mirror/tesseract
1
0
Fork 0
mirror of https://github.com/tesseract-ocr/tesseract.git synced 2024-11-24 11:09:06 +08:00
Code Issues Actions 10 Packages Projects Releases Wiki Activity
53fc4456cc
tesseract/api/pdfrenderer.cpp
Ray Smith d9699c4099 Fixed bidi handling in PDF output
2014-10-09 13:29:01 -07:00

802 lines
25 KiB
C++
Raw Blame History

// Include automatically generated configuration file if running autoconf.
#ifdef HAVE_CONFIG_H
#include "config_auto.h"
#endif
#include "baseapi.h"
#include "renderer.h"
#include "math.h"
#include "strngs.h"
#include "cube_utils.h"
#include "allheaders.h"
#ifdef _MSC_VER
#include "mathfix.h"
#endif
namespace tesseract {
// Use for PDF object fragments. Must be large enough
// to hold a colormap with 256 colors in the verbose
// PDF representation.
const int kBasicBufSize = 2048;
// If the font is 10 pts, nominal character width is 5 pts
const int kCharWidth = 2;
/**********************************************************************
* PDF Renderer interface implementation
**********************************************************************/
TessPDFRenderer::TessPDFRenderer(const char* outputbase, const char *datadir)
: TessResultRenderer(outputbase, "pdf") {
obj_ = 0;
datadir_ = datadir;
offsets_.push_back(0);
}
void TessPDFRenderer::AppendPDFObjectDIY(size_t objectsize) {
offsets_.push_back(objectsize + offsets_.back());
obj_++;
}
void TessPDFRenderer::AppendPDFObject(const char *data) {
AppendPDFObjectDIY(strlen(data));
AppendString((const char *)data);
}
// Helper function to prevent us from accidentaly writing
// scientific notation to an HOCR or PDF file. Besides, three
// decimal points are all you really need.
double prec(double x) {
double kPrecision = 1000.0;
double a = round(x * kPrecision) / kPrecision;
if (a == -0)
return 0;
return a;
}
long dist2(int x1, int y1, int x2, int y2) {
return (x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1);
}
// Viewers like evince can get really confused during copy-paste when
// the baseline wanders around. So I've decided to project every word
// onto the (straight) line baseline. All numbers are in the native
// PDF coordinate system, which has the origin in the bottom left and
// the unit is points, which is 1/72 inch. Tesseract reports baselines
// left-to-right no matter what the reading order is. We need the
// word baseline in reading order, so we do that conversion here. Returns
// the word's baseline origin and length.
void GetWordBaseline(int writing_direction, int ppi, int height,
int word_x1, int word_y1, int word_x2, int word_y2,
int line_x1, int line_y1, int line_x2, int line_y2,
double *x0, double *y0, double *length) {
if (writing_direction == WRITING_DIRECTION_RIGHT_TO_LEFT) {
Swap(&word_x1, &word_x2);
Swap(&word_y1, &word_y2);
}
double word_length;
double x, y;
{
int px = word_x1;
int py = word_y1;
double l2 = dist2(line_x1, line_y1, line_x2, line_y2);
if (l2 == 0) {
x = line_x1;
y = line_y1;
} else {
double t = ((px - line_x2) * (line_x2 - line_x1) +
(py - line_y2) * (line_y2 - line_y1)) / l2;
x = line_x2 + t * (line_x2 - line_x1);
y = line_y2 + t * (line_y2 - line_y1);
}
word_length = sqrt(static_cast<double>(dist2(word_x1, word_y1,
word_x2, word_y2)));
word_length = word_length * 72.0 / ppi;
x = x * 72 / ppi;
y = height - (y * 72.0 / ppi);
}
*x0 = x;
*y0 = y;
*length = word_length;
}
// Compute coefficients for an affine matrix describing the rotation
// of the text. If the text is right-to-left such as Arabic or Hebrew,
// we reflect over the Y-axis. This matrix will set the coordinate
// system for placing text in the PDF file.
//
// RTL
// [ x' ] = [ a b ][ x ] = [-1 0 ] [ cos sin ][ x ]
// [ y' ] [ c d ][ y ] [ 0 1 ] [-sin cos ][ y ]
void AffineMatrix(int writing_direction,
int line_x1, int line_y1, int line_x2, int line_y2,
double *a, double *b, double *c, double *d) {
double theta = atan2(static_cast<double>(line_y1 - line_y2),
static_cast<double>(line_x2 - line_x1));
*a = cos(theta);
*b = sin(theta);
*c = -sin(theta);
*d = cos(theta);
switch(writing_direction) {
case WRITING_DIRECTION_RIGHT_TO_LEFT:
*a = -*a;
*b = -*b;
break;
case WRITING_DIRECTION_TOP_TO_BOTTOM:
// TODO(jbreiden) Consider using the vertical PDF writing mode.
break;
default:
break;
}
}
// There are some really stupid PDF viewers in the wild, such as
// 'Preview' which ships with the Mac. They do a better job with text
// selection and highlighting when given perfectly flat baseline
// instead of very slightly tilted. We clip small tilts to appease
// these viewers. I chose this threshold large enough to absorb noise,
// but small enough that lines probably won't cross each other if the
// whole page is tilted at almost exactly the clipping threshold.
void ClipBaseline(int ppi, int x1, int y1, int x2, int y2,
int *line_x1, int *line_y1,
int *line_x2, int *line_y2) {
*line_x1 = x1;
*line_y1 = y1;
*line_x2 = x2;
*line_y2 = y2;
double rise = abs(y2 - y1) * 72 / ppi;
double run = abs(x2 - x1) * 72 / ppi;
if (rise < 2.0 && 2.0 < run)
*line_y1 = *line_y2 = (y1 + y2) / 2;
}
char* TessPDFRenderer::GetPDFTextObjects(TessBaseAPI* api,
double width, double height) {
STRING pdf_str("");
double ppi = api->GetSourceYResolution();
// These initial conditions are all arbitrary and will be overwritten
double old_x = 0.0, old_y = 0.0;
int old_fontsize = 0;
tesseract::WritingDirection old_writing_direction =
WRITING_DIRECTION_LEFT_TO_RIGHT;
bool new_block = true;
int fontsize = 0;
double a = 1;
double b = 0;
double c = 0;
double d = 1;
// TODO(jbreiden) This marries the text and image together.
// Slightly cleaner from an abstraction standpoint if this were to
// live inside a separate text object.
pdf_str += "q ";
pdf_str.add_str_double("", prec(width));
pdf_str += " 0 0 ";
pdf_str.add_str_double("", prec(height));
pdf_str += " 0 0 cm /Im1 Do Q\n";
ResultIterator *res_it = api->GetIterator();
while (!res_it->Empty(RIL_BLOCK)) {
if (res_it->IsAtBeginningOf(RIL_BLOCK)) {
pdf_str += "BT\n3 Tr"; // Begin text object, use invisible ink
old_fontsize = 0; // Every block will declare its fontsize
new_block = true; // Every block will declare its affine matrix
}
int line_x1, line_y1, line_x2, line_y2;
if (res_it->IsAtBeginningOf(RIL_TEXTLINE)) {
int x1, y1, x2, y2;
res_it->Baseline(RIL_TEXTLINE, &x1, &y1, &x2, &y2);
ClipBaseline(ppi, x1, y1, x2, y2, &line_x1, &line_y1, &line_x2, &line_y2);
}
if (res_it->Empty(RIL_WORD)) {
res_it->Next(RIL_WORD);
continue;
}
// Writing direction changes at a per-word granularity
tesseract::WritingDirection writing_direction;
{
tesseract::Orientation orientation;
tesseract::TextlineOrder textline_order;
float deskew_angle;
res_it->Orientation(&orientation, &writing_direction,
&textline_order, &deskew_angle);
if (writing_direction != WRITING_DIRECTION_TOP_TO_BOTTOM) {
switch (res_it->WordDirection()) {
case DIR_LEFT_TO_RIGHT:
writing_direction = WRITING_DIRECTION_LEFT_TO_RIGHT;
break;
case DIR_RIGHT_TO_LEFT:
writing_direction = WRITING_DIRECTION_RIGHT_TO_LEFT;
break;
default:
writing_direction = old_writing_direction;
}
}
}
// Where is word origin and how long is it?
double x, y, word_length;
{
int word_x1, word_y1, word_x2, word_y2;
res_it->Baseline(RIL_WORD, &word_x1, &word_y1, &word_x2, &word_y2);
GetWordBaseline(writing_direction, ppi, height,
word_x1, word_y1, word_x2, word_y2,
line_x1, line_y1, line_x2, line_y2,
&x, &y, &word_length);
}
if (writing_direction != old_writing_direction || new_block) {
AffineMatrix(writing_direction,
line_x1, line_y1, line_x2, line_y2, &a, &b, &c, &d);
pdf_str.add_str_double(" ", prec(a)); // . This affine matrix
pdf_str.add_str_double(" ", prec(b)); // . sets the coordinate
pdf_str.add_str_double(" ", prec(c)); // . system for all
pdf_str.add_str_double(" ", prec(d)); // . text that follows.
pdf_str.add_str_double(" ", prec(x)); // .
pdf_str.add_str_double(" ", prec(y)); // .
pdf_str += (" Tm "); // Place cursor absolutely
new_block = false;
} else {
double dx = x - old_x;
double dy = y - old_y;
pdf_str.add_str_double(" ", prec(dx * a + dy * b));
pdf_str.add_str_double(" ", prec(dx * c + dy * d));
pdf_str += (" Td "); // Relative moveto
}
old_x = x;
old_y = y;
old_writing_direction = writing_direction;
// Adjust font size on a per word granularity. Pay attention to
// fontsize, old_fontsize, and pdf_str. We've found that for
// in Arabic, Tesseract will happily return a fontsize of zero,
// so we make up a default number to protect ourselves.
{
bool bold, italic, underlined, monospace, serif, smallcaps;
int font_id;
res_it->WordFontAttributes(&bold, &italic, &underlined, &monospace,
&serif, &smallcaps, &fontsize, &font_id);
const int kDefaultFontsize = 8;
if (fontsize <= 0)
fontsize = kDefaultFontsize;
if (fontsize != old_fontsize) {
char textfont[20];
snprintf(textfont, sizeof(textfont), "/f-0-0 %d Tf ", fontsize);
pdf_str += textfont;
old_fontsize = fontsize;
}
}
bool last_word_in_line = res_it->IsAtFinalElement(RIL_TEXTLINE, RIL_WORD);
bool last_word_in_block = res_it->IsAtFinalElement(RIL_BLOCK, RIL_WORD);
STRING pdf_word("");
int pdf_word_len = 0;
do {
const char *grapheme = res_it->GetUTF8Text(RIL_SYMBOL);
if (grapheme && grapheme[0] != '\0') {
// TODO(jbreiden) Do a real UTF-16BE conversion
// http://en.wikipedia.org/wiki/UTF-16#Example_UTF-16_encoding_procedure
string_32 utf32;
CubeUtils::UTF8ToUTF32(grapheme, &utf32);
char utf16[20];
for (int i = 0; i < static_cast<int>(utf32.length()); i++) {
snprintf(utf16, sizeof(utf16), "<%04X>", utf32[i]);
pdf_word += utf16;
pdf_word_len++;
}
}
delete []grapheme;
res_it->Next(RIL_SYMBOL);
} while (!res_it->Empty(RIL_BLOCK) && !res_it->IsAtBeginningOf(RIL_WORD));
if (word_length > 0 && pdf_word_len > 0 && fontsize > 0) {
double h_stretch =
kCharWidth * prec(100.0 * word_length / (fontsize * pdf_word_len));
pdf_str.add_str_double("", h_stretch);
pdf_str += " Tz"; // horizontal stretch
pdf_str += " [ ";
pdf_str += pdf_word; // UTF-16BE representation
pdf_str += " ] TJ"; // show the text
}
if (last_word_in_line) {
pdf_str += " \n";
}
if (last_word_in_block) {
pdf_str += "ET\n"; // end the text object
}
}
char *ret = new char[pdf_str.length() + 1];
strcpy(ret, pdf_str.string());
delete res_it;
return ret;
}
bool TessPDFRenderer::BeginDocumentHandler() {
char buf[kBasicBufSize];
size_t n;
n = snprintf(buf, sizeof(buf),
"%%PDF-1.5\n"
"%%%c%c%c%c\n",
0xDE, 0xAD, 0xBE, 0xEB);
if (n >= sizeof(buf)) return false;
AppendPDFObject(buf);
// CATALOG
n = snprintf(buf, sizeof(buf),
"1 0 obj\n"
"<<\n"
" /Type /Catalog\n"
" /Pages %ld 0 R\n"
">>\n"
"endobj\n", 2L);
if (n >= sizeof(buf)) return false;
AppendPDFObject(buf);
// We are reserving object #2 for the /Pages
// object, which I am going to create and write
// at the end of the PDF file.
AppendPDFObject("");
// TYPE0 FONT
n = snprintf(buf, sizeof(buf),
"3 0 obj\n"
"<<\n"
" /BaseFont /GlyphLessFont\n"
" /DescendantFonts [ %ld 0 R ]\n"
" /Encoding /Identity-H\n"
" /Subtype /Type0\n"
" /ToUnicode %ld 0 R\n"
" /Type /Font\n"
">>\n"
"endobj\n",
4L, // CIDFontType2 font
5L // ToUnicode
);
if (n >= sizeof(buf)) return false;
AppendPDFObject(buf);
// CIDFONTTYPE2
n = snprintf(buf, sizeof(buf),
"4 0 obj\n"
"<<\n"
" /BaseFont /GlyphLessFont\n"
" /CIDToGIDMap /Identity\n"
" /CIDSystemInfo\n"
" <<\n"
" /Ordering (Identity)\n"
" /Registry (Adobe)\n"
" /Supplement 0\n"
" >>\n"
" /FontDescriptor %ld 0 R\n"
" /Subtype /CIDFontType2\n"
" /Type /Font\n"
" /DW %d\n"
">>\n"
"endobj\n",
6L, // Font descriptor
1000 / kCharWidth);
if (n >= sizeof(buf)) return false;
AppendPDFObject(buf);
const char *stream =
"/CIDInit /ProcSet findresource begin\n"
"12 dict begin\n"
"begincmap\n"
"/CIDSystemInfo\n"
"<<\n"
" /Registry (Adobe)\n"
" /Ordering (UCS)\n"
" /Supplement 0\n"
">> def\n"
"/CMapName /Adobe-Identify-UCS def\n"
"/CMapType 2 def\n"
"1 begincodespacerange\n"
"<0000> <FFFF>\n"
"endcodespacerange\n"
"1 beginbfrange\n"
"<0000> <FFFF> <0000>\n"
"endbfrange\n"
"endcmap\n"
"CMapName currentdict /CMap defineresource pop\n"
"end\n"
"end\n";
// TOUNICODE
n = snprintf(buf, sizeof(buf),
"5 0 obj\n"
"<< /Length %lu >>\n"
"stream\n"
"%s"
"endstream\n"
"endobj\n", (unsigned long) strlen(stream), stream);
if (n >= sizeof(buf)) return false;
AppendPDFObject(buf);
// FONT DESCRIPTOR
const int kCharHeight = 2; // Effect: highlights are half height
n = snprintf(buf, sizeof(buf),
"6 0 obj\n"
"<<\n"
" /Ascent %d\n"
" /CapHeight %d\n"
" /Descent -1\n" // Spec says must be negative
" /Flags 5\n" // FixedPitch + Symbolic
" /FontBBox [ 0 0 %d %d ]\n"
" /FontFile2 %ld 0 R\n"
" /FontName /GlyphLessFont\n"
" /ItalicAngle 0\n"
" /StemV 80\n"
" /Type /FontDescriptor\n"
">>\n"
"endobj\n",
1000 / kCharHeight,
1000 / kCharHeight,
1000 / kCharWidth,
1000 / kCharHeight,
7L // Font data
);
if (n >= sizeof(buf)) return false;
AppendPDFObject(buf);
n = snprintf(buf, sizeof(buf), "%s/pdf.ttf", datadir_);
if (n >= sizeof(buf)) return false;
FILE *fp = fopen(buf, "rb");
if (!fp)
return false;
fseek(fp, 0, SEEK_END);
long int size = ftell(fp);
fseek(fp, 0, SEEK_SET);
char *buffer = new char[size];
if (fread(buffer, 1, size, fp) != size) {
fclose(fp);
delete[] buffer;
return false;
}
fclose(fp);
// FONTFILE2
n = snprintf(buf, sizeof(buf),
"7 0 obj\n"
"<<\n"
" /Length %ld\n"
" /Length1 %ld\n"
">>\n"
"stream\n", size, size);
if (n >= sizeof(buf)) return false;
AppendString(buf);
size_t objsize = strlen(buf);
AppendData(buffer, size);
delete[] buffer;
objsize += size;
const char *b2 =
"endstream\n"
"endobj\n";
AppendString(b2);
objsize += strlen(b2);
AppendPDFObjectDIY(objsize);
return true;
}
bool TessPDFRenderer::imageToPDFObj(Pix *pix,
char *filename,
long int objnum,
char **pdf_object,
long int *pdf_object_size) {
size_t n;
char b0[kBasicBufSize];
char b1[kBasicBufSize];
char b2[kBasicBufSize];
if (!pdf_object_size || !pdf_object)
return false;
*pdf_object = NULL;
*pdf_object_size = 0;
if (!filename)
return false;
L_COMP_DATA *cid = NULL;
const int kJpegQuality = 85;
// TODO(jbreiden) Leptonica 1.71 doesn't correctly handle certain
// types of PNG files, especially if there are 2 samples per pixel.
// We can get rid of this logic after Leptonica 1.72 is released and
// has propagated everywhere. Bug discussion as follows.
// https://code.google.com/p/tesseract-ocr/issues/detail?id=1300
int format, sad;
findFileFormat(filename, &format);
if (pixGetSpp(pix) == 4 && format == IFF_PNG) {
pixSetSpp(pix, 3);
sad = pixGenerateCIData(pix, L_FLATE_ENCODE, 0, 0, &cid);
} else {
sad = l_generateCIDataForPdf(filename, pix, kJpegQuality, &cid);
}
if (sad || !cid) {
l_CIDataDestroy(&cid);
return false;
}
const char *group4 = "";
const char *filter;
switch(cid->type) {
case L_FLATE_ENCODE:
filter = "/FlateDecode";
break;
case L_JPEG_ENCODE:
filter = "/DCTDecode";
break;
case L_G4_ENCODE:
filter = "/CCITTFaxDecode";
group4 = " /K -1\n";
break;
case L_JP2K_ENCODE:
filter = "/JPXDecode";
break;
default:
l_CIDataDestroy(&cid);
return false;
}
// Maybe someday we will accept RGBA but today is not that day.
// It requires creating an /SMask for the alpha channel.
// http://stackoverflow.com/questions/14220221
const char *colorspace;
if (cid->ncolors > 0) {
n = snprintf(b0, sizeof(b0),
" /ColorSpace [ /Indexed /DeviceRGB %d %s ]\n",
cid->ncolors - 1, cid->cmapdatahex);
if (n >= sizeof(b0)) {
l_CIDataDestroy(&cid);
return false;
}
colorspace = b0;
} else {
switch (cid->spp) {
case 1:
colorspace = " /ColorSpace /DeviceGray\n";
break;
case 3:
colorspace = " /ColorSpace /DeviceRGB\n";
break;
default:
l_CIDataDestroy(&cid);
return false;
}
}
int predictor = (cid->predictor) ? 14 : 1;
// IMAGE
n = snprintf(b1, sizeof(b1),
"%ld 0 obj\n"
"<<\n"
" /Length %ld\n"
" /Subtype /Image\n",
objnum, (unsigned long) cid->nbytescomp);
if (n >= sizeof(b1)) {
l_CIDataDestroy(&cid);
return false;
}
n = snprintf(b2, sizeof(b2),
" /Width %d\n"
" /Height %d\n"
" /BitsPerComponent %d\n"
" /Filter %s\n"
" /DecodeParms\n"
" <<\n"
" /Predictor %d\n"
" /Colors %d\n"
"%s"
" /Columns %d\n"
" /BitsPerComponent %d\n"
" >>\n"
">>\n"
"stream\n",
cid->w, cid->h, cid->bps, filter, predictor, cid->spp,
group4, cid->w, cid->bps);
if (n >= sizeof(b2)) {
l_CIDataDestroy(&cid);
return false;
}
const char *b3 =
"endstream\n"
"endobj\n";
size_t b1_len = strlen(b1);
size_t b2_len = strlen(b2);
size_t b3_len = strlen(b3);
size_t colorspace_len = strlen(colorspace);
*pdf_object_size =
b1_len + colorspace_len + b2_len + cid->nbytescomp + b3_len;
*pdf_object = new char[*pdf_object_size];
if (!pdf_object) {
l_CIDataDestroy(&cid);
return false;
}
char *p = *pdf_object;
memcpy(p, b1, b1_len);
p += b1_len;
memcpy(p, colorspace, colorspace_len);
p += colorspace_len;
memcpy(p, b2, b2_len);
p += b2_len;
memcpy(p, cid->datacomp, cid->nbytescomp);
p += cid->nbytescomp;
memcpy(p, b3, b3_len);
l_CIDataDestroy(&cid);
return true;
}
bool TessPDFRenderer::AddImageHandler(TessBaseAPI* api) {
size_t n;
char buf[kBasicBufSize];
Pix *pix = api->GetInputImage();
char *filename = (char *)api->GetInputName();
int ppi = api->GetSourceYResolution();
if (!pix || ppi <= 0)
return false;
double width = pixGetWidth(pix) * 72.0 / ppi;
double height = pixGetHeight(pix) * 72.0 / ppi;
// PAGE
n = snprintf(buf, sizeof(buf),
"%ld 0 obj\n"
"<<\n"
" /Type /Page\n"
" /Parent %ld 0 R\n"
" /MediaBox [0 0 %.2f %.2f]\n"
" /Contents %ld 0 R\n"
" /Resources\n"
" <<\n"
" /XObject << /Im1 %ld 0 R >>\n"
" /ProcSet [ /PDF /Text /ImageB /ImageI /ImageC ]\n"
" /Font << /f-0-0 %ld 0 R >>\n"
" >>\n"
">>\n"
"endobj\n",
obj_,
2L, // Pages object
width,
height,
obj_ + 1, // Contents object
obj_ + 2, // Image object
3L); // Type0 Font
if (n >= sizeof(buf)) return false;
pages_.push_back(obj_);
AppendPDFObject(buf);
// CONTENTS
char* pdftext = GetPDFTextObjects(api, width, height);
long pdftext_len = strlen(pdftext);
unsigned char *pdftext_casted = reinterpret_cast<unsigned char *>(pdftext);
size_t len;
unsigned char *comp_pdftext =
zlibCompress(pdftext_casted,
pdftext_len,
&len);
long comp_pdftext_len = len;
n = snprintf(buf, sizeof(buf),
"%ld 0 obj\n"
"<<\n"
" /Length %ld /Filter /FlateDecode\n"
">>\n"
"stream\n", obj_, comp_pdftext_len);
if (n >= sizeof(buf)) {
delete[] pdftext;
lept_free(comp_pdftext);
return false;
}
AppendString(buf);
long objsize = strlen(buf);
AppendData(reinterpret_cast<char *>(comp_pdftext), comp_pdftext_len);
objsize += comp_pdftext_len;
lept_free(comp_pdftext);
delete[] pdftext;
const char *b2 =
"endstream\n"
"endobj\n";
AppendString(b2);
objsize += strlen(b2);
AppendPDFObjectDIY(objsize);
char *pdf_object;
if (!imageToPDFObj(pix, filename, obj_, &pdf_object, &objsize)) {
return false;
}
AppendData(pdf_object, objsize);
AppendPDFObjectDIY(objsize);
delete[] pdf_object;
return true;
}
bool TessPDFRenderer::EndDocumentHandler() {
size_t n;
char buf[kBasicBufSize];
// We reserved the /Pages object number early, so that the /Page
// objects could refer to their parent. We finally have enough
// information to go fill it in. Using lower level calls to manipulate
// the offset record in two spots, because we are placing objects
// out of order in the file.
// PAGES
const long int kPagesObjectNumber = 2;
offsets_[kPagesObjectNumber] = offsets_.back(); // manipulation #1
n = snprintf(buf, sizeof(buf),
"%ld 0 obj\n"
"<<\n"
" /Type /Pages\n"
" /Kids [ ", kPagesObjectNumber);
if (n >= sizeof(buf)) return false;
AppendString(buf);
size_t pages_objsize = strlen(buf);
for (size_t i = 0; i < pages_.size(); i++) {
n = snprintf(buf, sizeof(buf),
"%ld 0 R ", pages_[i]);
if (n >= sizeof(buf)) return false;
AppendString(buf);
pages_objsize += strlen(buf);
}
n = snprintf(buf, sizeof(buf),
"]\n"
" /Count %d\n"
">>\n"
"endobj\n", pages_.size());
if (n >= sizeof(buf)) return false;
AppendString(buf);
pages_objsize += strlen(buf);
offsets_.back() += pages_objsize; // manipulation #2
// INFO
char* datestr = l_getFormattedDate();
n = snprintf(buf, sizeof(buf),
"%ld 0 obj\n"
"<<\n"
" /Producer (Tesseract %s)\n"
" /CreationDate (D:%s)\n"
" /Title (%s)"
">>\n"
"endobj\n", obj_, TESSERACT_VERSION_STR, datestr, title());
lept_free(datestr);
if (n >= sizeof(buf)) return false;
AppendPDFObject(buf);
n = snprintf(buf, sizeof(buf),
"xref\n"
"0 %ld\n"
"0000000000 65535 f \n", obj_);
if (n >= sizeof(buf)) return false;
AppendString(buf);
for (int i = 1; i < obj_; i++) {
n = snprintf(buf, sizeof(buf), "%010ld 00000 n \n", offsets_[i]);
if (n >= sizeof(buf)) return false;
AppendString(buf);
}
n = snprintf(buf, sizeof(buf),
"trailer\n"
"<<\n"
" /Size %ld\n"
" /Root %ld 0 R\n"
" /Info %ld 0 R\n"
">>\n"
"startxref\n"
"%ld\n"
"%%%%EOF\n",
obj_,
1L, // catalog
obj_ - 1, // info
offsets_.back());
if (n >= sizeof(buf)) return false;
AppendString(buf);
return true;
}
} // namespace tesseract
Reference in New Issue View Git Blame Copy Permalink