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

@@ -11,5 +11,3 @@ 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/pfm/testcard_gray_half.phm binary
-autotests/read/pfm/testcard_rgb_half.phm binary

.gitlab-ci.yml

@@ -5,7 +5,6 @@ include:
   - project: sysadmin/ci-utilities
     file:
       - /gitlab-templates/linux-qt6.yml
-      - /gitlab-templates/alpine-qt6.yml
       - /gitlab-templates/android-qt6.yml
       - /gitlab-templates/freebsd-qt6.yml
       - /gitlab-templates/windows-qt6.yml

.kde-ci.yml

@@ -7,4 +7,3 @@ Dependencies:
 Options:
   test-before-installing: True
   require-passing-tests-on: [ 'Linux', 'FreeBSD', 'Windows' ]
-  cmake-options: "-DKIMAGEFORMATS_DDS=ON -DKIMAGEFORMATS_JXR=ON"

CMakeLists.txt

@@ -1,11 +1,11 @@
 cmake_minimum_required(VERSION 3.16)
 
-set(KF_VERSION "6.10.0") # handled by release scripts
-set(KF_DEP_VERSION "6.10.0") # handled by release scripts
+set(KF_VERSION "6.4.0") # handled by release scripts
+set(KF_DEP_VERSION "6.4.0") # handled by release scripts
 project(KImageFormats VERSION ${KF_VERSION})
 
 include(FeatureSummary)
-find_package(ECM 6.10.0  NO_MODULE)
+find_package(ECM 6.4.0  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 6.5.0)
 find_package(Qt6Gui ${REQUIRED_QT_VERSION} REQUIRED NO_MODULE)
 
 find_package(KF6Archive ${KF_DEP_VERSION})
@@ -62,8 +62,6 @@ set_package_properties(libavif PROPERTIES
     PURPOSE "Required for the QImage plugin for AVIF images"
 )
 
-option(KIMAGEFORMATS_DDS "Enable plugin for DDS format" ON)
-
 option(KIMAGEFORMATS_HEIF "Enable plugin for HEIF format" OFF)
 if(KIMAGEFORMATS_HEIF)
     pkg_check_modules(LibHeif IMPORTED_TARGET libheif>=1.10.0)
@@ -74,7 +72,6 @@ option(KIMAGEFORMATS_JXL "Enable plugin for JPEG XL format" ON)
 if(KIMAGEFORMATS_JXL)
     pkg_check_modules(LibJXL IMPORTED_TARGET libjxl>=0.7.0)
     pkg_check_modules(LibJXLThreads IMPORTED_TARGET libjxl_threads>=0.7.0)
-    pkg_check_modules(LibJXLCMS IMPORTED_TARGET libjxl_cms>=0.9.0)
 endif()
 add_feature_info(LibJXL LibJXL_FOUND "required for the QImage plugin for JPEG XL images")
 
@@ -84,7 +81,6 @@ set_package_properties(LibRaw PROPERTIES
     PURPOSE "Required for the QImage plugin for RAW images"
 )
 
-# JXR plugin disabled by default due to security issues
 option(KIMAGEFORMATS_JXR "Enable plugin for JPEG XR format" OFF)
 if(KIMAGEFORMATS_JXR)
     find_package(LibJXR)
@@ -92,8 +88,8 @@ endif()
 add_feature_info(LibJXR LibJXR_FOUND "required for the QImage plugin for JPEG XR images")
 
 ecm_set_disabled_deprecation_versions(
-    QT 6.8.0
-    KF 6.8.0
+    QT 6.5
+    KF 5.102
 )
 
 add_subdirectory(src)

README.md

@@ -1,7 +1,6 @@
 # KImageFormats
 
-Plugins to allow [`QImage`](https://doc.qt.io/qt-6/qimage.html) to support
-extra file formats.
+Plugins to allow QImage to support extra file formats.
 
 ## Introduction
 
@@ -20,20 +19,18 @@ The following image formats have read-only support:
 - Krita (kra)
 - OpenRaster (ora)
 - Pixar raster (pxr)
-- Portable FloatMap/HalfMap (pfm, phm)
+- Portable FloatMap (pfm)
 - Photoshop documents (psd, psb, pdd, psdt)
 - Radiance HDR (hdr)
-- Scitex CT (sct)
 - Sun Raster (im1, im8, im24, im32, ras, sun)
 
 The following image formats have read and write support:
 
 - AV1 Image File Format (avif)
-- DirectDraw Surface (dds)
 - Encapsulated PostScript (eps)
-- High Efficiency Image File Format (heif)
+- High Efficiency Image File Format (heif). Can be enabled with the KIMAGEFORMATS_HEIF build option.
 - JPEG XL (jxl)
-- JPEG XR (jxr)
+- JPEG XR (jxr). Can be enabled with the KIMAGEFORMATS_JXR build option.
 - OpenEXR (exr)
 - Personal Computer Exchange (pcx)
 - Quite OK Image format (qoi)
@@ -43,22 +40,16 @@ The following image formats have read and write support:
 
 ## Contributing
 
-See the [`QImageIOPlugin`](https://doc.qt.io/qt-6/qimageioplugin.html)
-documentation for information on how to write a new plugin.
+See the QImageIOPlugin documentation for information on how to write a
+new plugin.
 
-The main difference between this framework and the image formats of Qt is
-the license. As such, if you write an image format plugin and you are
-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
-- Pass the tests successfully
+The main difference between this framework and the qimageformats module
+of Qt is the license.  As such, if you write an imageformat plugin and
+you are willing to sign the Qt Project contributor agreement, it may be
+better to submit the plugin directly to the Qt Project.
 
 ## Duplicated Plugins
 
-### The TGA plugin
-
 The TGA plugin supports more formats than Qt's own TGA plugin;
 specifically, the one provided here supports indexed, greyscale and RLE
 images (types 1-3 and 9-11), while Qt's plugin only supports type 2
@@ -69,12 +60,6 @@ licensing.  If anyone were willing to write fresh code to improve Qt's
 TGA plugin, it would allow the TGA plugin in this framework to be
 removed.
 
-### The DDS plugin
-
-The DDS plugin is a fork from Qt 5.6 with bug fixes and improvements.
-
-The plugin was forked because Qt Project no longer supports its DDS plugin.
-
 ## License
 
 This framework is licensed under the
@@ -83,200 +68,3 @@ This framework is licensed under the
 The CMake code in this framework is licensed under the
 [BSD license](http://opensource.org/licenses/BSD-3-Clause).
 
-## Plugin status
-
-The current implementation of a plugin may not be complete or may have
-limitations of various kinds. Typically the limitations are on maximum size
-and color depth.
-
-The various plugins are also limited by the formats natively supported by Qt.
-For example, native support for CMYK images is only available since Qt 6.8.
-
-### HDR images
-
-HDR images are supported via floating point image formats from DDS, EXR, HDR,
-JXL, JXR, PFM and PSD plugins.
-It is important to note that in the past these plugins stripped away HDR
-information, returning SDR images.
-
-HDR images return R, G and B values ​​outside the range 0.0 - 1.0.
-While Qt painters handles HDR data correctly, some older programs may display
-strange artifacts if they do not use a tone mapping operator (or at least a
-clamp). This is not a plugin issue.
-
-### Metadata
-
-Metadata support is implemented in all formats that support it. In particular,
-in addition to the classic `"Description"`, `"Author"`, `"Copyright"`, etc... where 
-possible, XMP data is supported via the `"XML:com.adobe.xmp"` key.
-
-Please note that only the most common metadata is supported.
-
-### ICC profile support
-
-ICC support is fully implemented in all formats that support it. When saving, 
-some formats convert the image using color profiles according to
-specifications. In particular, HDR formats almost always convert to linear
-RGB.
-
-### Maximum image size
-
-Where possible, plugins support large images. By convention, many of the
-large image plugins are limited to a maximum of 300,000 x 300,000 pixels.
-Anyway, all plugins are also limited by the 
-`QImageIOReader::allocationLimit()`. Below are the maximum sizes for each
-plugin ('n/a' means no limit, i.e. the limit depends on the format encoding).
-
-- ANI: n/a
-- AVIF: 32,768 x 32,768 pixels, in any case no larger than 256 megapixels
-- DDS: n/a
-- EXR: 300,000 x 300,000 pixels
-- EPS: n/a
-- HDR: n/a (large image)
-- HEIF: n/a
-- JXL: 262,144 x 262,144 pixels, in any case no larger than 256 megapixels
-- JXR: n/a, in any case no larger than 4 GB
-- KRA: same size as Qt's PNG plugin
-- ORA: same size as Qt's PNG plugin
-- PCX: 65,535 x 65,535 pixels
-- PFM: n/a (large image)
-- PIC: 65,535 x 65,535 pixels
-- PSD: 300,000 x 300,000 pixels
-- PXR: 65,535 x 65,535 pixels
-- QOI: 300,000 x 300,000 pixels
-- RAS: n/a (large image)
-- RAW: n/a (depends on the RAW format loaded)
-- RGB: 65,535 x 65,535 pixels
-- SCT: 300,000 x 300,000 pixels
-- TGA: 65,535 x 65,535 pixels
-- XCF: 300,000 x 300,000 pixels
-
-### Sequential and random access devices
-
-All plugins work fine on random access devices while only some work on
-sequential access devices.
-Some plugins, such as PSD, allow reading RGB images on sequential access 
-devices, but cannot do the same for Lab files.
-
-**Important: some plugins use `QIODevice` transactions and/or 
-`QIODevice::ungetChar()`. Therefore, the device used to read the image must not
-have any active transactions.**
-
-### Memory usage
-
-Qt has added many image formats over time. In older plugins, to support new
-formats, `QImage` conversion functions have been used, causing memory
-consumption proportional to the size of the image to be saved.
-Normally this is not a source of problems because the affected plugins
-are limited to maximum images of 2GiB or less.
-
-On plugins for formats that support large images, progressive conversion has
-been used or the maximum size of the image that can be saved has been limited.
-
-### Non-RGB formats
-
-PSD plugin loads CMYK, Lab and Multichannel images and converts them to RGB 
-without using the ICC profile.
-
-JXR, PSD and SCT plugins natively support 4-channel CMYK images when compiled 
-with Qt 6.8+.
-
-### The DDS plugin
-
-**This plugin can be disabled by setting `KIMAGEFORMATS_DDS` to `OFF` 
-in your cmake options.**
-
-The following defines can be defined in cmake to modify the behavior of the plugin:
-- `DDS_DISABLE_STRIDE_ALIGNMENT`: disable the stride aligment based on DDS pitch: it is known that some writers do not set it correctly.
-
-### The HEIF plugin
-
-**This plugin is disabled by default. It can be enabled by settings
-`KIMAGEFORMATS_HEIF` to `ON` in your cmake options.**
-
-The plugin is disabled due to issues with the heif library on certain
-distributions. In particular, it is necessary that the HEIF library has
-support for HEVC codec. If HEVC codec is not available the plugin
-will compile but will fail the tests.
-
-### The EXR plugin
-
-The following defines can be defined in cmake to modify the behavior of the plugin:
-- `EXR_CONVERT_TO_SRGB`: the linear data is converted to sRGB on read to accommodate programs that do not support color profiles.
-- `EXR_DISABLE_XMP_ATTRIBUTE`: disables the stores XMP values in a non-standard attribute named "xmp". Note that Gimp reads the "xmp" attribute and Darktable writes it as well.
-
-### The EPS plugin
-
-The plugin uses `Ghostscript` to convert the raster image. When reading it
-converts the EPS to PPM and uses the Qt PPM plugin to read the image.
-When writing it uses [`QPrinter`](https://doc.qt.io/qt-6/qprinter.html) to
-create a temporary PDF file which is then converted to EPS. Therefore, if
-`Ghostscript` is not installed, the plugin will not work.
-
-### The HDR plugin
-
-The following defines can be defined in cmake to modify the behavior of the plugin:
-- `HDR_HALF_QUALITY`: on read, a 16-bit float image is returned instead of a 32-bit float one.
-
-### The JXL plugin
-
-**The current version of the plugin limits the image size to 256 megapixels
-according to feature level 5 of the JXL stream encoding.**
-
-The following defines can be defined in cmake to modify the behavior of the plugin:
-- `JXL_HDR_PRESERVATION_DISABLED`: disable floating point images (both read and write) by converting them to UINT16 images. Any HDR data is lost. Note that FP images are always disabled when compiling with libJXL less than v0.9.
-- `JXL_DECODE_BOXES_DISABLED`: disable reading of metadata (e.g. XMP).
-
-### The JXR plugin
-
-**This plugin is disabled by default. It can be enabled by settings
-`KIMAGEFORMATS_JXR` to `ON` in your cmake options.**
-
-The following defines can be defined in cmake to modify the behavior of the plugin:
-- `JXR_DENY_FLOAT_IMAGE`: disables the use of float images and consequently any HDR data will be lost.
-- `JXR_DISABLE_DEPTH_CONVERSION`: remove the neeeds of additional memory by disabling the conversion between different color depths (e.g. RGBA64bpp to RGBA32bpp) at the cost of reduced compatibility.
-- `JXR_DISABLE_BGRA_HACK`: Windows displays and opens JXR files correctly out of the box. Unfortunately it doesn't seem to open (P)RGBA @32bpp files as it only wants (P)BGRA32bpp files (a format not supported by Qt). Only for this format an hack is activated to guarantee total compatibility of the plugin with Windows.
-- `JXR_ENABLE_ADVANCED_METADATA`: enable metadata support (e.g. XMP). Some distributions use an incomplete JXR library that does not allow reading metadata, causing compilation errors.
-
-### The KRA plugin
-
-The KRA format is a ZIP archive containing image data. In particular, the
-rendered image in PNG format is saved in the root: the plugin reads this 
-image.
-
-### The ORA plugin
-
-The ORA format is a ZIP archive containing image data. In particular, the
-rendered image in PNG format is saved in the root: the plugin reads this 
-image.
-
-### The PSD plugin
-
-PSD support has the following limitations:
-- Only images saved by Photoshop using compatibility mode enabled (Photoshop default) can be decoded.
-- Multichannel images are treated as CMYK if they have 2 or more channels.
-- Multichannel images are treated as Grayscale if they have 1 channel.
-- Duotone images are treated as grayscale images.
-- Extra channels other than alpha are discarded.
-
-The following defines can be defined in cmake to modify the behavior of the plugin:
-- `PSD_FAST_LAB_CONVERSION`: the LAB image is converted to linear sRGB instead of sRGB which significantly increases performance.
-- `PSD_NATIVE_CMYK_SUPPORT_DISABLED`: disable native support for CMYK images when compiled with Qt 6.8+
-
-### The RAW plugin
-
-Loading RAW images always requires a conversion. To allow the user to
-choose how to convert the image, it was chosen to use the quality parameter
-to act on the converter. The quality parameter can be used with values ​​from 
-0 to 100 (0 = fast, 100 = maximum quality) or by setting flags to 
-selectively change the conversion (see also [raw_p.h](./src/imageformats/raw_p.h)).
-
-The default setting tries to balance quality and conversion speed.
-
-### The XCF plugin
-
-XCF support has the following limitations:
-- XCF format up to [version 12](https://testing.developer.gimp.org/core/standards/xcf/#version-history) (no support for GIMP 3).
-- The returned image is always 8-bit.
-- Cannot read zlib compressed files.
-- The rendered image may be slightly different (colors/transparencies) than in GIMP.

autotests/CMakeLists.txt

@@ -72,15 +72,9 @@ kimageformats_read_tests(
     qoi
     ras
     rgb
-    sct
     tga
 )
 
-if(KIMAGEFORMATS_DDS)
-    kimageformats_read_tests(dds)
-    kimageformats_write_tests(dds-nodatacheck-lossless)
-endif()
-
 if (KF6Archive_FOUND)
     kimageformats_read_tests(
         kra
@@ -111,12 +105,6 @@ if (LibHeif_FOUND)
             hej2
         )
     endif()
-
-    if (LibHeif_VERSION VERSION_GREATER_EQUAL "1.19.0")
-        kimageformats_read_tests(FUZZ 4
-            avci
-        )
-    endif()
 endif()
 
 if (LibJXL_FOUND AND LibJXLThreads_FOUND)

autotests/read/dds/earth-cubemap.license

@@ -1,2 +0,0 @@
-SPDX-FileCopyrightText: Copyright (c) 2006 - 2010 The Open Toolkit library.
-SPDX-License-Identifier: MIT

autotests/read/jxl/orientation6_notranfs.jxl.json

@@ -1,19 +0,0 @@
-[
-    {
-        "minQtVersion" : "6.5.7",
-        "maxQtVersion" : "6.5.99",
-        "disableAutoTransform": true,
-        "fileName" : "orientation6_notranfs.png",
-        "comment" : "Test with automatic transformation disabled."
-    },
-    {
-        "minQtVersion" : "6.7.3",
-        "disableAutoTransform": true,
-        "fileName" : "orientation6_notranfs.png",
-        "comment" : "Test with automatic transformation disabled."
-    },
-    {
-        "unsupportedFormat" : true,
-        "comment" : "It is not possible to disable the transformation with the current version of the plugin."
-    }
-]

autotests/read/jxl/testcard_rgba_fp16.jxl.json

@@ -1,21 +0,0 @@
-[
-    {
-        "minQtVersion" : "6.2.11",
-        "maxQtVersion" : "6.2.99",
-        "fileName" : "testcard_rgba_fp16.png"
-    },
-    {
-        "minQtVersion" : "6.5.5",
-        "maxQtVersion" : "6.5.99",
-        "fileName" : "testcard_rgba_fp16.png"
-    },
-    {
-        "minQtVersion" : "6.6.2",
-        "fileName" : "testcard_rgba_fp16.png"
-    },
-    {
-        "unsupportedFormat" : true,
-        "comment" : "Skipped due to QTBUG-120614.",
-        "seeAlso" : "https://bugreports.qt.io/browse/QTBUG-120614"
-    }
-]

autotests/read/jxl/testcard_rgba_fp32.jxl.json

@@ -1,21 +0,0 @@
-[
-    {
-        "minQtVersion" : "6.2.11",
-        "maxQtVersion" : "6.2.99",
-        "fileName" : "testcard_rgba_fp32.png"
-    },
-    {
-        "minQtVersion" : "6.5.5",
-        "maxQtVersion" : "6.5.99",
-        "fileName" : "testcard_rgba_fp32.png"
-    },
-    {
-        "minQtVersion" : "6.6.2",
-        "fileName" : "testcard_rgba_fp32.png"
-    },
-    {
-        "unsupportedFormat" : true,
-        "comment" : "Skipped due to QTBUG-120614.",
-        "seeAlso" : "https://bugreports.qt.io/browse/QTBUG-120614"
-    }
-]

autotests/read/pfm/comment_gray_half.phm.json

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