2019-04-25 23:08:17 +02:00

750 lines
17 KiB
C++

// kimgio module for SGI images
//
// Copyright (C) 2004 Melchior FRANZ <mfranz@kde.org>
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the Lesser GNU General Public License as
// published by the Free Software Foundation; either version 2 of the
// License, or (at your option) any later version.
/* this code supports:
* reading:
* everything, except images with 1 dimension or images with
* mapmode != NORMAL (e.g. dithered); Images with 16 bit
* precision or more than 4 layers are stripped down.
* writing:
* Run Length Encoded (RLE) or Verbatim (uncompressed)
* (whichever is smaller)
*
* Please report if you come across rgb/rgba/sgi/bw files that aren't
* recognized. Also report applications that can't deal with images
* saved by this filter.
*/
#include "rgb_p.h"
#include <QMap>
#include <QVector>
#include <QImage>
#include <QDebug>
class RLEData : public QVector<uchar>
{
public:
RLEData() {}
RLEData(const uchar *d, uint l, uint o) : _offset(o)
{
for (uint i = 0; i < l; i++) {
append(d[i]);
}
}
bool operator<(const RLEData &) const;
void write(QDataStream &s);
uint offset() const
{
return _offset;
}
private:
uint _offset;
};
class RLEMap : public QMap<RLEData, uint>
{
public:
RLEMap() : _counter(0), _offset(0) {}
uint insert(const uchar *d, uint l);
QVector<const RLEData *> vector();
void setBaseOffset(uint o)
{
_offset = o;
}
private:
uint _counter;
uint _offset;
};
class SGIImage
{
public:
SGIImage(QIODevice *device);
~SGIImage();
bool readImage(QImage &);
bool writeImage(const QImage &);
private:
enum { NORMAL, DITHERED, SCREEN, COLORMAP }; // colormap
QIODevice *_dev;
QDataStream _stream;
quint8 _rle;
quint8 _bpc;
quint16 _dim;
quint16 _xsize;
quint16 _ysize;
quint16 _zsize;
quint32 _pixmin;
quint32 _pixmax;
char _imagename[80];
quint32 _colormap;
quint32 *_starttab;
quint32 *_lengthtab;
QByteArray _data;
QByteArray::Iterator _pos;
RLEMap _rlemap;
QVector<const RLEData *> _rlevector;
uint _numrows;
bool readData(QImage &);
bool getRow(uchar *dest);
void writeHeader();
void writeRle();
void writeVerbatim(const QImage &);
bool scanData(const QImage &);
uint compact(uchar *, uchar *);
uchar intensity(uchar);
};
SGIImage::SGIImage(QIODevice *io) :
_starttab(nullptr),
_lengthtab(nullptr)
{
_dev = io;
_stream.setDevice(_dev);
}
SGIImage::~SGIImage()
{
delete[] _starttab;
delete[] _lengthtab;
}
///////////////////////////////////////////////////////////////////////////////
bool SGIImage::getRow(uchar *dest)
{
int n, i;
if (!_rle) {
for (i = 0; i < _xsize; i++) {
if (_pos >= _data.end()) {
return false;
}
dest[i] = uchar(*_pos);
_pos += _bpc;
}
return true;
}
for (i = 0; i < _xsize;) {
if (_bpc == 2) {
_pos++;
}
if (_pos >= _data.end()) {
return false;
}
n = *_pos & 0x7f;
if (!n) {
break;
}
if (*_pos++ & 0x80) {
for (; i < _xsize && _pos < _data.end() && n--; i++) {
*dest++ = *_pos;
_pos += _bpc;
}
} else {
for (; i < _xsize && n--; i++) {
*dest++ = *_pos;
}
_pos += _bpc;
}
}
return i == _xsize;
}
bool SGIImage::readData(QImage &img)
{
QRgb *c;
quint32 *start = _starttab;
QByteArray lguard(_xsize, 0);
uchar *line = (uchar *)lguard.data();
unsigned x, y;
if (!_rle) {
_pos = _data.begin();
}
for (y = 0; y < _ysize; y++) {
if (_rle) {
_pos = _data.begin() + *start++;
}
if (!getRow(line)) {
return false;
}
c = (QRgb *)img.scanLine(_ysize - y - 1);
for (x = 0; x < _xsize; x++, c++) {
*c = qRgb(line[x], line[x], line[x]);
}
}
if (_zsize == 1) {
return true;
}
if (_zsize != 2) {
for (y = 0; y < _ysize; y++) {
if (_rle) {
_pos = _data.begin() + *start++;
}
if (!getRow(line)) {
return false;
}
c = (QRgb *)img.scanLine(_ysize - y - 1);
for (x = 0; x < _xsize; x++, c++) {
*c = qRgb(qRed(*c), line[x], line[x]);
}
}
for (y = 0; y < _ysize; y++) {
if (_rle) {
_pos = _data.begin() + *start++;
}
if (!getRow(line)) {
return false;
}
c = (QRgb *)img.scanLine(_ysize - y - 1);
for (x = 0; x < _xsize; x++, c++) {
*c = qRgb(qRed(*c), qGreen(*c), line[x]);
}
}
if (_zsize == 3) {
return true;
}
}
for (y = 0; y < _ysize; y++) {
if (_rle) {
_pos = _data.begin() + *start++;
}
if (!getRow(line)) {
return false;
}
c = (QRgb *)img.scanLine(_ysize - y - 1);
for (x = 0; x < _xsize; x++, c++) {
*c = qRgba(qRed(*c), qGreen(*c), qBlue(*c), line[x]);
}
}
return true;
}
bool SGIImage::readImage(QImage &img)
{
qint8 u8;
qint16 u16;
qint32 u32;
// qDebug() << "reading rgb ";
// magic
_stream >> u16;
if (u16 != 0x01da) {
return false;
}
// verbatim/rle
_stream >> _rle;
// qDebug() << (_rle ? "RLE" : "verbatim");
if (_rle > 1) {
return false;
}
// bytes per channel
_stream >> _bpc;
// qDebug() << "bytes per channel: " << int(_bpc);
if (_bpc == 1)
;
else if (_bpc == 2) {
// qDebug() << "dropping least significant byte";
} else {
return false;
}
// number of dimensions
_stream >> _dim;
// qDebug() << "dimensions: " << _dim;
if (_dim < 1 || _dim > 3) {
return false;
}
_stream >> _xsize >> _ysize >> _zsize >> _pixmin >> _pixmax >> u32;
// qDebug() << "x: " << _xsize;
// qDebug() << "y: " << _ysize;
// qDebug() << "z: " << _zsize;
// name
_stream.readRawData(_imagename, 80);
_imagename[79] = '\0';
_stream >> _colormap;
// qDebug() << "colormap: " << _colormap;
if (_colormap != NORMAL) {
return false; // only NORMAL supported
}
for (int i = 0; i < 404; i++) {
_stream >> u8;
}
if (_dim == 1) {
// qDebug() << "1-dimensional images aren't supported yet";
return false;
}
if (_stream.atEnd()) {
return false;
}
img = QImage(_xsize, _ysize, QImage::Format_RGB32);
if (_zsize == 0 )
return false;
if (_zsize == 2 || _zsize == 4) {
img = img.convertToFormat(QImage::Format_ARGB32);
} else if (_zsize > 4) {
// qDebug() << "using first 4 of " << _zsize << " channels";
// Only let this continue if it won't cause a int overflow later
// this is most likely a broken file anyway
if (_ysize > std::numeric_limits<int>::max() / _zsize)
return false;
}
_numrows = _ysize * _zsize;
if (_rle) {
uint l;
_starttab = new quint32[_numrows];
for (l = 0; !_stream.atEnd() && l < _numrows; l++) {
_stream >> _starttab[l];
_starttab[l] -= 512 + _numrows * 2 * sizeof(quint32);
}
for (; l < _numrows; l++) {
_starttab[l] = 0;
}
_lengthtab = new quint32[_numrows];
for (l = 0; l < _numrows; l++) {
_stream >> _lengthtab[l];
}
}
_data = _dev->readAll();
// sanity check
if (_rle)
for (uint o = 0; o < _numrows; o++)
// don't change to greater-or-equal!
if (_starttab[o] + _lengthtab[o] > (uint)_data.size()) {
// qDebug() << "image corrupt (sanity check failed)";
return false;
}
if (!readData(img)) {
// qDebug() << "image corrupt (incomplete scanline)";
return false;
}
return true;
}
///////////////////////////////////////////////////////////////////////////////
void RLEData::write(QDataStream &s)
{
for (int i = 0; i < size(); i++) {
s << at(i);
}
}
bool RLEData::operator<(const RLEData &b) const
{
uchar ac, bc;
for (int i = 0; i < qMin(size(), b.size()); i++) {
ac = at(i);
bc = b[i];
if (ac != bc) {
return ac < bc;
}
}
return size() < b.size();
}
uint RLEMap::insert(const uchar *d, uint l)
{
RLEData data = RLEData(d, l, _offset);
Iterator it = find(data);
if (it != end()) {
return it.value();
}
_offset += l;
return QMap<RLEData, uint>::insert(data, _counter++).value();
}
QVector<const RLEData *> RLEMap::vector()
{
QVector<const RLEData *> v(size());
for (Iterator it = begin(); it != end(); ++it) {
v.replace(it.value(), &it.key());
}
return v;
}
uchar SGIImage::intensity(uchar c)
{
if (c < _pixmin) {
_pixmin = c;
}
if (c > _pixmax) {
_pixmax = c;
}
return c;
}
uint SGIImage::compact(uchar *d, uchar *s)
{
uchar *dest = d, *src = s, patt, *t, *end = s + _xsize;
int i, n;
while (src < end) {
for (n = 0, t = src; t + 2 < end && !(*t == t[1] && *t == t[2]); t++) {
n++;
}
while (n) {
i = n > 126 ? 126 : n;
n -= i;
*dest++ = 0x80 | i;
while (i--) {
*dest++ = *src++;
}
}
if (src == end) {
break;
}
patt = *src++;
for (n = 1; src < end && *src == patt; src++) {
n++;
}
while (n) {
i = n > 126 ? 126 : n;
n -= i;
*dest++ = i;
*dest++ = patt;
}
}
*dest++ = 0;
return dest - d;
}
bool SGIImage::scanData(const QImage &img)
{
quint32 *start = _starttab;
QByteArray lineguard(_xsize * 2, 0);
QByteArray bufguard(_xsize, 0);
uchar *line = (uchar *)lineguard.data();
uchar *buf = (uchar *)bufguard.data();
const QRgb *c;
unsigned x, y;
uint len;
for (y = 0; y < _ysize; y++) {
c = reinterpret_cast<const QRgb *>(img.scanLine(_ysize - y - 1));
for (x = 0; x < _xsize; x++) {
buf[x] = intensity(qRed(*c++));
}
len = compact(line, buf);
*start++ = _rlemap.insert(line, len);
}
if (_zsize == 1) {
return true;
}
if (_zsize != 2) {
for (y = 0; y < _ysize; y++) {
c = reinterpret_cast<const QRgb *>(img.scanLine(_ysize - y - 1));
for (x = 0; x < _xsize; x++) {
buf[x] = intensity(qGreen(*c++));
}
len = compact(line, buf);
*start++ = _rlemap.insert(line, len);
}
for (y = 0; y < _ysize; y++) {
c = reinterpret_cast<const QRgb *>(img.scanLine(_ysize - y - 1));
for (x = 0; x < _xsize; x++) {
buf[x] = intensity(qBlue(*c++));
}
len = compact(line, buf);
*start++ = _rlemap.insert(line, len);
}
if (_zsize == 3) {
return true;
}
}
for (y = 0; y < _ysize; y++) {
c = reinterpret_cast<const QRgb *>(img.scanLine(_ysize - y - 1));
for (x = 0; x < _xsize; x++) {
buf[x] = intensity(qAlpha(*c++));
}
len = compact(line, buf);
*start++ = _rlemap.insert(line, len);
}
return true;
}
void SGIImage::writeHeader()
{
_stream << quint16(0x01da);
_stream << _rle << _bpc << _dim;
_stream << _xsize << _ysize << _zsize;
_stream << _pixmin << _pixmax;
_stream << quint32(0);
for (int i = 0; i < 80; i++) {
_imagename[i] = '\0';
}
_stream.writeRawData(_imagename, 80);
_stream << _colormap;
for (int i = 0; i < 404; i++) {
_stream << quint8(0);
}
}
void SGIImage::writeRle()
{
_rle = 1;
// qDebug() << "writing RLE data";
writeHeader();
uint i;
// write start table
for (i = 0; i < _numrows; i++) {
_stream << quint32(_rlevector[_starttab[i]]->offset());
}
// write length table
for (i = 0; i < _numrows; i++) {
_stream << quint32(_rlevector[_starttab[i]]->size());
}
// write data
for (i = 0; (int)i < _rlevector.size(); i++) {
const_cast<RLEData *>(_rlevector[i])->write(_stream);
}
}
void SGIImage::writeVerbatim(const QImage &img)
{
_rle = 0;
// qDebug() << "writing verbatim data";
writeHeader();
const QRgb *c;
unsigned x, y;
for (y = 0; y < _ysize; y++) {
c = reinterpret_cast<const QRgb *>(img.scanLine(_ysize - y - 1));
for (x = 0; x < _xsize; x++) {
_stream << quint8(qRed(*c++));
}
}
if (_zsize == 1) {
return;
}
if (_zsize != 2) {
for (y = 0; y < _ysize; y++) {
c = reinterpret_cast<const QRgb *>(img.scanLine(_ysize - y - 1));
for (x = 0; x < _xsize; x++) {
_stream << quint8(qGreen(*c++));
}
}
for (y = 0; y < _ysize; y++) {
c = reinterpret_cast<const QRgb *>(img.scanLine(_ysize - y - 1));
for (x = 0; x < _xsize; x++) {
_stream << quint8(qBlue(*c++));
}
}
if (_zsize == 3) {
return;
}
}
for (y = 0; y < _ysize; y++) {
c = reinterpret_cast<const QRgb *>(img.scanLine(_ysize - y - 1));
for (x = 0; x < _xsize; x++) {
_stream << quint8(qAlpha(*c++));
}
}
}
bool SGIImage::writeImage(const QImage &image)
{
// qDebug() << "writing "; // TODO add filename
QImage img = image;
if (img.allGray()) {
_dim = 2, _zsize = 1;
} else {
_dim = 3, _zsize = 3;
}
if (img.format() == QImage::Format_ARGB32) {
_dim = 3, _zsize++;
}
img = img.convertToFormat(QImage::Format_RGB32);
if (img.isNull()) {
// qDebug() << "can't convert image to depth 32";
return false;
}
_bpc = 1;
_xsize = img.width();
_ysize = img.height();
_pixmin = ~0u;
_pixmax = 0;
_colormap = NORMAL;
_numrows = _ysize * _zsize;
_starttab = new quint32[_numrows];
_rlemap.setBaseOffset(512 + _numrows * 2 * sizeof(quint32));
if (!scanData(img)) {
// qDebug() << "this can't happen";
return false;
}
_rlevector = _rlemap.vector();
long verbatim_size = _numrows * _xsize;
long rle_size = _numrows * 2 * sizeof(quint32);
for (int i = 0; i < _rlevector.size(); i++) {
rle_size += _rlevector[i]->size();
}
// qDebug() << "minimum intensity: " << _pixmin;
// qDebug() << "maximum intensity: " << _pixmax;
// qDebug() << "saved scanlines: " << _numrows - _rlemap.size();
// qDebug() << "total savings: " << (verbatim_size - rle_size) << " bytes";
// qDebug() << "compression: " << (rle_size * 100.0 / verbatim_size) << '%';
if (verbatim_size <= rle_size) {
writeVerbatim(img);
} else {
writeRle();
}
return true;
}
///////////////////////////////////////////////////////////////////////////////
RGBHandler::RGBHandler()
{
}
bool RGBHandler::canRead() const
{
if (canRead(device())) {
setFormat("rgb");
return true;
}
return false;
}
bool RGBHandler::read(QImage *outImage)
{
SGIImage sgi(device());
return sgi.readImage(*outImage);
}
bool RGBHandler::write(const QImage &image)
{
SGIImage sgi(device());
return sgi.writeImage(image);
}
bool RGBHandler::canRead(QIODevice *device)
{
if (!device) {
qWarning("RGBHandler::canRead() called with no device");
return false;
}
const qint64 oldPos = device->pos();
const QByteArray head = device->readLine(64);
int readBytes = head.size();
if (device->isSequential()) {
while (readBytes > 0) {
device->ungetChar(head[readBytes-- - 1]);
}
} else {
device->seek(oldPos);
}
return head.size() >= 4 && head.startsWith("\x01\xda") && (head[2] == 0 || head[2] == 1) && (head[3] == 1 || head[3] == 2);
}
///////////////////////////////////////////////////////////////////////////////
QImageIOPlugin::Capabilities RGBPlugin::capabilities(QIODevice *device, const QByteArray &format) const
{
if (format == "rgb" || format == "rgba" ||
format == "bw" || format == "sgi") {
return Capabilities(CanRead | CanWrite);
}
if (!format.isEmpty()) {
return {};
}
if (!device->isOpen()) {
return {};
}
Capabilities cap;
if (device->isReadable() && RGBHandler::canRead(device)) {
cap |= CanRead;
}
if (device->isWritable()) {
cap |= CanWrite;
}
return cap;
}
QImageIOHandler *RGBPlugin::create(QIODevice *device, const QByteArray &format) const
{
QImageIOHandler *handler = new RGBHandler;
handler->setDevice(device);
handler->setFormat(format);
return handler;
}