EXR: support for metadata saved by Photoshop

oss-fuzz:
 issue #558190560
 testcase #6629308500869120

CMakeLists.txt

@@ -1,11 +1,11 @@
 cmake_minimum_required(VERSION 3.29)
 
-set(KF_VERSION "6.29.0") # handled by release scripts
-set(KF_DEP_VERSION "6.29.0") # handled by release scripts
+set(KF_VERSION "6.31.0") # handled by release scripts
+set(KF_DEP_VERSION "6.30.0") # handled by release scripts
 project(KImageFormats VERSION ${KF_VERSION})
 
 include(FeatureSummary)
-find_package(ECM 6.29.0  NO_MODULE)
+find_package(ECM 6.30.0  NO_MODULE)
 set_package_properties(ECM PROPERTIES TYPE REQUIRED DESCRIPTION "Extra CMake Modules." URL "https://commits.kde.org/extra-cmake-modules")
 feature_summary(WHAT REQUIRED_PACKAGES_NOT_FOUND FATAL_ON_MISSING_REQUIRED_PACKAGES)
 

README.md

@@ -392,6 +392,22 @@ The plugin can set the following additional metadata:
 - `EXRLayerName`: A string containing the name of the EXR layer used to decode 
    the image.
 
+When writing, it is possible to specify compression ratio and quality. The 
+values ​​you can set depend on the version of the OpenEXR library you're using.
+Please check the [exr_p.h](./src/imageformats/exr_p.h) for more 
+info.
+
+When writing, it is also possible to specify a subtype:
+- `RGB` (default): preserves full-resolution color data (R, G, B) without 
+  subsampling or loss of chromatic detail.
+- `YC`: converts RGB data into luminance (Y) and 2x2 subsampled chroma 
+  (RY, BY), cutting raw color data by ~50% for significantly smaller file 
+  sizes. **If the image does not have a height and width that are multiples 
+  of 2, `RGB` is used.**
+
+> [!note]
+> When writing grayscale images, the subtype makes no difference.
+
 ### The EPS plugin
 
 The plugin uses `Ghostscript` to convert the raster image. When reading it

autotests/ossfuzz/build_fuzzers.sh

@@ -101,7 +101,7 @@ cd $SRC/aom
 mkdir build.libavif
 cd build.libavif
 extra_libaom_flags='-DAOM_MAX_ALLOCABLE_MEMORY=536870912 -DDO_RANGE_CHECK_CLAMP=1'
-cmake -G Ninja -DBUILD_SHARED_LIBS=0 -DENABLE_DOCS=0 -DENABLE_EXAMPLES=0 -DENABLE_TESTDATA=0 -DENABLE_TESTS=0 -DENABLE_TOOLS=0 -DCONFIG_PIC=1 -DAOM_TARGET_CPU=generic -DCONFIG_SIZE_LIMIT=1 -DDECODE_HEIGHT_LIMIT=12288 -DDECODE_WIDTH_LIMIT=12288 -DAOM_EXTRA_C_FLAGS="${extra_libaom_flags}" -DAOM_EXTRA_CXX_FLAGS="${extra_libaom_flags}" ..
+cmake -G Ninja -DBUILD_SHARED_LIBS=0 -DENABLE_APPS=0 -DENABLE_DOCS=0 -DENABLE_EXAMPLES=0 -DENABLE_TESTDATA=0 -DENABLE_TESTS=0 -DENABLE_TOOLS=0 -DCONFIG_PIC=1 -DAOM_TARGET_CPU=generic -DCONFIG_SIZE_LIMIT=1 -DDECODE_HEIGHT_LIMIT=12288 -DDECODE_WIDTH_LIMIT=12288 -DAOM_EXTRA_C_FLAGS="${extra_libaom_flags}" -DAOM_EXTRA_CXX_FLAGS="${extra_libaom_flags}" ..
 ninja install
 
 # Build libavif
@@ -186,7 +186,7 @@ echo "$HANDLER_TYPES" | while read format; do
   /usr/libexec/moc $SRC/kimageformats/src/imageformats/$format.cpp -o $format.moc
   header=`ls $SRC/kimageformats/src/imageformats/$format*.h`
   /usr/libexec/moc $header -o moc_`basename $header .h`.cpp
-  $CXX $CXXFLAGS $LDFLAGS -fPIC -DKIMG_FUZZER_${format}=1 -std=c++17 autotests/ossfuzz/kimgio_fuzzer.cc $SRC/kimageformats/src/imageformats/$format.cpp $SRC/kimageformats/src/imageformats/scanlineconverter.cpp $SRC/kimageformats/src/imageformats/microexif.cpp $SRC/kimageformats/src/imageformats/chunks.cpp -o $OUT/$fuzz_target_name -DJXL_STATIC_DEFINE -DJXL_THREADS_STATIC_DEFINE -DJXL_CMS_STATIC_DEFINE -D__ANSI__ -I $SRC/kimageformats/src/imageformats/ -I $SRC/libavif/include/ -I $SRC/libjxl/build/lib/include/ -I $SRC/libjxl/lib/include/ -I /usr/local/include/OpenEXR/ -I /usr/local/include/KF6/KArchive/ -I /usr/local/include/openjpeg-2.5 -I /usr/local/include/Imath -I $SRC/jxrlib/common/include -I $SRC/jxrlib/jxrgluelib -I $SRC/jxrlib/image/sys -I /usr/include/QtCore/ -I /usr/include/QtGui/ -I . $SRC/libavif/build/libavif.a /usr/local/lib/libheif.a /usr/local/lib/libde265.a /usr/local/lib/libopenh264.a $SRC/aom/build.libavif/libaom.a $SRC/libjxl/build/lib/libjxl_threads.a $SRC/libjxl/build/lib/libjxl.a $SRC/libjxl/build/lib/libjxl_cms.a $SRC/libjxl/build/third_party/highway/libhwy.a $SRC/libjxl/build/third_party/brotli/libbrotlidec.a $SRC/libjxl/build/third_party/brotli/libbrotlienc.a $SRC/libjxl/build/third_party/brotli/libbrotlicommon.a -lQt6Gui -lQt6Core -lQt6BundledLibpng -lQt6BundledHarfbuzz -lm -lQt6BundledPcre2 -ldl -lpthread $LIB_FUZZING_ENGINE /usr/local/lib/libz.a /usr/local/lib/x86_64-linux-gnu/libKF6Archive.a /usr/local/lib/libz.a /usr/local/lib/libraw.a /usr/local/lib/libOpenEXR-3_4.a /usr/local/lib/libIex-3_4.a /usr/local/lib/libImath-3_2.a /usr/local/lib/libIlmThread-3_4.a /usr/local/lib/libOpenEXRCore-3_4.a /usr/local/lib/libOpenEXRUtil-3_4.a /usr/local/lib/libopenjp2.a /usr/local/lib/libzstd.a $SRC/jxrlib/build/libjxrglue.a $SRC/jxrlib/build/libjpegxr.a /usr/local/lib/liblzma.a /usr/local/lib/libbz2.a -lclang_rt.builtins
+  $CXX $CXXFLAGS $LDFLAGS -fPIC -DKIMG_FUZZER_${format}=1 -std=c++17 autotests/ossfuzz/kimgio_fuzzer.cc $SRC/kimageformats/src/imageformats/$format.cpp $SRC/kimageformats/src/imageformats/scanlineconverter.cpp $SRC/kimageformats/src/imageformats/photoshop.cpp $SRC/kimageformats/src/imageformats/microexif.cpp $SRC/kimageformats/src/imageformats/chunks.cpp -o $OUT/$fuzz_target_name -DJXL_STATIC_DEFINE -DJXL_THREADS_STATIC_DEFINE -DJXL_CMS_STATIC_DEFINE -D__ANSI__ -I $SRC/kimageformats/src/imageformats/ -I $SRC/libavif/include/ -I $SRC/libjxl/build/lib/include/ -I $SRC/libjxl/lib/include/ -I /usr/local/include/OpenEXR/ -I /usr/local/include/KF6/KArchive/ -I /usr/local/include/openjpeg-2.5 -I /usr/local/include/Imath -I $SRC/jxrlib/common/include -I $SRC/jxrlib/jxrgluelib -I $SRC/jxrlib/image/sys -I /usr/include/QtCore/ -I /usr/include/QtGui/ -I . $SRC/libavif/build/libavif.a /usr/local/lib/libheif.a /usr/local/lib/libde265.a /usr/local/lib/libopenh264.a $SRC/aom/build.libavif/libaom.a $SRC/libjxl/build/lib/libjxl_threads.a $SRC/libjxl/build/lib/libjxl.a $SRC/libjxl/build/lib/libjxl_cms.a $SRC/libjxl/build/third_party/highway/libhwy.a $SRC/libjxl/build/third_party/brotli/libbrotlidec.a $SRC/libjxl/build/third_party/brotli/libbrotlienc.a $SRC/libjxl/build/third_party/brotli/libbrotlicommon.a -lQt6Gui -lQt6Core -lQt6BundledLibpng -lQt6BundledHarfbuzz -lm -lQt6BundledPcre2 -ldl -lpthread $LIB_FUZZING_ENGINE /usr/local/lib/libz.a /usr/local/lib/x86_64-linux-gnu/libKF6Archive.a /usr/local/lib/libz.a /usr/local/lib/libraw.a /usr/local/lib/libOpenEXR-3_4.a /usr/local/lib/libIex-3_4.a /usr/local/lib/libImath-3_2.a /usr/local/lib/libIlmThread-3_4.a /usr/local/lib/libOpenEXRCore-3_4.a /usr/local/lib/libOpenEXRUtil-3_4.a /usr/local/lib/libopenjp2.a /usr/local/lib/libzstd.a $SRC/jxrlib/build/libjxrglue.a $SRC/jxrlib/build/libjpegxr.a /usr/local/lib/liblzma.a /usr/local/lib/libbz2.a -lclang_rt.builtins
 
   # -lclang_rt.builtins in the previous line is a temporary workaround to avoid a linker error "undefined reference to __truncsfhf2". Investigate why this is needed here, but not anywhere else, and possibly remove it.
 

autotests/ossfuzz/kimgio_fuzzer.cc

@@ -125,7 +125,27 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
     b.open(QIODevice::ReadOnly);
     handler->setDevice(&b);
     handler->canRead();
+
+    bool is_animated = false;
+    if (handler->supportsOption(QImageIOHandler::Animation)) {
+        is_animated = handler->option(QImageIOHandler::Animation).toBool();
+    }
+
+    if (is_animated) { // animated image
+        if (handler->supportsOption(QImageIOHandler::Size)) {
+            handler->option(QImageIOHandler::Size).toSize();
+        }
+
+        handler->imageCount();
+        handler->loopCount();
         handler->read(&i);
+        handler->nextImageDelay();
+        handler->currentImageNumber();
+        handler->jumpToImage(0);
+        handler->jumpToNextImage();
+    } else { // static image
+        handler->read(&i);
+    }
 
     delete handler;
 

autotests/ossfuzz/prepare_build.sh

@@ -33,7 +33,7 @@ git clone --depth 1 -b master https://invent.kde.org/frameworks/extra-cmake-modu
 git clone --depth 1 --branch=dev git://code.qt.io/qt/qtbase.git
 git clone --depth 1 --branch=dev git://code.qt.io/qt/qttools.git
 git clone --depth 1 -b master https://invent.kde.org/frameworks/karchive.git
-git clone --depth 1 -b v3.14.1 https://aomedia.googlesource.com/aom
+git clone --depth 1 -b v3.15.0 https://aomedia.googlesource.com/aom
 git clone --depth 1 -b v1.4.2 https://github.com/AOMediaCodec/libavif.git
 git clone --depth 1 https://github.com/strukturag/libde265.git
 git clone --depth 1 -b v2.5.4 https://github.com/uclouvain/openjpeg.git

autotests/read/avif/grid.avif.json

@@ -0,0 +1,7 @@
+[
+    {
+        "fileName": "grid.png",
+        "fuzziness": 2,
+        "description": "Minimum fuzziness value to pass the test on all architectures."
+    }
+]

autotests/read/exr/alphatest_rgba.exr.json

@@ -0,0 +1,33 @@
+[
+    {
+        "fileName" : "alphatest_rgba.tif",
+        "colorSpace" : {
+            "description" : "sRGB build-in (Profilo RGB lineare)",
+            "primaries" : "SRgb",
+            "transferFunction" : "Linear",
+            "gamma" : 1
+        },
+        "metadata" : [
+            {
+                "key" : "ModificationDate",
+                "value" : "2026-09-04T11:45:06"
+            },
+            {
+                "key" : "Software" ,
+                "value" : "Adobe Photoshop 27.10 (Windows)"
+            },
+            {
+                "key" : "Author",
+                "value" : "Mirco Miranda"
+            },
+            {
+                "key" : "Description",
+                "value" : "This test is designed to detect problems with alpha encoding. Specifically, it detects incorrect use of associated values ​​(premultiplied alpha) and unassociated values ​​(normal alpha)."
+            }
+        ],
+        "resolution" : {
+            "dotsPerMeterX" : 11811,
+            "dotsPerMeterY" : 11811
+        }
+    }
+]

autotests/read/exr/ps2026_testcard_rgb.exr.json

@@ -7,9 +7,19 @@
             "transferFunction" : "Linear",
             "gamma" : 1
         },
+        "metadata" : [
+            {
+                "key" : "ModificationDate",
+                "value" : "2026-04-15T10:48:48"
+            },
+            {
+                "key" : "Software" ,
+                "value" : "Adobe Photoshop 27.5 (Windows)"
+            }
+        ],
         "resolution" : {
-            "dotsPerMeterX" : 3937,
-            "dotsPerMeterY" : 3937
+            "dotsPerMeterX" : 11811,
+            "dotsPerMeterY" : 11811
         }
     }
 ]

autotests/read/heic/konqi.heic.json

@@ -0,0 +1,7 @@
+[
+    {
+        "fileName": "konqi.jpg",
+        "fuzziness": 72,
+        "description": "Minimum fuzziness value to pass the test on all architectures."
+    }
+]

src/imageformats/CMakeLists.txt

@@ -57,7 +57,7 @@ endif()
 ##################################
 
 if(OpenEXR_FOUND)
-    kimageformats_add_plugin(kimg_exr SOURCES exr.cpp scanlineconverter.cpp)
+    kimageformats_add_plugin(kimg_exr SOURCES exr.cpp microexif.cpp photoshop.cpp scanlineconverter.cpp)
     if(TARGET OpenEXR::OpenEXR)
         target_link_libraries(kimg_exr PRIVATE OpenEXR::OpenEXR)
     else()
@@ -117,7 +117,7 @@ kimageformats_add_plugin(kimg_pfm SOURCES pfm.cpp)
 
 ##################################
 
-kimageformats_add_plugin(kimg_psd SOURCES psd.cpp microexif.cpp scanlineconverter.cpp)
+kimageformats_add_plugin(kimg_psd SOURCES psd.cpp microexif.cpp photoshop.cpp scanlineconverter.cpp)
 
 ##################################
 

src/imageformats/ani.cpp

@@ -12,6 +12,7 @@
 #include <QScopeGuard>
 #include <QVariant>
 #include <QtEndian>
+#include <QtNumeric>
 
 #include <cstring>
 
@@ -267,7 +268,17 @@ int ANIHandler::nextImageDelay() const
         rate = m_displayRates.at(previousImage);
     }
 
-    return rate * 1000 / 60;
+    int delayNumerator;
+    if (qMulOverflow(rate, 1000, &delayNumerator)) {
+        int delay;
+        // We're losing a bit of precision by dividing first and multiplying later
+        // but this is most probably a broken file so not much of an issue
+        if (qMulOverflow(rate / 60, 1000, &delay)) {
+            return 0;
+        }
+        return delay;
+    }
+    return delayNumerator / 60;
 }
 
 bool ANIHandler::supportsOption(ImageOption option) const

src/imageformats/avif.cpp

@@ -1160,25 +1160,19 @@ bool QAVIFHandler::jumpToNextImage()
         return false;
     }
 
-    avifResult decodeResult;
-
     if (m_decoder->imageIndex >= 0) {
         if (m_decoder->imageCount < 2) {
-            m_parseState = ParseAvifSuccess;
+            // single image, there is no next image
             return false;
         }
 
-        if (m_decoder->imageIndex >= m_decoder->imageCount - 1) { // start from beginning
-            decodeResult = avifDecoderReset(m_decoder);
-            if (decodeResult != AVIF_RESULT_OK) {
-                qCWarning(LOG_AVIFPLUGIN, "ERROR in avifDecoderReset: %s", avifResultToString(decodeResult));
-                m_parseState = ParseAvifError;
+        if (m_decoder->imageIndex >= m_decoder->imageCount - 1) {
+            // do not start from beginning when at the end already
             return false;
         }
     }
-    }
 
-    decodeResult = avifDecoderNextImage(m_decoder);
+    avifResult decodeResult = avifDecoderNextImage(m_decoder);
 
     if (decodeResult != AVIF_RESULT_OK) {
         qCWarning(LOG_AVIFPLUGIN, "ERROR: Failed to decode Next image in sequence: %s", avifResultToString(decodeResult));

src/imageformats/exr.cpp

@@ -8,6 +8,8 @@
 */
 
 #include "exr_p.h"
+#include "microexif_p.h"
+#include "photoshop_p.h"
 #include "scanlineconverter_p.h"
 #include "util_p.h"
 
@@ -200,12 +202,17 @@ void K_OStream::seekg(Imf::Int64 pos)
     m_dev->seek(pos);
 }
 
+#define EXR_SUBFORMAT_RGB QByteArray("RGB")
+
+#define EXR_SUBFORMAT_YC QByteArray("YC")
+
 EXRHandler::EXRHandler()
     : m_compressionRatio(-1)
     , m_quality(-1)
     , m_imageNumber(0)
     , m_imageCount(0)
     , m_startPos(-1)
+    , m_subType(EXR_SUBFORMAT_RGB)
 {
     // Set the number of threads to use (0 is allowed)
     Imf::setGlobalThreadCount(QThread::idealThreadCount() / 2);
@@ -225,7 +232,7 @@ bool EXRHandler::canRead() const
 static QImage::Format imageFormat(const Imf::RgbaInputFile &file)
 {
     auto isRgba = file.channels() & Imf::RgbaChannels::WRITE_A;
-    return (isRgba ? QImage::Format_RGBA16FPx4 : QImage::Format_RGBX16FPx4);
+    return (isRgba ? QImage::Format_RGBA16FPx4_Premultiplied : QImage::Format_RGBX16FPx4);
 }
 
 /*!
@@ -368,7 +375,8 @@ static void readMetadata(const Imf::Header &header, QImage &image)
 
     // shot metadata
     if (auto isoSpeed = header.findTypedAttribute<Imf::FloatAttribute>("isoSpeed")) {
-        image.setText(QStringLiteral(META_KEY_ISOSPEEDRATINGS), QLocale::c().toString(qRound(isoSpeed->value())));
+        if (auto v = qRoundOrZero(isoSpeed->value()))
+            image.setText(QStringLiteral(META_KEY_ISOSPEEDRATINGS), QLocale::c().toString(v));
     }
     if (auto expTime = header.findTypedAttribute<Imf::FloatAttribute>("expTime")) {
         image.setText(QStringLiteral(META_KEY_EXPOSURETIME), QLocale::c().toString(expTime->value()));
@@ -379,6 +387,34 @@ static void readMetadata(const Imf::Header &header, QImage &image)
     if (auto focalLen = header.findTypedAttribute<Imf::FloatAttribute>("effectiveFocalLength")) {
         image.setText(QStringLiteral(META_KEY_FOCALLENGTH), QLocale::c().toString(focalLen->value()));
     }
+
+    // Photoshop image resource section
+    if (auto adobe = header.findTypedAttribute<Imf::OpaqueAttribute>("adobe_rsrc")) {
+        auto &&data = adobe->data();
+        auto ba = QByteArray(data, data.size());
+        ba.prepend((data.size()) & 0xFF);
+        ba.prepend((data.size() >> 8) & 0xFF);
+        ba.prepend((data.size() >> 16) & 0xFF);
+        ba.prepend((data.size() >> 24) & 0xFF);
+        QDataStream ds(ba);
+        ds.setByteOrder(QDataStream::BigEndian);
+        auto ok = false;
+        auto irs = readImageResourceSection(ds, &ok);
+        if (ok) {
+            if (irs.contains(IRI_EXIFDATA1)) {
+                auto exif = MicroExif::fromByteArray(irs.value(IRI_EXIFDATA1).data);
+                exif.updateImageMetadata(image);
+                exif.updateImageResolution(image);
+            }
+
+            if (irs.contains(IRI_XMPMETADATA)) {
+                auto irb = irs.value(IRI_XMPMETADATA);
+                auto xmp = QString::fromUtf8(irb.data);
+                if (!xmp.isEmpty())
+                    image.setText(QStringLiteral(META_KEY_XMP_ADOBE), xmp);
+            }
+        }
+    }
 }
 
 /*!
@@ -513,9 +549,9 @@ bool makePreview(const QImage &image, Imf::Array2D<Imf::PreviewRgba> &pixels)
 
     QImage preview;
     if (w > h) {
-        preview = image.scaledToWidth(256).convertToFormat(QImage::Format_ARGB32);
+        preview = image.scaledToWidth(256).convertToFormat(QImage::Format_ARGB32_Premultiplied);
     } else {
-        preview = image.scaledToHeight(256).convertToFormat(QImage::Format_ARGB32);
+        preview = image.scaledToHeight(256).convertToFormat(QImage::Format_ARGB32_Premultiplied);
     }
     if (preview.isNull()) {
         return false;
@@ -687,6 +723,10 @@ bool EXRHandler::write(const QImage &image)
         // write the EXR
         K_OStream ostr(device());
         auto channelsType = image.hasAlphaChannel() ? Imf::RgbaChannels::WRITE_RGBA : Imf::RgbaChannels::WRITE_RGB;
+        if (m_subType == EXR_SUBFORMAT_YC && !(width % 2) && !(height % 2)) {
+            // Works only with images with height and width that are multiples of 2.
+            channelsType = channelsType == Imf::RgbaChannels::WRITE_RGBA ? Imf::RgbaChannels::WRITE_YCA : Imf::RgbaChannels::WRITE_YC;
+        }
         if (image.format() == QImage::Format_Mono ||
             image.format() == QImage::Format_MonoLSB ||
             image.format() == QImage::Format_Grayscale16 ||
@@ -698,7 +738,7 @@ bool EXRHandler::write(const QImage &image)
         pixels.resizeErase(EXR_LINES_PER_BLOCK, width);
 
         // convert the image and write into the stream
-        auto convFormat = image.hasAlphaChannel() ? QImage::Format_RGBA32FPx4 : QImage::Format_RGBX32FPx4;
+        auto convFormat = image.hasAlphaChannel() ? QImage::Format_RGBA32FPx4_Premultiplied : QImage::Format_RGBX32FPx4;
         ScanLineConverter slc(convFormat);
         slc.setDefaultSourceColorSpace(QColorSpace(QColorSpace::SRgb));
         slc.setTargetColorSpace(QColorSpace(QColorSpace::SRgbLinear));
@@ -742,6 +782,15 @@ void EXRHandler::setOption(ImageOption option, const QVariant &value)
             m_quality = q;
         }
     }
+    if (option == QImageIOHandler::SubType) {
+        auto subType = value.toByteArray();
+        auto list = EXRHandler::option(QImageIOHandler::SupportedSubTypes).value<QList<QByteArray>>();
+        if (list.contains(subType)) {
+            m_subType = subType;
+        } else {
+            m_subType = EXR_SUBFORMAT_RGB;
+        }
+    }
 }
 
 bool EXRHandler::supportsOption(ImageOption option) const
@@ -760,6 +809,12 @@ bool EXRHandler::supportsOption(ImageOption option) const
     if (option == QImageIOHandler::Quality) {
         return true;
     }
+    if (option == QImageIOHandler::SubType) {
+        return true;
+    }
+    if (option == QImageIOHandler::SupportedSubTypes) {
+        return true;
+    }
     return false;
 }
 
@@ -814,6 +869,14 @@ QVariant EXRHandler::option(ImageOption option) const
         v = QVariant(m_quality);
     }
 
+    if (option == QImageIOHandler::SupportedSubTypes) {
+        return QVariant::fromValue(QList<QByteArray>() << EXR_SUBFORMAT_RGB << EXR_SUBFORMAT_YC);
+    }
+
+    if (option == QImageIOHandler::SubType) {
+        return QVariant::fromValue(m_subType);
+    }
+
     return v;
 }
 

src/imageformats/exr_p.h

@@ -118,6 +118,14 @@ private:
      * The initial device position to allow multi image load (cache value).
      */
     qint64 m_startPos;
+
+    /*!
+     * \brief m_subType
+     * The EXR subtype to use when writing:
+     * - RGB: preserves full-resolution color data (R, G, B) without subsampling or loss of chromatic detail (default).
+     * - YC: converts RGB data into luminance (Y) and 2x2 subsampled chroma (RY, BY), cutting raw color data by ~50% for significantly smaller file sizes.
+     */
+    QByteArray m_subType;
 };
 
 class EXRPlugin : public QImageIOPlugin

src/imageformats/heif.cpp

@@ -642,10 +642,31 @@ bool HEIFHandler::read_crop(void *heif_handle, const void *heif_ctx, const QSize
     if (heif_item_get_properties_of_type(ctx, item_id, heif_item_property_type_transform_crop, &crop_id, 1) > 0) {
         int l = 0, t = 0, r = 0, b = 0;
         heif_item_get_property_transform_crop_borders(ctx, item_id, crop_id, size.width(), size.height(), &l, &t, &r, &b);
-        crop = QRect(QPoint(t, l), size - QSize(b + t, r + l));
+
+        if (l >= size.width() || r >= size.width() || t >= size.height() || b >= size.height()) {
+            qCWarning(LOG_HEIFPLUGIN) << "Invalid crop values: left=" << l << "top=" << t << "right=" << r << "bottom=" << b;
+        }
+        if (l < 0) {
+            l = 0;
+        }
+        if (t < 0) {
+            t = 0;
+        }
+        if (r < 0) {
+            r = 0;
+        }
+        if (b < 0) {
+            b = 0;
+        }
+        if (l == 0 && t == 0 && r == 0 && b == 0) {
+            // no cropping needed
+            return false;
+        }
+        crop = QRect(QPoint(l, t), size - QSize(l + r, t + b));
+        return crop.isValid();
     }
 
-    return crop.isValid();
+    return false;
 }
 
 bool HEIFHandler::isSupportedBMFFType(const QByteArray &header)
@@ -930,8 +951,8 @@ bool HEIFHandler::ensureDecoder()
     struct heif_image *img = nullptr;
     err = heif_decode_image(handle, &img, heif_colorspace_RGB, chroma, decoder_option);
 
-    if (err.code == heif_error_Invalid_input && err.subcode == heif_suberror_Unknown_NCLX_matrix_coefficients && img == nullptr && buffer.contains("Xiaomi")) {
-        qCWarning(LOG_HEIFPLUGIN) << "Non-standard HEIF image with invalid matrix_coefficients, probably made by a Xiaomi device!";
+    if (err.code == heif_error_Invalid_input && err.subcode == heif_suberror_Unknown_NCLX_matrix_coefficients && img == nullptr) {
+        qCWarning(LOG_HEIFPLUGIN) << "Non-standard HEIF image with invalid matrix_coefficients!";
 
         // second try to decode with strict decoding disabled
         decoder_option->strict_decoding = 0;

src/imageformats/jp2.cpp

@@ -622,21 +622,20 @@ public:
             m_cparameters.tcp_rates[0] = 100.0 - (m_quality < 10 ? m_quality : 10 + (std::log10(m_quality) - 1) * 90);
         }
 
-        std::unique_ptr<opj_image_cmptparm_t> cmptparm(new opj_image_cmptparm_t[ncomp]);
-        for (int i = 0; i < ncomp; ++i) {
-            auto &&p = cmptparm.get() + i;
-            memset(p, 0, sizeof(opj_image_cmptparm_t));
-            p->dx = m_cparameters.subsampling_dx;
-            p->dy = m_cparameters.subsampling_dy;
-            p->w = image.width();
-            p->h = image.height();
-            p->x0 = 0;
-            p->y0 = 0;
-            p->prec = prec;
-            p->sgnd = 0;
+        std::vector<opj_image_cmptparm_t> cmptparm(ncomp);
+        for (opj_image_cmptparm_t &p : cmptparm) {
+            memset(&p, 0, sizeof(opj_image_cmptparm_t));
+            p.dx = m_cparameters.subsampling_dx;
+            p.dy = m_cparameters.subsampling_dy;
+            p.w = image.width();
+            p.h = image.height();
+            p.x0 = 0;
+            p.y0 = 0;
+            p.prec = prec;
+            p.sgnd = 0;
         }
 
-        m_jp2_image = opj_image_create(ncomp, cmptparm.get(), cs);
+        m_jp2_image = opj_image_create(ncomp, cmptparm.data(), cs);
         if (m_jp2_image == nullptr) {
             return false;
         }

src/imageformats/jxl.cpp

@@ -75,8 +75,7 @@ void QtJXLMemoryManagerFree(void *, void *address)
 QJpegXLHandler::QJpegXLHandler()
     : m_parseState(ParseJpegXLNotParsed)
     , m_quality(90)
-    , m_currentimage_index(0)
-    , m_previousimage_index(-1)
+    , m_currentimage_index(-1)
     , m_transformations(QImageIOHandler::TransformationNone)
     , m_decoder(nullptr)
     , m_runner(nullptr)
@@ -183,11 +182,7 @@ bool QJpegXLHandler::ensureDecoder()
     }
 
     // Creating a simple memory manager
-    JxlMemoryManager memory_manager = {
-        .opaque = &m_maxBytes,
-        .alloc = QtJXLMemoryManagerAlloc,
-        .free = QtJXLMemoryManagerFree
-    };
+    JxlMemoryManager memory_manager = {.opaque = &m_maxBytes, .alloc = QtJXLMemoryManagerAlloc, .free = QtJXLMemoryManagerFree};
     // Creating the decoder (it makes a deep copy of memory manager)
     m_decoder = JxlDecoderCreate(&memory_manager);
     if (!m_decoder) {
@@ -817,17 +812,11 @@ bool QJpegXLHandler::decode_one_frame()
         exif.updateImageMetadata(m_current_image);
     }
 
+    m_currentimage_index++;
     m_next_image_delay = m_framedelays[m_currentimage_index];
-    m_previousimage_index = m_currentimage_index;
 
     if (m_framedelays.count() > 1) {
-        m_currentimage_index++;
-
-        if (m_currentimage_index >= m_framedelays.count()) {
-            if (!rewind()) {
-                return false;
-            }
-
+        if (m_currentimage_index >= m_framedelays.count() - 1) {
             // all frames in animation have been read
             m_parseState = ParseJpegXLFinished;
         } else {
@@ -847,9 +836,9 @@ bool QJpegXLHandler::read(QImage *image)
         return false;
     }
 
-    if (m_currentimage_index == m_previousimage_index) {
-        *image = m_current_image;
-        return jumpToNextImage();
+    if (m_parseState == ParseJpegXLFinished) {
+        // at the end already
+        return false;
     }
 
     if (decode_one_frame()) {
@@ -1757,19 +1746,26 @@ bool QJpegXLHandler::jumpToNextImage()
     }
 
     if (m_framedelays.count() > 1) {
-        m_currentimage_index++;
-
-        if (m_currentimage_index >= m_framedelays.count()) {
-            if (!rewind()) {
+        if (m_currentimage_index >= (m_framedelays.count() - 1)) {
+            // we are already at the last frame
             return false;
-            }
         } else {
+            m_currentimage_index++;
+            m_next_image_delay = m_framedelays[m_currentimage_index];
             JxlDecoderSkipFrames(m_decoder, 1);
+            if (m_currentimage_index >= (m_framedelays.count() - 1)) {
+                // last frame reached but no more reading is possible
+                m_parseState = ParseJpegXLFinished;
+            } else {
+                m_parseState = ParseJpegXLSuccess;
+            }
+
+            return true;
         }
     }
 
-    m_parseState = ParseJpegXLSuccess;
-    return true;
+    // static image, there is no next frame
+    return false;
 }
 
 bool QJpegXLHandler::jumpToImage(int imageNumber)
@@ -1782,14 +1778,17 @@ bool QJpegXLHandler::jumpToImage(int imageNumber)
         return false;
     }
 
-    if (imageNumber == m_currentimage_index) {
+    const int next_image_index = m_currentimage_index + 1;
+
+    if (imageNumber == next_image_index) {
+        // This the already the next image to read, no action
         m_parseState = ParseJpegXLSuccess;
         return true;
     }
 
-    if (imageNumber > m_currentimage_index) {
-        JxlDecoderSkipFrames(m_decoder, imageNumber - m_currentimage_index);
-        m_currentimage_index = imageNumber;
+    if (imageNumber > next_image_index) {
+        JxlDecoderSkipFrames(m_decoder, imageNumber - next_image_index);
+        m_currentimage_index = imageNumber - 1;
         m_parseState = ParseJpegXLSuccess;
         return true;
     }
@@ -1801,7 +1800,7 @@ bool QJpegXLHandler::jumpToImage(int imageNumber)
     if (imageNumber > 0) {
         JxlDecoderSkipFrames(m_decoder, imageNumber);
     }
-    m_currentimage_index = imageNumber;
+    m_currentimage_index = imageNumber - 1;
     m_parseState = ParseJpegXLSuccess;
     return true;
 }
@@ -1834,7 +1833,7 @@ int QJpegXLHandler::loopCount() const
 
 bool QJpegXLHandler::rewind()
 {
-    m_currentimage_index = 0;
+    m_currentimage_index = -1;
 
     JxlDecoderReleaseInput(m_decoder);
     JxlDecoderRewind(m_decoder);

src/imageformats/jxl_p.h

@@ -65,7 +65,6 @@ private:
     ParseJpegXLState m_parseState;
     int m_quality;
     int m_currentimage_index;
-    int m_previousimage_index;
     QImageIOHandler::Transformations m_transformations;
 
     QByteArray m_rawData;

src/imageformats/photoshop.cpp

@@ -0,0 +1,140 @@
+/*
+    This file is part of the KDE project
+    SPDX-FileCopyrightText: 2026 Mirco Miranda <mircomir@outlook.com>
+
+    SPDX-License-Identifier: LGPL-2.1-or-later
+*/
+#include "photoshop_p.h"
+#include "util_p.h"
+
+#include <QLoggingCategory>
+
+#ifdef QT_DEBUG
+Q_LOGGING_CATEGORY(LOG_PSDSHARED, "kf.imageformats.plugins.psdshared", QtDebugMsg)
+#else
+Q_LOGGING_CATEGORY(LOG_PSDSHARED, "kf.imageformats.plugins.psdshared", QtWarningMsg)
+#endif
+
+QString readPascalString(QDataStream &s, qint32 alignBytes, qint32 *size)
+{
+    qint32 tmp = 0;
+    if (size == nullptr)
+        size = &tmp;
+
+    quint8 stringSize;
+    s >> stringSize;
+    *size = sizeof(stringSize);
+
+    QString str;
+    if (stringSize > 0) {
+        QByteArray ba;
+        ba.resize(stringSize);
+        auto read = s.readRawData(ba.data(), ba.size());
+        if (read > 0) {
+            *size += read;
+            str = QString::fromLatin1(ba);
+        }
+    }
+
+    // align
+    if (alignBytes > 1)
+        if (auto pad = *size % alignBytes)
+            *size += s.skipRawData(alignBytes - pad);
+
+    return str;
+}
+
+PSDImageResourceSection readImageResourceSection(QDataStream &s, bool *ok)
+{
+    PSDImageResourceSection irs;
+
+    bool tmp = true;
+    if (ok == nullptr)
+        ok = &tmp;
+    *ok = true;
+
+    // Section size
+    quint32 tmpSize;
+    s >> tmpSize;
+    qint64 sectioSize = tmpSize;
+
+    // Reading Image resource block
+    for (auto size = sectioSize; size > 0;) {
+
+#define DEC_SIZE(value) \
+        if ((size -= qint64(value)) < 0) { \
+                *ok = false; \
+                break; }
+
+        // Length      Description
+        // -------------------------------------------------------------------
+        // 4           Signature: '8BIM'
+        // 2           Unique identifier for the resource. Image resource IDs
+        //             contains a list of resource IDs used by Photoshop.
+        // Variable    Name: Pascal string, padded to make the size even
+        //             (a null name consists of two bytes of 0)
+        // 4           Actual size of resource data that follows
+        // Variable    The resource data, described in the sections on the
+        //             individual resource types. It is padded to make the size
+        //             even.
+
+        quint32 signature;
+        s >> signature;
+        DEC_SIZE(sizeof(signature))
+        // NOTE: MeSa signature is not documented but found in some old PSD take from Photoshop 7.0 CD.
+        if (signature != S_8BIM && signature != S_MeSa) { // 8BIM and MeSa
+            qCDebug(LOG_PSDSHARED) << "Invalid Image Resource Block Signature!";
+            *ok = false;
+            break;
+        }
+
+        // id
+        quint16 id;
+        s >> id;
+        DEC_SIZE(sizeof(id))
+
+        // getting data
+        PSDImageResourceBlock irb;
+
+        // name
+        qint32 bytes = 0;
+        irb.name = readPascalString(s, 2, &bytes);
+        DEC_SIZE(bytes)
+
+        // data read
+        quint32 dataSize;
+        s >> dataSize;
+        DEC_SIZE(sizeof(dataSize))
+        if (auto dev = s.device()) {
+            if (dataSize > size) {
+                qCDebug(LOG_PSDSHARED) << "Invalid Image Resource Block Data Size!";
+                *ok = false;
+                break;
+            }
+            irb.data = deviceRead(dev, dataSize);
+        }
+        auto read = irb.data.size();
+        if (read > 0) {
+            DEC_SIZE(read)
+        }
+        if (read != qint64(dataSize)) {
+            qCDebug(LOG_PSDSHARED) << "Image Resource Block Read Error!";
+            *ok = false;
+            break;
+        }
+
+        if (auto pad = dataSize % 2) {
+            auto skipped = s.skipRawData(pad);
+            if (skipped > 0) {
+                DEC_SIZE(skipped);
+            }
+        }
+
+        // insert IRB
+        irs.insert(ImageResourceId(id), irb);
+
+#undef DEC_SIZE
+    }
+
+    return irs;
+}

src/imageformats/photoshop_p.h

@@ -0,0 +1,80 @@
+/*
+    This file is part of the KDE project
+    SPDX-FileCopyrightText: 2026 Mirco Miranda <mircomir@outlook.com>
+
+    SPDX-License-Identifier: LGPL-2.1-or-later
+*/
+#ifndef PHOTOSHOP_P_H
+#define PHOTOSHOP_P_H
+
+#include <QDataStream>
+#include <QHash>
+#include <QString>
+
+enum Signature : quint32 {
+    S_8BIM = 0x3842494D, // '8BIM'
+    S_8B64 = 0x38423634, // '8B64'
+
+    S_MeSa = 0x4D655361   // 'MeSa'
+};
+
+enum ColorMode : quint16 {
+    CM_BITMAP = 0,
+    CM_GRAYSCALE = 1,
+    CM_INDEXED = 2,
+    CM_RGB = 3,
+    CM_CMYK = 4,
+    CM_MULTICHANNEL = 7,
+    CM_DUOTONE = 8,
+    CM_LABCOLOR = 9,
+};
+
+enum ImageResourceId : quint16 {
+    IRI_RESOLUTIONINFO = 0x03ED,
+    IRI_ICCPROFILE = 0x040F,
+    IRI_TRANSPARENCYINDEX = 0x0417,
+    IRI_ALPHAIDENTIFIERS = 0x041D,
+    IRI_VERSIONINFO = 0x0421,
+    IRI_EXIFDATA1 = 0x0422,
+    IRI_EXIFDATA3 = 0x0423, // never seen
+    IRI_XMPMETADATA = 0x0424
+};
+
+enum LayerId : quint32 {
+    LI_MT16 = 0x4D743136,   // 'Mt16',
+    LI_MT32 = 0x4D743332,   // 'Mt32',
+    LI_MTRN = 0x4D74726E    // 'Mtrn'
+};
+
+/*!
+ * \brief The PSDImageResourceBlock class
+ * Raw data of a PSD image resource block
+ */
+struct PSDImageResourceBlock {
+    QString name;
+    QByteArray data;
+};
+
+using PSDImageResourceSection = QHash<ImageResourceId, PSDImageResourceBlock>;
+
+
+/*!
+ * \brief readPascalString
+ * Reads the Pascal string as defined in the PSD specification.
+ * \param s The stream.
+ * \param alignBytes Alignment of the string.
+ * \param size Number of stream bytes used.
+ * \return The string read.
+ */
+QString readPascalString(QDataStream &s, qint32 alignBytes = 1, qint32 *size = nullptr);
+
+/*!
+ * \brief readImageResourceSection
+ * Reads the image resource section.
+ * \param s The stream.
+ * \param ok Pointer to the operation result variable.
+ * \return The image resource section raw data.
+ */
+PSDImageResourceSection readImageResourceSection(QDataStream &s, bool *ok = nullptr);
+
+#endif // PHOTOSHOP_P_H

src/imageformats/psd.cpp

@@ -29,12 +29,12 @@
 #include "fastmath_p.h"
 #include "microexif_p.h"
 #include "packbits_p.h"
+#include "photoshop_p.h"
 #include "psd_p.h"
 #include "scanlineconverter_p.h"
 #include "util_p.h"
 
 #include <QColorSpace>
-#include <QDataStream>
 #include <QImage>
 #include <QLoggingCategory>
 
@@ -99,41 +99,6 @@ namespace // Private.
 
 #define NATIVE_CMYK (CMYK_FORMAT != QImage::Format_Invalid)
 
-enum Signature : quint32 {
-    S_8BIM = 0x3842494D, // '8BIM'
-    S_8B64 = 0x38423634, // '8B64'
-
-    S_MeSa = 0x4D655361   // 'MeSa'
-};
-
-enum ColorMode : quint16 {
-    CM_BITMAP = 0,
-    CM_GRAYSCALE = 1,
-    CM_INDEXED = 2,
-    CM_RGB = 3,
-    CM_CMYK = 4,
-    CM_MULTICHANNEL = 7,
-    CM_DUOTONE = 8,
-    CM_LABCOLOR = 9,
-};
-
-enum ImageResourceId : quint16 {
-    IRI_RESOLUTIONINFO = 0x03ED,
-    IRI_ICCPROFILE = 0x040F,
-    IRI_TRANSPARENCYINDEX = 0x0417,
-    IRI_ALPHAIDENTIFIERS = 0x041D,
-    IRI_VERSIONINFO = 0x0421,
-    IRI_EXIFDATA1 = 0x0422,
-    IRI_EXIFDATA3 = 0x0423, // never seen
-    IRI_XMPMETADATA = 0x0424
-};
-
-enum LayerId : quint32 {
-    LI_MT16 = 0x4D743136,   // 'Mt16',
-    LI_MT32 = 0x4D743332,   // 'Mt32',
-    LI_MTRN = 0x4D74726E    // 'Mtrn'
-};
-
 struct PSDHeader {
     PSDHeader() {
         memset(this, 0, sizeof(PSDHeader));
@@ -149,11 +114,6 @@ struct PSDHeader {
     ushort color_mode;
 };
 
-struct PSDImageResourceBlock {
-    QString name;
-    QByteArray data;
-};
-
 /*!
  * \brief The PSDDuotoneOptions struct
  * \note You can decode the duotone data using the "Duotone Options"
@@ -172,7 +132,6 @@ struct PSDColorModeDataSection {
     QList<QRgb> palette;
 };
 
-using PSDImageResourceSection = QHash<quint16, PSDImageResourceBlock>;
 
 struct PSDLayerInfo {
     qint64 size = -1;
@@ -273,145 +232,6 @@ static bool skip_section(QDataStream &s, bool psb = false)
     return skip_data(s, section_length);
 }
 
-/*!
- * \brief readPascalString
- * Reads the Pascal string as defined in the PSD specification.
- * \param s The stream.
- * \param alignBytes Alignment of the string.
- * \param size Number of stream bytes used.
- * \return The string read.
- */
-static QString readPascalString(QDataStream &s, qint32 alignBytes = 1, qint32 *size = nullptr)
-{
-    qint32 tmp = 0;
-    if (size == nullptr)
-        size = &tmp;
-
-    quint8 stringSize;
-    s >> stringSize;
-    *size = sizeof(stringSize);
-
-    QString str;
-    if (stringSize > 0) {
-        QByteArray ba;
-        ba.resize(stringSize);
-        auto read = s.readRawData(ba.data(), ba.size());
-        if (read > 0) {
-            *size += read;
-            str = QString::fromLatin1(ba);
-        }
-    }
-
-    // align
-    if (alignBytes > 1)
-        if (auto pad = *size % alignBytes)
-            *size += s.skipRawData(alignBytes - pad);
-
-    return str;
-}
-
-/*!
- * \brief readImageResourceSection
- * Reads the image resource section.
- * \param s The stream.
- * \param ok Pointer to the operation result variable.
- * \return The image resource section raw data.
- */
-static PSDImageResourceSection readImageResourceSection(QDataStream &s, bool *ok = nullptr)
-{
-    PSDImageResourceSection irs;
-
-    bool tmp = true;
-    if (ok == nullptr)
-        ok = &tmp;
-    *ok = true;
-
-    // Section size
-    quint32 tmpSize;
-    s >> tmpSize;
-    qint64 sectioSize = tmpSize;
-
-    // Reading Image resource block
-    for (auto size = sectioSize; size > 0;) {
-
-#define DEC_SIZE(value) \
-        if ((size -= qint64(value)) < 0) { \
-            *ok = false; \
-            break; }
-
-        // Length      Description
-        // -------------------------------------------------------------------
-        // 4           Signature: '8BIM'
-        // 2           Unique identifier for the resource. Image resource IDs
-        //             contains a list of resource IDs used by Photoshop.
-        // Variable    Name: Pascal string, padded to make the size even
-        //             (a null name consists of two bytes of 0)
-        // 4           Actual size of resource data that follows
-        // Variable    The resource data, described in the sections on the
-        //             individual resource types. It is padded to make the size
-        //             even.
-
-        quint32 signature;
-        s >> signature;
-        DEC_SIZE(sizeof(signature))
-        // NOTE: MeSa signature is not documented but found in some old PSD take from Photoshop 7.0 CD.
-        if (signature != S_8BIM && signature != S_MeSa) { // 8BIM and MeSa
-            qCDebug(LOG_PSDPLUGIN) << "Invalid Image Resource Block Signature!";
-            *ok = false;
-            break;
-        }
-
-        // id
-        quint16 id;
-        s >> id;
-        DEC_SIZE(sizeof(id))
-
-        // getting data
-        PSDImageResourceBlock irb;
-
-        // name
-        qint32 bytes = 0;
-        irb.name = readPascalString(s, 2, &bytes);
-        DEC_SIZE(bytes)
-
-        // data read
-        quint32 dataSize;
-        s >> dataSize;
-        DEC_SIZE(sizeof(dataSize))
-        if (auto dev = s.device()) {
-            if (dataSize > size) {
-                qCDebug(LOG_PSDPLUGIN) << "Invalid Image Resource Block Data Size!";
-                *ok = false;
-                break;
-            }
-            irb.data = deviceRead(dev, dataSize);
-        }
-        auto read = irb.data.size();
-        if (read > 0) {
-            DEC_SIZE(read)
-        }
-        if (read != qint64(dataSize)) {
-            qCDebug(LOG_PSDPLUGIN) << "Image Resource Block Read Error!";
-            *ok = false;
-            break;
-        }
-
-        if (auto pad = dataSize % 2) {
-            auto skipped = s.skipRawData(pad);
-            if (skipped > 0) {
-                DEC_SIZE(skipped);
-            }
-        }
-
-        // insert IRB
-        irs.insert(id, irb);
-
-#undef DEC_SIZE
-    }
-
-    return irs;
-}
-
 PSDAdditionalLayerInfo readAdditionalLayer(QDataStream &s, bool *ok = nullptr)
 {
     PSDAdditionalLayerInfo li;

src/imageformats/rgb.cpp

@@ -314,6 +314,8 @@ bool SGIImagePrivate::readImage(QImage &img)
     _numrows = _ysize * _zsize;
 
     if (_rle) {
+        // start table holds file offsets; raster data follows header + both tables
+        const quint32 dataOff = 512 + _numrows * 2 * sizeof(quint32);
         uint l;
         _starttab = new (std::nothrow) quint32[_numrows];
         if (_starttab == nullptr) {
@@ -321,7 +323,10 @@ bool SGIImagePrivate::readImage(QImage &img)
         }
         for (l = 0; !_stream.atEnd() && l < _numrows; l++) {
             _stream >> _starttab[l];
-            _starttab[l] -= 512 + _numrows * 2 * sizeof(quint32);
+            if (_starttab[l] < dataOff) {
+                return false;
+            }
+            _starttab[l] -= dataOff;
             if (_stream.status() != QDataStream::Ok) {
                 return false;
             }
@@ -353,9 +358,10 @@ bool SGIImagePrivate::readImage(QImage &img)
 
     // sanity check
     if (_rle) {
+        const uint dataSize = uint(_data.size());
         for (uint o = 0; o < _numrows; o++) {
-            // don't change to greater-or-equal!
-            if (_starttab[o] + _lengthtab[o] > (uint)_data.size()) {
+            // don't add start+length: uint32 wrap would pass a corrupt file
+            if (_starttab[o] > dataSize || _lengthtab[o] > dataSize - _starttab[o]) {
                 //                 qCDebug(LOG_RGBPLUGIN) << "image corrupt (sanity check failed)";
                 return false;
             }

src/imageformats/util_p.h

@@ -165,20 +165,27 @@ inline bool checkImageSize(const QSize& size, qint32 bytesPerPixel)
     return checkImageSize(size.width(), size.height(), bytesPerPixel);
 }
 
+/*!
+ * \brief qRoundOrZero_T
+ * In images, many float values ​​can only be positive (e.g., resolution). This function calculates
+ * the roundness of the passed value, returning 0 if the value is negative or invalid.
+ * \return 0 when \a d is negative, NaN, Inf or std::numeric_limits<TI>::max(). Otherwise the qRound of \a d.
+ */
 template<class TI, class SF> // SF = source FP, TI = target INT
 TI qRoundOrZero_T(SF d, bool *ok = nullptr)
 {
+    bool tmp = false;
+    if (ok == nullptr) {
+        ok = &tmp;
+    }
+
     // checks for undefined behavior
-    if (qIsNaN(d) || qIsInf(d) || d < SF() || d > SF(std::numeric_limits<TI>::max())) {
-        if (ok) {
+    if (qIsNaN(d) || qIsInf(d) || d < SF()) {
         *ok = false;
+    } else {
+        *ok = d < SF(std::numeric_limits<TI>::max());
     }
-        return 0;
-    }
-    if (ok) {
-        *ok = true;
-    }
-    return qRound(d);
+    return *ok ? qRound(d) : 0;
 }
 
 inline qint32 qRoundOrZero(double d, bool *ok = nullptr)