/*====================================================================* - 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. *====================================================================*/ /* * finditalic.c * * Locate italic words. This is an example of the use of * hit-miss binary morphology with binary reconstruction (filling * from a seed into a mask). * Example: use with prog/italics.png * * l_int32 pixItalicWords() */ #include "allheaders.h" /* --------------------------------------------------------------- * * These hit-miss sels match the slanted edge of italic characters * * --------------------------------------------------------------- */ static const char *str_ital1 = " o x" " " " " " " " o x " " " " C " " " " o x " " " " " " " "o x "; static const char *str_ital2 = " o x" " " " " " o x " " C " " " " o x " " " " " "o x "; /* ------------------------------------------------------------- * * This sel removes noise that is not oriented as a slanted edge * * ------------------------------------------------------------- */ static const char *str_ital3 = " x" "Cx" "x " "x "; /*! * pixItalicWords() * * Input: pixs (1 bpp) * boxaw ( word bounding boxes; can be NULL) * pixw ( word box mask; can be NULL) * &boxa ( boxa of italian words) * debugflag (1 for debug output; 0 otherwise) * Return: 0 if OK, 1 on error * * Notes: * (1) You can input the bounding boxes for the words in one of * two forms: as bounding boxes (@boxaw) or as a word mask with * the word bounding boxes filled (@pixw). For example, * to compute @pixw, you can use pixWordMaskByDilation(). * (2) Alternatively, you can set both of these inputs to NULL, * in which case the word mask is generated here. This is * done by dilating and closing the input image to connect * letters within a word, while leaving the words separated. * The parameters are chosen under the assumption that the * input is 10 to 12 pt text, scanned at about 300 ppi. * (3) sel_ital1 and sel_ital2 detect the right edges that are * nearly vertical, at approximately the angle of italic * strokes. We use the right edge to avoid getting seeds * from lower-case 'y'. The typical italic slant has a smaller * angle with the vertical than the 'W', so in most cases we * will not trigger on the slanted lines in the 'W'. * (4) Note that sel_ital2 is shorter than sel_ital1. It is * more appropriate for a typical font scanned at 200 ppi. */ l_int32 pixItalicWords(PIX *pixs, BOXA *boxaw, PIX *pixw, BOXA **pboxa, l_int32 debugflag) { BOXA *boxa; PIX *pixsd, *pixm, *pixd; SEL *sel_ital1, *sel_ital2, *sel_ital3; PROCNAME("pixItalicWords"); if (!pixs) return ERROR_INT("pixs not defined", procName, 1); if (!pboxa) return ERROR_INT("&boxa not defined", procName, 1); if (boxaw && pixw) return ERROR_INT("both boxaw and pixw are defined", procName, 1); sel_ital1 = selCreateFromString(str_ital1, 13, 6, NULL); sel_ital2 = selCreateFromString(str_ital2, 10, 6, NULL); sel_ital3 = selCreateFromString(str_ital3, 4, 2, NULL); /* Make the italic seed: extract with HMT; remove noise. * The noise removal close/open is important to exclude * situations where a small slanted line accidentally * matches sel_ital1. */ pixsd = pixHMT(NULL, pixs, sel_ital1); pixClose(pixsd, pixsd, sel_ital3); pixOpen(pixsd, pixsd, sel_ital3); /* Make the word mask. Use input boxes or mask if given. */ if (boxaw) { pixm = pixCreateTemplate(pixs); pixMaskBoxa(pixm, pixm, boxaw, L_SET_PIXELS); } else if (pixw) { pixm = pixClone(pixw); } else pixm = pixMorphSequence(pixs, "d1.5 + c6.1", 0); /* Binary reconstruction to fill in those word mask * components for which there is at least one seed pixel. */ pixd = pixSeedfillBinary(NULL, pixsd, pixm, 8); boxa = pixConnComp(pixd, NULL, 8); *pboxa = boxa; if (debugflag) { l_int32 res; BOXA *boxat; PIXA *pad; PIX *pixt1, *pixt2; pad = pixaCreate(0); /* Save these at 2x reduction */ pixSaveTiledOutline(pixs, pad, 2, 1, 20, 2, 32); pixSaveTiledOutline(pixsd, pad, 2, 1, 20, 2, 0); boxat = pixConnComp(pixm, NULL, 8); boxaWrite("/tmp/junkital.ba", boxat); pixt1 = pixConvertTo32(pixm); pixRenderBoxaArb(pixt1, boxat, 3, 255, 0, 0); pixSaveTiledOutline(pixt1, pad, 2, 1, 20, 2, 0); pixDestroy(&pixt1); pixSaveTiledOutline(pixd, pad, 2, 1, 20, 2, 0); pixt1 = pixConvertTo32(pixs); pixRenderBoxaArb(pixt1, boxa, 3, 255, 0, 0); pixSaveTiledOutline(pixt1, pad, 2, 1, 20, 2, 0); pixt2 = pixaDisplay(pad, 0, 0); pixWrite("/tmp/junkital.png", pixt2, IFF_PNG); /* The pixs resolution is approximately: * 300 * (width of pixs) / 2000 * and the images have been saved at half this resolution. */ res = (150 * pixGetWidth(pixs)) / 2000; L_INFO_INT("resolution = %d", procName, res); pixaConvertToPdf(pad, res, 1.0, 3, 75, "Italic Finder", "/tmp/junkital.pdf"); pixaDestroy(&pad); pixDestroy(&pixt1); pixDestroy(&pixt2); boxaDestroy(&boxat); } selDestroy(&sel_ital1); selDestroy(&sel_ital2); selDestroy(&sel_ital3); pixDestroy(&pixsd); pixDestroy(&pixm); pixDestroy(&pixd); return 0; }