Full range HDR support

EXR, HDR, JXR and PFM formats support High Dynamic Range images (FP values grater than 1).

In summary, here is the list of changes:

    EXR, HDR, JXR and PFM: When working with FP formats, the clamp between 0 and 1 ​​is no longer done.
    EXR: Removed old SDR code and conversions. Due to the lack of a QImage Gray FP format, Gray images are output as RGB FP (recently added code for Qt 6.8 has been removed).
    PFM: Due to the lack of a QImage Gray FP format, Gray images are output as RGB FP.
    HDR: Added rotation and exposure support.

With this patch, EXR, JXR, HDR, PFM behave like Qt's TIFF plugin when working with FP images.

.gitattributes

@@ -1 +1,13 @@
 autotests/read/raw/RAW_KODAK_C330_FORMAT_NONE_YRGB.raw binary
+autotests/read/hdr/orientation1.hdr binary
+autotests/read/hdr/orientation2.hdr binary
+autotests/read/hdr/orientation3.hdr binary
+autotests/read/hdr/orientation4.hdr binary
+autotests/read/hdr/orientation5.hdr binary
+autotests/read/hdr/orientation6.hdr binary
+autotests/read/hdr/orientation7.hdr binary
+autotests/read/hdr/orientation8.hdr binary
+autotests/read/hdr/fake_earth.hdr binary
+autotests/read/hdr/rgb.hdr binary
+autotests/read/hdr/rgb-landscape.hdr binary
+autotests/read/hdr/rgb-portrait.hdr binary

autotests/read/hdr/orientation1.hdr.json

@@ -0,0 +1,5 @@
+[
+    {
+        "fileName" : "orientation_all.png"
+    }
+]

autotests/read/hdr/orientation2.hdr.json

@@ -0,0 +1,5 @@
+[
+    {
+        "fileName" : "orientation_all.png"
+    }
+]

autotests/read/hdr/orientation3.hdr.json

@@ -0,0 +1,5 @@
+[
+    {
+        "fileName" : "orientation_all.png"
+    }
+]

autotests/read/hdr/orientation4.hdr.json

@@ -0,0 +1,5 @@
+[
+    {
+        "fileName" : "orientation_all.png"
+    }
+]

autotests/read/hdr/orientation5.hdr.json

@@ -0,0 +1,5 @@
+[
+    {
+        "fileName" : "orientation_all.png"
+    }
+]

autotests/read/hdr/orientation6.hdr.json

@@ -0,0 +1,5 @@
+[
+    {
+        "fileName" : "orientation_all.png"
+    }
+]

autotests/read/hdr/orientation7.hdr.json

@@ -0,0 +1,5 @@
+[
+    {
+        "fileName" : "orientation_all.png"
+    }
+]

autotests/read/hdr/orientation8.hdr.json

@@ -0,0 +1,5 @@
+[
+    {
+        "fileName" : "orientation_all.png"
+    }
+]

autotests/readtest.cpp

@@ -177,7 +177,8 @@ public:
     {
         bool ok = true;
         if (!m_size.isEmpty()) {
-            ok = ok && (m_size == image.size());
+            // Size option return the size without transformation (tested with Qt TIFF plugin).
+            ok = ok && (m_size == image.size() || m_size == image.size().transposed());
         }
         if (m_format != QImage::Format_Invalid) {
             ok = ok && (m_format == image.format());

src/imageformats/exr.cpp

@@ -7,20 +7,11 @@
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
-/* *** EXR_USE_LEGACY_CONVERSIONS ***
- * If defined, the result image is an 8-bit RGB(A) converted
- * without icc profiles. Otherwise, a 16-bit images is generated.
- * NOTE: The use of legacy conversions are discouraged due to
- *       imprecise image result.
- */
-//#define EXR_USE_LEGACY_CONVERSIONS // default commented -> you should define it in your cmake file
-
 /* *** EXR_CONVERT_TO_SRGB ***
  * If defined, the linear data is converted to sRGB on read to accommodate
  * programs that do not support color profiles.
  * Otherwise the data are kept as is and it is the display program that
  * must convert to the monitor profile.
- * NOTE: If EXR_USE_LEGACY_CONVERSIONS is active, this is ignored.
  */
 //#define EXR_CONVERT_TO_SRGB // default: commented -> you should define it in your cmake file
 
@@ -92,18 +83,6 @@
 #include <QThread>
 #include <QTimeZone>
 
-// Allow the code to works on all QT versions supported by KDE
-// project (Qt 5.15 and Qt 6.x) to easy backports fixes.
-#if !defined(EXR_USE_LEGACY_CONVERSIONS)
-// If uncommented, the image is rendered in a float16 format, the result is very precise
-#define EXR_USE_QT6_FLOAT_IMAGE // default uncommented
-#endif
-
-// Qt 6.8 allow to create and use Gray profile, so we can load a Gray image as Grayscale format instead RGB one.
-#if QT_VERSION >= QT_VERSION_CHECK(6, 8, 0)
-#define EXR_GRAY_SUPPORT_ENABLED
-#endif
-
 class K_IStream : public Imf::IStream
 {
 public:
@@ -214,22 +193,6 @@ void K_OStream::seekg(Imf::Int64 pos)
     m_dev->seek(pos);
 }
 
-#ifdef EXR_USE_LEGACY_CONVERSIONS
-// source: https://openexr.com/en/latest/ReadingAndWritingImageFiles.html
-inline unsigned char gamma(float x)
-{
-    x = std::pow(5.5555f * std::max(0.f, x), 0.4545f) * 84.66f;
-    return (unsigned char)qBound(0.f, x, 255.f);
-}
-inline QRgb RgbaToQrgba(struct Imf::Rgba &imagePixel)
-{
-    return qRgba(gamma(float(imagePixel.r)),
-                 gamma(float(imagePixel.g)),
-                 gamma(float(imagePixel.b)),
-                 (unsigned char)(qBound(0.f, imagePixel.a * 255.f, 255.f) + 0.5f));
-}
-#endif
-
 EXRHandler::EXRHandler()
     : m_compressionRatio(-1)
     , m_quality(-1)
@@ -253,18 +216,7 @@ bool EXRHandler::canRead() const
 static QImage::Format imageFormat(const Imf::RgbaInputFile &file)
 {
     auto isRgba = file.channels() & Imf::RgbaChannels::WRITE_A;
-#ifdef EXR_GRAY_SUPPORT_ENABLED
-    auto isGray = file.channels() & Imf::RgbaChannels::WRITE_Y;
-#else
-    auto isGray = false;
-#endif
-#if defined(EXR_USE_LEGACY_CONVERSIONS)
-    return (isRgba ? QImage::Format_ARGB32 : QImage::Format_RGB32);
-#elif defined(EXR_USE_QT6_FLOAT_IMAGE)
-    return (isRgba ? QImage::Format_RGBA16FPx4 : isGray ? QImage::Format_Grayscale16 : QImage::Format_RGBX16FPx4);
-#else
-    return (isRgba ? QImage::Format_RGBA64 : QImage::Format_RGBX64);
-#endif
+    return (isRgba ? QImage::Format_RGBA16FPx4 : QImage::Format_RGBX16FPx4);
 }
 
 /*!
@@ -371,8 +323,6 @@ static void readMetadata(const Imf::Header &header, QImage &image)
 static void readColorSpace(const Imf::Header &header, QImage &image)
 {
     // final color operations
-#ifndef EXR_USE_LEGACY_CONVERSIONS
-
     QColorSpace cs;
     if (auto chroma = header.findTypedAttribute<Imf::ChromaticitiesAttribute>("chromaticities")) {
         auto &&v = chroma->value();
@@ -383,24 +333,13 @@ static void readColorSpace(const Imf::Header &header, QImage &image)
                          QColorSpace::TransferFunction::Linear);
     }
     if (!cs.isValid()) {
-#ifdef EXR_GRAY_SUPPORT_ENABLED
-        if (image.format() == QImage::Format_Grayscale16 || image.format() == QImage::Format_Grayscale8) {
-            cs = QColorSpace(QPointF(0.31271, 0.32902), QColorSpace::TransferFunction::Linear);
-            cs.setDescription(QStringLiteral("Gray Linear build-in"));
-        } else {
-            cs = QColorSpace(QColorSpace::SRgbLinear);
-        }
-#else
         cs = QColorSpace(QColorSpace::SRgbLinear);
-#endif
     }
     image.setColorSpace(cs);
 
 #ifdef EXR_CONVERT_TO_SRGB
     image.convertToColorSpace(QColorSpace(QColorSpace::SRgb));
 #endif
-
-#endif // !EXR_USE_LEGACY_CONVERSIONS
 }
 
 bool EXRHandler::read(QImage *outImage)
@@ -451,7 +390,6 @@ bool EXRHandler::read(QImage *outImage)
         pixels.resizeErase(EXR_LINES_PER_BLOCK, width);
         bool isRgba = image.hasAlphaChannel();
 
-        // somehow copy pixels into image
         for (int y = 0, n = 0; y < height; y += n) {
             auto my = dw.min.y + y;
             if (my > dw.max.y) { // paranoia check
@@ -462,37 +400,14 @@ bool EXRHandler::read(QImage *outImage)
             file.readPixels(my, std::min(my + EXR_LINES_PER_BLOCK - 1, dw.max.y));
 
             for (n = 0; n < std::min(EXR_LINES_PER_BLOCK, height - y); ++n) {
-                if (image.format() == QImage::Format_Grayscale16) { // grayscale image
-                    auto scanLine = reinterpret_cast<quint16 *>(image.scanLine(y + n));
-                    for (int x = 0; x < width; ++x) {
-                        *(scanLine + x) = quint16(qBound(0.f, float(pixels[n][x].r) * 65535.f + 0.5f, 65535.f));
-                    }
-                    continue;
-                }
-#if defined(EXR_USE_LEGACY_CONVERSIONS)
-                Q_UNUSED(isRgba)
-                auto scanLine = reinterpret_cast<QRgb *>(image.scanLine(y + n));
-                for (int x = 0; x < width; ++x) {
-                    *(scanLine + x) = RgbaToQrgba(pixels[n][x]);
-                }
-#elif defined(EXR_USE_QT6_FLOAT_IMAGE)
                 auto scanLine = reinterpret_cast<qfloat16 *>(image.scanLine(y + n));
                 for (int x = 0; x < width; ++x) {
                     auto xcs = x * 4;
-                    *(scanLine + xcs) = qfloat16(qBound(0.f, float(pixels[n][x].r), 1.f));
-                    *(scanLine + xcs + 1) = qfloat16(qBound(0.f, float(pixels[n][x].g), 1.f));
-                    *(scanLine + xcs + 2) = qfloat16(qBound(0.f, float(pixels[n][x].b), 1.f));
-                    *(scanLine + xcs + 3) = qfloat16(isRgba ? qBound(0.f, float(pixels[n][x].a), 1.f) : 1.f);
+                    *(scanLine + xcs) = qfloat16(float(pixels[n][x].r));
+                    *(scanLine + xcs + 1) = qfloat16(float(pixels[n][x].g));
+                    *(scanLine + xcs + 2) = qfloat16(float(pixels[n][x].b));
+                    *(scanLine + xcs + 3) = qfloat16(isRgba ? std::clamp(float(pixels[n][x].a), 0.f, 1.f) : 1.f);
                 }
-#else
-                auto scanLine = reinterpret_cast<QRgba64 *>(image.scanLine(y + n));
-                for (int x = 0; x < width; ++x) {
-                    *(scanLine + x) = QRgba64::fromRgba64(quint16(qBound(0.f, float(pixels[n][x].r) * 65535.f + 0.5f, 65535.f)),
-                                                          quint16(qBound(0.f, float(pixels[n][x].g) * 65535.f + 0.5f, 65535.f)),
-                                                          quint16(qBound(0.f, float(pixels[n][x].b) * 65535.f + 0.5f, 65535.f)),
-                                                          isRgba ? quint16(qBound(0.f, float(pixels[n][x].a) * 65535.f + 0.5f, 65535.f)) : quint16(65535));
-                }
-#endif
             }
         }
 
@@ -659,26 +574,12 @@ bool EXRHandler::write(const QImage &image)
         pixels.resizeErase(EXR_LINES_PER_BLOCK, width);
 
         // convert the image and write into the stream
-#if defined(EXR_USE_QT6_FLOAT_IMAGE)
         auto convFormat = image.hasAlphaChannel() ? QImage::Format_RGBA16FPx4 : QImage::Format_RGBX16FPx4;
-#else
-        auto convFormat = image.hasAlphaChannel() ? QImage::Format_RGBA64 : QImage::Format_RGBX64;
-#endif
         ScanLineConverter slc(convFormat);
-#ifdef EXR_GRAY_SUPPORT_ENABLED
-        if (channelsType == Imf::RgbaChannels::WRITE_Y) {
-            slc.setDefaultSourceColorSpace(QColorSpace(QColorSpace(QColorSpace::SRgb).whitePoint(), QColorSpace::TransferFunction::SRgb)); // Creates a custom grayscale color space
-        } else {
-            slc.setDefaultSourceColorSpace(QColorSpace(QColorSpace::SRgb));
-        }
-#else
         slc.setDefaultSourceColorSpace(QColorSpace(QColorSpace::SRgb));
-#endif
-
         slc.setTargetColorSpace(QColorSpace(QColorSpace::SRgbLinear));
         for (int y = 0, n = 0; y < height; y += n) {
             for (n = 0; n < std::min(EXR_LINES_PER_BLOCK, height - y); ++n) {
-#if defined(EXR_USE_QT6_FLOAT_IMAGE)
                 auto scanLine = reinterpret_cast<const qfloat16 *>(slc.convertedScanLine(image, y + n));
                 if (scanLine == nullptr) {
                     return false;
@@ -690,18 +591,6 @@ bool EXRHandler::write(const QImage &image)
                     pixels[n][x].b = float(*(scanLine + xcs + 2));
                     pixels[n][x].a = float(*(scanLine + xcs + 3));
                 }
-#else
-                auto scanLine = reinterpret_cast<const QRgba64 *>(slc.convertedScanLine(image, y + n));
-                if (scanLine == nullptr) {
-                    return false;
-                }
-                for (int x = 0; x < width; ++x) {
-                    pixels[n][x].r = float((scanLine + x)->red() / 65535.f);
-                    pixels[n][x].g = float((scanLine + x)->green() / 65535.f);
-                    pixels[n][x].b = float((scanLine + x)->blue() / 65535.f);
-                    pixels[n][x].a = float((scanLine + x)->alpha() / 65535.f);
-                }
-#endif
             }
             file.setFrameBuffer(&pixels[0][0] - qint64(y) * width, 1, width);
             file.writePixels(n);

src/imageformats/hdr.cpp

@@ -27,12 +27,194 @@ typedef unsigned char uchar;
 
 Q_LOGGING_CATEGORY(HDRPLUGIN, "kf.imageformats.plugins.hdr", QtWarningMsg)
 
-namespace // Private.
-{
 #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; }
+    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 len;
+        QByteArray line(MAXLINE + 1, Qt::Uninitialized);
+        QByteArray format;
+
+        // Parse header
+        do {
+            len = device->readLine(line.data(), MAXLINE);
+
+            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'));
+
+        if (format != "32-bit_rle_rgbe") {
+            qCDebug(HDRPLUGIN) << "Unknown HDR format:" << format;
+            return h;
+        }
+
+        len = device->readLine(line.data(), MAXLINE);
+        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)
@@ -76,9 +258,10 @@ static bool Read_Old_Line(uchar *image, int width, QDataStream &s)
 }
 
 template<class float_T>
-void RGBE_To_QRgbLine(uchar *image, float_T *scanline, int width)
+void RGBE_To_QRgbLine(uchar *image, float_T *scanline, const Header& h)
 {
-    for (int j = 0; j < width; j++) {
+    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);
@@ -90,9 +273,13 @@ void RGBE_To_QRgbLine(uchar *image, float_T *scanline, int width)
 
         auto j4 = j * 4;
         auto vn = v / 255.0f;
-        scanline[j4] = float_T(std::min(float(image[0]) * vn, 1.0f));
-        scanline[j4 + 1] = float_T(std::min(float(image[1]) * vn, 1.0f));
-        scanline[j4 + 2] = float_T(std::min(float(image[2]) * vn, 1.0f));
+        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;
     }
@@ -108,11 +295,14 @@ QImage::Format imageFormat()
 }
 
 // Load the HDR image.
-static bool LoadHDR(QDataStream &s, const int width, const int height, QImage &img)
+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()) {
@@ -134,7 +324,7 @@ static bool LoadHDR(QDataStream &s, const int width, const int height, QImage &i
         // determine scanline type
         if ((width < MINELEN) || (MAXELEN < width)) {
             Read_Old_Line(image, width, s);
-            RGBE_To_QRgbLine(image, scanline, width);
+            RGBE_To_QRgbLine(image, scanline, h);
             continue;
         }
 
@@ -147,7 +337,7 @@ static bool LoadHDR(QDataStream &s, const int width, const int height, QImage &i
         if (val != 2) {
             s.device()->ungetChar(val);
             Read_Old_Line(image, width, s);
-            RGBE_To_QRgbLine(image, scanline, width);
+            RGBE_To_QRgbLine(image, scanline, h);
             continue;
         }
 
@@ -162,7 +352,7 @@ static bool LoadHDR(QDataStream &s, const int width, const int height, QImage &i
         if ((image[1] != 2) || (image[2] & 128)) {
             image[0] = 2;
             Read_Old_Line(image + 4, width - 1, s);
-            RGBE_To_QRgbLine(image, scanline, width);
+            RGBE_To_QRgbLine(image, scanline, h);
             continue;
         }
 
@@ -204,84 +394,34 @@ static bool LoadHDR(QDataStream &s, const int width, const int height, QImage &i
                 }
             }
         }
-
-        RGBE_To_QRgbLine(image, scanline, width);
+        RGBE_To_QRgbLine(image, scanline, h);
     }
 
     return true;
 }
 
-static QSize readHeaderSize(QIODevice *device)
-{
-    int len;
-    QByteArray line(MAXLINE + 1, Qt::Uninitialized);
-    QByteArray format;
-
-    // Parse header
-    do {
-        len = device->readLine(line.data(), MAXLINE);
-
-        if (line.startsWith("FORMAT=")) {
-            format = line.mid(7, len - 7 - 1 /*\n*/);
-        }
-
-    } while ((len > 0) && (line[0] != '\n'));
-
-    if (format != "32-bit_rle_rgbe") {
-        qCDebug(HDRPLUGIN) << "Unknown HDR format:" << format;
-        return QSize();
-    }
-
-    len = device->readLine(line.data(), MAXLINE);
-    line.resize(len);
-
-    /*
-       TODO: 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]) ([0-9]+) ([+\\-][XY]) ([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 QSize();
-    }
-
-    if ((match.captured(1).at(1) != u'Y') || (match.captured(3).at(1) != u'X')) {
-        qCDebug(HDRPLUGIN) << "Unsupported image orientation in HDR file.";
-        return QSize();
-    }
-
-    return QSize(match.captured(4).toInt(), match.captured(2).toInt());
-}
-
-} // namespace
-
 bool HDRHandler::read(QImage *outImage)
 {
     QDataStream s(device());
 
-    m_imageSize = readHeaderSize(s.device());
-    if (!m_imageSize.isValid()) {
+    const Header& h = d->header(s.device());
+    if (!h.isValid()) {
         return false;
     }
 
     QImage img;
-    if (!LoadHDR(s, m_imageSize.width(), m_imageSize.height(), img)) {
+    if (!LoadHDR(s, h, img)) {
         // qDebug() << "Error loading HDR file.";
         return false;
     }
-    // The images read by Gimp and Photoshop (including those of the tests) are interpreted with linear color space.
+
     // By setting the linear color space, programs that support profiles display HDR files as in GIMP and Photoshop.
-    img.setColorSpace(QColorSpace(QColorSpace::SRgbLinear));
+    img.setColorSpace(h.colorSpace());
+
+    // Metadata
+    if (!h.software().isEmpty()) {
+        img.setText(QStringLiteral(META_KEY_SOFTWARE), h.software());
+    }
 
     *outImage = img;
     return true;
@@ -295,6 +435,9 @@ bool HDRHandler::supportsOption(ImageOption option) const
     if (option == QImageIOHandler::ImageFormat) {
         return true;
     }
+    if (option == QImageIOHandler::ImageTransformation) {
+        return true;
+    }
     return false;
 }
 
@@ -303,15 +446,10 @@ QVariant HDRHandler::option(ImageOption option) const
     QVariant v;
 
     if (option == QImageIOHandler::Size) {
-        if (!m_imageSize.isEmpty()) {
-            v = QVariant::fromValue(m_imageSize);
-        } else if (auto d = device()) {
-            // transactions works on both random and sequential devices
-            d->startTransaction();
-            auto size = readHeaderSize(d);
-            d->rollbackTransaction();
-            if (size.isValid()) {
-                v = QVariant::fromValue(size);
+        if (auto dev = device()) {
+            auto&& h = d->header(dev);
+            if (h.isValid()) {
+                v = QVariant::fromValue(h.m_size);
             }
         }
     }
@@ -320,10 +458,21 @@ QVariant HDRHandler::option(ImageOption option) const
         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)
 {
 }
 
@@ -350,9 +499,9 @@ bool HDRHandler::canRead(QIODevice *device)
 
     // allow to load offical test cases: https://radsite.lbl.gov/radiance/framed.html
     device->startTransaction();
-    QSize size = readHeaderSize(device);
+    auto h = HDRHandlerPrivate::readHeader(device);
     device->rollbackTransaction();
-    if (size.isValid()) {
+    if (h.isValid()) {
         return true;
     }
 

src/imageformats/hdr_p.h

@@ -9,7 +9,9 @@
 #define KIMG_HDR_P_H
 
 #include <QImageIOPlugin>
+#include <QScopedPointer>
 
+class HDRHandlerPrivate;
 class HDRHandler : public QImageIOHandler
 {
 public:
@@ -24,11 +26,7 @@ public:
     static bool canRead(QIODevice *device);
 
 private:
-    /*!
-     * \brief m_imageSize
-     * Image size cache used by option()
-     */
-    QSize m_imageSize;
+    const QScopedPointer<HDRHandlerPrivate> d;
 };
 
 class HDRPlugin : public QImageIOPlugin

src/imageformats/jxr.cpp

@@ -436,6 +436,13 @@ public:
 #if QT_VERSION >= QT_VERSION_CHECK(6, 8, 0)
             << QImage::Format_CMYK8888
 #endif
+#ifndef JXR_DENY_FLOAT_IMAGE
+            << QImage::Format_RGBA16FPx4
+            << QImage::Format_RGBX16FPx4
+            << QImage::Format_RGBA32FPx4
+            << QImage::Format_RGBA32FPx4_Premultiplied
+            << QImage::Format_RGBX32FPx4
+#endif // JXR_DENY_FLOAT_IMAGE
             << QImage::Format_RGBA64
             << QImage::Format_RGBA64_Premultiplied
             << QImage::Format_RGBA8888
@@ -476,7 +483,18 @@ public:
             } else {
                 qi = qi.convertToFormat(alpha ? QImage::Format_RGBA8888 : QImage::Format_RGB888);
             }
+#ifndef JXR_DENY_FLOAT_IMAGE
+        } else if(qi.format() == QImage::Format_RGBA16FPx4 ||
+                  qi.format() == QImage::Format_RGBX16FPx4 ||
+                  qi.format() == QImage::Format_RGBA32FPx4 ||
+                  qi.format() == QImage::Format_RGBA32FPx4_Premultiplied ||
+                  qi.format() == QImage::Format_RGBX32FPx4) {
+            auto cs = qi.colorSpace();
+            if (cs.isValid() && cs.transferFunction() != QColorSpace::TransferFunction::Linear) {
+                qi = qi.convertedToColorSpace(QColorSpace(QColorSpace::SRgbLinear));
+            }
         }
+#endif // JXR_DENY_FLOAT_IMAGE
 
         return qi;
     }
@@ -759,35 +777,6 @@ private:
     }
 };
 
-template<class T>
-inline T scRGBTosRGB(T f)
-{
-    // convert from linear scRGB to non-linear sRGB
-    if (f <= T(0)) {
-        return T(0);
-    }
-    if (f <= T(0.0031308f)) {
-        return qBound(T(0), f * T(12.92f), T(1));
-    }
-    if (f < T(1)) {
-        return qBound(T(0), T(1.055f) * T(pow(f, T(1.0) / T(2.4))) - T(0.055), T(1));
-    }
-    return T(1);
-}
-
-template<class T>
-inline T alpha_scRGBTosRGB(T f)
-{
-    // alpha is converted differently than RGB in scRGB
-    if (f <= T(0)) {
-        return T(0);
-    }
-    if (f < T(1.0)) {
-        return T(f);
-    }
-    return T(1);
-}
-
 bool JXRHandler::read(QImage *outImage)
 {
     if (!d->initForReading(device())) {
@@ -841,13 +830,11 @@ bool JXRHandler::read(QImage *outImage)
         } else { // additional buffer needed
             qint64 convStrideSize = (img.width() * d->pDecoder->WMP.wmiI.cBitsPerUnit + 7) / 8;
             qint64 buffSize = convStrideSize * img.height();
-#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
             qint64 limit = QImageReader::allocationLimit();
             if (limit && (buffSize + img.sizeInBytes()) > limit * 1024 * 1024) {
                 qCWarning(LOG_JXRPLUGIN) << "JXRHandler::read() unable to covert due to allocation limit set:" << limit << "MiB";
                 return false;
             }
-#endif
             QVector<quint8> ba(buffSize);
             if (auto err = pConverter->Copy(pConverter, &rect, ba.data(), convStrideSize)) {
                 PKFormatConverter_Release(&pConverter);
@@ -866,34 +853,24 @@ bool JXRHandler::read(QImage *outImage)
     d->setTextMetadata(img);
 
 #ifndef JXR_DENY_FLOAT_IMAGE
-    // JXR float are stored in scRGB -> range -0,5 to 7,5 (source Wikipedia)
-    if (img.format() == QImage::Format_RGBX16FPx4 || img.format() == QImage::Format_RGBA16FPx4 || img.format() == QImage::Format_RGBA16FPx4_Premultiplied) {
+    // JXR float are stored in scRGB.
+    if (img.format() == QImage::Format_RGBX16FPx4 || img.format() == QImage::Format_RGBA16FPx4 || img.format() == QImage::Format_RGBA16FPx4_Premultiplied ||
+        img.format() == QImage::Format_RGBX32FPx4 || img.format() == QImage::Format_RGBA32FPx4 || img.format() == QImage::Format_RGBA32FPx4_Premultiplied) {
         auto hasAlpha = img.hasAlphaChannel();
         for (qint32 y = 0, h = img.height(); y < h; ++y) {
-            qfloat16 *line = reinterpret_cast<qfloat16 *>(img.scanLine(y));
-            for (int x = 0, w = img.width(); x < w; ++x) {
-                const auto x4 = x * 4;
-                line[x4 + 0] = scRGBTosRGB(line[x4 + 0]);
-                line[x4 + 1] = scRGBTosRGB(line[x4 + 1]);
-                line[x4 + 2] = scRGBTosRGB(line[x4 + 2]);
-                line[x4 + 3] = hasAlpha ? alpha_scRGBTosRGB(line[x4 + 3]) : qfloat16(1);
+            if (img.depth() == 64) {
+                auto line = reinterpret_cast<qfloat16 *>(img.scanLine(y));
+                for (int x = 0, w = img.width() * 4; x < w; x += 4)
+                    line[x + 3] = hasAlpha ? std::clamp(line[x + 3], qfloat16(0), qfloat16(1)) : qfloat16(1);
+            } else {
+                auto line = reinterpret_cast<float *>(img.scanLine(y));
+                for (int x = 0, w = img.width() * 4; x < w; x += 4)
+                    line[x + 3] = hasAlpha ? std::clamp(line[x + 3], float(0), float(1)) : float(1);
             }
         }
-        img.setColorSpace(QColorSpace(QColorSpace::SRgb));
-    } else if (img.format() == QImage::Format_RGBX32FPx4 || img.format() == QImage::Format_RGBA32FPx4
-               || img.format() == QImage::Format_RGBA32FPx4_Premultiplied) {
-        auto hasAlpha = img.hasAlphaChannel();
-        for (qint32 y = 0, h = img.height(); y < h; ++y) {
-            float *line = reinterpret_cast<float *>(img.scanLine(y));
-            for (int x = 0, w = img.width(); x < w; ++x) {
-                const auto x4 = x * 4;
-                line[x4 + 0] = scRGBTosRGB(line[x4 + 0]);
-                line[x4 + 1] = scRGBTosRGB(line[x4 + 1]);
-                line[x4 + 2] = scRGBTosRGB(line[x4 + 2]);
-                line[x4 + 3] = hasAlpha ? alpha_scRGBTosRGB(line[x4 + 3]) : float(1);
-            }
+        if(!img.colorSpace().isValid()) {
+            img.setColorSpace(QColorSpace(QColorSpace::SRgbLinear));
         }
-        img.setColorSpace(QColorSpace(QColorSpace::SRgb));
     }
 #endif
 
@@ -922,19 +899,11 @@ bool JXRHandler::write(const QImage &image)
 #ifndef JXR_DISABLE_BGRA_HACK
     if (IsEqualGUID(jxlfmt, GUID_PKPixelFormat32bppRGBA)) {
         jxlfmt = GUID_PKPixelFormat32bppBGRA;
-#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
-        qi = qi.rgbSwapped();
-#else
         qi.rgbSwap();
-#endif
     }
     if (IsEqualGUID(jxlfmt, GUID_PKPixelFormat32bppPRGBA)) {
         jxlfmt = GUID_PKPixelFormat32bppPBGRA;
-#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
-        qi = qi.rgbSwapped();
-#else
         qi.rgbSwap();
-#endif
     }
 #endif
 
@@ -968,7 +937,7 @@ bool JXRHandler::write(const QImage &image)
     }
 
     // setting metadata (a failure of setting metadata doesn't stop the encoding)
-    auto cs = image.colorSpace().iccProfile();
+    auto cs = qi.colorSpace().iccProfile();
     if (!cs.isEmpty()) {
         if (auto err = d->pEncoder->SetColorContext(d->pEncoder, reinterpret_cast<quint8 *>(cs.data()), cs.size())) {
             qCWarning(LOG_JXRPLUGIN) << "JXRHandler::write() error while setting ICC profile:" << err;
@@ -1043,28 +1012,28 @@ QVariant JXRHandler::option(ImageOption option) const
         if (d->initForReading(device())) {
             switch (d->pDecoder->WMP.oOrientationFromContainer) {
             case O_FLIPV:
-                v = QImageIOHandler::TransformationFlip;
+                v = int(QImageIOHandler::TransformationFlip);
                 break;
             case O_FLIPH:
-                v = QImageIOHandler::TransformationMirror;
+                v = int(QImageIOHandler::TransformationMirror);
                 break;
             case O_FLIPVH:
-                v = QImageIOHandler::TransformationRotate180;
+                v = int(QImageIOHandler::TransformationRotate180);
                 break;
             case O_RCW:
-                v = QImageIOHandler::TransformationRotate90;
+                v = int(QImageIOHandler::TransformationRotate90);
                 break;
             case O_RCW_FLIPV:
-                v = QImageIOHandler::TransformationFlipAndRotate90;
+                v = int(QImageIOHandler::TransformationFlipAndRotate90);
                 break;
             case O_RCW_FLIPH:
-                v = QImageIOHandler::TransformationMirrorAndRotate90;
+                v = int(QImageIOHandler::TransformationMirrorAndRotate90);
                 break;
             case O_RCW_FLIPVH:
-                v = QImageIOHandler::TransformationRotate270;
+                v = int(QImageIOHandler::TransformationRotate270);
                 break;
             default:
-                v = QImageIOHandler::TransformationNone;
+                v = int(QImageIOHandler::TransformationNone);
                 break;
             }
         }

src/imageformats/pfm.cpp

@@ -109,7 +109,7 @@ public:
     QImage::Format format() const
     {
         if (isValid()) {
-            return isBlackAndWhite() ? QImage::Format_Grayscale16 : QImage::Format_RGBX32FPx4;
+            return QImage::Format_RGBX32FPx4;
         }
         return QImage::Format_Invalid;
     }
@@ -155,7 +155,7 @@ public:
         d->rollbackTransaction();
         return ok;
     }
-} ;
+};
 
 class PFMHandlerPrivate
 {
@@ -215,42 +215,26 @@ bool PFMHandler::read(QImage *image)
     }
 
     for (auto y = 0, h = img.height(); y < h; ++y) {
-        float f;
-        if (header.isBlackAndWhite()) {
-            auto line = reinterpret_cast<quint16*>(img.scanLine(header.isPhotoshop() ? y : h - y - 1));
-            for (auto x = 0, w = img.width(); x < w; ++x) {
-                s >> f;
-                // QColorSpace does not handle gray linear profile, so I have to convert to non-linear
-                f = f < 0.0031308f ? (f * 12.92f) : (1.055 * std::pow(f, 1.0 / 2.4) - 0.055);
-                line[x] = quint16(std::clamp(f, float(0), float(1)) * std::numeric_limits<quint16>::max() + float(0.5));
-
-                if (s.status() != QDataStream::Ok) {
-                    qCWarning(LOG_PFMPLUGIN) << "PFMHandler::read() detected corrupted data";
-                    return false;
-                }
+        auto bw = header.isBlackAndWhite();
+        auto line = reinterpret_cast<float *>(img.scanLine(header.isPhotoshop() ? y : h - y - 1));
+        for (auto x = 0, n = img.width() * 4; x < n; x += 4) {
+            line[x + 3] = float(1);
+            s >> line[x];
+            if (bw) {
+                line[x + 1] = line[x];
+                line[x + 2] = line[x];
+            } else {
+                s >> line[x + 1];
+                s >> line[x + 2];
             }
-        } else {
-            auto line = reinterpret_cast<float*>(img.scanLine(header.isPhotoshop() ? y : h - y - 1));
-            for (auto x = 0, n = img.width() * 4; x < n; x += 4) {
-                s >> f;
-                line[x] = std::clamp(f, float(0), float(1));
-                s >> f;
-                line[x + 1] = std::clamp(f, float(0), float(1));
-                s >> f;
-                line[x + 2] = std::clamp(f, float(0), float(1));
-                line[x + 3] = float(1);
-
-                if (s.status() != QDataStream::Ok) {
-                    qCWarning(LOG_PFMPLUGIN) << "PFMHandler::read() detected corrupted data";
-                    return false;
-                }
+            if (s.status() != QDataStream::Ok) {
+                qCWarning(LOG_PFMPLUGIN) << "PFMHandler::read() detected corrupted data";
+                return false;
             }
         }
     }
 
-    if (!header.isBlackAndWhite()) {
-        img.setColorSpace(QColorSpace(QColorSpace::SRgbLinear));
-    }
+    img.setColorSpace(QColorSpace(QColorSpace::SRgbLinear));
 
     *image = img;
     return true;