELECT_WIDTH && type != L_SELECT_HEIGHT)
return ERROR_INT("invalid type", procName, 1);
if (!pdel_evenodd && !prms_even && !prms_odd && !prms_all)
return ERROR_INT("nothing to do", procName, 1);
n = boxaGetCount(boxa);
if (n < 4)
return ERROR_INT("too few boxes", procName, 1);
boxaSplitEvenOdd(boxa, 0, &boxae, &boxao);
ne = boxaGetCount(boxae);
no = boxaGetCount(boxao);
nmin = L_MIN(ne, no);
if (nmin == 0) {
boxaDestroy(&boxae);
boxaDestroy(&boxao);
return ERROR_INT("either no even or no odd boxes", procName, 1);
}
if (type == L_SELECT_WIDTH) {
boxaGetSizes(boxae, &nae, NULL);
boxaGetSizes(boxao, &nao, NULL);
boxaGetSizes(boxa, &na_all, NULL);
} else { /* L_SELECT_HEIGHT) */
boxaGetSizes(boxae, NULL, &nae);
boxaGetSizes(boxao, NULL, &nao);
boxaGetSizes(boxa, NULL, &na_all);
}
if (pdel_evenodd) {
sum = 0.0;
for (i = 0; i < nmin; i++) {
numaGetIValue(nae, i, &vale);
numaGetIValue(nao, i, &valo);
sum += L_ABS(vale - valo);
}
*pdel_evenodd = sum / nmin;
}
if (prms_even)
numaSimpleStats(nae, 0, -1, NULL, NULL, prms_even);
if (prms_odd)
numaSimpleStats(nao, 0, -1, NULL, NULL, prms_odd);
if (prms_all)
numaSimpleStats(na_all, 0, -1, NULL, NULL, prms_all);
boxaDestroy(&boxae);
boxaDestroy(&boxao);
numaDestroy(&nae);
numaDestroy(&nao);
numaDestroy(&na_all);
return 0;
}
/*!
* \brief boxaMedianDimensions()
*
* \param[in] boxas containing at least 3 valid boxes in even and odd
* \param[out] pmedw [optional] median width of all boxes
* \param[out] pmedh [optional] median height of all boxes
* \param[out] pmedwe [optional] median width of even boxes
* \param[out] pmedwo [optional] median width of odd boxes
* \param[out] pmedhe [optional] median height of even boxes
* \param[out] pmedho [optional] median height of odd boxes
* \param[out] pnadelw [optional] width diff of each box from median
* \param[out] pnadelh [optional] height diff of each box from median
* \return 0 if OK, 1 on error
*
* <pre>
* Notes:
* (1) This provides information that (1) allows identification of
* boxes that have unusual (outlier) width or height, and (2) can
* be used to regularize the sizes of the outlier boxes, assuming
* that the boxes satisfy a fairly regular sequence and should
* mostly have the same width and height.
* (2) This finds the median width and height, as well as separate
* median widths and heights of even and odd boxes. It also
* generates arrays that give the difference in width and height
* of each box from the median, which can be used to correct
* individual boxes.
* (3) All return values are optional.
* </pre>
*/
l_ok
boxaMedianDimensions(BOXA *boxas,
l_int32 *pmedw,
l_int32 *pmedh,
l_int32 *pmedwe,
l_int32 *pmedwo,
l_int32 *pmedhe,
l_int32 *pmedho,
NUMA **pnadelw,
NUMA **pnadelh)
{
l_int32 i, n, bw, bh, medw, medh, medwe, medwo, medhe, medho;
BOXA *boxae, *boxao;
NUMA *nadelw, *nadelh;
PROCNAME("boxaMedianDimensions");
if (pmedw) *pmedw = 0;
if (pmedh) *pmedh = 0;
if (pmedwe) *pmedwe= 0;
if (pmedwo) *pmedwo= 0;
if (pmedhe) *pmedhe= 0;
if (pmedho) *pmedho= 0;
if (pnadelw) *pnadelw = NULL;
if (pnadelh) *pnadelh = NULL;
if (!boxas)
return ERROR_INT("boxas not defined", procName, 1);
if (boxaGetValidCount(boxas) < 6)
return ERROR_INT("need at least 6 valid boxes", procName, 1);
/* Require at least 3 valid boxes of both types */
boxaSplitEvenOdd(boxas, 0, &boxae, &boxao);
if (boxaGetValidCount(boxae) < 3 || boxaGetValidCount(boxao) < 3) {
boxaDestroy(&boxae);
boxaDestroy(&boxao);
return ERROR_INT("don't have 3+ valid boxes of each type", procName, 1);
}
/* Get the relevant median widths and heights */
boxaGetMedianVals(boxas, NULL, NULL, NULL, NULL, &medw, &medh);
boxaGetMedianVals(boxae, NULL, NULL, NULL, NULL, &medwe, &medhe);
boxaGetMedianVals(boxao, NULL, NULL, NULL, NULL, &medwo, &medho);
if (pmedw) *pmedw = medw;
if (pmedh) *pmedh = medh;
if (pmedwe) *pmedwe = medwe;
if (pmedwo) *pmedwo = medwo;
if (pmedhe) *pmedhe = medhe;
if (pmedho) *pmedho = medho;
/* Find the variation from median dimension for each box */
n = boxaGetCount(boxas);
nadelw = numaCreate(n);
nadelh = numaCreate(n);
for (i = 0; i < n; i++) {
boxaGetBoxGeometry(boxas, i, NULL, NULL, &bw, &bh);
if (bw == 0 || bh == 0) { /* invalid box */
numaAddNumber(nadelw, 0);
numaAddNumber(nadelh, 0);
} else {
numaAddNumber(nadelw, bw - medw);
numaAddNumber(nadelh, bh - medh);
}
}
if (pnadelw)
*pnadelw = nadelw;
else
numaDestroy(&nadelw);
if (pnadelh)
*pnadelh = nadelh;
else
numaDestroy(&nadelh);
boxaDestroy(&boxae);
boxaDestroy(&boxao);
return 0;
}