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kimageformats/src/imageformats/hdr.cpp
2025-11-22 09:41:25 +01:00

556 lines
17 KiB
C++

/*
This file is part of the KDE project
SPDX-FileCopyrightText: 2005 Christoph Hormann <chris_hormann@gmx.de>
SPDX-FileCopyrightText: 2005 Ignacio Castaño <castanyo@yahoo.es>
SPDX-License-Identifier: LGPL-2.0-or-later
*/
#include "hdr_p.h"
#include "util_p.h"
#include <QColorSpace>
#include <QDataStream>
#include <QFloat16>
#include <QImage>
#include <QLoggingCategory>
#include <QRegularExpressionMatch>
/* *** HDR_HALF_QUALITY ***
* If defined, a 16-bits float image is created, otherwise a 32-bits float ones (default).
*/
//#define HDR_HALF_QUALITY // default commented -> you should define it in your cmake file
/* *** HDR_MAX_IMAGE_WIDTH and HDR_MAX_IMAGE_HEIGHT ***
* The maximum size in pixel allowed by the plugin.
*/
#ifndef HDR_MAX_IMAGE_WIDTH
#define HDR_MAX_IMAGE_WIDTH KIF_LARGE_IMAGE_PIXEL_LIMIT
#endif
#ifndef HDR_MAX_IMAGE_HEIGHT
#define HDR_MAX_IMAGE_HEIGHT HDR_MAX_IMAGE_WIDTH
#endif
typedef unsigned char uchar;
Q_LOGGING_CATEGORY(HDRPLUGIN, "kf.imageformats.plugins.hdr", QtWarningMsg)
#define MAXLINE 1024
#define MINELEN 8 // minimum scanline length for encoding
#define MAXELEN 0x7fff // maximum scanline length for encoding
class Header
{
public:
Header()
{
m_colorSpace = QColorSpace(QColorSpace::SRgbLinear);
m_transformation = QImageIOHandler::TransformationNone;
}
Header(const Header&) = default;
Header& operator=(const Header&) = default;
bool isValid() const
{
return width() > 0 && height() > 0 && width() <= HDR_MAX_IMAGE_WIDTH && height() <= HDR_MAX_IMAGE_HEIGHT;
}
qint32 width() const { return(m_size.width()); }
qint32 height() const { return(m_size.height()); }
QString software() const { return(m_software); }
QImageIOHandler::Transformations transformation() const { return(m_transformation); }
/*!
* \brief colorSpace
*
* The color space for the image.
*
* The CIE (x,y) chromaticity coordinates of the three (RGB)
* primaries and the white point used to standardize the picture's
* color system. This is used mainly by the ra_xyze program to
* convert between color systems. If no PRIMARIES line
* appears, we assume the standard primaries defined in
* src/common/color.h, namely "0.640 0.330 0.290
* 0.600 0.150 0.060 0.333 0.333" for red, green, blue
* and white, respectively.
*/
QColorSpace colorSpace() const { return(m_colorSpace); }
/*!
* \brief exposure
*
* A single floating point number indicating a multiplier that has
* been applied to all the pixels in the file. EXPOSURE values are
* cumulative, so the original pixel values (i.e., radiances in
* watts/steradian/m^2) must be derived by taking the values in the
* file and dividing by all the EXPOSURE settings multiplied
* together. No EXPOSURE setting implies that no exposure
* changes have taken place.
*/
float exposure() const {
float mul = 1;
for (auto&& v : m_exposure)
mul *= v;
return mul;
}
QImageIOHandler::Transformations m_transformation;
QColorSpace m_colorSpace;
QString m_software;
QSize m_size;
QList<float> m_exposure;
};
class HDRHandlerPrivate
{
public:
HDRHandlerPrivate()
{
}
~HDRHandlerPrivate()
{
}
const Header& header(QIODevice *device)
{
auto&& h = m_header;
if (h.isValid()) {
return h;
}
h = readHeader(device);
return h;
}
static Header readHeader(QIODevice *device)
{
Header h;
int cnt = 0;
int len = 0;
QByteArray line(MAXLINE, char());
QByteArray format;
// Parse header
do {
len = device->readLine(line.data(), line.size());
if (len < 0) {
break;
}
if (line.startsWith("FORMAT=")) {
format = line.mid(7, len - 7).trimmed();
}
if (line.startsWith("SOFTWARE=")) {
h.m_software = QString::fromUtf8(line.mid(9, len - 9)).trimmed();
}
if (line.startsWith("EXPOSURE=")) {
auto ok = false;
auto ex = QLocale::c().toFloat(QString::fromLatin1(line.mid(9, len - 9)).trimmed(), &ok);
if (ok)
h.m_exposure << ex;
}
if (line.startsWith("PRIMARIES=")) {
auto list = line.mid(10, len - 10).trimmed().split(' ');
QList<double> primaries;
for (auto&& v : list) {
auto ok = false;
auto d = QLocale::c().toDouble(QString::fromLatin1(v), &ok);
if (ok)
primaries << d;
}
if (primaries.size() == 8) {
auto cs = QColorSpace(QPointF(primaries.at(6), primaries.at(7)),
QPointF(primaries.at(0), primaries.at(1)),
QPointF(primaries.at(2), primaries.at(3)),
QPointF(primaries.at(4), primaries.at(5)),
QColorSpace::TransferFunction::Linear);
cs.setDescription(QStringLiteral("Embedded RGB"));
if (cs.isValid())
h.m_colorSpace = cs;
}
}
} while ((len > 0) && (line[0] != '\n') && (cnt++ < 128));
if (format != "32-bit_rle_rgbe") {
qCDebug(HDRPLUGIN) << "Unknown HDR format:" << format;
return h;
}
len = device->readLine(line.data(), line.size());
if (len < 0) {
qCDebug(HDRPLUGIN) << "Invalid HDR file, error while reading the first line after the header";
return h;
}
line.resize(len);
/*
* Handle flipping and rotation, as per the spec below.
* The single resolution line consists of 4 values, a X and Y label each followed by a numerical
* integer value. The X and Y are immediately preceded by a sign which can be used to indicate
* flipping, the order of the X and Y indicate rotation. The standard coordinate system for
* Radiance images would have the following resolution string -Y N +X N. This indicates that the
* vertical axis runs down the file and the X axis is to the right (imagining the image as a
* rectangular block of data). A -X would indicate a horizontal flip of the image. A +Y would
* indicate a vertical flip. If the X value appears before the Y value then that indicates that
* the image is stored in column order rather than row order, that is, it is rotated by 90 degrees.
* The reader can convince themselves that the 8 combinations cover all the possible image orientations
* and rotations.
*/
QRegularExpression resolutionRegExp(QStringLiteral("([+\\-][XY])\\s+([0-9]+)\\s+([+\\-][XY])\\s+([0-9]+)\n"));
QRegularExpressionMatch match = resolutionRegExp.match(QString::fromLatin1(line));
if (!match.hasMatch()) {
qCDebug(HDRPLUGIN) << "Invalid HDR file, the first line after the header didn't have the expected format:" << line;
return h;
}
auto c0 = match.captured(1);
auto c1 = match.captured(3);
if (c0.at(1) == u'Y') {
if (c0.at(0) == u'-' && c1.at(0) == u'+')
h.m_transformation = QImageIOHandler::TransformationNone;
if (c0.at(0) == u'-' && c1.at(0) == u'-')
h.m_transformation = QImageIOHandler::TransformationMirror;
if (c0.at(0) == u'+' && c1.at(0) == u'+')
h.m_transformation = QImageIOHandler::TransformationFlip;
if (c0.at(0) == u'+' && c1.at(0) == u'-')
h.m_transformation = QImageIOHandler::TransformationRotate180;
}
else {
if (c0.at(0) == u'-' && c1.at(0) == u'+')
h.m_transformation = QImageIOHandler::TransformationRotate90;
if (c0.at(0) == u'-' && c1.at(0) == u'-')
h.m_transformation = QImageIOHandler::TransformationMirrorAndRotate90;
if (c0.at(0) == u'+' && c1.at(0) == u'+')
h.m_transformation = QImageIOHandler::TransformationFlipAndRotate90;
if (c0.at(0) == u'+' && c1.at(0) == u'-')
h.m_transformation = QImageIOHandler::TransformationRotate270;
}
h.m_size = QSize(match.captured(4).toInt(), match.captured(2).toInt());
return h;
}
private:
Header m_header;
};
// read an old style line from the hdr image file
// if 'first' is true the first byte is already read
static bool Read_Old_Line(uchar *image, int width, QDataStream &s)
{
int rshift = 0;
int i;
uchar *start = image;
while (width > 0) {
s >> image[0];
s >> image[1];
s >> image[2];
s >> image[3];
if (s.atEnd()) {
return false;
}
if ((image[0] == 1) && (image[1] == 1) && (image[2] == 1)) {
// NOTE: we don't have an image sample that cover this code
if (rshift > 31) {
return false;
}
for (i = image[3] << rshift; i > 0 && width > 0; i--) {
if (image == start) {
return false; // you cannot be here at the first run
}
// memcpy(image, image-4, 4);
(uint &)image[0] = (uint &)image[0 - 4];
image += 4;
width--;
}
rshift += 8;
} else {
image += 4;
width--;
rshift = 0;
}
}
return true;
}
template<class float_T>
void RGBE_To_QRgbLine(uchar *image, float_T *scanline, const Header& h)
{
auto exposure = h.exposure();
for (int j = 0, width = h.width(); j < width; j++) {
// v = ldexp(1.0, int(image[3]) - 128);
float v;
int e = qBound(-31, int(image[3]) - 128, 31);
if (e > 0) {
v = float(1 << e);
} else {
v = 1.0f / float(1 << -e);
}
auto j4 = j * 4;
auto vn = v / 255.0f;
if (exposure > 0) {
vn /= exposure;
}
scanline[j4] = float_T(float(image[0]) * vn);
scanline[j4 + 1] = float_T(float(image[1]) * vn);
scanline[j4 + 2] = float_T(float(image[2]) * vn);
scanline[j4 + 3] = float_T(1.0f);
image += 4;
}
}
QImage::Format imageFormat()
{
#ifdef HDR_HALF_QUALITY
return QImage::Format_RGBX16FPx4;
#else
return QImage::Format_RGBX32FPx4;
#endif
}
// Load the HDR image.
static bool LoadHDR(QDataStream &s, const Header& h, QImage &img)
{
uchar val;
uchar code;
const int width = h.width();
const int height = h.height();
// Create dst image.
img = imageAlloc(width, height, imageFormat());
if (img.isNull()) {
qCDebug(HDRPLUGIN) << "Couldn't create image with size" << width << height << "and format RGB32";
return false;
}
QByteArray lineArray(4 * width, char());
uchar *image = reinterpret_cast<uchar *>(lineArray.data());
for (int cline = 0; cline < height; cline++) {
#ifdef HDR_HALF_QUALITY
auto scanline = reinterpret_cast<qfloat16 *>(img.scanLine(cline));
#else
auto scanline = reinterpret_cast<float *>(img.scanLine(cline));
#endif
// determine scanline type
if ((width < MINELEN) || (MAXELEN < width)) {
Read_Old_Line(image, width, s);
RGBE_To_QRgbLine(image, scanline, h);
continue;
}
s >> val;
if (s.atEnd()) {
return true;
}
if (val != 2) {
s.device()->ungetChar(val);
Read_Old_Line(image, width, s);
RGBE_To_QRgbLine(image, scanline, h);
continue;
}
s >> image[1];
s >> image[2];
s >> image[3];
if (s.atEnd()) {
return true;
}
if ((image[1] != 2) || (image[2] & 128)) {
image[0] = 2;
Read_Old_Line(image + 4, width - 1, s);
RGBE_To_QRgbLine(image, scanline, h);
continue;
}
if ((image[2] << 8 | image[3]) != width) {
qCDebug(HDRPLUGIN) << "Line of pixels had width" << (image[2] << 8 | image[3]) << "instead of" << width;
return false;
}
// read each component
for (int i = 0, len = int(lineArray.size()); i < 4; i++) {
for (int j = 0; j < width;) {
s >> code;
if (s.atEnd()) {
qCDebug(HDRPLUGIN) << "Truncated HDR file";
return false;
}
if (code > 128) {
// run
code &= 127;
s >> val;
while (code != 0) {
auto idx = i + j * 4;
if (idx < len) {
image[idx] = val;
}
j++;
code--;
}
} else {
// non-run
while (code != 0) {
auto idx = i + j * 4;
if (idx < len) {
s >> image[idx];
}
j++;
code--;
}
}
}
}
RGBE_To_QRgbLine(image, scanline, h);
}
return true;
}
bool HDRHandler::read(QImage *outImage)
{
QDataStream s(device());
const Header& h = d->header(s.device());
if (!h.isValid()) {
return false;
}
QImage img;
if (!LoadHDR(s, h, img)) {
// qCWarning(HDRPLUGIN) << "Error loading HDR file.";
return false;
}
// By setting the linear color space, programs that support profiles display HDR files as in GIMP and Photoshop.
img.setColorSpace(h.colorSpace());
// Metadata
if (!h.software().isEmpty()) {
img.setText(QStringLiteral(META_KEY_SOFTWARE), h.software());
}
*outImage = img;
return true;
}
bool HDRHandler::supportsOption(ImageOption option) const
{
if (option == QImageIOHandler::Size) {
return true;
}
if (option == QImageIOHandler::ImageFormat) {
return true;
}
if (option == QImageIOHandler::ImageTransformation) {
return true;
}
return false;
}
QVariant HDRHandler::option(ImageOption option) const
{
QVariant v;
if (option == QImageIOHandler::Size) {
if (auto dev = device()) {
auto&& h = d->header(dev);
if (h.isValid()) {
v = QVariant::fromValue(h.m_size);
}
}
}
if (option == QImageIOHandler::ImageFormat) {
v = QVariant::fromValue(imageFormat());
}
if (option == QImageIOHandler::ImageTransformation) {
if (auto dev = device()) {
auto&& h = d->header(dev);
if (h.isValid()) {
v = QVariant::fromValue(h.transformation());
}
}
}
return v;
}
HDRHandler::HDRHandler()
: QImageIOHandler()
, d(new HDRHandlerPrivate)
{
}
bool HDRHandler::canRead() const
{
if (canRead(device())) {
setFormat("hdr");
return true;
}
return false;
}
bool HDRHandler::canRead(QIODevice *device)
{
if (!device) {
qCWarning(HDRPLUGIN) << "HDRHandler::canRead() called with no device";
return false;
}
// the .pic taken from official test cases does not start with this string but can be loaded.
if(device->peek(11) == "#?RADIANCE\n" || device->peek(7) == "#?RGBE\n") {
return true;
}
// allow to load offical test cases: https://radsite.lbl.gov/radiance/framed.html
device->startTransaction();
auto h = HDRHandlerPrivate::readHeader(device);
device->rollbackTransaction();
if (h.isValid()) {
return true;
}
return false;
}
QImageIOPlugin::Capabilities HDRPlugin::capabilities(QIODevice *device, const QByteArray &format) const
{
if (format == "hdr") {
return Capabilities(CanRead);
}
if (!format.isEmpty()) {
return {};
}
if (!device->isOpen()) {
return {};
}
Capabilities cap;
if (device->isReadable() && HDRHandler::canRead(device)) {
cap |= CanRead;
}
return cap;
}
QImageIOHandler *HDRPlugin::create(QIODevice *device, const QByteArray &format) const
{
QImageIOHandler *handler = new HDRHandler;
handler->setDevice(device);
handler->setFormat(format);
return handler;
}
#include "moc_hdr_p.cpp"