153 lines
4.5 KiB
C++
153 lines
4.5 KiB
C++
//=============================================================================
|
|
// MusE Reader
|
|
// Music Score Reader
|
|
//
|
|
// Copyright (C) 2010 Werner Schweer
|
|
//
|
|
// This program is free software; you can redistribute it and/or modify
|
|
// it under the terms of the GNU General Public License version 2.
|
|
//
|
|
// This program is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU General Public License
|
|
// along with this program; if not, write to the Free Software
|
|
// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
//=============================================================================
|
|
|
|
#include "pdf.h"
|
|
|
|
namespace Ms {
|
|
|
|
|
|
int Pdf::references;
|
|
|
|
//---------------------------------------------------------
|
|
// numPages
|
|
//---------------------------------------------------------
|
|
|
|
int Pdf::numPages() const
|
|
{
|
|
return _document->numPages();
|
|
}
|
|
|
|
//---------------------------------------------------------
|
|
// Pdf
|
|
//---------------------------------------------------------
|
|
|
|
Pdf::Pdf()
|
|
{
|
|
++references;
|
|
}
|
|
|
|
//---------------------------------------------------------
|
|
// open
|
|
//---------------------------------------------------------
|
|
|
|
bool Pdf::open(const QString& path)
|
|
{
|
|
_document = Poppler::Document::load(path);
|
|
if (!_document || _document->isLocked()) {
|
|
delete _document;
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
//---------------------------------------------------------
|
|
// ~Pdf
|
|
//---------------------------------------------------------
|
|
|
|
Pdf::~Pdf()
|
|
{
|
|
if(_document)
|
|
delete(_document);
|
|
--references;
|
|
}
|
|
|
|
//---------------------------------------------------------
|
|
// binarization
|
|
//---------------------------------------------------------
|
|
|
|
QImage Pdf::binarization(QImage image){
|
|
QImage bw = QImage(image.width(), image.height(), QImage::Format_MonoLSB);
|
|
QVector<QRgb> ct(2);
|
|
ct[0] = qRgb(255, 255, 255);
|
|
ct[1] = qRgb(0, 0, 0);
|
|
bw.setColorTable(ct);
|
|
bw.fill(0);
|
|
float thresh = 128;
|
|
float new_thresh = 0;
|
|
|
|
while (thresh != new_thresh) {
|
|
float sum_black = 0;
|
|
float sum_white = 0;
|
|
int num_black = 0;
|
|
int num_white = 0;
|
|
new_thresh = thresh;
|
|
for (int x = 0; x < image.width(); x++){
|
|
for (int y = 0; y < image.height(); y++) {
|
|
QRgb c = image.pixel(x, y);
|
|
float g = qGray(c);
|
|
if (g < thresh) {
|
|
sum_black += g;
|
|
num_black++;
|
|
}
|
|
else {
|
|
sum_white += g;
|
|
num_white++;
|
|
}
|
|
|
|
}
|
|
}
|
|
thresh = (sum_black/num_black + sum_white/num_white)/2.0;
|
|
}
|
|
|
|
int stride = (bw.width() + 7) / 8;
|
|
uchar* p = bw.bits();
|
|
|
|
for (int y = 0; y < bw.height(); ++y) {
|
|
p = bw.scanLine(y);
|
|
for (int x = 0; x < stride; ++x) {
|
|
int temp = 0;
|
|
for (int i = 0; i < 8; i++) {
|
|
if (x*8 + i >= bw.width()) continue;
|
|
QRgb c = image.pixel(x*8 + i, y);
|
|
float g = qGray(c);
|
|
temp += ((g<thresh) ? 1:0)<<i;
|
|
}
|
|
*p++ = temp;
|
|
}
|
|
}
|
|
return bw;
|
|
}
|
|
|
|
//---------------------------------------------------------
|
|
// page
|
|
//---------------------------------------------------------
|
|
|
|
QImage Pdf::page(int i)
|
|
{
|
|
QImage image;
|
|
// Paranoid safety check
|
|
if (_document == 0) {
|
|
return image;
|
|
}
|
|
|
|
Poppler::Page* pdfPage = _document->page(i); // Document starts at page 0
|
|
if (pdfPage == 0) {
|
|
return image;
|
|
}
|
|
|
|
QSize size = pdfPage->pageSize();
|
|
float scale = 2.0;
|
|
// the size can be decided more intelligently
|
|
image = pdfPage->renderToImage(scale*72.0, scale*72.0, 0, 0, scale*size.width(), scale*size.height());
|
|
delete pdfPage;
|
|
return binarization(image);
|
|
}
|
|
}
|
|
|