diff options
Diffstat (limited to 'leptonica/src/dewarp2.c')
| -rw-r--r-- | leptonica/src/dewarp2.c | 2017 |
1 files changed, 2017 insertions, 0 deletions
diff --git a/leptonica/src/dewarp2.c b/leptonica/src/dewarp2.c new file mode 100644 index 00000000..97458865 --- /dev/null +++ b/leptonica/src/dewarp2.c @@ -0,0 +1,2017 @@ +/*====================================================================* + - 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 dewarp2.c + * <pre> + * + * Build the page disparity model + * + * Build basic page disparity model + * l_int32 dewarpBuildPageModel() + * l_int32 dewarpFindVertDisparity() + * l_int32 dewarpFindHorizDisparity() + * PTAA *dewarpGetTextlineCenters() + * static PTA *dewarpGetMeanVerticals() + * PTAA *dewarpRemoveShortLines() + * static l_int32 dewarpGetLineEndPoints() + * static l_int32 dewarpFilterLineEndPoints() + * static PTA *dewarpRemoveBadEndPoints() + * static l_int32 dewarpIsLineCoverageValid() + * static l_int32 dewarpLinearLSF() + * static l_int32 dewarpQuadraticLSF() + * + * Build disparity model for slope near binding + * l_int32 dewarpFindHorizSlopeDisparity() + * + * Build the line disparity model + * l_int32 dewarpBuildLineModel() + * + * Query model status + * l_int32 dewarpaModelStatus() + * + * Rendering helpers + * static l_int32 pixRenderMidYs() + * static l_int32 pixRenderHorizEndPoints + * </pre> + */ + +#ifdef HAVE_CONFIG_H +#include <config_auto.h> +#endif /* HAVE_CONFIG_H */ + +#include <math.h> +#include "allheaders.h" + +static PTA *dewarpGetMeanVerticals(PIX *pixs, l_int32 x, l_int32 y); +static l_int32 dewarpGetLineEndPoints(l_int32 h, PTAA *ptaa, PTA **pptal, + PTA **pptar); +static l_int32 dewarpFilterLineEndPoints(L_DEWARP *dew, PTA *ptal1, PTA *ptar1, + PTA **pptal2, PTA **pptar2); +static PTA *dewarpRemoveBadEndPoints(l_int32 w, PTA *ptas); +static l_int32 dewarpIsLineCoverageValid(PTAA *ptaa2, l_int32 h, + l_int32 *pntop, l_int32 *pnbot, + l_int32 *pytop, l_int32 *pybot); +static l_int32 dewarpLinearLSF(PTA *ptad, l_float32 *pa, l_float32 *pb, + l_float32 *pmederr); +static l_int32 dewarpQuadraticLSF(PTA *ptad, l_float32 *pa, l_float32 *pb, + l_float32 *pc, l_float32 *pmederr); +static l_int32 pixRenderMidYs(PIX *pixs, NUMA *namidys, l_int32 linew); +static l_int32 pixRenderHorizEndPoints(PIX *pixs, PTA *ptal, PTA *ptar, + l_uint32 color); + + +#ifndef NO_CONSOLE_IO +#define DEBUG_TEXTLINE_CENTERS 0 /* set this to 1 for debugging */ +#define DEBUG_SHORT_LINES 0 /* ditto */ +#else +#define DEBUG_TEXTLINE_CENTERS 0 /* always must be 0 */ +#define DEBUG_SHORT_LINES 0 /* ditto */ +#endif /* !NO_CONSOLE_IO */ + + /* Special parameter values for reducing horizontal disparity */ +static const l_float32 MinRatioLinesToHeight = 0.45f; +static const l_int32 MinLinesForHoriz1 = 10; /* initially */ +static const l_int32 MinLinesForHoriz2 = 3; /* after, in each half */ +static const l_float32 AllowedWidthFract = 0.05f; /* no bigger */ + + +/*----------------------------------------------------------------------* + * Build basic page disparity model * + *----------------------------------------------------------------------*/ +/*! + * \brief dewarpBuildPageModel() + * + * \param[in] dew + * \param[in] debugfile use NULL to skip writing this + * \return 0 if OK, 1 if unable to build the model or on error + * + * <pre> + * Notes: + * (1) This is the basic function that builds the horizontal and + * vertical disparity arrays, which allow determination of the + * src pixel in the input image corresponding to each + * dest pixel in the dewarped image. + * (2) Sets vsuccess = 1 if the vertical disparity array builds. + * Always attempts to build the horizontal disparity array, + * even if it will not be requested (useboth == 0). + * Sets hsuccess = 1 if horizontal disparity builds. + * (3) The method is as follows: + * (a) Estimate the points along the centers of all the + * long textlines. If there are too few lines, no + * disparity models are built. + * (b) From the vertical deviation of the lines, estimate + * the vertical disparity. + * (c) From the ends of the lines, estimate the horizontal + * disparity, assuming that the text is made of lines + * that are close to left and right justified. + * (d) One can also compute an additional contribution to the + * horizontal disparity, inferred from slopes of the top + * and bottom lines. We do not do this. + * (4) In more detail for the vertical disparity: + * (a) Fit a LS quadratic to center locations along each line. + * This smooths the curves. + * (b) Sample each curve at a regular interval, find the y-value + * of the mid-point on each curve, and subtract the sampled + * curve value from this value. This is the vertical + * disparity at sampled points along each curve. + * (c) Fit a LS quadratic to each set of vertically aligned + * disparity samples. This smooths the disparity values + * in the vertical direction. Then resample at the same + * regular interval. We now have a regular grid of smoothed + * vertical disparity valuels. + * (5) Once the sampled vertical disparity array is found, it can be + * interpolated to get a full resolution vertical disparity map. + * This can be applied directly to the src image pixels + * to dewarp the image in the vertical direction, making + * all textlines horizontal. Likewise, the horizontal + * disparity array is used to left- and right-align the + * longest textlines. + * </pre> + */ +l_ok +dewarpBuildPageModel(L_DEWARP *dew, + const char *debugfile) +{ +l_int32 linecount, ntop, nbot, ytop, ybot, ret; +PIX *pixs, *pix1, *pix2, *pix3; +PTA *pta; +PTAA *ptaa1, *ptaa2; + + PROCNAME("dewarpBuildPageModel"); + + if (!dew) + return ERROR_INT("dew not defined", procName, 1); + + dew->debug = (debugfile) ? 1 : 0; + dew->vsuccess = dew->hsuccess = 0; + pixs = dew->pixs; + if (debugfile) { + lept_rmdir("lept/dewmod"); /* erase previous images */ + lept_mkdir("lept/dewmod"); + pixDisplayWithTitle(pixs, 0, 0, "pixs", 1); + pixWriteDebug("/tmp/lept/dewmod/0010.png", pixs, IFF_PNG); + } + + /* Make initial estimate of centers of textlines */ + ptaa1 = dewarpGetTextlineCenters(pixs, debugfile || DEBUG_TEXTLINE_CENTERS); + if (!ptaa1) { + L_WARNING("textline centers not found; model not built\n", procName); + return 1; + } + if (debugfile) { + pix1 = pixConvertTo32(pixs); + pta = generatePtaFilledCircle(1); + pix2 = pixGenerateFromPta(pta, 5, 5); + pix3 = pixDisplayPtaaPattern(NULL, pix1, ptaa1, pix2, 2, 2); + pixWriteDebug("/tmp/lept/dewmod/0020.png", pix3, IFF_PNG); + pixDestroy(&pix1); + pixDestroy(&pix2); + pixDestroy(&pix3); + ptaDestroy(&pta); + } + + /* Remove all lines that are not at least 0.8 times the length + * of the longest line. */ + ptaa2 = dewarpRemoveShortLines(pixs, ptaa1, 0.8f, + debugfile || DEBUG_SHORT_LINES); + if (debugfile) { + pix1 = pixConvertTo32(pixs); + pta = generatePtaFilledCircle(1); + pix2 = pixGenerateFromPta(pta, 5, 5); + pix3 = pixDisplayPtaaPattern(NULL, pix1, ptaa2, pix2, 2, 2); + pixWriteDebug("/tmp/lept/dewmod/0030.png", pix3, IFF_PNG); + pixDestroy(&pix1); + pixDestroy(&pix2); + pixDestroy(&pix3); + ptaDestroy(&pta); + } + ptaaDestroy(&ptaa1); + + /* Verify that there are sufficient "long" lines */ + linecount = ptaaGetCount(ptaa2); + if (linecount < dew->minlines) { + ptaaDestroy(&ptaa2); + L_WARNING("linecount %d < min req'd number of lines (%d) for model\n", + procName, linecount, dew->minlines); + return 1; + } + + /* Verify that the lines have a reasonable coverage of the + * vertical extent of the page. */ + if (dewarpIsLineCoverageValid(ptaa2, pixGetHeight(pixs), + &ntop, &nbot, &ytop, &ybot) == FALSE) { + ptaaDestroy(&ptaa2); + L_WARNING("invalid line coverage: ntop = %d, nbot = %d;" + " spanning [%d ... %d] in height %d\n", procName, + ntop, nbot, ytop, ybot, pixGetHeight(pixs)); + return 1; + } + + /* Get the sampled vertical disparity from the textline centers. + * The disparity array will push pixels vertically so that each + * textline is flat and centered at the y-position of the mid-point. */ + if (dewarpFindVertDisparity(dew, ptaa2, 0) != 0) { + L_WARNING("vertical disparity not built\n", procName); + ptaaDestroy(&ptaa2); + return 1; + } + + /* Get the sampled horizontal disparity from the left and right + * edges of the text. The disparity array will expand the image + * linearly outward to align the text edges vertically. + * Do this even if useboth == 0; we still calculate it even + * if we don't plan to use it. */ + if ((ret = dewarpFindHorizDisparity(dew, ptaa2)) == 0) + L_INFO("hsuccess = 1\n", procName); + + /* Debug output */ + if (debugfile) { + dewarpPopulateFullRes(dew, NULL, 0, 0); + pix1 = fpixRenderContours(dew->fullvdispar, 3.0, 0.15f); + pixWriteDebug("/tmp/lept/dewmod/0060.png", pix1, IFF_PNG); + pixDisplay(pix1, 1000, 0); + pixDestroy(&pix1); + if (ret == 0) { + pix1 = fpixRenderContours(dew->fullhdispar, 3.0, 0.15f); + pixWriteDebug("/tmp/lept/dewmod/0070.png", pix1, IFF_PNG); + pixDisplay(pix1, 1000, 0); + pixDestroy(&pix1); + } + convertFilesToPdf("/tmp/lept/dewmod", NULL, 135, 1.0, 0, 0, + "Dewarp Build Model", debugfile); + lept_stderr("pdf file: %s\n", debugfile); + } + + ptaaDestroy(&ptaa2); + return 0; +} + + +/*! + * \brief dewarpFindVertDisparity() + * + * \param[in] dew + * \param[in] ptaa unsmoothed lines, not vertically ordered + * \param[in] rotflag 0 if using dew->pixs; 1 if rotated by 90 degrees cw + * \return 0 if OK, 1 on error + * + * <pre> + * Notes: + * (1) This starts with points along the centers of textlines. + * It does quadratic fitting (and smoothing), first along the + * lines and then in the vertical direction, to generate + * the sampled vertical disparity map. This can then be + * interpolated to full resolution and used to remove + * the vertical line warping. + * (2) Use %rotflag == 1 if you are dewarping vertical lines, as + * is done in dewarpBuildLineModel(). The usual case is for + * %rotflag == 0. + * (3) Note that this builds a vertical disparity model (VDM), but + * does not check it against constraints for validity. + * Constraint checking is done after building the models, + * and before inserting reference models. + * (4) This sets the vsuccess flag to 1 on success. + * (5) Pix debug output goes to /tmp/dewvert/ for collection into + * a pdf. Non-pix debug output goes to /tmp. + * </pre> + */ +l_ok +dewarpFindVertDisparity(L_DEWARP *dew, + PTAA *ptaa, + l_int32 rotflag) +{ +l_int32 i, j, nlines, npts, nx, ny, sampling; +l_float32 c0, c1, c2, x, y, midy, val, medval, meddev, minval, maxval; +l_float32 *famidys; +NUMA *nax, *nafit, *nacurve0, *nacurve1, *nacurves; +NUMA *namidy, *namidys, *namidysi; +PIX *pix1, *pix2, *pixcirc, *pixdb; +PTA *pta, *ptad, *ptacirc; +PTAA *ptaa0, *ptaa1, *ptaa2, *ptaa3, *ptaa4, *ptaa5, *ptaat; +FPIX *fpix; + + PROCNAME("dewarpFindVertDisparity"); + + if (!dew) + return ERROR_INT("dew not defined", procName, 1); + dew->vsuccess = 0; + if (!ptaa) + return ERROR_INT("ptaa not defined", procName, 1); + + if (dew->debug) L_INFO("finding vertical disparity\n", procName); + + /* Do quadratic fit to smooth each line. A single quadratic + * over the entire width of the line appears to be sufficient. + * Quartics tend to overfit to noise. Each line is thus + * represented by three coefficients: y(x) = c2 * x^2 + c1 * x + c0. + * Using the coefficients, sample each fitted curve uniformly + * across the full width of the image. The result is in ptaa0. */ + sampling = dew->sampling; + nx = (rotflag) ? dew->ny : dew->nx; + ny = (rotflag) ? dew->nx : dew->ny; + nlines = ptaaGetCount(ptaa); + dew->nlines = nlines; + ptaa0 = ptaaCreate(nlines); + nacurve0 = numaCreate(nlines); /* stores curvature coeff c2 */ + pixdb = (rotflag) ? pixRotateOrth(dew->pixs, 1) : pixClone(dew->pixs); + for (i = 0; i < nlines; i++) { /* for each line */ + pta = ptaaGetPta(ptaa, i, L_CLONE); + ptaGetQuadraticLSF(pta, &c2, &c1, &c0, NULL); + numaAddNumber(nacurve0, c2); + ptad = ptaCreate(nx); + for (j = 0; j < nx; j++) { /* uniformly sampled in x */ + x = j * sampling; + applyQuadraticFit(c2, c1, c0, x, &y); + ptaAddPt(ptad, x, y); + } + ptaaAddPta(ptaa0, ptad, L_INSERT); + ptaDestroy(&pta); + } + if (dew->debug) { + lept_mkdir("lept/dewarp"); + lept_mkdir("lept/dewdebug"); + lept_mkdir("lept/dewmod"); + ptaat = ptaaCreate(nlines); + for (i = 0; i < nlines; i++) { + pta = ptaaGetPta(ptaa, i, L_CLONE); + ptaGetArrays(pta, &nax, NULL); + ptaGetQuadraticLSF(pta, NULL, NULL, NULL, &nafit); + ptad = ptaCreateFromNuma(nax, nafit); + ptaaAddPta(ptaat, ptad, L_INSERT); + ptaDestroy(&pta); + numaDestroy(&nax); + numaDestroy(&nafit); + } + pix1 = pixConvertTo32(pixdb); + pta = generatePtaFilledCircle(1); + pixcirc = pixGenerateFromPta(pta, 5, 5); + pix2 = pixDisplayPtaaPattern(NULL, pix1, ptaat, pixcirc, 2, 2); + pixWriteDebug("/tmp/lept/dewmod/0041.png", pix2, IFF_PNG); + pixDestroy(&pix1); + pixDestroy(&pix2); + ptaDestroy(&pta); + pixDestroy(&pixcirc); + ptaaDestroy(&ptaat); + } + + /* Remove lines with outlier curvatures. + * Note that this is just looking for internal consistency in + * the line curvatures. It is not rejecting lines based on + * the magnitude of the curvature. That is done when constraints + * are applied for valid models. */ + numaGetMedianDevFromMedian(nacurve0, &medval, &meddev); + L_INFO("\nPage %d\n", procName, dew->pageno); + L_INFO("Pass 1: Curvature: medval = %f, meddev = %f\n", + procName, medval, meddev); + ptaa1 = ptaaCreate(nlines); + nacurve1 = numaCreate(nlines); + for (i = 0; i < nlines; i++) { /* for each line */ + numaGetFValue(nacurve0, i, &val); + if (L_ABS(val - medval) > 7.0 * meddev) /* TODO: reduce to ~ 3.0 */ + continue; + pta = ptaaGetPta(ptaa0, i, L_CLONE); + ptaaAddPta(ptaa1, pta, L_INSERT); + numaAddNumber(nacurve1, val); + } + nlines = ptaaGetCount(ptaa1); + numaDestroy(&nacurve0); + + /* Save the min and max curvature (in micro-units) */ + numaGetMin(nacurve1, &minval, NULL); + numaGetMax(nacurve1, &maxval, NULL); + dew->mincurv = lept_roundftoi(1000000. * minval); + dew->maxcurv = lept_roundftoi(1000000. * maxval); + L_INFO("Pass 2: Min/max curvature = (%d, %d)\n", procName, + dew->mincurv, dew->maxcurv); + + /* Find and save the y values at the mid-points in each curve. + * If the slope is zero anywhere, it will typically be here. */ + namidy = numaCreate(nlines); + for (i = 0; i < nlines; i++) { + pta = ptaaGetPta(ptaa1, i, L_CLONE); + npts = ptaGetCount(pta); + ptaGetPt(pta, npts / 2, NULL, &midy); + numaAddNumber(namidy, midy); + ptaDestroy(&pta); + } + + /* Sort the lines in ptaa1c by their vertical position, going down */ + namidysi = numaGetSortIndex(namidy, L_SORT_INCREASING); + namidys = numaSortByIndex(namidy, namidysi); + nacurves = numaSortByIndex(nacurve1, namidysi); + numaDestroy(&dew->namidys); /* in case previously made */ + numaDestroy(&dew->nacurves); + dew->namidys = namidys; + dew->nacurves = nacurves; + ptaa2 = ptaaSortByIndex(ptaa1, namidysi); + numaDestroy(&namidy); + numaDestroy(&nacurve1); + numaDestroy(&namidysi); + if (dew->debug) { + numaWriteDebug("/tmp/lept/dewdebug/midys.na", namidys); + numaWriteDebug("/tmp/lept/dewdebug/curves.na", nacurves); + pix1 = pixConvertTo32(pixdb); + ptacirc = generatePtaFilledCircle(5); + pixcirc = pixGenerateFromPta(ptacirc, 11, 11); + srand(3); + pixDisplayPtaaPattern(pix1, pix1, ptaa2, pixcirc, 5, 5); + srand(3); /* use the same colors for text and reference lines */ + pixRenderMidYs(pix1, namidys, 2); + pix2 = (rotflag) ? pixRotateOrth(pix1, 3) : pixClone(pix1); + pixWriteDebug("/tmp/lept/dewmod/0042.png", pix2, IFF_PNG); + pixDisplay(pix2, 0, 0); + ptaDestroy(&ptacirc); + pixDestroy(&pixcirc); + pixDestroy(&pix1); + pixDestroy(&pix2); + } + pixDestroy(&pixdb); + + /* Convert the sampled points in ptaa2 to a sampled disparity with + * with respect to the y value at the mid point in the curve. + * The disparity is the distance the point needs to move; + * plus is downward. */ + ptaa3 = ptaaCreate(nlines); + for (i = 0; i < nlines; i++) { + pta = ptaaGetPta(ptaa2, i, L_CLONE); + numaGetFValue(namidys, i, &midy); + ptad = ptaCreate(nx); + for (j = 0; j < nx; j++) { + ptaGetPt(pta, j, &x, &y); + ptaAddPt(ptad, x, midy - y); + } + ptaaAddPta(ptaa3, ptad, L_INSERT); + ptaDestroy(&pta); + } + if (dew->debug) { + ptaaWriteDebug("/tmp/lept/dewdebug/ptaa3.ptaa", ptaa3, 0); + } + + /* Generate ptaa4 by taking vertical 'columns' from ptaa3. + * We want to fit the vertical disparity on the column to the + * vertical position of the line, which we call 'y' here and + * obtain from namidys. So each pta in ptaa4 is the set of + * vertical disparities down a column of points. The columns + * in ptaa4 are equally spaced in x. */ + ptaa4 = ptaaCreate(nx); + famidys = numaGetFArray(namidys, L_NOCOPY); + for (j = 0; j < nx; j++) { + pta = ptaCreate(nlines); + for (i = 0; i < nlines; i++) { + y = famidys[i]; + ptaaGetPt(ptaa3, i, j, NULL, &val); /* disparity value */ + ptaAddPt(pta, y, val); + } + ptaaAddPta(ptaa4, pta, L_INSERT); + } + if (dew->debug) { + ptaaWriteDebug("/tmp/lept/dewdebug/ptaa4.ptaa", ptaa4, 0); + } + + /* Do quadratic fit vertically on each of the pixel columns + * in ptaa4, for the vertical displacement (which identifies the + * src pixel(s) for each dest pixel) as a function of y (the + * y value of the mid-points for each line). Then generate + * ptaa5 by sampling the fitted vertical displacement on a + * regular grid in the vertical direction. Each pta in ptaa5 + * gives the vertical displacement for regularly sampled y values + * at a fixed x. */ + ptaa5 = ptaaCreate(nx); /* uniformly sampled across full height of image */ + for (j = 0; j < nx; j++) { /* for each column */ + pta = ptaaGetPta(ptaa4, j, L_CLONE); + ptaGetQuadraticLSF(pta, &c2, &c1, &c0, NULL); + ptad = ptaCreate(ny); + for (i = 0; i < ny; i++) { /* uniformly sampled in y */ + y = i * sampling; + applyQuadraticFit(c2, c1, c0, y, &val); + ptaAddPt(ptad, y, val); + } + ptaaAddPta(ptaa5, ptad, L_INSERT); + ptaDestroy(&pta); + } + if (dew->debug) { + ptaaWriteDebug("/tmp/lept/dewdebug/ptaa5.ptaa", ptaa5, 0); + convertFilesToPdf("/tmp/lept/dewmod", "004", 135, 1.0, 0, 0, + "Dewarp Vert Disparity", + "/tmp/lept/dewarp/vert_disparity.pdf"); + lept_stderr("pdf file: /tmp/lept/dewarp/vert_disparity.pdf\n"); + } + + /* Save the result in a fpix at the specified subsampling */ + fpix = fpixCreate(nx, ny); + for (i = 0; i < ny; i++) { + for (j = 0; j < nx; j++) { + ptaaGetPt(ptaa5, j, i, NULL, &val); + fpixSetPixel(fpix, j, i, val); + } + } + dew->sampvdispar = fpix; + dew->vsuccess = 1; + + ptaaDestroy(&ptaa0); + ptaaDestroy(&ptaa1); + ptaaDestroy(&ptaa2); + ptaaDestroy(&ptaa3); + ptaaDestroy(&ptaa4); + ptaaDestroy(&ptaa5); + return 0; +} + + +/*! + * \brief dewarpFindHorizDisparity() + * + * \param[in] dew + * \param[in] ptaa unsmoothed lines, not vertically ordered + * \return 0 if OK, 1 if horizontal disparity array is not built, or on error + * + * <pre> + * Notes: + * (1) This builds a horizontal disparity model (HDM), but + * does not check it against constraints for validity. + * Constraint checking is done at rendering time. + * (2) Horizontal disparity is not required for a successful model; + * only the vertical disparity is required. This will not be + * called if the function to build the vertical disparity fails. + * (3) This sets the hsuccess flag to 1 on success. + * (4) Internally in ptal1, ptar1, ptal2, ptar2: x and y are reversed, + * so the 'y' value is horizontal distance across the image width. + * (5) Debug output goes to /tmp/lept/dewmod/ for collection into a pdf. + * </pre> + */ +l_ok +dewarpFindHorizDisparity(L_DEWARP *dew, + PTAA *ptaa) +{ +l_int32 i, j, h, nx, ny, sampling, ret, linear_edgefit; +l_float32 c0, c1, cl0, cl1, cl2, cr0, cr1, cr2; +l_float32 x, y, refl, refr; +l_float32 val, mederr; +NUMA *nald, *nard; +PIX *pix1; +PTA *ptal1, *ptar1; /* left/right end points of lines; initial */ +PTA *ptal2, *ptar2; /* left/right end points; after filtering */ +PTA *ptal3, *ptar3; /* left and right block, fitted, uniform spacing */ +PTA *pta, *ptat, *pta1, *pta2; +PTAA *ptaah; +FPIX *fpix; + + PROCNAME("dewarpFindHorizDisparity"); + + if (!dew) + return ERROR_INT("dew not defined", procName, 1); + dew->hsuccess = 0; + if (!ptaa) + return ERROR_INT("ptaa not defined", procName, 1); + + if (dew->debug) L_INFO("finding horizontal disparity\n", procName); + + /* Get the endpoints of the lines, and sort from top to bottom */ + h = pixGetHeight(dew->pixs); + ret = dewarpGetLineEndPoints(h, ptaa, &ptal1, &ptar1); + if (ret) { + L_INFO("Horiz disparity not built\n", procName); + return 1; + } + if (dew->debug) { + lept_mkdir("lept/dewdebug"); + lept_mkdir("lept/dewarp"); + ptaWriteDebug("/tmp/lept/dewdebug/endpts_left1.pta", ptal1, 1); + ptaWriteDebug("/tmp/lept/dewdebug/endpts_right1.pta", ptar1, 1); + } + + /* Filter the points by x-location to prevent 2-column images + * from getting confused about left and right endpoints. We + * require valid left points to not be farther than + * 0.20 * (remaining distance to the right edge of the image) + * to the right of the leftmost endpoint, and similarly for + * the right endpoints. (Note: x and y are reversed in the pta.) + * Also require end points to be near the medians in the + * upper and lower halves. */ + ret = dewarpFilterLineEndPoints(dew, ptal1, ptar1, &ptal2, &ptar2); + ptaDestroy(&ptal1); + ptaDestroy(&ptar1); + if (ret) { + L_INFO("Not enough filtered end points\n", procName); + return 1; + } + + /* Do either a linear or a quadratic fit to the left and right + * endpoints of the longest lines. It is not necessary to use + * the noisy LSF fit function, because we've removed outlier + * end points by selecting the long lines. + * For the linear fit, each line is represented by 2 coefficients: + * x(y) = c1 * y + c0. + * For the quadratic fit, each line is represented by 3 coefficients: + * x(y) = c2 * y^2 + c1 * y + c0. + * Then using the coefficients, sample each fitted curve uniformly + * along the full height of the image. */ + sampling = dew->sampling; + nx = dew->nx; + ny = dew->ny; + linear_edgefit = (dew->dewa->max_edgecurv == 0) ? TRUE : FALSE; + + if (linear_edgefit) { + /* Fit the left side, using linear LSF on the set of long lines. */ + dewarpLinearLSF(ptal2, &cl1, &cl0, &mederr); + dew->leftslope = lept_roundftoi(1000. * cl1); /* milli-units */ + dew->leftcurv = 0; /* micro-units */ + L_INFO("Left linear LSF median error = %5.2f\n", procName, mederr); + L_INFO("Left edge slope = %d\n", procName, dew->leftslope); + ptal3 = ptaCreate(ny); + for (i = 0; i < ny; i++) { /* uniformly sample in y */ + y = i * sampling; + applyLinearFit(cl1, cl0, y, &x); + ptaAddPt(ptal3, x, y); + } + + /* Do a linear LSF on the right side. */ + dewarpLinearLSF(ptar2, &cr1, &cr0, &mederr); + dew->rightslope = lept_roundftoi(1000.0 * cr1); /* milli-units */ + dew->rightcurv = 0; /* micro-units */ + L_INFO("Right linear LSF median error = %5.2f\n", procName, mederr); + L_INFO("Right edge slope = %d\n", procName, dew->rightslope); + ptar3 = ptaCreate(ny); + for (i = 0; i < ny; i++) { /* uniformly sample in y */ + y = i * sampling; + applyLinearFit(cr1, cr0, y, &x); + ptaAddPt(ptar3, x, y); + } + } else { /* quadratic edge fit */ + /* Fit the left side, using quadratic LSF on the long lines. */ + dewarpQuadraticLSF(ptal2, &cl2, &cl1, &cl0, &mederr); + dew->leftslope = lept_roundftoi(1000. * cl1); /* milli-units */ + dew->leftcurv = lept_roundftoi(1000000. * cl2); /* micro-units */ + L_INFO("Left quad LSF median error = %5.2f\n", procName, mederr); + L_INFO("Left edge slope = %d\n", procName, dew->leftslope); + L_INFO("Left edge curvature = %d\n", procName, dew->leftcurv); + ptal3 = ptaCreate(ny); + for (i = 0; i < ny; i++) { /* uniformly sample in y */ + y = i * sampling; + applyQuadraticFit(cl2, cl1, cl0, y, &x); + ptaAddPt(ptal3, x, y); + } + + /* Do a quadratic LSF on the right side. */ + dewarpQuadraticLSF(ptar2, &cr2, &cr1, &cr0, &mederr); + dew->rightslope = lept_roundftoi(1000.0 * cr1); /* milli-units */ + dew->rightcurv = lept_roundftoi(1000000. * cr2); /* micro-units */ + L_INFO("Right quad LSF median error = %5.2f\n", procName, mederr); + L_INFO("Right edge slope = %d\n", procName, dew->rightslope); + L_INFO("Right edge curvature = %d\n", procName, dew->rightcurv); + ptar3 = ptaCreate(ny); + for (i = 0; i < ny; i++) { /* uniformly sample in y */ + y = i * sampling; + applyQuadraticFit(cr2, cr1, cr0, y, &x); + ptaAddPt(ptar3, x, y); + } + } + + if (dew->debug) { + PTA *ptalft, *ptarft; + h = pixGetHeight(dew->pixs); + pta1 = ptaCreate(h); + pta2 = ptaCreate(h); + if (linear_edgefit) { + for (i = 0; i < h; i++) { + applyLinearFit(cl1, cl0, i, &x); + ptaAddPt(pta1, x, i); + applyLinearFit(cr1, cr0, i, &x); + ptaAddPt(pta2, x, i); + } + } else { /* quadratic edge fit */ + for (i = 0; i < h; i++) { + applyQuadraticFit(cl2, cl1, cl0, i, &x); + ptaAddPt(pta1, x, i); + applyQuadraticFit(cr2, cr1, cr0, i, &x); + ptaAddPt(pta2, x, i); + } + } + pix1 = pixDisplayPta(NULL, dew->pixs, pta1); + pixDisplayPta(pix1, pix1, pta2); + pixRenderHorizEndPoints(pix1, ptal2, ptar2, 0xff000000); + pixDisplay(pix1, 600, 800); + pixWriteDebug("/tmp/lept/dewmod/0051.png", pix1, IFF_PNG); + pixDestroy(&pix1); + + pix1 = pixDisplayPta(NULL, dew->pixs, pta1); + pixDisplayPta(pix1, pix1, pta2); + ptalft = ptaTranspose(ptal3); + ptarft = ptaTranspose(ptar3); + pixRenderHorizEndPoints(pix1, ptalft, ptarft, 0x0000ff00); + pixDisplay(pix1, 800, 800); + pixWriteDebug("/tmp/lept/dewmod/0052.png", pix1, IFF_PNG); + convertFilesToPdf("/tmp/lept/dewmod", "005", 135, 1.0, 0, 0, + "Dewarp Horiz Disparity", + "/tmp/lept/dewarp/horiz_disparity.pdf"); + lept_stderr("pdf file: /tmp/lept/dewarp/horiz_disparity.pdf\n"); + pixDestroy(&pix1); + ptaDestroy(&pta1); + ptaDestroy(&pta2); + ptaDestroy(&ptalft); + ptaDestroy(&ptarft); + } + + /* Find the x value at the midpoints (in y) of the two vertical lines, + * ptal3 and ptar3. These are the reference values for each of the + * lines. Then use the difference between the these midpoint + * values and the actual x coordinates of the lines to represent + * the horizontal disparity (nald, nard) on the vertical lines + * for the sampled y values. */ + ptaGetPt(ptal3, ny / 2, &refl, NULL); + ptaGetPt(ptar3, ny / 2, &refr, NULL); + nald = numaCreate(ny); + nard = numaCreate(ny); + for (i = 0; i < ny; i++) { + ptaGetPt(ptal3, i, &x, NULL); + numaAddNumber(nald, refl - x); + ptaGetPt(ptar3, i, &x, NULL); + numaAddNumber(nard, refr - x); + } + + /* Now for each pair of sampled values of the two lines (at the + * same value of y), do a linear interpolation to generate + * the horizontal disparity on all sampled points between them. */ + ptaah = ptaaCreate(ny); + for (i = 0; i < ny; i++) { + pta = ptaCreate(2); + numaGetFValue(nald, i, &val); + ptaAddPt(pta, refl, val); + numaGetFValue(nard, i, &val); + ptaAddPt(pta, refr, val); + ptaGetLinearLSF(pta, &c1, &c0, NULL); /* horiz disparity along line */ + ptat = ptaCreate(nx); + for (j = 0; j < nx; j++) { + x = j * sampling; + applyLinearFit(c1, c0, x, &val); + ptaAddPt(ptat, x, val); + } + ptaaAddPta(ptaah, ptat, L_INSERT); + ptaDestroy(&pta); + } + numaDestroy(&nald); + numaDestroy(&nard); + + /* Save the result in a fpix at the specified subsampling */ + fpix = fpixCreate(nx, ny); + for (i = 0; i < ny; i++) { + for (j = 0; j < nx; j++) { + ptaaGetPt(ptaah, i, j, NULL, &val); + fpixSetPixel(fpix, j, i, val); + } + } + dew->samphdispar = fpix; + dew->hsuccess = 1; + ptaDestroy(&ptal2); + ptaDestroy(&ptar2); + ptaDestroy(&ptal3); + ptaDestroy(&ptar3); + ptaaDestroy(&ptaah); + return 0; +} + + +/*! + * \brief dewarpGetTextlineCenters() + * + * \param[in] pixs 1 bpp + * \param[in] debugflag 1 for debug output + * \return ptaa of center values of textlines + * + * <pre> + * Notes: + * (1) This in general does not have a point for each value + * of x, because there will be gaps between words. + * It doesn't matter because we will fit a quadratic to the + * points that we do have. + * </pre> + */ +PTAA * +dewarpGetTextlineCenters(PIX *pixs, + l_int32 debugflag) +{ +char buf[64]; +l_int32 i, w, h, bx, by, nsegs, csize1, csize2; +BOXA *boxa; +PIX *pix1, *pix2; +PIXA *pixa1, *pixa2; +PTA *pta; +PTAA *ptaa; + + PROCNAME("dewarpGetTextlineCenters"); + + if (!pixs || pixGetDepth(pixs) != 1) + return (PTAA *)ERROR_PTR("pixs undefined or not 1 bpp", procName, NULL); + pixGetDimensions(pixs, &w, &h, NULL); + + if (debugflag) L_INFO("finding text line centers\n", procName); + + /* Filter to solidify the text lines within the x-height region, + * and to remove most of the ascenders and descenders. + * We start with a small vertical opening to remove noise beyond + * the line that can cause an error in the line end points. + * The small closing (csize1) is used to bridge the gaps between + * letters. The large closing (csize2) bridges the gaps between + * words; using 1/30 of the page width usually suffices. */ + csize1 = L_MAX(15, w / 80); + csize2 = L_MAX(40, w / 30); + snprintf(buf, sizeof(buf), "o1.3 + c%d.1 + o%d.1 + c%d.1", + csize1, csize1, csize2); + pix1 = pixMorphSequence(pixs, buf, 0); + + /* Remove the components (e.g., embedded images) that have + * long vertical runs (>= 50 pixels). You can't use bounding + * boxes because connected component b.b. of lines can be quite + * tall due to slope and curvature. */ + pix2 = pixMorphSequence(pix1, "e1.50", 0); /* seed */ + pixSeedfillBinary(pix2, pix2, pix1, 8); /* tall components */ + pixXor(pix2, pix2, pix1); /* remove tall */ + + if (debugflag) { + lept_mkdir("lept/dewmod"); + pixWriteDebug("/tmp/lept/dewmod/0011.tif", pix1, IFF_TIFF_G4); + pixDisplayWithTitle(pix1, 0, 600, "pix1", 1); + pixWriteDebug("/tmp/lept/dewmod/0012.tif", pix2, IFF_TIFF_G4); + pixDisplayWithTitle(pix2, 0, 800, "pix2", 1); + } + pixDestroy(&pix1); + + /* Get the 8-connected components ... */ + boxa = pixConnComp(pix2, &pixa1, 8); + pixDestroy(&pix2); + boxaDestroy(&boxa); + if (pixaGetCount(pixa1) == 0) { + pixaDestroy(&pixa1); + return NULL; + } + + /* ... and remove the short width and very short height c.c */ + pixa2 = pixaSelectBySize(pixa1, 100, 4, L_SELECT_IF_BOTH, + L_SELECT_IF_GT, NULL); + if ((nsegs = pixaGetCount(pixa2)) == 0) { + pixaDestroy(&pixa1); + pixaDestroy(&pixa2); + return NULL; + } + if (debugflag) { + pix2 = pixaDisplay(pixa2, w, h); + pixWriteDebug("/tmp/lept/dewmod/0013.tif", pix2, IFF_TIFF_G4); + pixDisplayWithTitle(pix2, 0, 1000, "pix2", 1); + pixDestroy(&pix2); + } + + /* For each c.c., get the weighted center of each vertical column. + * The result is a set of points going approximately through + * the center of the x-height part of the text line. */ + ptaa = ptaaCreate(nsegs); + for (i = 0; i < nsegs; i++) { + pixaGetBoxGeometry(pixa2, i, &bx, &by, NULL, NULL); + pix2 = pixaGetPix(pixa2, i, L_CLONE); + pta = dewarpGetMeanVerticals(pix2, bx, by); + ptaaAddPta(ptaa, pta, L_INSERT); + pixDestroy(&pix2); + } + if (debugflag) { + pix1 = pixCreateTemplate(pixs); + pix2 = pixDisplayPtaa(pix1, ptaa); + pixWriteDebug("/tmp/lept/dewmod/0014.tif", pix2, IFF_PNG); + pixDisplayWithTitle(pix2, 0, 1200, "pix3", 1); + pixDestroy(&pix1); + pixDestroy(&pix2); + } + + pixaDestroy(&pixa1); + pixaDestroy(&pixa2); + return ptaa; +} + + +/*! + * \brief dewarpGetMeanVerticals() + * + * \param[in] pixs 1 bpp, single c.c. + * \param[in] x,y location of UL corner of pixs, relative to page image + * \return pta (mean y-values in component for each x-value, + * both translated by (x,y + */ +static PTA * +dewarpGetMeanVerticals(PIX *pixs, + l_int32 x, + l_int32 y) +{ +l_int32 w, h, i, j, wpl, sum, count; +l_uint32 *line, *data; +PTA *pta; + + PROCNAME("pixGetMeanVerticals"); + + if (!pixs || pixGetDepth(pixs) != 1) + return (PTA *)ERROR_PTR("pixs undefined or not 1 bpp", procName, NULL); + + pixGetDimensions(pixs, &w, &h, NULL); + pta = ptaCreate(w); + data = pixGetData(pixs); + wpl = pixGetWpl(pixs); + for (j = 0; j < w; j++) { + line = data; + sum = count = 0; + for (i = 0; i < h; i++) { + if (GET_DATA_BIT(line, j) == 1) { + sum += i; + count += 1; + } + line += wpl; + } + if (count == 0) continue; + ptaAddPt(pta, x + j, y + (sum / count)); + } + + return pta; +} + + +/*! + * \brief dewarpRemoveShortLines() + * + * \param[in] pixs 1 bpp + * \param[in] ptaas input lines + * \param[in] fract minimum fraction of longest line to keep + * \param[in] debugflag + * \return ptaad containing only lines of sufficient length, + * or NULL on error + */ +PTAA * +dewarpRemoveShortLines(PIX *pixs, + PTAA *ptaas, + l_float32 fract, + l_int32 debugflag) +{ +l_int32 w, n, i, index, maxlen, len; +l_float32 minx, maxx; +NUMA *na, *naindex; +PIX *pix1, *pix2; +PTA *pta; +PTAA *ptaad; + + PROCNAME("dewarpRemoveShortLines"); + + if (!pixs || pixGetDepth(pixs) != 1) + return (PTAA *)ERROR_PTR("pixs undefined or not 1 bpp", procName, NULL); + if (!ptaas) + return (PTAA *)ERROR_PTR("ptaas undefined", procName, NULL); + + pixGetDimensions(pixs, &w, NULL, NULL); + n = ptaaGetCount(ptaas); + ptaad = ptaaCreate(n); + na = numaCreate(n); + for (i = 0; i < n; i++) { + pta = ptaaGetPta(ptaas, i, L_CLONE); + ptaGetRange(pta, &minx, &maxx, NULL, NULL); + numaAddNumber(na, maxx - minx + 1); + ptaDestroy(&pta); + } + + /* Sort by length and find all that are long enough */ + naindex = numaGetSortIndex(na, L_SORT_DECREASING); + numaGetIValue(naindex, 0, &index); + numaGetIValue(na, index, &maxlen); + if (maxlen < 0.5 * w) + L_WARNING("lines are relatively short\n", procName); + pta = ptaaGetPta(ptaas, index, L_CLONE); + ptaaAddPta(ptaad, pta, L_INSERT); + for (i = 1; i < n; i++) { + numaGetIValue(naindex, i, &index); + numaGetIValue(na, index, &len); + if (len < fract * maxlen) break; + pta = ptaaGetPta(ptaas, index, L_CLONE); + ptaaAddPta(ptaad, pta, L_INSERT); + } + + if (debugflag) { + pix1 = pixCopy(NULL, pixs); + pix2 = pixDisplayPtaa(pix1, ptaad); + pixDisplayWithTitle(pix2, 0, 200, "pix4", 1); + pixDestroy(&pix1); + pixDestroy(&pix2); + } + + numaDestroy(&na); + numaDestroy(&naindex); + return ptaad; +} + + +/*! + * \brief dewarpGetLineEndPoints() + * + * \param[in] h height of pixs + * \param[in] ptaa lines + * \param[out] pptal left end points of each line + * \param[out] pptar right end points of each line + * \return 0 if OK, 1 on error. + * + * <pre> + * Notes: + * (1) We require that the set of end points extends over 45% of the + * height of the input image, to insure good coverage and + * avoid extrapolating the curvature too far beyond the + * actual textlines. Large extrapolations are particularly + * dangerous if used as a reference model. We also require + * at least 10 lines of text. + * (2) We sort the lines from top to bottom (sort by x in the ptas). + * (3) For fitting the endpoints, x = f(y), we transpose x and y. + * Thus all these ptas have x and y swapped! + * </pre> + */ +static l_int32 +dewarpGetLineEndPoints(l_int32 h, + PTAA *ptaa, + PTA **pptal, + PTA **pptar) +{ +l_int32 i, n, npt, x, y; +l_float32 miny, maxy, ratio; +PTA *pta, *ptal1, *ptar1; + + PROCNAME("dewarpGetLineEndPoints"); + + if (!pptal || !pptar) + return ERROR_INT("&ptal and &ptar not both defined", procName, 1); + *pptal = *pptar = NULL; + if (!ptaa) + return ERROR_INT("ptaa undefined", procName, 1); + + /* Are there at least 10 lines? */ + n = ptaaGetCount(ptaa); + if (n < MinLinesForHoriz1) { + L_INFO("only %d lines; too few\n", procName, n); + return 1; + } + + /* Extract the line end points, and transpose x and y values */ + ptal1 = ptaCreate(n); + ptar1 = ptaCreate(n); + for (i = 0; i < n; i++) { + pta = ptaaGetPta(ptaa, i, L_CLONE); + ptaGetIPt(pta, 0, &x, &y); + ptaAddPt(ptal1, y, x); /* transpose */ + npt = ptaGetCount(pta); + ptaGetIPt(pta, npt - 1, &x, &y); + ptaAddPt(ptar1, y, x); /* transpose */ + ptaDestroy(&pta); + } + + /* Use the min and max of the y value on the left side. */ + ptaGetRange(ptal1, &miny, &maxy, NULL, NULL); + ratio = (maxy - miny) / (l_float32)h; + if (ratio < MinRatioLinesToHeight) { + L_INFO("ratio lines to height, %f, too small\n", procName, ratio); + ptaDestroy(&ptal1); + ptaDestroy(&ptar1); + return 1; + } + + /* Sort from top to bottom */ + *pptal = ptaSort(ptal1, L_SORT_BY_X, L_SORT_INCREASING, NULL); + *pptar = ptaSort(ptar1, L_SORT_BY_X, L_SORT_INCREASING, NULL); + ptaDestroy(&ptal1); + ptaDestroy(&ptar1); + return 0; +} + + +/*! + * \brief dewarpFilterLineEndPoints() + * + * \param[in] dew + * \param[in] ptal input left end points of each line + * \param[in] ptar input right end points of each line + * \param[out] pptalf filtered left end points + * \param[out] pptarf filtered right end points + * \return 0 if OK, 1 on error. + * + * <pre> + * Notes: + * (1) Avoid confusion with multiple columns by requiring that line + * end points be close enough to leftmost and rightmost end points. + * Must have at least 8 points on left and right after this step. + * (2) Apply second filtering step, find the median positions in + * top and bottom halves, and removing end points that are + * displaced too much from these in the x direction. + * Must have at least 6 points on left and right after this step. + * (3) Reminder: x and y in the pta are transposed; think x = f(y). + * </pre> + */ +static l_int32 +dewarpFilterLineEndPoints(L_DEWARP *dew, + PTA *ptal, + PTA *ptar, + PTA **pptalf, + PTA **pptarf) +{ +l_int32 w, i, n; +l_float32 ymin, ymax, xvall, xvalr, yvall, yvalr; +PTA *ptal1, *ptar1, *ptal2, *ptar2; + + PROCNAME("dewarpFilterLineEndPoints"); + if (!ptal || !ptar) + return ERROR_INT("ptal or ptar not defined", procName, 1); + *pptalf = *pptarf = NULL; + + /* First filter for lines near left and right margins */ + w = pixGetWidth(dew->pixs); + ptaGetMinMax(ptal, NULL, &ymin, NULL, NULL); + ptaGetMinMax(ptar, NULL, NULL, NULL, &ymax); + n = ptaGetCount(ptal); /* ptar is the same size; at least 10 */ + ptal1 = ptaCreate(n); + ptar1 = ptaCreate(n); + for (i = 0; i < n; i++) { + ptaGetPt(ptal, i, &xvall, &yvall); + ptaGetPt(ptar, i, &xvalr, &yvalr); + if (yvall < ymin + 0.20 * (w - ymin) && + yvalr > 0.80 * ymax) { + ptaAddPt(ptal1, xvall, yvall); + ptaAddPt(ptar1, xvalr, yvalr); + } + } + if (dew->debug) { + ptaWriteDebug("/tmp/lept/dewdebug/endpts_left2.pta", ptal1, 1); + ptaWriteDebug("/tmp/lept/dewdebug/endpts_right2.pta", ptar1, 1); + } + + n = L_MIN(ptaGetCount(ptal1), ptaGetCount(ptar1)); + if (n < MinLinesForHoriz1 - 2) { + ptaDestroy(&ptal1); + ptaDestroy(&ptar1); + L_INFO("First filter: only %d endpoints; needed 8\n", procName, n); + return 1; + } + + /* Remove outlier points */ + ptal2 = dewarpRemoveBadEndPoints(w, ptal1); + ptar2 = dewarpRemoveBadEndPoints(w, ptar1); + ptaDestroy(&ptal1); + ptaDestroy(&ptar1); + if (!ptal2 || !ptar2) { + ptaDestroy(&ptal2); + ptaDestroy(&ptar2); + L_INFO("Second filter: too few endpoints left after outliers removed\n", + procName); + return 1; + } + if (dew->debug) { + ptaWriteDebug("/tmp/lept/dewdebug/endpts_left3.pta", ptal2, 1); + ptaWriteDebug("/tmp/lept/dewdebug/endpts_right3.pta", ptar2, 1); + } + + *pptalf = ptal2; + *pptarf = ptar2; + return 0; +} + + +/*! + * \brief dewarpRemoveBadEndPoints() + * + * \param[in] w width of input image + * \param[in] ptas left or right line end points + * \return ptad filtered left or right end points, or NULL on error. + * + * <pre> + * Notes: + * (1) The input set is sorted by line position (x value). + * Break into two (upper and lower); for each find the median + * horizontal (y value), and remove all points farther than + * a fraction of the image width from this. Make sure each + * part still has at least 3 points, and join the two sections + * before returning. + * (2) Reminder: x and y in the pta are transposed; think x = f(y). + * </pre> + */ +static PTA * +dewarpRemoveBadEndPoints(l_int32 w, + PTA *ptas) +{ +l_int32 i, n, nu, nd; +l_float32 rval, xval, yval, delta; +PTA *ptau1, *ptau2, *ptad1, *ptad2; + + PROCNAME("dewarpRemoveBadEndPoints"); + + if (!ptas) + return (PTA *)ERROR_PTR("ptas not defined", procName, NULL); + + delta = AllowedWidthFract * w; + n = ptaGetCount(ptas); /* will be at least 8 */ + + /* Check the upper half */ + ptau1 = ptaSelectRange(ptas, 0, n / 2); + ptaGetRankValue(ptau1, 0.5, NULL, L_SORT_BY_Y, &rval); + nu = ptaGetCount(ptau1); + ptau2 = ptaCreate(nu); + for (i = 0; i < nu; i++) { + ptaGetPt(ptau1, i, &xval, &yval); /* transposed */ + if (L_ABS(rval - yval) <= delta) + ptaAddPt(ptau2, xval, yval); + } + ptaDestroy(&ptau1); + if (ptaGetCount(ptau2) < MinLinesForHoriz2) { + ptaDestroy(&ptau2); + L_INFO("Second filter: upper set is too small after outliers removed\n", + procName); + return NULL; + } + + /* Check the lower half */ + ptad1 = ptaSelectRange(ptas, n / 2 + 1, -1); + ptaGetRankValue(ptad1, 0.5, NULL, L_SORT_BY_Y, &rval); + nd = ptaGetCount(ptad1); + ptad2 = ptaCreate(nd); + for (i = 0; i < nd; i++) { + ptaGetPt(ptad1, i, &xval, &yval); /* transposed */ + if (L_ABS(rval - yval) <= delta) + ptaAddPt(ptad2, xval, yval); + } + ptaDestroy(&ptad1); + if (ptaGetCount(ptad2) < MinLinesForHoriz2) { + ptaDestroy(&ptau2); + ptaDestroy(&ptad2); + L_INFO("Second filter: lower set is too small after outliers removed\n", + procName); + return NULL; + } + + ptaJoin(ptau2, ptad2, 0, -1); + ptaDestroy(&ptad2); + return ptau2; +} + + +/*! + * \brief dewarpIsLineCoverageValid() + * + * \param[in] ptaa of validated lines + * \param[in] h height of pix + * \param[out] pntop number of lines in top half + * \param[out] pnbot number of lines in bottom half + * \param[out] pytop location of top line + * \param[out] pybot location of bottom line + * \return 1 if coverage is valid, 0 if not or on error. + * + * <pre> + * Notes: + * (1) The criterion for valid coverage is: + * (a) there must be at least 4 lines in each half (top and bottom) + * of the image. + * (b) the coverage must be at least 50% of the image height + * </pre> + */ +static l_int32 +dewarpIsLineCoverageValid(PTAA *ptaa, + l_int32 h, + l_int32 *pntop, + l_int32 *pnbot, + l_int32 *pytop, + l_int32 *pybot) +{ +l_int32 i, n, iy, both_halves, ntop, nbot, ytop, ybot, nmin; +l_float32 y, fraction; +NUMA *na; + + PROCNAME("dewarpIsLineCoverageValid"); + + if (!ptaa) + return ERROR_INT("ptaa not defined", procName, 0); + if ((n = ptaaGetCount(ptaa)) == 0) + return ERROR_INT("ptaa empty", procName, 0); + if (h <= 0) + return ERROR_INT("invalid h", procName, 0); + if (!pntop || !pnbot) + return ERROR_INT("&ntop and &nbot not defined", procName, 0); + if (!pytop || !pybot) + return ERROR_INT("&ytop and &ybot not defined", procName, 0); + + na = numaCreate(n); + for (i = 0; i < n; i++) { + ptaaGetPt(ptaa, i, 0, NULL, &y); + numaAddNumber(na, y); + } + numaSort(na, na, L_SORT_INCREASING); + for (i = 0, ntop = 0; i < n; i++) { + numaGetIValue(na, i, &iy); + if (i == 0) ytop = iy; + if (i == n - 1) ybot = iy; + if (iy < 0.5 * h) + ntop++; + } + numaDestroy(&na); + nbot = n - ntop; + *pntop = ntop; + *pnbot = nbot; + *pytop = ytop; + *pybot = ybot; + nmin = 4; /* minimum number of lines required in each half */ + both_halves = (ntop >= nmin) && (nbot >= nmin); + fraction = (l_float32)(ybot - ytop) / (l_float32)h; + if (both_halves && fraction > 0.50) + return 1; + return 0; +} + + +/*! + * \brief dewarpLinearLSF() + * + * \param[in] ptad left or right end points of longest lines + * \param[out] pa coeff a of LSF: y = ax + b + * \param[out] pb coeff b of LSF: y = ax + b + * \param[out] pmederr [optional] median error + * \return 0 if OK, 1 on error. + * + * <pre> + * Notes: + * (1) This is used for finding the left or right sides of the text + * block, computed as a best-fit line. Only the longest lines + * are input, so there are no outlier line ends. + * (2) The ptas for the end points all have x and y swapped. + * </pre> + */ +static l_int32 +dewarpLinearLSF(PTA *ptad, + l_float32 *pa, + l_float32 *pb, + l_float32 *pmederr) +{ +l_int32 i, n; +l_float32 x, y, xp, c0, c1; +NUMA *naerr; + + PROCNAME("dewarpLinearLSF"); + + if (pmederr) *pmederr = 0.0; + if (!pa || !pb) + return ERROR_INT("not all ptrs are defined", procName, 1); + *pa = *pb = 0.0; + if (!ptad) + return ERROR_INT("ptad not defined", procName, 1); + + /* Fit to the longest lines */ + ptaGetLinearLSF(ptad, &c1, &c0, NULL); + *pa = c1; + *pb = c0; + + /* Optionally, find the median error */ + if (pmederr) { + n = ptaGetCount(ptad); + naerr = numaCreate(n); + for (i = 0; i < n; i++) { + ptaGetPt(ptad, i, &y, &xp); + applyLinearFit(c1, c0, y, &x); + numaAddNumber(naerr, L_ABS(x - xp)); + } + numaGetMedian(naerr, pmederr); + numaDestroy(&naerr); + } + return 0; +} + + +/*! + * \brief dewarpQuadraticLSF() + * + * \param[in] ptad left or right end points of longest lines + * \param[out] pa coeff a of LSF: y = ax^2 + bx + c + * \param[out] pb coeff b of LSF: y = ax^2 + bx + c + * \param[out] pc coeff c of LSF: y = ax^2 + bx + c + * \param[out] pmederr [optional] median error + * \return 0 if OK, 1 on error. + * + * <pre> + * Notes: + * (1) This is used for finding the left or right sides of the text + * block, computed as a best-fit quadratic curve. Only the + * longest lines are input, so there are no outlier line ends. + * (2) The ptas for the end points all have x and y swapped. + * </pre> + */ +static l_int32 +dewarpQuadraticLSF(PTA *ptad, + l_float32 *pa, + l_float32 *pb, + l_float32 *pc, + l_float32 *pmederr) +{ +l_int32 i, n; +l_float32 x, y, xp, c0, c1, c2; +NUMA *naerr; + + PROCNAME("dewarpQuadraticLSF"); + + if (pmederr) *pmederr = 0.0; + if (!pa || !pb || !pc) + return ERROR_INT("not all ptrs are defined", procName, 1); + *pa = *pb = *pc = 0.0; + if (!ptad) + return ERROR_INT("ptad not defined", procName, 1); + + /* Fit to the longest lines */ + ptaGetQuadraticLSF(ptad, &c2, &c1, &c0, NULL); + *pa = c2; + *pb = c1; + *pc = c0; + + /* Optionally, find the median error */ + if (pmederr) { + n = ptaGetCount(ptad); + naerr = numaCreate(n); + for (i = 0; i < n; i++) { + ptaGetPt(ptad, i, &y, &xp); + applyQuadraticFit(c2, c1, c0, y, &x); + numaAddNumber(naerr, L_ABS(x - xp)); + } + numaGetMedian(naerr, pmederr); + numaDestroy(&naerr); + } + return 0; +} + + +/*----------------------------------------------------------------------* + * Build disparity model for slope near binding * + *----------------------------------------------------------------------*/ +/*! + * \brief dewarpFindHorizSlopeDisparity() + * + * \param[in] dew + * \param[in] pixb 1 bpp, with vert and horiz disparity removed + * \param[in] fractthresh threshold fractional difference in density + * \param[in] parity 0 if even page, 1 if odd page + * \return 0 if OK, 1 on error + * + * <pre> + * Notes: + * (1) %fractthresh is a threshold on the fractional difference in stroke + * density between between left and right sides. Process this + * disparity only if the absolute value of the fractional + * difference equals or exceeds this threshold. + * (2) %parity indicates where the binding is: on the left for + * %parity == 0 and on the right for %parity == 1. + * (3) This takes a 1 bpp %pixb where both vertical and horizontal + * disparity have been applied, so the text lines are straight and, + * more importantly, the line end points are vertically aligned. + * It estimates the foreshortening of the characters on the + * binding side, and if significant, computes a one-dimensional + * horizontal disparity function to compensate. + * (4) The first attempt was to use the average width of the + * connected components (c.c.) in vertical slices. This does not work + * reliably, because the horizontal compression of the text is + * often accompanied by horizontal joining of c.c. + * (5) We use the density of vertical strokes, measured by first using + * a vertical opening, which improves the signal. The result + * is relatively insensitive to the size of the opening; we use + * a 10-pixel opening. The relative density is measured by + * finding the number of c.c. in a full height sliding window + * of width 50 pixels, and compute every 25 pixels. Similar results + * are obtained counting c.c. that either intersect the window + * or are fully contained within it. + * (6) Debug output goes to /tmp/lept/dewmod/ for collection into a pdf. + * </pre> + */ +l_ok +dewarpFindHorizSlopeDisparity(L_DEWARP *dew, + PIX *pixb, + l_float32 fractthresh, + l_int32 parity) +{ +l_int32 i, j, x, n1, n2, nb, ne, count, w, h, ival, prev; +l_int32 istart, iend, first, last, x0, x1, nx, ny; +l_float32 fract, delta, sum, aveval, fval, del, denom; +l_float32 ca, cb, cc, cd, ce, y; +BOX *box; +BOXA *boxa1, *boxa2; +GPLOT *gplot; +NUMA *na1, *na2, *na3, *na4, *nasum; +PIX *pix1; +PTA *pta1; +FPIX *fpix; + + PROCNAME("dewarpFindHorizSlopeDisparity"); + + if (!dew) + return ERROR_INT("dew not defined", procName, 1); + if (!dew->vvalid || !dew->hvalid) + return ERROR_INT("invalid vert or horiz disparity model", procName, 1); + if (!pixb || pixGetDepth(pixb) != 1) + return ERROR_INT("pixb not defined or not 1 bpp", procName, 1); + + if (dew->debug) L_INFO("finding slope horizontal disparity\n", procName); + + /* Find the bounding boxes of the vertical strokes; remove noise */ + pix1 = pixMorphSequence(pixb, "o1.10", 0); + pixDisplay(pix1, 100, 100); + boxa1 = pixConnCompBB(pix1, 4); + boxa2 = boxaSelectBySize(boxa1, 0, 5, L_SELECT_HEIGHT, L_SELECT_IF_GT, + NULL); + nb = boxaGetCount(boxa2); + lept_stderr("number of components: %d\n", nb); + boxaDestroy(&boxa1); + + /* Estimate the horizontal density of vertical strokes */ + na1 = numaCreate(0); + numaSetParameters(na1, 0, 25); + pixGetDimensions(pixb, &w, &h, NULL); + for (x = 0; x + 50 < w; x += 25) { + box = boxCreate(x, 0, 50, h); + boxaContainedInBoxCount(boxa2, box, &count); + numaAddNumber(na1, count); + boxDestroy(&box); + } + if (dew->debug) { + lept_mkdir("lept/dew"); + gplotSimple1(na1, GPLOT_PNG, "/tmp/lept/dew/0091", NULL); + lept_mv("/tmp/lept/dew/0091.png", "lept/dewmod", NULL, NULL); + pixWriteDebug("/tmp/lept/dewmod/0090.png", pix1, IFF_PNG); + } + pixDestroy(&pix1); + boxaDestroy(&boxa2); + + /* Find the left and right end local maxima; if the difference + * is small, quit. */ + n1 = numaGetCount(na1); + prev = 0; + istart = 0; + first = 0; + for (i = 0; i < n1; i++) { + numaGetIValue(na1, i, &ival); + if (ival >= prev) { + prev = ival; + continue; + } else { + first = prev; + istart = i - 1; + break; + } + } + prev = 0; + last = 0; + iend = n1 - 1; + for (i = n1 - 1; i >= 0; i--) { + numaGetIValue(na1, i, &ival); + if (ival >= prev) { + prev = ival; + continue; + } else { + last = prev; + iend = i + 1; + break; + } + } + na2 = numaClipToInterval(na1, istart, iend); + numaDestroy(&na1); + n2 = numaGetCount(na2); + delta = (parity == 0) ? last - first : first - last; + denom = L_MAX(1.0, (l_float32)(L_MIN(first, last))); + fract = (l_float32)delta / denom; + if (dew->debug) { + L_INFO("Slope-disparity: first = %d, last = %d, fract = %7.3f\n", + procName, first, last, fract); + gplotSimple1(na2, GPLOT_PNG, "/tmp/lept/dew/0092", NULL); + lept_mv("/tmp/lept/dew/0092.png", "lept/dewmod", NULL, NULL); + } + if (fract < fractthresh) { + L_INFO("Small slope-disparity: first = %d, last = %d, fract = %7.3f\n", + procName, first, last, fract); + numaDestroy(&na2); + return 0; + } + + /* Find the density far from the binding, and normalize to 1. */ + ne = n2 - n2 % 2; + if (parity == 0) + numaGetSumOnInterval(na2, 0, ne / 2 - 1, &sum); + else /* parity == 1 */ + numaGetSumOnInterval(na2, ne / 2, ne - 1, &sum); + denom = L_MAX(1.0, (l_float32)(ne / 2)); + aveval = sum / denom; + na3 = numaMakeConstant(aveval, n2); + numaArithOp(na2, na2, na3, L_ARITH_DIVIDE); + numaDestroy(&na3); + if (dew->debug) { + L_INFO("Average background density: %5.1f\n", procName, aveval); + gplotSimple1(na2, GPLOT_PNG, "/tmp/lept/dew/0093", NULL); + lept_mv("/tmp/lept/dew/0093.png", "lept/dewmod", NULL, NULL); + } + + /* Fit the normalized density curve to a quartic */ + pta1 = numaConvertToPta1(na2); + ptaWriteStream(stderr, pta1, 0); +/* ptaGetQuadraticLSF(pta1, NULL, NULL, NULL, &na3); */ + ptaGetQuarticLSF(pta1, &ca, &cb, &cc, &cd, &ce, &na3); + ptaGetArrays(pta1, &na4, NULL); + if (dew->debug) { + gplot = gplotSimpleXY1(na4, na3, GPLOT_LINES, GPLOT_PNG, + "/tmp/lept/dew/0094", NULL); + gplotDestroy(&gplot); + lept_mv("/tmp/lept/dew/0094.png", "lept/dewmod", NULL, NULL); + } + ptaDestroy(&pta1); + + /* Integrate from the high point down to 1 (or v.v) to get the + * disparity needed to make the density constant. */ + nasum = numaMakeConstant(0, w); /* area under the curve above 1.0 */ + if (parity == 0) { + for (i = n2 - 1; i >= 0; i--) { + numaGetFValue(na3, i, &fval); + if (fval < 1.0) break; + } + numaGetIValue(na4, i + 1, &x0); + numaGetIValue(na4, n2 - 1, &x1); + numaSetParameters(nasum, x0, 1); + sum = 0.0; + for (x = x0; x < x1; x++) { + applyQuarticFit(ca, cb, cc, cd, ce, (l_float32)x, &y); + sum += (y - 1.0); + numaReplaceNumber(nasum, x, sum); + } + for (x = x1; x < w; x++) + numaReplaceNumber(nasum, x, sum); + } else { /* parity == 1 */ + for (i = 0; i < n2; i++) { + numaGetFValue(na3, i, &fval); + if (fval < 1.0) break; + } + numaGetIValue(na4, 0, &x0); + numaGetIValue(na4, i - 1, &x1); + numaSetParameters(nasum, x0, 1); + sum = 0.0; + for (x = x1; x >= x0; x--) { + applyQuarticFit(ca, cb, cc, cd, ce, (l_float32)x, &y); + sum += (y - 1.0); + numaReplaceNumber(nasum, x, sum); + } + for (x = x0; x >= 0; x--) + numaReplaceNumber(nasum, x, sum); + } + + /* Save the result in a fpix at the specified subsampling */ + nx = dew->nx; + ny = dew->ny; + fpix = fpixCreate(nx, ny); + del = (l_float32)w / (l_float32)nx; + for (i = 0; i < ny; i++) { + for (j = 0; j < nx; j++) { + x = del * j; + numaGetFValue(nasum, x, &fval); + fpixSetPixel(fpix, j, i, fval); + } + } + dew->sampydispar = fpix; + dew->ysuccess = 1; + + numaDestroy(&na2); + numaDestroy(&na3); + numaDestroy(&na4); + numaDestroy(&nasum); + return 0; +} + + +/*----------------------------------------------------------------------* + * Build line disparity model * + *----------------------------------------------------------------------*/ +/*! + * \brief dewarpBuildLineModel() + * + * \param[in] dew + * \param[in] opensize size of opening to remove perpendicular lines + * \param[in] debugfile use NULL to skip writing this + * \return 0 if OK, 1 if unable to build the model or on error + * + * <pre> + * Notes: + * (1) This builds the horizontal and vertical disparity arrays + * for an input of ruled lines, typically for calibration. + * In book scanning, you could lay the ruled paper over a page. + * Then for that page and several below it, you can use the + * disparity correction of the line model to dewarp the pages. + * (2) The dew has been initialized with the image of ruled lines. + * These lines must be continuous, but we do a small amount + * of pre-processing here to insure that. + * (3) %opensize is typically about 8. It must be larger than + * the thickness of the lines to be extracted. This is the + * default value, which is applied if %opensize < 3. + * (4) Sets vsuccess = 1 and hsuccess = 1 if the vertical and/or + * horizontal disparity arrays build. + * (5) Similar to dewarpBuildPageModel(), except here the vertical + * and horizontal disparity arrays are both built from ruled lines. + * See notes there. + * </pre> + */ +l_ok +dewarpBuildLineModel(L_DEWARP *dew, + l_int32 opensize, + const char *debugfile) +{ +char buf[64]; +l_int32 i, j, bx, by, ret, nlines; +BOXA *boxa; +PIX *pixs, *pixh, *pixv, *pix, *pix1, *pix2; +PIXA *pixa1, *pixa2; +PTA *pta; +PTAA *ptaa1, *ptaa2; + + PROCNAME("dewarpBuildLineModel"); + + if (!dew) + return ERROR_INT("dew not defined", procName, 1); + if (opensize < 3) { + L_WARNING("opensize should be >= 3; setting to 8\n", procName); + opensize = 8; /* default */ + } + + dew->debug = (debugfile) ? 1 : 0; + dew->vsuccess = dew->hsuccess = 0; + pixs = dew->pixs; + if (debugfile) { + lept_rmdir("lept/dewline"); /* erase previous images */ + lept_mkdir("lept/dewline"); + lept_rmdir("lept/dewmod"); /* erase previous images */ + lept_mkdir("lept/dewmod"); + lept_mkdir("lept/dewarp"); + pixDisplayWithTitle(pixs, 0, 0, "pixs", 1); + pixWriteDebug("/tmp/lept/dewline/001.png", pixs, IFF_PNG); + } + + /* Extract and solidify the horizontal and vertical lines. We use + * the horizontal lines to derive the vertical disparity, and v.v. + * Both disparities are computed using the vertical disparity + * algorithm; the horizontal disparity is found from the + * vertical lines by rotating them clockwise by 90 degrees. + * On the first pass, we compute the horizontal disparity, from + * the vertical lines, by rotating them by 90 degrees (so they + * are horizontal) and computing the vertical disparity on them; + * we rotate the resulting fpix array for the horizontal disparity + * back by -90 degrees. On the second pass, we compute the vertical + * disparity from the horizontal lines in the usual fashion. */ + snprintf(buf, sizeof(buf), "d1.3 + c%d.1 + o%d.1", opensize - 2, opensize); + pixh = pixMorphSequence(pixs, buf, 0); /* horiz */ + snprintf(buf, sizeof(buf), "d3.1 + c1.%d + o1.%d", opensize - 2, opensize); + pix1 = pixMorphSequence(pixs, buf, 0); /* vert */ + pixv = pixRotateOrth(pix1, 1); /* vert rotated to horizontal */ + pixa1 = pixaCreate(2); + pixaAddPix(pixa1, pixv, L_INSERT); /* get horizontal disparity first */ + pixaAddPix(pixa1, pixh, L_INSERT); + pixDestroy(&pix1); + + /*--------------------------------------------------------------*/ + /* Process twice: first for horiz disparity, then for vert */ + /*--------------------------------------------------------------*/ + for (i = 0; i < 2; i++) { + pix = pixaGetPix(pixa1, i, L_CLONE); + pixDisplay(pix, 0, 900); + boxa = pixConnComp(pix, &pixa2, 8); + nlines = boxaGetCount(boxa); + boxaDestroy(&boxa); + if (nlines < dew->minlines) { + L_WARNING("only found %d lines\n", procName, nlines); + pixDestroy(&pix); + pixaDestroy(&pixa1); + continue; + } + + /* Identify the pixels along the skeleton of each line */ + ptaa1 = ptaaCreate(nlines); + for (j = 0; j < nlines; j++) { + pixaGetBoxGeometry(pixa2, j, &bx, &by, NULL, NULL); + pix1 = pixaGetPix(pixa2, j, L_CLONE); + pta = dewarpGetMeanVerticals(pix1, bx, by); + ptaaAddPta(ptaa1, pta, L_INSERT); + pixDestroy(&pix1); + } + pixaDestroy(&pixa2); + if (debugfile) { + pix1 = pixConvertTo32(pix); + pix2 = pixDisplayPtaa(pix1, ptaa1); + snprintf(buf, sizeof(buf), "/tmp/lept/dewline/%03d.png", 2 + 2 * i); + pixWriteDebug(buf, pix2, IFF_PNG); + pixDestroy(&pix1); + pixDestroy(&pix2); + } + + /* Remove all lines that are not at least 0.75 times the length + * of the longest line. */ + ptaa2 = dewarpRemoveShortLines(pix, ptaa1, 0.75, DEBUG_SHORT_LINES); + if (debugfile) { + pix1 = pixConvertTo32(pix); + pix2 = pixDisplayPtaa(pix1, ptaa2); + snprintf(buf, sizeof(buf), "/tmp/lept/dewline/%03d.png", 3 + 2 * i); + pixWriteDebug(buf, pix2, IFF_PNG); + pixDestroy(&pix1); + pixDestroy(&pix2); + } + ptaaDestroy(&ptaa1); + nlines = ptaaGetCount(ptaa2); + if (nlines < dew->minlines) { + pixDestroy(&pix); + ptaaDestroy(&ptaa2); + L_WARNING("%d lines: too few to build model\n", procName, nlines); + continue; + } + + /* Get the sampled 'vertical' disparity from the textline + * centers. The disparity array will push pixels vertically + * so that each line is flat and centered at the y-position + * of the mid-point. */ + ret = dewarpFindVertDisparity(dew, ptaa2, 1 - i); + + /* If i == 0, move the result to the horizontal disparity, + * rotating it back by -90 degrees. */ + if (i == 0) { /* horizontal disparity, really */ + if (ret) { + L_WARNING("horizontal disparity not built\n", procName); + } else { + L_INFO("hsuccess = 1\n", procName); + dew->samphdispar = fpixRotateOrth(dew->sampvdispar, 3); + fpixDestroy(&dew->sampvdispar); + if (debugfile) + lept_mv("/tmp/lept/dewarp/vert_disparity.pdf", + "lept/dewarp", "horiz_disparity.pdf", NULL); + } + dew->hsuccess = dew->vsuccess; + dew->vsuccess = 0; + } else { /* i == 1 */ + if (ret) + L_WARNING("vertical disparity not built\n", procName); + else + L_INFO("vsuccess = 1\n", procName); + } + ptaaDestroy(&ptaa2); + pixDestroy(&pix); + } + pixaDestroy(&pixa1); + + /* Debug output */ + if (debugfile) { + if (dew->vsuccess == 1) { + dewarpPopulateFullRes(dew, NULL, 0, 0); + pix1 = fpixRenderContours(dew->fullvdispar, 3.0, 0.15f); + pixWriteDebug("/tmp/lept/dewline/006.png", pix1, IFF_PNG); + pixDisplay(pix1, 1000, 0); + pixDestroy(&pix1); + } + if (dew->hsuccess == 1) { + pix1 = fpixRenderContours(dew->fullhdispar, 3.0, 0.15f); + pixWriteDebug("/tmp/lept/dewline/007.png", pix1, IFF_PNG); + pixDisplay(pix1, 1000, 0); + pixDestroy(&pix1); + } + convertFilesToPdf("/tmp/lept/dewline", NULL, 135, 1.0, 0, 0, + "Dewarp Build Line Model", debugfile); + lept_stderr("pdf file: %s\n", debugfile); + } + + return 0; +} + + +/*----------------------------------------------------------------------* + * Query model status * + *----------------------------------------------------------------------*/ +/*! + * \brief dewarpaModelStatus() + * + * \param[in] dewa + * \param[in] pageno + * \param[out] pvsuccess [optional] 1 on success + * \param[out] phsuccess [optional] 1 on success + * \return 0 if OK, 1 on error + * + * <pre> + * Notes: + * (1) This tests if a model has been built, not if it is valid. + * </pre> + */ +l_ok +dewarpaModelStatus(L_DEWARPA *dewa, + l_int32 pageno, + l_int32 *pvsuccess, + l_int32 *phsuccess) +{ +L_DEWARP *dew; + + PROCNAME("dewarpaModelStatus"); + + if (pvsuccess) *pvsuccess = 0; + if (phsuccess) *phsuccess = 0; + if (!dewa) + return ERROR_INT("dewa not defined", procName, 1); + + if ((dew = dewarpaGetDewarp(dewa, pageno)) == NULL) + return ERROR_INT("dew not retrieved", procName, 1); + if (pvsuccess) *pvsuccess = dew->vsuccess; + if (phsuccess) *phsuccess = dew->hsuccess; + return 0; +} + + +/*----------------------------------------------------------------------* + * Rendering helpers * + *----------------------------------------------------------------------*/ +/*! + * \brief pixRenderMidYs() + * + * \param[in] pixs 32 bpp + * \param[in] namidys y location of reference lines for vertical disparity + * \param[in] linew width of rendered line; typ 2 + * \return 0 if OK, 1 on error + */ +static l_int32 +pixRenderMidYs(PIX *pixs, + NUMA *namidys, + l_int32 linew) +{ +l_int32 i, n, w, yval, rval, gval, bval; +PIXCMAP *cmap; + + PROCNAME("pixRenderMidYs"); + + if (!pixs) + return ERROR_INT("pixs not defined", procName, 1); + if (!namidys) + return ERROR_INT("namidys not defined", procName, 1); + + w = pixGetWidth(pixs); + n = numaGetCount(namidys); + cmap = pixcmapCreateRandom(8, 0, 0); + for (i = 0; i < n; i++) { + pixcmapGetColor(cmap, i % 256, &rval, &gval, &bval); + numaGetIValue(namidys, i, &yval); + pixRenderLineArb(pixs, 0, yval, w, yval, linew, rval, gval, bval); + } + pixcmapDestroy(&cmap); + return 0; +} + + +/*! + * \brief pixRenderHorizEndPoints() + * + * \param[in] pixs 32 bpp + * \param[in] ptal left side line end points + * \param[in] ptar right side line end points + * \param[in] color 0xrrggbb00 + * \return 0 if OK, 1 on error + */ +static l_int32 +pixRenderHorizEndPoints(PIX *pixs, + PTA *ptal, + PTA *ptar, + l_uint32 color) +{ +PIX *pixcirc; +PTA *ptalt, *ptart, *ptacirc; + + PROCNAME("pixRenderHorizEndPoints"); + + if (!pixs) + return ERROR_INT("pixs not defined", procName, 1); + if (!ptal || !ptar) + return ERROR_INT("ptal and ptar not both defined", procName, 1); + + ptacirc = generatePtaFilledCircle(5); + pixcirc = pixGenerateFromPta(ptacirc, 11, 11); + ptalt = ptaTranspose(ptal); + ptart = ptaTranspose(ptar); + + pixDisplayPtaPattern(pixs, pixs, ptalt, pixcirc, 5, 5, color); + pixDisplayPtaPattern(pixs, pixs, ptart, pixcirc, 5, 5, color); + ptaDestroy(&ptacirc); + ptaDestroy(&ptalt); + ptaDestroy(&ptart); + pixDestroy(&pixcirc); + return 0; +} |