cmake: add cmake config

That way, other projects can declare to have a runtime dependency on KImageFormats

CMakeLists.txt

@@ -1,11 +1,11 @@
 cmake_minimum_required(VERSION 3.16)
 
-set(KF_VERSION "6.13.0") # handled by release scripts
+set(KF_VERSION "6.15.0") # handled by release scripts
-set(KF_DEP_VERSION "6.13.0") # handled by release scripts
+set(KF_DEP_VERSION "6.14.0") # handled by release scripts
 project(KImageFormats VERSION ${KF_VERSION})
 
 include(FeatureSummary)
-find_package(ECM 6.13.0  NO_MODULE)
+find_package(ECM 6.14.0  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)
 
@@ -21,7 +21,7 @@ include(ECMDeprecationSettings)
 include(CheckIncludeFiles)
 include(FindPkgConfig)
 
-set(REQUIRED_QT_VERSION 6.6.0)
+set(REQUIRED_QT_VERSION 6.7.0)
 find_package(Qt6Gui ${REQUIRED_QT_VERSION} REQUIRED NO_MODULE)
 
 find_package(KF6Archive ${KF_DEP_VERSION})
@@ -100,7 +100,7 @@ add_feature_info(LibJXR LibJXR_FOUND "required for the QImage plugin for JPEG XR
 
 ecm_set_disabled_deprecation_versions(
     QT 6.9.0
-    KF 6.12.0
+    KF 6.13.0
 )
 
 add_subdirectory(src)
@@ -109,6 +109,28 @@ if (BUILD_TESTING)
     add_subdirectory(tests)
 endif()
 
+set(CMAKECONFIG_INSTALL_DIR "${KDE_INSTALL_CMAKEPACKAGEDIR}/KF6ImageFormats")
+include(CMakePackageConfigHelpers)
+
+write_basic_package_version_file(
+    "${CMAKE_CURRENT_BINARY_DIR}/KF6ImageFormatsConfigVersion.cmake"
+    VERSION ${PROJECT_VERSION}
+    COMPATIBILITY AnyNewerVersion
+)
+
+configure_package_config_file(
+    "${CMAKE_CURRENT_SOURCE_DIR}/KF6ImageFormatsConfig.cmake.in"
+    "${CMAKE_CURRENT_BINARY_DIR}/KF6ImageFormatsConfig.cmake"
+    INSTALL_DESTINATION "${CMAKECONFIG_INSTALL_DIR}"
+)
+
+install(FILES
+  "${CMAKE_CURRENT_BINARY_DIR}/KF6ImageFormatsConfig.cmake"
+  "${CMAKE_CURRENT_BINARY_DIR}/KF6ImageFormatsConfigVersion.cmake"
+  DESTINATION "${CMAKECONFIG_INSTALL_DIR}"
+  COMPONENT Devel
+)
+
 include(ECMFeatureSummary)
 ecm_feature_summary(WHAT ALL FATAL_ON_MISSING_REQUIRED_PACKAGES)
 

KF6ImageFormatsConfig.cmake.in

@@ -0,0 +1,5 @@
+# SPDX-FileCopyrightText: 2025 Xaver Hugl <xaver.hugl@gmail.com>
+# SPDX-License-Identifier: BSD-2-Clause
+
+@PACKAGE_INIT@
+# empty, because this is plugins for Qt instead of a library to link against

README.md

@@ -53,8 +53,10 @@ willing to sign the Qt Project contributor agreement, it may be better to
 submit the plugin directly to the Qt Project.
 
 To be accepted, contributions must:
-- Contain the test images needed to verify that the changes work correctly
+- Contain the test images needed to verify that the changes work correctly.
-- Pass the tests successfully
+- Pass the tests successfully.
+
+For more info about tests, see also [Autotests README](autotests/README.md).
 
 ## Duplicated Plugins
 

autotests/README.md

@@ -0,0 +1,253 @@
+# Autotests
+
+Automated testing for plugins to allow 
+[`QImage`](https://doc.qt.io/qt-6/qimage.html) to support
+extra file formats.
+
+## Introduction
+
+The testing part is essential for the correct functioning of the plugins. 
+There are generic read/write tests and specific tests for the plugins that
+require them.
+
+## Read tests
+
+The generic reading tests are contained in the `read` folder. Inside the 
+`read` folder, there are one or more folders for each plugin to be tested.
+A plugin can support multiple image file types, and if you need different 
+parameters for each type, you need to create a folder for each type supported
+by the plugin (see e.g. HEIF plugin). If all formats supported by the plugin 
+do not require different parameters, a single folder approach is simpler (see 
+e.g. PSD plugin).
+
+The reading tests are mainly based on comparing the image read by the plugin 
+with a template in a known and working format. For this reason, the template 
+formats chosen are those distributed by the Qt project: PNG in the first 
+instance and TIFF for image formats not supported by PNG (e.g. CMYK images).
+
+Some image options such as `QImageIOHandler::Size`, 
+`QImageIOHandler::ImageFormat` and `QImageIOHandler::ImageTransformation` are 
+also checked. If supported by the plugin, the resulting image is checked to 
+see if it is compatible with the option's specification.
+
+Optionally, for each image, you can also create a JSON file to modify the test 
+behavior and/or verify data other than image pixels, such as metadata.
+
+Finally, two tests are run for each test case:
+- On a random access device: this test must not fail.
+- On a sequential access device: a plugin may not support sequential operation. 
+In this case, the test is skipped. However, if an image is returned, the test 
+must succeed.
+
+### The readtest command
+
+To start a test, run the `readtest` command with the format to test as an 
+argument. The format is one of those supported by plugins and a folder with 
+the name of the format must be present inside the `read` folder.
+Depending on the format, you can specify the following additional options.
+
+- `--help`: Displays help on commandline options.
+- `--fuzz <max>`: The fuzziness. Used to add some deviation in ARGB data 
+(nornally used on lossy codec).
+- `--perceptive-fuzz`: Used to scale dynamically the fuzziness based on 
+the alpha channel value. This is useful on images with pre-multiplied and 
+small alphas. Qt can use different roundings based on optimizations resulting 
+in very different RGB values. Since the alpha is small visually there is no 
+difference (so it is not considered an error).
+- `--skip-optional-tests`: Used to skip the optional test such as metadata 
+and resolution tests.
+
+Note that some tests may fail if the correct options are not used. The correct
+options for each test are defined in [CMakeLists.txt](CMakeLists.txt).
+See also [Add a test to CMakeLists.txt](#add-a-test-to-cmakeliststxt).
+
+### Test image nomenclature
+
+Each test consists of the image to test, the verification image(s) (template)
+and, optionally, the additional JSON file.
+To be a test, the names of these files must be the same (except for 
+the extension). A test for a JXL image would be, for example, composed like 
+this:
+- `testRGB.jxl`: The image to test.
+- `testRGB.jxl.json`: The test behavior modifier (note that it must contain 
+the double extension).
+- `testRGB.png`: How the image should look (template). The template name 
+can be different if specified in the JSON file.
+
+Although there is no precise rule for the name of a test, it is good to have 
+a name that is explanatory.
+
+### JSON behavior file
+
+The behavior file was initially introduced to solve compatibility issues 
+between different versions of Qt supported by the framework. It was later 
+extended to also check image metadata.
+
+The JSON file consists of an array of JSON objects. The objects in the array 
+are iterated sequentially and the first object that matches the requirements 
+is used for testing (successes are ignored).
+
+Supported values ​​for JSON objects:
+- `comment`: Type string. A string shown by the test when a condition occurs.
+- `description`: Type string. A description of the object. Not used by the 
+test.
+- `disableAutoTransform`: Type boolean. By default, tests are run with 
+autotransform enabled (i.e. rotation is applied if the plugin supports it).
+Set to `true` to disable autotransform.
+- `filename`: Type string. Name of the template file to use. E.g. 
+"testRGB_Qt_6_2.png".
+- `fuzziness`: Type integer. Set the fuzziness only if not already set on the 
+command line. The value set on the command line wins over the one in the JSON 
+file.
+- `maxQtVersion`: Type string. Maximum Qt version this object is compatible 
+with (if not set means all). E.g. "6.2.99".
+- `metadata`: Type Array. An array of key/value objects (string type) 
+containing the image metadata as returned by `QImage::text`.
+- `minQtVersion`: Type string. Minimum Qt version this object is compatible 
+with (if not set means all). E.g. "6.2.0".
+- `perceptiveFuzziness` Type boolean. Set the perceptive fuzziness only if not
+already set on the command line. The value set on the command line wins over 
+the one in the JSON file.
+- `resolution`: Type object. An object with the `dotsPerMeterX` and
+`dotsPerMeterY` (integer) values ​​of the image.
+- `seeAlso`: Type string. More info about the object. Normally used to point
+to bug reports. Not used by the test.
+- `unsupportedFormat`: Type `boolean`. When true, the test is skipped.
+
+Some examples:
+- Example 1: [Runs only on Qt without alpha bug on float formats](read/jxl/testcard_rgba_fp16.jxl.json)
+- Example 2: [Rotation disabled](read/jxl/orientation6_notranfs.jxl.json)
+- Example 3: [Metadata](read/psd/metadata.psd.json)
+- Example 4: [Check Qt version, resolution and metadata](read/psd/mch-16bits.psd.json)
+- Example 5: [Fuzziness setting](read/xcf/birthday16.xcf.json)
+ 
+These are just a few examples. More examples can be found in the test folders.
+
+## Write tests
+
+The generic writing tests are contained in the `write/basic` and 
+`write/format` folders. Similar to the read tests, they verify the written 
+(and then reread) image with a template.
+
+The write test is composed of several phases:
+- Basic test: Uses the `write/basic` folder and checks the most common images 
+and, optionally, metadata and resolution via a JSON properties file.
+- Format test: Uses the `write/format` folder and checks that all QImage image
+formats are written correctly.
+- Dimensional test: Uses the `write/format` folder and check images of 
+different sizes (odd numbers, prime numbers, etc.) to verify internal 
+alignments.
+- Null device test: Verify that there are no crashes if the device is null.
+
+### The writetest command
+
+To start a test, run the `writetest` command with the format to test as an 
+argument. The format is one of those supported by plugins, a folder with 
+the name of the format must be present inside the `write/format` folder and 
+may need a template image in `write/basic`.
+Depending on the format, you can specify the following additional options.
+
+- `--help`: Displays help on commandline options.
+- `--create-format-templates`: Create template images for all formats 
+supported by the QImage in `write/format`. Command to simplify the creation of
+format test images when adding a new plugin or modifying an old one. This 
+command is not intended to be used from the CMakeLists file as it must be used
+manually and the generated images must be verified one by one.
+- `--fuzz <max>`: The fuzziness. Used to add some deviation in ARGB data 
+(nornally used on lossy codec).
+- `--lossless`: Check that reading back the data gives the same image.
+- `--no-data-check`: Don't check that write data is exactly the same.
+- `--skip-optional-tests`: Skip optional data tests (metadata, resolution,
+etc...).
+
+Note that some tests may fail if the correct options are not used. The correct
+options for each test are defined in [CMakeLists.txt](CMakeLists.txt).
+See also [Add a test to CMakeLists.txt](#add-a-test-to-cmakeliststxt).
+
+### JSON properties file
+
+The properties file must be located in `write/basic` and must have the name 
+of the file format (e.g. jxl.json). It is a JSON object composed of the 
+following values:
+- `format`: Type string. The format tested.
+- `metadata`: Type Array. An array of key/value objects (string type) 
+containing the image metadata as returned by `QImage::text`.
+- `resolution`: Type object. An object with the `dotsPerMeterX` and `
+dotsPerMeterY` (integer) values ​​of the image.
+
+[This is an example](write/basic/jxl.json) of property file.
+
+
+## Custom tests
+
+If the generic read/write tests do not meet the requirements of a plugin, 
+it is possible to write a custom test. 
+In general it makes sense to write a dedicated test for a format if and 
+only if you are testing unique features not present in other plugins.
+
+### The PIC test
+
+The PIC test is generated using Qt Test class. For more information 
+see [Qt Test](https://doc.qt.io/qt-6/qttest-index.html).
+
+### The ANI test
+
+The ANI test is generated using Qt Test class. For more information 
+see [Qt Test](https://doc.qt.io/qt-6/qttest-index.html).
+
+
+## Add a test to CMakeLists.txt
+
+To add a test to CMake use the `kimageformats_read_tests` and 
+`kimageformats_write_tests` functions. For example, to add the read 
+tests for the PSD you just write `kimageformats_read_tests(psd)`.
+
+It is also possible to pass command line arguments to the test by 
+appropriately composing the string passed to the test functions.
+For boolean parameters you need to add a string starting with '-' 
+after the image format. For example, to pass `--skip-optional-tests` 
+to the PSD plugin write `kimageformats_read_tests(psd-skipoptional)`.
+
+To add a fuzziness of 4, you must first set it as follows: 
+`kimageformats_read_tests(FUZZ 4 psd-skipoptional)`.
+
+The possible modifiers for `kimageformats_read_tests` are as follows:
+- `-skipoptional`: Add the `--skip-optional-tests` command line parameter.
+
+The possible modifiers for `kimageformats_write_tests` are as follows:
+- `-lossless`: Add the `--lossless` command line parameter.
+- `-nodatacheck`: Add the `--no-data-check` command line parameter.
+- `-skipoptional`: Add the `--skip-optional-tests` command line parameter.
+
+To set multiple parameters, you can enter multiple modifiers. For example:
+```
+kimageformats_write_tests(FUZZ 1
+    hej2-nodatacheck-lossless
+)
+```
+
+## OSS-Fuzz
+
+Plugins are also tested with [OSS-Fuzz](https://google.github.io/oss-fuzz/)
+project to identify possible security issues. When adding a new plugin it is 
+also necessary to add it to the test in the [kimageformats 
+project](https://github.com/google/oss-fuzz/tree/master/projects/kimageformats) 
+on OSS-Fuzz.
+
+## TODO
+
+List of tests not implemented or only partially implemented.
+
+### Color Profiles Test
+
+Many plugins support color profiles via [`QColorSpace`](https://doc.qt.io/qt-6/qcolorspace.html). 
+Checking for correct color management is increasingly necessary especially now
+that monitors are HDR and other than RGB color spaces have been added to Qt.
+
+Furthermore, lossy plugins often have different color management behaviors 
+depending on how the image is saved.
+
+### Animations Test
+
+Few plugins support animations. There are currently no plans for 
+implementation.

autotests/write/basic/avif.json

@@ -31,7 +31,7 @@
         },
         {
             "key" : "Description",
-            "value" : "TV broadcast test image."
+            "value" : "テレビ放送テスト映像。(TV broadcast test image.)"
         },
         {
             "key" : "Latitude",

autotests/write/basic/heif.json

@@ -31,7 +31,7 @@
         },
         {
             "key" : "Description",
-            "value" : "TV broadcast test image."
+            "value" : "テレビ放送テスト映像。(TV broadcast test image.)"
         },
         {
             "key" : "Latitude",

autotests/write/basic/jxl.json

@@ -31,7 +31,7 @@
         },
         {
             "key" : "Description",
-            "value" : "TV broadcast test image."
+            "value" : "テレビ放送テスト映像。(TV broadcast test image.)"
         },
         {
             "key" : "Latitude",

src/imageformats/CMakeLists.txt

@@ -15,6 +15,16 @@ function(kimageformats_add_plugin plugin)
     target_sources(${plugin} PRIVATE ${KIF_ADD_PLUGIN_SOURCES})
     set_target_properties(${plugin} PROPERTIES LIBRARY_OUTPUT_DIRECTORY ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/imageformats)
     target_link_libraries(${plugin} PRIVATE Qt6::Gui)
+
+    if(ANDROID)
+        # Plugins should be named with lib prefix on Android
+        # Working name: libplugins_imageformats_kimg_avif_armeabi-v7a.so
+        # Doesn't work: plugins_imageformats_kimg_avif_armeabi-v7a.so
+        if(NOT ${CMAKE_SHARED_LIBRARY_PREFIX} STREQUAL "")
+            set_target_properties(${plugin} PROPERTIES PREFIX ${CMAKE_SHARED_LIBRARY_PREFIX})
+        endif()
+    endif()
+
     install(TARGETS ${plugin} DESTINATION ${KDE_INSTALL_QTPLUGINDIR}/imageformats)
 endfunction()
 

src/imageformats/jxl.cpp

@@ -20,7 +20,7 @@
 #include <string.h>
 
 // Avoid rotation on buggy Qts (see also https://bugreports.qt.io/browse/QTBUG-126575)
-#if (QT_VERSION >= QT_VERSION_CHECK(6, 5, 7) && QT_VERSION < QT_VERSION_CHECK(6, 6, 0)) || (QT_VERSION >= QT_VERSION_CHECK(6, 7, 3))
+#if QT_VERSION >= QT_VERSION_CHECK(6, 7, 3)
 #ifndef JXL_QT_AUTOTRANSFORM
 #define JXL_QT_AUTOTRANSFORM
 #endif

src/imageformats/jxr.cpp

@@ -243,6 +243,24 @@ public:
         return true;
     }
 
+    /*!
+     * \brief initForReadingAndRollBack
+     * Initialize the device for reading and rollback the device to start position.
+     * \param device The source device.
+     * \return True on success, otherwise false.
+     */
+    bool initForReadingAndRollBack(QIODevice *device)
+    {
+        if (device) {
+            device->startTransaction();
+        }
+        auto ok = initForReading(device);
+        if (device) {
+            device->rollbackTransaction();
+        }
+        return ok;
+    }
+
     /*!
      * \brief jxrFormat
      * \return The JXR format.
@@ -720,11 +738,11 @@ public:
 
         auto exif = MicroExif::fromImage(image);
         if (!exif.isEmpty()) {
-            auto exifIfd = exif.exifIfdByteArray(QDataStream::LittleEndian);
+            auto exifIfd = exif.exifIfdByteArray(QDataStream::LittleEndian, MicroExif::V2);
             if (auto err = PKImageEncode_SetEXIFMetadata_WMP(pEncoder, reinterpret_cast<const quint8 *>(exifIfd.constData()), exifIfd.size())) {
                 qCWarning(LOG_JXRPLUGIN) << "JXRHandler::write() error while setting EXIF data:" << err;
             }
-            auto gpsIfd = exif.gpsIfdByteArray(QDataStream::LittleEndian);
+            auto gpsIfd = exif.gpsIfdByteArray(QDataStream::LittleEndian, MicroExif::V2);
             if (auto err = PKImageEncode_SetGPSInfoMetadata_WMP(pEncoder, reinterpret_cast<const quint8 *>(gpsIfd.constData()), gpsIfd.size())) {
                 qCWarning(LOG_JXRPLUGIN) << "JXRHandler::write() error while setting GPS data:" << err;
             }
@@ -991,7 +1009,7 @@ bool JXRHandler::read(QImage *outImage)
                 return false;
             }
             for (qint32 y = 0, h = img.height(); y < h; ++y) {
-                std::memcpy(img.scanLine(y), ba.data() + convStrideSize * y, (std::min)(convStrideSize, img.bytesPerLine()));
+                std::memcpy(img.scanLine(y), ba.data() + convStrideSize * y, (std::min)(convStrideSize, qint64(img.bytesPerLine())));
             }
         }
         PKFormatConverter_Release(&pConverter);
@@ -1153,7 +1171,7 @@ QVariant JXRHandler::option(ImageOption option) const
     QVariant v;
 
     if (option == QImageIOHandler::Size) {
-        if (d->initForReading(device())) {
+        if (d->initForReadingAndRollBack(device())) {
             auto size = d->imageSize();
             if (size.isValid()) {
                 v = QVariant::fromValue(size);
@@ -1162,7 +1180,7 @@ QVariant JXRHandler::option(ImageOption option) const
     }
 
     if (option == QImageIOHandler::ImageFormat) {
-        if (d->initForReading(device())) {
+        if (d->initForReadingAndRollBack(device())) {
             v = QVariant::fromValue(d->imageFormat());
         }
     }
@@ -1173,7 +1191,7 @@ QVariant JXRHandler::option(ImageOption option) const
 
     if (option == QImageIOHandler::ImageTransformation) {
         // ignore result: I might want to read the value set in writing
-        d->initForReading(device());
+        d->initForReadingAndRollBack(device());
         v = int(d->transformation());
     }
 

src/imageformats/microexif.cpp

@@ -12,6 +12,7 @@
 #include <QCoreApplication>
 #include <QDataStream>
 #include <QHash>
+#include <QStringDecoder>
 #include <QTimeZone>
 
 // TIFF 6 specs
@@ -111,17 +112,17 @@ static const KnownTags staticTagTypes = {
     TagInfo(TIFF_IMAGEWIDTH, ExifTagType::Long),
     TagInfo(TIFF_IMAGEHEIGHT, ExifTagType::Long),
     TagInfo(TIFF_BITSPERSAMPLE, ExifTagType::Short),
-    TagInfo(TIFF_IMAGEDESCRIPTION, ExifTagType::Ascii),
+    TagInfo(TIFF_IMAGEDESCRIPTION, ExifTagType::Utf8),
-    TagInfo(TIFF_MAKE, ExifTagType::Ascii),
+    TagInfo(TIFF_MAKE, ExifTagType::Utf8),
-    TagInfo(TIFF_MODEL, ExifTagType::Ascii),
+    TagInfo(TIFF_MODEL, ExifTagType::Utf8),
     TagInfo(TIFF_ORIENT, ExifTagType::Short),
     TagInfo(TIFF_XRES, ExifTagType::Rational),
     TagInfo(TIFF_YRES, ExifTagType::Rational),
     TagInfo(TIFF_URES, ExifTagType::Short),
-    TagInfo(TIFF_SOFTWARE, ExifTagType::Ascii),
+    TagInfo(TIFF_SOFTWARE, ExifTagType::Utf8),
-    TagInfo(TIFF_ARTIST, ExifTagType::Ascii),
+    TagInfo(TIFF_ARTIST, ExifTagType::Utf8),
     TagInfo(TIFF_DATETIME, ExifTagType::Ascii),
-    TagInfo(TIFF_COPYRIGHT, ExifTagType::Ascii),
+    TagInfo(TIFF_COPYRIGHT, ExifTagType::Utf8),
     TagInfo(EXIF_EXIFIFD, ExifTagType::Long),
     TagInfo(EXIF_GPSIFD, ExifTagType::Long),
     TagInfo(EXIF_DATETIMEORIGINAL, ExifTagType::Ascii),
@@ -134,10 +135,10 @@ static const KnownTags staticTagTypes = {
     TagInfo(EXIF_PIXELYDIM, ExifTagType::Long),
     TagInfo(EXIF_IMAGEUNIQUEID, ExifTagType::Ascii),
     TagInfo(EXIF_BODYSERIALNUMBER, ExifTagType::Ascii),
-    TagInfo(EXIF_LENSMAKE, ExifTagType::Ascii),
+    TagInfo(EXIF_LENSMAKE, ExifTagType::Utf8),
-    TagInfo(EXIF_LENSMODEL, ExifTagType::Ascii),
+    TagInfo(EXIF_LENSMODEL, ExifTagType::Utf8),
     TagInfo(EXIF_LENSSERIALNUMBER, ExifTagType::Ascii),
-    TagInfo(EXIF_IMAGETITLE, ExifTagType::Ascii),
+    TagInfo(EXIF_IMAGETITLE, ExifTagType::Utf8),
     TagInfo(EXIF_EXIFVERSION, ExifTagType::Undefined)
 };
 // clang-format on
@@ -367,6 +368,28 @@ static void writeData(QDataStream &ds, const QVariant &value, const ExifTagType&
     }
 }
 
+static ExifTagType updateDataType(const ExifTagType &dataType, const QVariant &value, const MicroExif::Version &ver)
+{
+    if (dataType != ExifTagType::Utf8)
+        return dataType;
+
+    if (ver == MicroExif::V2)
+        return ExifTagType::Ascii;
+
+    // Note that in EXIF specs, UTF-8 is backward compatible with ASCII: all UTF-8 tags can also be ASCII.
+    // To maximize compatibility, I check if the string can be encoded in ASCII.
+    auto txt = value.toString();
+
+    // Exif ASCII data type allow only values up to 127 (7-bit ASCII).
+    auto u8 = txt.toUtf8();
+    for (auto &&c : u8) {
+        if (uchar(c) > 127)
+            return dataType;
+    }
+
+    return ExifTagType::Ascii;
+}
+
 /*!
  * \brief writeIfd
  * \param ds The stream.
@@ -375,7 +398,12 @@ static void writeData(QDataStream &ds, const QVariant &value, const ExifTagType&
  * \param knownTags List of known and supported tags.
  * \return True on success, otherwise false.
  */
-static bool writeIfd(QDataStream &ds, const MicroExif::Tags &tags, TagPos &positions, quint32 pos = 0, const KnownTags &knownTags = staticTagTypes)
+static bool writeIfd(QDataStream &ds,
+                     const MicroExif::Version &ver,
+                     const MicroExif::Tags &tags,
+                     TagPos &positions,
+                     quint32 pos = 0,
+                     const KnownTags &knownTags = staticTagTypes)
 {
     if (tags.isEmpty())
         return true;
@@ -390,7 +418,7 @@ static bool writeIfd(QDataStream &ds, const MicroExif::Tags &tags, TagPos &posit
             continue;
         }
         auto value = tags.value(key);
-        auto dataType = knownTags.value(key);
+        auto dataType = updateDataType(knownTags.value(key), value, ver);
         auto count = countBytes(dataType, value);
 
         ds << quint16(key);
@@ -412,9 +440,8 @@ static bool writeIfd(QDataStream &ds, const MicroExif::Tags &tags, TagPos &posit
         if (!knownTags.contains(key)) {
             continue;
         }
-
         auto value = tags.value(key);
-        auto dataType = knownTags.value(key);
+        auto dataType = updateDataType(knownTags.value(key), value, ver);
         auto count = countBytes(dataType, value);
         auto valueSize = count * EXIF_TAG_SIZEOF(dataType);
         if (valueSize <= 4)
@@ -534,8 +561,16 @@ static bool readIfd(QDataStream &ds, MicroExif::Tags &tags, quint32 pos = 0, con
 
         if (dataType == EXIF_TAG_DATATYPE(ExifTagType::Ascii) || dataType == EXIF_TAG_DATATYPE(ExifTagType::Utf8)) {
             auto l = readBytes(ds, count, true);
-            if (!l.isEmpty())
+            if (!l.isEmpty()) {
-                tags.insert(tagId, dataType == EXIF_TAG_DATATYPE(ExifTagType::Utf8) ? QString::fromUtf8(l) : QString::fromLatin1(l));
+                // It seems that converting to Latin 1 never detects errors so, using UTF-8.
+                // Note that if the dataType is ASCII, by EXIF specification, it must use only the
+                // first 128 values ​​so the UTF-8 conversion is correct.
+                auto dec = QStringDecoder(QStringDecoder::Utf8);
+                // QStringDecoder raise an error only after converting to QString
+                auto ut8 = QString(dec(l));
+                // If there are errors in the conversion to UTF-8, then I try with latin1 (extended ASCII)
+                tags.insert(tagId, dec.hasError() ? QString::fromLatin1(l) : ut8);
+            }
         } else if (dataType == EXIF_TAG_DATATYPE(ExifTagType::Undefined)) {
             auto l = readBytes(ds, count, false);
             if (!l.isEmpty())
@@ -1032,7 +1067,7 @@ void MicroExif::setImageDirection(double degree, bool isMagnetic)
     m_gpsTags.insert(GPS_IMGDIRECTION, degree);
 }
 
-QByteArray MicroExif::toByteArray(const QDataStream::ByteOrder &byteOrder) const
+QByteArray MicroExif::toByteArray(const QDataStream::ByteOrder &byteOrder, const Version &version) const
 {
     QByteArray ba;
     {
@@ -1043,16 +1078,16 @@ QByteArray MicroExif::toByteArray(const QDataStream::ByteOrder &byteOrder) const
     return ba;
 }
 
-QByteArray MicroExif::exifIfdByteArray(const QDataStream::ByteOrder &byteOrder) const
+QByteArray MicroExif::exifIfdByteArray(const QDataStream::ByteOrder &byteOrder, const Version &version) const
 {
     QByteArray ba;
     {
         QDataStream ds(&ba, QIODevice::WriteOnly);
         ds.setByteOrder(byteOrder);
         auto exifTags = m_exifTags;
-        exifTags.insert(EXIF_EXIFVERSION, QByteArray("0300"));
+        exifTags.insert(EXIF_EXIFVERSION, version == Version::V3 ? QByteArray("0300") : QByteArray("0232"));
         TagPos positions;
-        if (!writeIfd(ds, exifTags, positions))
+        if (!writeIfd(ds, version, exifTags, positions))
             return {};
     }
     return ba;
@@ -1065,7 +1100,7 @@ bool MicroExif::setExifIfdByteArray(const QByteArray &ba, const QDataStream::Byt
     return readIfd(ds, m_exifTags, 0, staticTagTypes);
 }
 
-QByteArray MicroExif::gpsIfdByteArray(const QDataStream::ByteOrder &byteOrder) const
+QByteArray MicroExif::gpsIfdByteArray(const QDataStream::ByteOrder &byteOrder, const Version &version) const
 {
     QByteArray ba;
     {
@@ -1074,7 +1109,7 @@ QByteArray MicroExif::gpsIfdByteArray(const QDataStream::ByteOrder &byteOrder) c
         auto gpsTags = m_gpsTags;
         gpsTags.insert(GPS_GPSVERSION, QByteArray("2400"));
         TagPos positions;
-        if (!writeIfd(ds, gpsTags, positions, 0, staticGpsTagTypes))
+        if (!writeIfd(ds, version, gpsTags, positions, 0, staticGpsTagTypes))
             return {};
         return ba;
     }
@@ -1087,7 +1122,7 @@ bool MicroExif::setGpsIfdByteArray(const QByteArray &ba, const QDataStream::Byte
     return readIfd(ds, m_gpsTags, 0, staticGpsTagTypes);
 }
 
-bool MicroExif::write(QIODevice *device, const QDataStream::ByteOrder &byteOrder) const
+bool MicroExif::write(QIODevice *device, const QDataStream::ByteOrder &byteOrder, const Version &version) const
 {
     if (device == nullptr || device->isSequential() || isEmpty())
         return false;
@@ -1096,7 +1131,7 @@ bool MicroExif::write(QIODevice *device, const QDataStream::ByteOrder &byteOrder
         ds.setByteOrder(byteOrder);
         if (!writeHeader(ds))
             return false;
-        if (!writeIfds(ds))
+        if (!writeIfds(ds, version))
             return false;
     }
     device->close();
@@ -1327,30 +1362,30 @@ bool MicroExif::writeHeader(QDataStream &ds) const
     return ds.status() ==  QDataStream::Ok;
 }
 
-bool MicroExif::writeIfds(QDataStream &ds) const
+bool MicroExif::writeIfds(QDataStream &ds, const Version &version) const
 {
     auto tiffTags = m_tiffTags;
     auto exifTags = m_exifTags;
     auto gpsTags = m_gpsTags;
-    updateTags(tiffTags, exifTags, gpsTags);
+    updateTags(tiffTags, exifTags, gpsTags, version);
 
     TagPos positions;
-    if (!writeIfd(ds, tiffTags, positions))
+    if (!writeIfd(ds, version, tiffTags, positions))
         return false;
-    if (!writeIfd(ds, exifTags, positions, positions.value(EXIF_EXIFIFD)))
+    if (!writeIfd(ds, version, exifTags, positions, positions.value(EXIF_EXIFIFD)))
         return false;
-    if (!writeIfd(ds, gpsTags, positions, positions.value(EXIF_GPSIFD), staticGpsTagTypes))
+    if (!writeIfd(ds, version, gpsTags, positions, positions.value(EXIF_GPSIFD), staticGpsTagTypes))
         return false;
     return true;
 }
 
-void MicroExif::updateTags(Tags &tiffTags, Tags &exifTags, Tags &gpsTags) const
+void MicroExif::updateTags(Tags &tiffTags, Tags &exifTags, Tags &gpsTags, const Version &version) const
 {
     if (exifTags.isEmpty()) {
         tiffTags.remove(EXIF_EXIFIFD);
     } else {
         tiffTags.insert(EXIF_EXIFIFD, quint32());
-        exifTags.insert(EXIF_EXIFVERSION, QByteArray("0300"));
+        exifTags.insert(EXIF_EXIFVERSION, version == Version::V3 ? QByteArray("0300") : QByteArray("0232"));
     }
     if (gpsTags.isEmpty()) {
         tiffTags.remove(EXIF_GPSIFD);

src/imageformats/microexif_p.h

@@ -37,6 +37,15 @@ class MicroExif
 public:
     using Tags = QMap<quint16, QVariant>;
 
+    /*!
+     * \brief The Version enum
+     * Exif specs version used when writing.
+     */
+    enum Version {
+        V2, // V2.xx
+        V3 // V3.xx, use of UTF-8 data type (default)
+    };
+
     /*!
      * \brief MicroExif
      * Constructs an empty class.
@@ -265,18 +274,20 @@ public:
      * - EXIF IFD
      * - GPS IFD
      * \param byteOrder Sets the serialization byte order for EXIF data.
+     * \param version The EXIF specs version to use.
      * \return A byte array containing the serialized data.
      * \sa write
      */
-    QByteArray toByteArray(const QDataStream::ByteOrder &byteOrder = EXIF_DEFAULT_BYTEORDER) const;
+    QByteArray toByteArray(const QDataStream::ByteOrder &byteOrder = EXIF_DEFAULT_BYTEORDER, const Version &version = Version::V3) const;
 
     /*!
      * \brief exifIfdByteArray
      * Convert the EXIF IFD only to RAW data. Useful when you want to add EXIF data to an existing TIFF container.
      * \param byteOrder Sets the serialization byte order for the data.
+     * \param version The EXIF specs version to use.
      * \return A byte array containing the serialized data.
      */
-    QByteArray exifIfdByteArray(const QDataStream::ByteOrder &byteOrder = EXIF_DEFAULT_BYTEORDER) const;
+    QByteArray exifIfdByteArray(const QDataStream::ByteOrder &byteOrder = EXIF_DEFAULT_BYTEORDER, const Version &version = Version::V3) const;
     /*!
      * \brief setExifIfdByteArray
      * \param ba The RAW data of EXIF IFD.
@@ -289,9 +300,10 @@ public:
      * \brief gpsIfdByteArray
      * Convert the GPS IFD only to RAW data. Useful when you want to add GPS data to an existing TIFF container.
      * \param byteOrder Sets the serialization byte order for the data.
+     * \param version The EXIF specs version to use.
      * \return A byte array containing the serialized data.
      */
-    QByteArray gpsIfdByteArray(const QDataStream::ByteOrder &byteOrder = EXIF_DEFAULT_BYTEORDER) const;
+    QByteArray gpsIfdByteArray(const QDataStream::ByteOrder &byteOrder = EXIF_DEFAULT_BYTEORDER, const Version &version = Version::V3) const;
     /*!
      * \brief setGpsIfdByteArray
      * \param ba The RAW data of GPS IFD.
@@ -309,10 +321,11 @@ public:
      * - GPS IFD
      * \param device A random access device.
      * \param byteOrder Sets the serialization byte order for EXIF data.
+     * \param version The EXIF specs version to use.
      * \return True on success, otherwise false.
      * \sa toByteArray
      */
-    bool write(QIODevice *device, const QDataStream::ByteOrder &byteOrder = EXIF_DEFAULT_BYTEORDER) const;
+    bool write(QIODevice *device, const QDataStream::ByteOrder &byteOrder = EXIF_DEFAULT_BYTEORDER, const Version &version = Version::V3) const;
 
     /*!
      * \brief updateImageMetadata
@@ -373,8 +386,8 @@ private:
     void setGpsString(quint16 tagId, const QString& s);
     QString gpsString(quint16 tagId) const;
     bool writeHeader(QDataStream &ds) const;
-    bool writeIfds(QDataStream &ds) const;
+    bool writeIfds(QDataStream &ds, const Version &version) const;
-    void updateTags(Tags &tiffTags, Tags &exifTags, Tags &gpsTags) const;
+    void updateTags(Tags &tiffTags, Tags &exifTags, Tags &gpsTags, const Version &version) const;
 
     static void setString(Tags &tags, quint16 tagId, const QString &s);
     static QString string(const Tags &tags, quint16 tagId);

src/imageformats/xcf.cpp

@@ -962,11 +962,7 @@ bool XCFImageFormat::loadImageProperties(QDataStream &xcf_io, XCFImage &xcf_imag
         case PROP_PARASITES:
             while (!property.atEnd()) {
                 char *tag;
-#if QT_VERSION < QT_VERSION_CHECK(6, 7, 0)
-                quint32 size;
-#else
                 qint64 size;
-#endif
 
                 property.readBytes(tag, size);