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/*
This file is part of libextractor.
(C) 2006, 2009 Vidyut Samanta and Christian Grothoff
libextractor is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
by the Free Software Foundation; either version 2, or (at your
option) any later version.
libextractor 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 libextractor; see the file COPYING. If not, write to the
Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.
*/
/**
* @file thumbnailqt_extractor.cc
* @author Nils Durner
* @brief this extractor produces a binary (!) encoded
* thumbnail of images (using Qt).
*/
#include "platform.h"
#include "extractor.h"
#include <Qt/qpixmap.h>
#include <Qt/qbytearray.h>
#include <Qt/qbuffer.h>
#include <Qt/qapplication.h>
#include <pthread.h>
#ifdef HAVE_QT_SVG
#include <Qt/qsvgrenderer.h>
#include <Qt/qpainter.h>
#endif
#define THUMBSIZE 128
extern "C"
{
int
EXTRACTOR_thumbnailqt_extract (const char *data,
size_t size,
EXTRACTOR_MetaDataProcessor proc,
void *proc_cls,
const char *options)
{
QImage *img;
QByteArray bytes;
QBuffer buffer;
unsigned long width;
unsigned long height;
char format[64];
QImage::Format colors;
/* Determine image format to use */
if (options == NULL)
colors = QImage::Format_Indexed8;
else
switch (atoi(options))
{
case 1:
colors = QImage::Format_Mono;
break;
case 8:
colors = QImage::Format_Indexed8;
break;
case 16:
case 24:
colors = QImage::Format_RGB32;
break;
default:
colors = QImage::Format_ARGB32;
break;
}
QByteArray din (data, (int) size);
#ifdef HAVE_QT_SVG
/* Render SVG image */
QSvgRenderer svg;
QSize qsize;
if (svg.load(din))
{
qsize = svg.defaultSize();
img = new QImage(qsize, QImage::Format_ARGB32);
QPainter painter(img);
painter.setViewport(0, 0, qsize.width(), qsize.height());
painter.eraseRect(0, 0, qsize.width(), qsize.height());
svg.render(&painter);
}
else
#endif
{
/* Load image */
img = new QImage();
img->loadFromData(din);
}
height = img->height();
width = img->width();
snprintf(format,
sizeof(format),
"%ux%u",
(unsigned int) width,
(unsigned int) height);
if (0 != proc (proc_cls,
"thumbnailqt",
EXTRACTOR_METATYPE_IMAGE_DIMENSIONS,
EXTRACTOR_METAFORMAT_UTF8,
"text/plain",
format,
strlen(format)+1))
{
delete img;
return 1;
}
if (height == 0)
height = 1;
if (width == 0)
width = 1;
/* Change color depth */
QImage thumb = img->convertToFormat(colors);
delete img;
/* Resize image
*
* Qt's scaled() produces poor quality if the image is resized to less than
* half the size. Therefore, we resize the image in multiple steps.
* http://lists.trolltech.com/qt-interest/2006-04/msg00376.html */
while ( (width > THUMBSIZE) || (height > THUMBSIZE) )
{
width /= 2;
if (width < THUMBSIZE)
width = THUMBSIZE;
height /= 2;
if (height < THUMBSIZE)
height = THUMBSIZE;
thumb = thumb.scaled(width,
height,
Qt::KeepAspectRatio,
Qt::SmoothTransformation);
}
buffer.setBuffer(&bytes);
buffer.open(QIODevice::WriteOnly);
thumb.save(&buffer, "PNG");
return proc (proc_cls,
"thumbnailqt",
EXTRACTOR_METATYPE_THUMBNAIL,
EXTRACTOR_METAFORMAT_BINARY,
"image/png",
bytes.data(),
bytes.length());
}
int
EXTRACTOR_thumbnail_extract (const unsigned char *data,
size_t size,
EXTRACTOR_MetaDataProcessor proc,
void *proc_cls,
const char *options)
{
return EXTRACTOR_thumbnail_extract (data, size, proc, proc_cls, options);
}
} // extern "C"
/* end of thumbnailqt_extractor.cc */
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