{scene,image}converter: add --info options for plugins.

Lists features, aliases as well as documented contents of the whole
configuration file. Useful to not need to look up online docs when
working on the command line.

doc/changelog.dox

@@ -229,6 +229,9 @@ See also:
     correctly handle all corner cases yet and may assert on certain inputs.
 -   The @ref magnum-sceneconverter "magnum-sceneconverter" `--info` output is
     now more compact and colored for better readability
+-   Added `--info-importer`, `--info-converter` and `--info-image-converter`
+    options to @ref magnum-sceneconverter "magnum-sceneconverter", listing
+    plugin features and configuration file contents
 
 @subsubsection changelog-latest-new-shaders Shaders library
 
@@ -321,6 +324,9 @@ See also:
     converters together
 -   The @ref magnum-imageconverter "magnum-imageconverter" `--info` output is
     now more compact and colored for better readability
+-   Added `--info-importer` and `--info-converter` options to
+    @ref magnum-imageconverter "magnum-imageconverter", listing plugin features
+    and configuration file contents
 
 @subsubsection changelog-latest-new-vk Vk library
 

src/Magnum/SceneTools/Implementation/sceneConverterUtilities.h

@@ -33,6 +33,7 @@
 #include <Corrade/Utility/Arguments.h>
 
 #include "Magnum/Math/FunctionsBatch.h"
+#include "Magnum/Trade/AbstractSceneConverter.h"
 #include "Magnum/Trade/AnimationData.h"
 #include "Magnum/Trade/CameraData.h"
 #include "Magnum/Trade/LightData.h"
@@ -52,6 +53,11 @@ using namespace Containers::Literals;
    particular magnum-sceneconverter and its tests */
 namespace {
 
+void printSceneConverterInfo(const Debug::Flags useColor, const Trade::AbstractSceneConverter& converter) {
+    Trade::Implementation::printPluginInfo(useColor, converter);
+    Trade::Implementation::printPluginConfigurationInfo(useColor, converter);
+}
+
 /** @todo const Array& doesn't work, minmax() would fail to match */
 template<class T> Containers::String calculateBounds(Containers::Array<T>&& attribute) {
     /** @todo clean up when Debug::toString() exists */

src/Magnum/SceneTools/Test/CMakeLists.txt

@@ -40,6 +40,9 @@ endif()
 if(MAGNUM_WITH_SCENECONVERTER AND CORRADE_TARGET_UNIX)
     set(SCENECONVERTER_EXECUTABLE_FILENAME $<TARGET_FILE:magnum-sceneconverter>)
 endif()
+if(MAGNUM_WITH_ANYSCENECONVERTER AND NOT MAGNUM_BUILD_PLUGINS_STATIC AND NOT MAGNUM_ANYSCENECONVERTER_BUILD_STATIC)
+    set(ANYSCENECONVERTER_PLUGIN_FILENAME $<TARGET_FILE:AnySceneConverter>)
+endif()
 
 # First replace ${} variables, then $<> generator expressions
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/configure.h.cmake
@@ -69,6 +72,14 @@ corrade_add_test(SceneToolsSceneConverterImple___Test SceneConverterImplementati
         SceneConverterImplementationTestFiles/info-skins.txt
         SceneConverterImplementationTestFiles/info-textures.txt)
 target_include_directories(SceneToolsSceneConverterImple___Test PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/$<CONFIG>)
+if(MAGNUM_WITH_ANYSCENECONVERTER)
+    if(MAGNUM_BUILD_PLUGINS_STATIC OR MAGNUM_ANYSCENECONVERTER_BUILD_STATIC)
+        target_link_libraries(SceneToolsSceneConverterImple___Test PRIVATE AnySceneConverter)
+    else()
+        # So the plugins get properly built when building the test
+        add_dependencies(SceneToolsSceneConverterImple___Test AnySceneConverter)
+    endif()
+endif()
 
 # Executable testing is implemented on Unix platforms only at the moment
 if(CORRADE_TARGET_UNIX AND NOT CORRADE_PLUGINMANAGER_NO_DYNAMIC_PLUGIN_SUPPORT)
@@ -97,6 +108,10 @@ if(CORRADE_TARGET_UNIX AND NOT CORRADE_PLUGINMANAGER_NO_DYNAMIC_PLUGIN_SUPPORT)
             SceneConverterTestFiles/images-3d-1x1x1.gltf
             SceneConverterTestFiles/info-data.txt
             SceneConverterTestFiles/info-data-ignored-output.txt
+            SceneConverterTestFiles/info-converter.txt
+            SceneConverterTestFiles/info-image-converter.txt
+            SceneConverterTestFiles/info-importer.txt
+            SceneConverterTestFiles/info-importer-ignored-input-output.txt
             SceneConverterTestFiles/point.obj
             SceneConverterTestFiles/quad-duplicates-fuzzy.obj
             SceneConverterTestFiles/quad-duplicates.obj

src/Magnum/SceneTools/Test/SceneConverterImplementationTest.cpp

@@ -44,6 +44,11 @@ namespace Magnum { namespace SceneTools { namespace Test { namespace {
 struct SceneConverterImplementationTest: TestSuite::Tester {
     explicit SceneConverterImplementationTest();
 
+    /* printPluginInfo(), printPluginConfigurationInfo() and
+       printImporterInfo() tested thoroughly in
+       Trade/Test/ImageConverterImplementationTest.cpp already */
+    void converterInfo();
+
     void infoEmpty();
     void infoScenesObjects();
     void infoAnimations();
@@ -60,6 +65,9 @@ struct SceneConverterImplementationTest: TestSuite::Tester {
     void infoError();
 
     Utility::Arguments _infoArgs;
+
+    /* Explicitly forbid system-wide plugin dependencies */
+    PluginManager::Manager<Trade::AbstractSceneConverter> _converterManager{"nonexistent"};
 };
 
 using namespace Containers::Literals;
@@ -86,7 +94,9 @@ const struct {
 };
 
 SceneConverterImplementationTest::SceneConverterImplementationTest() {
-    addTests({&SceneConverterImplementationTest::infoEmpty});
+    addTests({&SceneConverterImplementationTest::converterInfo,
+
+              &SceneConverterImplementationTest::infoEmpty});
 
     addInstancedTests({&SceneConverterImplementationTest::infoScenesObjects},
         Containers::arraySize(InfoScenesObjectsData));
@@ -121,6 +131,47 @@ SceneConverterImplementationTest::SceneConverterImplementationTest() {
              .addBooleanOption("info-textures")
              .addBooleanOption("info-images")
              .addBooleanOption("bounds");
+
+    /* Load the plugin directly from the build tree. Otherwise it's static and
+       already loaded. */
+    #ifdef ANYSCENECONVERTER_PLUGIN_FILENAME
+    CORRADE_INTERNAL_ASSERT_OUTPUT(_converterManager.load(ANYSCENECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
+    #endif
+
+    /* To avoid warnings that printImageConverterInfo() / printImporterInfo()
+       is unused. Again, those are tested in ImageConverterImplementationTest
+       already. */
+    static_cast<void>(Trade::Implementation::printImageConverterInfo);
+    static_cast<void>(Trade::Implementation::printImporterInfo);
+}
+
+void SceneConverterImplementationTest::converterInfo() {
+    /* Check if the required plugin can be loaded. Catches also ABI and
+       interface mismatch errors. */
+    if(!(_converterManager.load("AnySceneConverter") & PluginManager::LoadState::Loaded))
+        CORRADE_SKIP("AnySceneConverter plugin can't be loaded.");
+
+    Containers::Pointer<Trade::AbstractSceneConverter> converter = _converterManager.instantiate("AnySceneConverter");
+    /** @todo pick a plugin that has some actual configuration */
+    converter->configuration().setValue("something", "is there");
+
+    /* Print to visually verify coloring */
+    {
+        Debug{} << "======================== visual color verification start =======================";
+        Implementation::printSceneConverterInfo(Debug::isTty() ? Debug::Flags{} : Debug::Flag::DisableColors, *converter);
+        Debug{} << "======================== visual color verification end =========================";
+    }
+
+    std::ostringstream out;
+    Debug redirectOutput{&out};
+    Implementation::printSceneConverterInfo(Debug::Flag::DisableColors, *converter);
+    CORRADE_COMPARE(out.str(),
+        "Plugin name: AnySceneConverter\n"
+        "Features:\n"
+        "  ConvertMeshToFile\n"
+        "  ConvertMultipleToFile\n"
+        "Configuration:\n"
+        "  something=is there\n");
 }
 
 void SceneConverterImplementationTest::infoEmpty() {

src/Magnum/SceneTools/Test/SceneConverterTest.cpp

@@ -57,21 +57,47 @@ const struct {
     const char* name;
     Containers::Array<Containers::String> args;
     const char* requiresImporter;
+    const char* requiresConverter;
+    const char* requiresImageConverter;
     const char* expected;
 } InfoData[]{
+    {"importer", Containers::array<Containers::String>({
+        "--info-importer", "-i", "someOption=yes"}),
+        "AnySceneImporter", nullptr, nullptr,
+        "info-importer.txt"},
+    {"converter", Containers::array<Containers::String>({
+        "-C", "AnySceneConverter", "--info-converter", "-c", "someOption=yes"}),
+        nullptr, "AnySceneConverter", nullptr,
+        "info-converter.txt"},
+    {"converter, implicit", Containers::array<Containers::String>({
+        "--info-converter", "-c", "someOption=yes"}),
+        nullptr, "AnySceneConverter", nullptr,
+        "info-converter.txt"},
+    {"image converter", Containers::array<Containers::String>({
+        "-P", "AnyImageConverter", "--info-image-converter", "-p", "someOption=yes"}),
+        nullptr, nullptr, "AnyImageConverter",
+        "info-image-converter.txt"},
+    {"image converter, implicit", Containers::array<Containers::String>({
+        "--info-image-converter", "-p", "someOption=yes"}),
+        nullptr, nullptr, "AnyImageConverter",
+        "info-image-converter.txt"},
+    {"importer, ignored input and output", Containers::array<Containers::String>({
+        "--info-importer", "input.obj", "output.ply"}),
+        "AnySceneImporter", nullptr, nullptr,
+        "info-importer-ignored-input-output.txt"},
     {"data", Containers::array<Containers::String>({
         "-I", "ObjImporter", "--info", Utility::Path::join(SCENETOOLS_TEST_DIR, "SceneConverterTestFiles/point.obj")}),
-        "ObjImporter",
+        "ObjImporter", nullptr, nullptr,
         "info-data.txt"},
     {"data, map", Containers::array<Containers::String>({
         "--map", "-I", "ObjImporter", "--info", Utility::Path::join(SCENETOOLS_TEST_DIR, "SceneConverterTestFiles/point.obj")}),
-        "ObjImporter",
+        "ObjImporter", nullptr, nullptr,
         /** @todo change to something else once we have a plugin that can
             zero-copy pass the imported data */
         "info-data.txt"},
     {"data, ignored output file", Containers::array<Containers::String>({
         "-I", "ObjImporter", "--info", Utility::Path::join(SCENETOOLS_TEST_DIR, "SceneConverterTestFiles/point.obj"), "whatever.ply"}),
-        "ObjImporter",
+        "ObjImporter", nullptr, nullptr,
         "info-data-ignored-output.txt"}
 };
 
@@ -783,8 +809,14 @@ void SceneConverterTest::info() {
     /* Check if required plugins can be loaded. Catches also ABI and interface
        mismatch errors. */
     PluginManager::Manager<Trade::AbstractImporter> importerManager{MAGNUM_PLUGINS_IMPORTER_INSTALL_DIR};
+    PluginManager::Manager<Trade::AbstractImageConverter> imageConverterManager{MAGNUM_PLUGINS_IMAGECONVERTER_INSTALL_DIR};
+    PluginManager::Manager<Trade::AbstractSceneConverter> converterManager{MAGNUM_PLUGINS_SCENECONVERTER_INSTALL_DIR};
     if(data.requiresImporter && !(importerManager.load(data.requiresImporter) & PluginManager::LoadState::Loaded))
         CORRADE_SKIP(data.requiresImporter << "plugin can't be loaded.");
+    if(data.requiresConverter && !(converterManager.load(data.requiresConverter) & PluginManager::LoadState::Loaded))
+        CORRADE_SKIP(data.requiresConverter << "plugin can't be loaded.");
+    if(data.requiresImageConverter && !(imageConverterManager.load(data.requiresImageConverter) & PluginManager::LoadState::Loaded))
+        CORRADE_SKIP(data.requiresImageConverter << "plugin can't be loaded.");
 
     CORRADE_VERIFY(true); /* capture correct function name */
 

src/Magnum/SceneTools/Test/SceneConverterTestFiles/info-converter.txt

@@ -0,0 +1,6 @@
+Plugin name: AnySceneConverter
+Features:
+  ConvertMeshToFile
+  ConvertMultipleToFile
+Configuration:
+  someOption=yes

src/Magnum/SceneTools/Test/SceneConverterTestFiles/info-image-converter.txt

@@ -0,0 +1,11 @@
+Plugin name: AnyImageConverter
+Features:
+  Convert1DToFile
+  Convert2DToFile
+  Convert3DToFile
+  ConvertCompressed1DToFile
+  ConvertCompressed2DToFile
+  ConvertCompressed3DToFile
+  Levels
+Configuration:
+  someOption=yes

src/Magnum/SceneTools/Test/SceneConverterTestFiles/info-importer-ignored-input-output.txt

@@ -0,0 +1,5 @@
+Ignoring input file for --info: input.obj
+Ignoring output file for --info: output.ply
+Plugin name: AnySceneImporter
+Features:
+  FileCallback

src/Magnum/SceneTools/Test/SceneConverterTestFiles/info-importer.txt

@@ -0,0 +1,5 @@
+Plugin name: AnySceneImporter
+Features:
+  FileCallback
+Configuration:
+  someOption=yes

src/Magnum/SceneTools/Test/configure.h.cmake

@@ -26,6 +26,7 @@
 #define SCENETOOLS_TEST_DIR "${SCENETOOLS_TEST_DIR}"
 #define SCENETOOLS_TEST_OUTPUT_DIR "${SCENETOOLS_TEST_OUTPUT_DIR}"
 #cmakedefine SCENECONVERTER_EXECUTABLE_FILENAME "${SCENECONVERTER_EXECUTABLE_FILENAME}"
+#cmakedefine ANYSCENECONVERTER_PLUGIN_FILENAME "${ANYSCENECONVERTER_PLUGIN_FILENAME}"
 
 #ifdef CORRADE_TARGET_WINDOWS
 #ifdef CORRADE_IS_DEBUG_BUILD

src/Magnum/SceneTools/sceneconverter.cpp

@@ -126,7 +126,8 @@ magnum-sceneconverter [-h|--help] [-I|--importer PLUGIN]
     [-c|--converter-options key=val,key2=val2,…]...
     [-p|--image-converter-options key=val,key2=val2,…]...
     [-m|--mesh-converter-options key=val,key2=val2,…]...
-    [--mesh ID] [--mesh-level INDEX] [--concatenate-meshes] [--info-animations]
+    [--mesh ID] [--mesh-level INDEX] [--concatenate-meshes] [--info-importer]
+    [--info-converter] [--info-image-converter] [--info-animations]
     [--info-images] [--info-lights] [--info-cameras] [--info-materials]
     [--info-meshes] [--info-objects] [--info-scenes] [--info-skins]
     [--info-textures] [--info] [--color on|4bit|off|auto] [--bounds]
@@ -169,6 +170,11 @@ Arguments:
 -   `--mesh-level LEVEL` --- level to select for single-mesh conversion
 -   `--concatenate-meshes` -- flatten mesh hierarchy and concatenate them all
     together @m_class{m-label m-warning} **experimental**
+-   `--info-importer` --- print info about the importer plugin and exit
+-   `--info-converter` --- print info about the scene or mesh converter plugin
+    and exit
+-   `--info-image-converter` --- print info about the image converter plugin
+    and exit
 -   `--info-animations` --- print into about animations in the input file and
     exit
 -   `--info-images` --- print into about images in the input file and exit
@@ -182,18 +188,25 @@ Arguments:
 -   `--info-skins` --- print into about skins in the input file and exit
 -   `--info-textures` --- print into about textures in the input file and exit
 -   `--info` --- print info about everything in the input file and exit, same
-    as specifying all other `--info-*` options together
+    as specifying all other data-related `--info-*` options together
 -   `--color` --- colored output for `--info` (default: `auto`)
 -   `--bounds` --- show bounds of known attributes in `--info` output
 -   `-v`, `--verbose` --- verbose output from importer and converter plugins
 -   `--profile` --- measure import and conversion time
 
-If any of the `--info-*` options are given, the utility will print information
-about given data present in the file. In this case no conversion is done and
-output file doesn't need to be specified. In case one data references another
-and both `--info-*` options are specified, the output will also list reference
-count (for example, `--info-scenes` together with `--info-meshes` will print
-how many objects reference given mesh).
+If any of the `--info-importer`, `--info-converter` or `--info-image-converter`
+options are given, the utility will print information about given plugin
+specified via the `-I`, `-C` or `-P` option, including its configuration
+options potentially overriden with `-i`, `-c` or `-p`. In this case no file is
+read and no conversion is done and neither the input nor the output file needs
+to be specified.
+
+If any of the other `--info-*` options are given, the utility will print
+information about given data. In this case the input file is read but no
+conversion is done and the output file doesn't need to be specified. In case
+one data references another and both `--info-*` options are specified, the
+output will also list reference count (for example, `--info-scenes` together
+with `--info-meshes` will print how many objects reference given mesh).
 
 The `-i`, `-c` and `-m` arguments accept a comma-separated list of key/value
 pairs to set in the importer / converter plugin configuration. If the `=`
@@ -239,7 +252,13 @@ using namespace Containers::Literals;
 
 namespace {
 
-bool isInfoRequested(const Utility::Arguments& args) {
+bool isPluginInfoRequested(const Utility::Arguments& args) {
+    return args.isSet("info-importer") ||
+           args.isSet("info-converter") ||
+           args.isSet("info-image-converter");
+}
+
+bool isDataInfoRequested(const Utility::Arguments& args) {
     return args.isSet("info-animations") ||
            args.isSet("info-images") ||
            args.isSet("info-lights") ||
@@ -333,6 +352,9 @@ int main(int argc, char** argv) {
         .addOption("mesh").setHelp("mesh", "convert just a single mesh instead of the whole scene, ignored if --concatenate-meshes is specified", "ID")
         .addOption("mesh-level").setHelp("mesh-level", "level to select for single-mesh conversion", "index")
         .addBooleanOption("concatenate-meshes").setHelp("concatenate-meshes", "flatten mesh hierarchy and concatenate them all together")
+        .addBooleanOption("info-importer").setHelp("info-importer", "print info about the importer plugin and exit")
+        .addBooleanOption("info-converter").setHelp("info-converter", "print info about the scene or mesh converter plugin and exit")
+        .addBooleanOption("info-image-converter").setHelp("info-image-converter", "print info about the image converter plugin and exit")
         .addBooleanOption("info-animations").setHelp("info-animations", "print info about animations in the input file and exit")
         .addBooleanOption("info-images").setHelp("info-images", "print info about images in the input file and exit")
         .addBooleanOption("info-lights").setHelp("info-lights", "print info about images in the input file and exit")
@@ -343,27 +365,39 @@ int main(int argc, char** argv) {
         .addBooleanOption("info-scenes").setHelp("info-scenes", "print info about scenes in the input file and exit")
         .addBooleanOption("info-skins").setHelp("info-skins", "print info about skins in the input file and exit")
         .addBooleanOption("info-textures").setHelp("info-textures", "print info about textures in the input file and exit")
-        .addBooleanOption("info").setHelp("info", "print info about everything in the input file and exit, same as specifying all other --info-* options together")
+        .addBooleanOption("info").setHelp("info", "print info about everything in the input file and exit, same as specifying all other data-related --info-* options together")
         .addOption("color", "auto").setHelp("color", "colored output for --info", "on|4bit|off|auto")
         .addBooleanOption("bounds").setHelp("bounds", "show bounds of known attributes in --info output")
         .addBooleanOption('v', "verbose").setHelp("verbose", "verbose output from importer and converter plugins")
         .addBooleanOption("profile").setHelp("profile", "measure import and conversion time")
         .setParseErrorCallback([](const Utility::Arguments& args, Utility::Arguments::ParseError error, const std::string& key) {
-            /* If --info is passed, we don't need the output argument */
+            /* If --info for plugins is passed, we don't need the input */
+            if(error == Utility::Arguments::ParseError::MissingArgument &&
+               key == "input" && isPluginInfoRequested(args))
+                return true;
+            /* If --info for plugins or data is passed, we don't need the
+               output argument */
             if(error == Utility::Arguments::ParseError::MissingArgument &&
-                key == "output" && isInfoRequested(args)) return true;
+                key == "output" && (isPluginInfoRequested(args) || isDataInfoRequested(args)))
+                return true;
 
             /* Handle all other errors as usual */
             return false;
         })
         .setGlobalHelp(R"(Converts scenes of different formats.
 
-If any of the --info-* options are given, the utility will print information
-about given data present in the file. In this case no conversion is done and
-output file doesn't need to be specified. In case one data references another
-and both --info-* options are specified, the output will also list reference
-count (for example, --info-scenes together with --info-meshes will print how
-many objects reference given mesh).
+If any of the --info-importer, --info-converter or --info-image-converter
+options are given, the utility will print information about given plugin
+specified via the -I, -C or -P option. In this case no file is read and no
+conversion is done and neither the input nor the output file needs to be
+specified.
+
+If any of the other --info-* options are given, the utility will print
+information about given data. In this case the input file is read but no
+conversion is done and the output file doesn't need to be specified. In case
+one data references another and both --info-* options are specified, the output
+will also list reference count (for example, --info-scenes together with
+--info-meshes will print how many objects reference given mesh).
 
 The -i, -c and -m arguments accept a comma-separated list of key/value
 pairs to set in the importer / converter plugin configuration. If the =
@@ -421,11 +455,17 @@ well, the IDs reference attributes of the first mesh.)")
     }
 
     /* Generic checks */
-    if(args.value<Containers::StringView>("output")) {
+    if(args.value<Containers::StringView>("input")) {
         /* Not an error in this case, it should be possible to just append
            --info* to existing command line without having to remove anything.
            But print a warning at least, it could also be a mistyped option. */
-        if(isInfoRequested(args))
+        if(isPluginInfoRequested(args))
+            Warning{} << "Ignoring input file for --info:" << args.value<Containers::StringView>("input");
+    }
+    if(args.value<Containers::StringView>("output")) {
+        /* Same as above, it should be possible to just append --info* to
+           existing command line */
+        if(isPluginInfoRequested(args) || isDataInfoRequested(args))
             Warning{} << "Ignoring output file for --info:" << args.value<Containers::StringView>("output");
     }
     if(args.isSet("concatenate-meshes") && args.value<Containers::StringView>("mesh")) {
@@ -471,6 +511,40 @@ well, the IDs reference attributes of the first mesh.)")
     if(args.isSet("verbose")) importer->addFlags(Trade::ImporterFlag::Verbose);
     Implementation::setOptions(*importer, "AnySceneImporter", args.value("importer-options"));
 
+    /* Print plugin info, if requested */
+    if(args.isSet("info-importer")) {
+        Trade::Implementation::printImporterInfo(useColor, *importer);
+        return 0;
+    }
+    if(args.isSet("info-converter")) {
+        Containers::Pointer<Trade::AbstractSceneConverter> converter = converterManager.loadAndInstantiate(args.arrayValueCount("converter") ? args.arrayValue("converter", 0) : "AnySceneConverter");
+        if(!converter) {
+            Debug{} << "Available converter plugins:" << ", "_s.join(converterManager.aliasList());
+            return 1;
+        }
+
+        /* Set options, if passed */
+        if(args.isSet("verbose")) converter->addFlags(Trade::SceneConverterFlag::Verbose);
+        if(args.arrayValueCount("converter-options"))
+            Implementation::setOptions(*converter, "AnySceneConverter", args.arrayValue("converter-options", 0));
+        SceneTools::Implementation::printSceneConverterInfo(useColor, *converter);
+        return 0;
+    }
+    if(args.isSet("info-image-converter")) {
+        Containers::Pointer<Trade::AbstractImageConverter> converter = imageConverterManager.loadAndInstantiate(args.arrayValueCount("image-converter") ? args.arrayValue("image-converter", 0) : "AnyImageConverter");
+        if(!converter) {
+            Debug{} << "Available image converter plugins:" << ", "_s.join(imageConverterManager.aliasList());
+            return 1;
+        }
+
+        /* Set options, if passed */
+        if(args.isSet("verbose")) converter->addFlags(Trade::ImageConverterFlag::Verbose);
+        if(args.arrayValueCount("image-converter-options"))
+            Implementation::setOptions(*converter, "AnyImageConverter", args.arrayValue("image-converter-options", 0));
+        Trade::Implementation::printImageConverterInfo(useColor, *converter);
+        return 0;
+    }
+
     /* Wow, C++, you suck. This implicitly initializes to random shit?!
 
        Also, because of addSupportedImporterContents() it's not really possible
@@ -499,7 +573,7 @@ well, the IDs reference attributes of the first mesh.)")
     }
 
     /* Print file info, if requested */
-    if(isInfoRequested(args)) {
+    if(isDataInfoRequested(args)) {
         const bool error = SceneTools::Implementation::printInfo(useColor, useColor24, args, *importer, importConversionTime);
 
         if(args.isSet("profile")) {

src/Magnum/Trade/Implementation/converterUtilities.h

@@ -26,13 +26,21 @@
 */
 
 #include <chrono>
+#include <sstream> /** @todo remove when Debug is stream-free */
 #include <Corrade/Containers/GrowableArray.h>
 #include <Corrade/Containers/Optional.h>
+#include <Corrade/Containers/Pair.h>
+#include <Corrade/Containers/Reference.h>
 #include <Corrade/Containers/String.h>
+#include <Corrade/PluginManager/PluginMetadata.h>
 #include <Corrade/Utility/Format.h>
+#include <Corrade/Utility/FormatStl.h> /** @todo drop once String::replaceAll() has a StringView overload */
+#include <Corrade/Utility/String.h>
+#include <Corrade/Utility/ConfigurationGroup.h>
 
 #include "Magnum/PixelFormat.h"
 #include "Magnum/Trade/AbstractImporter.h"
+#include "Magnum/Trade/AbstractImageConverter.h"
 #include "Magnum/Trade/ImageData.h"
 
 namespace Magnum { namespace Trade { namespace Implementation {
@@ -41,6 +49,101 @@ namespace Magnum { namespace Trade { namespace Implementation {
    particular magnum-imageconverter, magnum-sceneconverter and their tests */
 namespace {
 
+/** @todo move these to Magnum/Implementation/converterUtilities.h once also
+    shaderconverter / fontconverter / etc implements --info-converter etc */
+template<class T> void printPluginInfo(const Debug::Flags useColor, const T& plugin) {
+        const PluginManager::PluginMetadata* metadata = plugin.metadata();
+        CORRADE_INTERNAL_ASSERT(metadata);
+
+        Debug d{useColor};
+        d << Debug::boldColor(Debug::Color::Default) << "Plugin name:" << Debug::boldColor(Debug::Color::Yellow) << metadata->name() << Debug::resetColor;
+        const std::vector<std::string> aliases = metadata->provides();
+        if(!aliases.empty()) {
+            d << Debug::newline << Debug::boldColor(Debug::Color::Default) << "Aliases:" << Debug::resetColor;
+            for(const std::string& alias: aliases) {
+                d << Debug::newline << " ";
+                if(alias == plugin.plugin())
+                    d << Debug::color(Debug::Color::Yellow);
+                d << alias;
+                if(alias == plugin.plugin())
+                    d << Debug::resetColor;
+            }
+        }
+
+        /* Ugly, eh? */
+        std::ostringstream out;
+        Debug{&out, Debug::Flag::NoNewlineAtTheEnd} << Debug::packed << plugin.features();
+        d << Debug::newline << Debug::boldColor(Debug::Color::Default) << "Features:" << Debug::color(Debug::Color::Cyan) << Debug::newline << " " << Utility::String::replaceAll(out.str(), "|", "\n  ") << Debug::resetColor;
+}
+
+void printPluginConfigurationInfo(Debug& d, const Utility::ConfigurationGroup& configuration, const Containers::StringView prefix) {
+    using namespace Containers::Literals;
+
+    for(Containers::Pair<Containers::StringView, Containers::StringView> i: configuration.valuesComments()) {
+        if(i.first()) {
+            d << Debug::newline << " " << Debug::boldColor(Debug::Color::Blue) << i.first() << Debug::nospace << Debug::color(Debug::Color::Blue) << "=" << Debug::nospace << Debug::color(Debug::Color::Red);
+            /* Print the value wrapped in quotes if it contains spaces, indent
+               also all newlines */
+            if(i.second().contains('\n'))
+                /** @todo replaceAll() without std::string */
+                d << Utility::format("\"\"\"\n  {}\n  \"\"\"", Utility::String::replaceAll(i.second(), "\n", "\n  "));
+            /** @todo less wasteful API for checking leading/trailing zeros? */
+            else if(i.second().trimmed() != i.second())
+                d << Utility::format("\"{}\"", i.second());
+            else
+                d << i.second();
+            d << Debug::resetColor;
+        } else {
+            /* Configuration contents are delimited by these markers in order
+               to include them in Doxygen-generated docs. If we reach them,
+               it's the end of the (public) configuration values. Don't print
+               them, don't print even the last newline, and exit. */
+            if(i.second() == "# [configuration_]"_s) {
+                return;
+            }
+
+            /* Print leading space only if there's actually something */
+            d << Debug::newline;
+            if(i.second()) d << " " << Debug::boldColor(Debug::Color::Black) << i.second() << Debug::resetColor;
+        }
+    }
+
+    for(Containers::Pair<Containers::StringView, Containers::Reference<const Utility::ConfigurationGroup>> i: configuration.groups()) {
+        const Containers::String name = prefix ? "/"_s.join({prefix, i.first()}) : Containers::String{i.first()};
+
+        d << Debug::newline << " " << Debug::color(Debug::Color::Blue) << "[" << Debug::nospace << Debug::boldColor(Debug::Color::Blue) << name << Debug::color(Debug::Color::Blue) << Debug::nospace << "]" << Debug::resetColor;
+
+        printPluginConfigurationInfo(d, i.second(), name);
+    }
+}
+
+void printPluginConfigurationInfo(const Debug::Flags useColor, const PluginManager::AbstractPlugin& plugin) {
+    const Utility::ConfigurationGroup& configuration = plugin.configuration();
+    if(configuration.isEmpty()) return;
+
+    Debug d{useColor};
+    d << Debug::boldColor(Debug::Color::Default) << "Configuration:" << Debug::resetColor;
+    printPluginConfigurationInfo(d, configuration, {});
+}
+
+void printImporterInfo(const Debug::Flags useColor, const Trade::AbstractImporter& importer) {
+    printPluginInfo(useColor, importer);
+    printPluginConfigurationInfo(useColor, importer);
+}
+
+void printImageConverterInfo(const Debug::Flags useColor, const Trade::AbstractImageConverter& converter) {
+    printPluginInfo(useColor, converter);
+
+    Debug d{useColor|Debug::Flag::NoNewlineAtTheEnd};
+
+    if(const Containers::String extension = converter.extension())
+        d << Debug::boldColor(Debug::Color::Default) << "File extension:" << Debug::resetColor << extension << Debug::newline;
+    if(const Containers::String mimeType = converter.mimeType())
+        d << Debug::boldColor(Debug::Color::Default) << "MIME type:" << Debug::resetColor << mimeType << Debug::newline;
+
+    printPluginConfigurationInfo(useColor, converter);
+}
+
 struct Duration {
     explicit Duration(std::chrono::high_resolution_clock::duration& output): _output(output), _t{std::chrono::high_resolution_clock::now()} {}
 

src/Magnum/Trade/Test/CMakeLists.txt

@@ -40,6 +40,17 @@ endif()
 if(MAGNUM_WITH_IMAGECONVERTER AND CORRADE_TARGET_UNIX)
     set(IMAGECONVERTER_EXECUTABLE_FILENAME $<TARGET_FILE:magnum-imageconverter>)
 endif()
+if(NOT MAGNUM_BUILD_PLUGINS_STATIC)
+    if(MAGNUM_WITH_ANYIMAGEIMPORTER AND NOT MAGNUM_ANYIMAGEIMPORTER_BUILD_STATIC)
+        set(ANYIMAGEIMPORTER_PLUGIN_FILENAME $<TARGET_FILE:AnyImageImporter>)
+    endif()
+    if(MAGNUM_WITH_ANYIMAGECONVERTER AND NOT MAGNUM_ANYIMAGECONVERTER_BUILD_STATIC)
+        set(ANYIMAGECONVERTER_PLUGIN_FILENAME $<TARGET_FILE:AnyImageConverter>)
+    endif()
+    if(MAGNUM_WITH_TGAIMAGECONVERTER AND NOT MAGNUM_TGAIMAGECONVERTER_BUILD_STATIC)
+        set(TGAIMAGECONVERTER_PLUGIN_FILENAME $<TARGET_FILE:TgaImageConverter>)
+    endif()
+endif()
 
 # First replace ${} variables, then $<> generator expressions
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/configure.h.cmake
@@ -69,6 +80,30 @@ corrade_add_test(TradeImageConverterImplementa___Test ImageConverterImplementati
     FILES
         ImageConverterImplementationTestFiles/info.txt)
 target_include_directories(TradeImageConverterImplementa___Test PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/$<CONFIG>)
+if(MAGNUM_WITH_ANYIMAGEIMPORTER)
+    if(MAGNUM_BUILD_PLUGINS_STATIC OR MAGNUM_ANYIMAGEIMPORTER_BUILD_STATIC)
+        target_link_libraries(TradeImageConverterImplementa___Test PRIVATE AnyImageImporter)
+    else()
+        # So the plugins get properly built when building the test
+        add_dependencies(TradeImageConverterImplementa___Test AnyImageImporter)
+    endif()
+endif()
+if(MAGNUM_WITH_ANYIMAGECONVERTER)
+    if(MAGNUM_BUILD_PLUGINS_STATIC OR MAGNUM_ANYIMAGECONVERTER_BUILD_STATIC)
+        target_link_libraries(TradeImageConverterImplementa___Test PRIVATE AnyImageConverter)
+    else()
+        # So the plugins get properly built when building the test
+        add_dependencies(TradeImageConverterImplementa___Test AnyImageConverter)
+    endif()
+endif()
+if(MAGNUM_WITH_TGAIMAGECONVERTER)
+    if(MAGNUM_BUILD_PLUGINS_STATIC OR MAGNUM_TGAIMAGECONVERTER_BUILD_STATIC)
+        target_link_libraries(TradeImageConverterImplementa___Test PRIVATE TgaImageConverter)
+    else()
+        # So the plugins get properly built when building the test
+        add_dependencies(TradeImageConverterImplementa___Test TgaImageConverter)
+    endif()
+endif()
 
 # Executable testing is implemented on Unix platforms only at the moment
 if(CORRADE_TARGET_UNIX AND NOT CORRADE_PLUGINMANAGER_NO_DYNAMIC_PLUGIN_SUPPORT)
@@ -81,6 +116,9 @@ if(CORRADE_TARGET_UNIX AND NOT CORRADE_PLUGINMANAGER_NO_DYNAMIC_PLUGIN_SUPPORT)
         FILES
             ImageConverterTestFiles/info-data.txt
             ImageConverterTestFiles/info-data-ignored-output.txt
+            ImageConverterTestFiles/info-converter.txt
+            ImageConverterTestFiles/info-importer.txt
+            ImageConverterTestFiles/info-importer-ignored-input-output.txt
             ImageConverterTestFiles/file.tga)
     target_include_directories(TradeImageConverterTest PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/$<CONFIG>)
     if(MAGNUM_WITH_IMAGECONVERTER)

src/Magnum/Trade/Test/ImageConverterImplementationTest.cpp

@@ -27,6 +27,7 @@
 #include <Corrade/Containers/StringStl.h> /** @todo remove once Debug is stream-free */
 #include <Corrade/TestSuite/Tester.h>
 #include <Corrade/TestSuite/Compare/StringToFile.h>
+#include <Corrade/Utility/Configuration.h>
 #include <Corrade/Utility/DebugStl.h> /** @todo remove once Debug is stream-free */
 #include <Corrade/Utility/Path.h>
 
@@ -39,13 +40,325 @@ namespace Magnum { namespace Trade { namespace Test { namespace {
 struct ImageConverterImplementationTest: TestSuite::Tester {
     explicit ImageConverterImplementationTest();
 
+    void pluginInfo();
+    void pluginInfoAliases();
+    void pluginConfigurationInfoEmpty();
+    void pluginConfigurationInfo();
+    void pluginConfigurationInfoDoxygenDelimiter();
+    void importerInfo();
+    void converterInfo();
+    void converterInfoExtensionMimeType();
+
     void info();
     void infoError();
+
+    /* Explicitly forbid system-wide plugin dependencies */
+    PluginManager::Manager<Trade::AbstractImporter> _importerManager{"nonexistent"};
+    PluginManager::Manager<Trade::AbstractImageConverter> _converterManager{"nonexistent"};
 };
 
 ImageConverterImplementationTest::ImageConverterImplementationTest() {
-    addTests({&ImageConverterImplementationTest::info,
+    addTests({&ImageConverterImplementationTest::pluginInfo,
+              &ImageConverterImplementationTest::pluginInfoAliases,
+              &ImageConverterImplementationTest::pluginConfigurationInfoEmpty,
+              &ImageConverterImplementationTest::pluginConfigurationInfo,
+              &ImageConverterImplementationTest::pluginConfigurationInfoDoxygenDelimiter,
+              &ImageConverterImplementationTest::importerInfo,
+              &ImageConverterImplementationTest::converterInfo,
+              &ImageConverterImplementationTest::converterInfoExtensionMimeType,
+
+              &ImageConverterImplementationTest::info,
               &ImageConverterImplementationTest::infoError});
+
+    /* Load the plugin directly from the build tree. Otherwise it's static and
+       already loaded. */
+    #ifdef ANYIMAGEIMPORTER_PLUGIN_FILENAME
+    CORRADE_INTERNAL_ASSERT_OUTPUT(_importerManager.load(ANYIMAGEIMPORTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
+    #endif
+    #ifdef ANYIMAGECONVERTER_PLUGIN_FILENAME
+    CORRADE_INTERNAL_ASSERT_OUTPUT(_converterManager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
+    #endif
+    #ifdef TGAIMAGECONVERTER_PLUGIN_FILENAME
+    CORRADE_INTERNAL_ASSERT_OUTPUT(_converterManager.load(TGAIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
+    #endif
+}
+
+void ImageConverterImplementationTest::pluginInfo() {
+    /* Check if the required plugin can be loaded. Catches also ABI and
+       interface mismatch errors. */
+    if(!(_converterManager.load("AnyImageConverter") & PluginManager::LoadState::Loaded))
+        CORRADE_SKIP("AnyImageConverter plugin can't be loaded.");
+
+    Containers::Pointer<Trade::AbstractImageConverter> converter = _converterManager.instantiate("AnyImageConverter");
+
+    /* Print to visually verify coloring */
+    {
+        Debug{} << "======================== visual color verification start =======================";
+        Implementation::printPluginInfo(Debug::isTty() ? Debug::Flags{} : Debug::Flag::DisableColors, *converter);
+        Debug{} << "======================== visual color verification end =========================";
+    }
+
+    std::ostringstream out;
+    Debug redirectOutput{&out};
+    Implementation::printPluginInfo(Debug::Flag::DisableColors, *converter);
+    CORRADE_COMPARE(out.str(),
+        "Plugin name: AnyImageConverter\n"
+        "Features:\n"
+        "  Convert1DToFile\n"
+        "  Convert2DToFile\n"
+        "  Convert3DToFile\n"
+        "  ConvertCompressed1DToFile\n"
+        "  ConvertCompressed2DToFile\n"
+        "  ConvertCompressed3DToFile\n"
+        "  Levels\n");
+}
+
+void ImageConverterImplementationTest::pluginInfoAliases() {
+    PluginManager::Manager<Trade::AbstractImporter> importerManager{MAGNUM_PLUGINS_IMPORTER_INSTALL_DIR};
+
+    /* Check if the required plugin can be loaded. Catches also ABI and
+       interface mismatch errors. */
+    if(!(importerManager.load("StbImageImporter") & PluginManager::LoadState::Loaded))
+        CORRADE_SKIP("StbImageImporter plugin can't be loaded.");
+
+    /* Loading under an alias to verify that it's highlighted. Make
+       StbImageImporter *the* plugin to load PPMs, so it's not replaced by e.g.
+       DevIlImageImporter. */
+    importerManager.setPreferredPlugins("PpmImporter", {"StbImageImporter"});
+    Containers::Pointer<Trade::AbstractImporter> importer = importerManager.instantiate("PpmImporter");
+
+    /* Print to visually verify coloring */
+    {
+        Debug{} << "======================== visual color verification start =======================";
+        Implementation::printPluginInfo(Debug::isTty() ? Debug::Flags{} : Debug::Flag::DisableColors, *importer);
+        Debug{} << "======================== visual color verification end =========================";
+    }
+
+    std::ostringstream out;
+    Debug redirectOutput{&out};
+    Implementation::printPluginInfo(Debug::Flag::DisableColors, *importer);
+    CORRADE_COMPARE(out.str(),
+        "Plugin name: StbImageImporter\n"
+        "Aliases:\n"
+        "  BmpImporter\n"
+        "  GifImporter\n"
+        "  HdrImporter\n"
+        "  JpegImporter\n"
+        "  PgmImporter\n"
+        "  PicImporter\n"
+        "  PngImporter\n"
+        "  PpmImporter\n"
+        "  PsdImporter\n"
+        "  TgaImporter\n"
+        "Features:\n"
+        "  OpenData\n");
+}
+
+void ImageConverterImplementationTest::pluginConfigurationInfoEmpty() {
+    struct: Trade::AbstractImporter {
+        Trade::ImporterFeatures doFeatures() const override {
+            return Trade::ImporterFeature::FileCallback|
+                   Trade::ImporterFeature::OpenState;
+        }
+        bool doIsOpened() const override { return false; }
+        void doClose() override {}
+    } importer;
+
+    std::ostringstream out;
+    Debug redirectOutput{&out};
+    Implementation::printPluginConfigurationInfo(Debug::Flag::DisableColors, importer);
+    CORRADE_COMPARE(out.str(), "");
+}
+
+void ImageConverterImplementationTest::pluginConfigurationInfo() {
+    struct: Trade::AbstractImporter {
+        Trade::ImporterFeatures doFeatures() const override { return {}; }
+        bool doIsOpened() const override { return false; }
+        void doClose() override {}
+    } importer;
+
+    std::stringstream in;
+    in << R"([configuration]
+# A comment
+; Another
+value=yes
+another=42
+# Empty lines should not have trailing whitespace
+
+[configuration/group]
+spaces="  YES  "
+newlines="""
+A
+ L
+  S
+   O
+"""
+
+[configuration/group/subgroup]
+subvalue=35
+
+# Another instance of the same group
+[configuration/group]
+true=false
+)";
+    Utility::Configuration conf{in};
+
+    importer.configuration() = Utility::ConfigurationGroup{*conf.group("configuration")};
+
+    /* Print to visually verify coloring */
+    {
+        Debug{} << "======================== visual color verification start =======================";
+        Implementation::printPluginConfigurationInfo(Debug::isTty() ? Debug::Flags{} : Debug::Flag::DisableColors, importer);
+        Debug{} << "======================== visual color verification end =========================";
+    }
+
+    std::ostringstream out;
+    Debug redirectOutput{&out};
+    Implementation::printPluginConfigurationInfo(Debug::Flag::DisableColors, importer);
+    CORRADE_COMPARE(out.str(),
+        "Configuration:\n"
+        "  # A comment\n"
+        "  ; Another\n"
+        "  value=yes\n"
+        "  another=42\n"
+        "  # Empty lines should not have trailing whitespace\n"
+        "\n"
+        "  [group]\n"
+        "  spaces=\"  YES  \"\n"
+        "  newlines=\"\"\"\n"
+        "  A\n"
+        "   L\n"
+        "    S\n"
+        "     O\n"
+        "  \"\"\"\n"
+        "\n"
+        "  [group/subgroup]\n"
+        "  subvalue=35\n"
+        "\n"
+        "  # Another instance of the same group\n"
+        "  [group]\n"
+        "  true=false\n");
+}
+
+void ImageConverterImplementationTest::pluginConfigurationInfoDoxygenDelimiter() {
+    struct: Trade::AbstractImporter {
+        Trade::ImporterFeatures doFeatures() const override { return {}; }
+        bool doIsOpened() const override { return false; }
+        void doClose() override {}
+    } importer;
+
+    std::stringstream in;
+    in << R"(# [configuration_]
+[configuration]
+# A comment
+value=yes
+# [configuration_]
+privateValue=SECRET
+)";
+    Utility::Configuration conf{in};
+
+    importer.configuration() = Utility::ConfigurationGroup{*conf.group("configuration")};
+
+    std::ostringstream out;
+    Debug redirectOutput{&out};
+    Implementation::printPluginConfigurationInfo(Debug::Flag::DisableColors, importer);
+    CORRADE_COMPARE(out.str(),
+        "Configuration:\n"
+        "  # A comment\n"
+        "  value=yes\n");
+}
+
+void ImageConverterImplementationTest::importerInfo() {
+    /* Check if the required plugin can be loaded. Catches also ABI and
+       interface mismatch errors. */
+    if(!(_importerManager.load("AnyImageImporter") & PluginManager::LoadState::Loaded))
+        CORRADE_SKIP("AnyImageImporter plugin can't be loaded.");
+
+    Containers::Pointer<Trade::AbstractImporter> importer = _importerManager.instantiate("AnyImageImporter");
+    /** @todo pick a plugin that has some actual configuration */
+    importer->configuration().setValue("something", "is there");
+
+    /* Print to visually verify coloring */
+    {
+        Debug{} << "======================== visual color verification start =======================";
+        Implementation::printImporterInfo(Debug::isTty() ? Debug::Flags{} : Debug::Flag::DisableColors, *importer);
+        Debug{} << "======================== visual color verification end =========================";
+    }
+
+    std::ostringstream out;
+    Debug redirectOutput{&out};
+    Implementation::printImporterInfo(Debug::Flag::DisableColors, *importer);
+    CORRADE_COMPARE(out.str(),
+        "Plugin name: AnyImageImporter\n"
+        "Features:\n"
+        "  OpenData\n"
+        "  FileCallback\n"
+        "Configuration:\n"
+        "  something=is there\n");
+}
+
+void ImageConverterImplementationTest::converterInfo() {
+    /* Check if the required plugin can be loaded. Catches also ABI and
+       interface mismatch errors. */
+    if(!(_converterManager.load("AnyImageConverter") & PluginManager::LoadState::Loaded))
+        CORRADE_SKIP("AnyImageConverter plugin can't be loaded.");
+
+    Containers::Pointer<Trade::AbstractImageConverter> converter = _converterManager.instantiate("AnyImageConverter");
+    /** @todo pick a plugin that has some actual configuration */
+    converter->configuration().setValue("something", "is there");
+
+    /* Print to visually verify coloring */
+    {
+        Debug{} << "======================== visual color verification start =======================";
+        Implementation::printImageConverterInfo(Debug::isTty() ? Debug::Flags{} : Debug::Flag::DisableColors, *converter);
+        Debug{} << "======================== visual color verification end =========================";
+    }
+
+    std::ostringstream out;
+    Debug redirectOutput{&out};
+    Implementation::printImageConverterInfo(Debug::Flag::DisableColors, *converter);
+    CORRADE_COMPARE(out.str(),
+        "Plugin name: AnyImageConverter\n"
+        "Features:\n"
+        "  Convert1DToFile\n"
+        "  Convert2DToFile\n"
+        "  Convert3DToFile\n"
+        "  ConvertCompressed1DToFile\n"
+        "  ConvertCompressed2DToFile\n"
+        "  ConvertCompressed3DToFile\n"
+        "  Levels\n"
+        "Configuration:\n"
+        "  something=is there\n");
+}
+
+void ImageConverterImplementationTest::converterInfoExtensionMimeType() {
+    /* Check if the required plugin can be loaded. Catches also ABI and
+       interface mismatch errors. */
+    if(!(_converterManager.load("TgaImageConverter") & PluginManager::LoadState::Loaded))
+        CORRADE_SKIP("TgaImageConverter plugin can't be loaded.");
+
+    Containers::Pointer<Trade::AbstractImageConverter> converter = _converterManager.instantiate("TgaImageConverter");
+    /** @todo pick a plugin that has some actual configuration */
+    converter->configuration().setValue("something", "is there");
+
+    /* Print to visually verify coloring */
+    {
+        Debug{} << "======================== visual color verification start =======================";
+        Implementation::printImageConverterInfo(Debug::isTty() ? Debug::Flags{} : Debug::Flag::DisableColors, *converter);
+        Debug{} << "======================== visual color verification end =========================";
+    }
+
+    std::ostringstream out;
+    Debug redirectOutput{&out};
+    Implementation::printImageConverterInfo(Debug::Flag::DisableColors, *converter);
+    CORRADE_COMPARE(out.str(),
+        "Plugin name: TgaImageConverter\n"
+        "Features:\n"
+        "  Convert2DToData\n"
+        "File extension: tga\n"
+        "MIME type: image/x-tga\n"
+        "Configuration:\n"
+        "  something=is there\n");
 }
 
 void ImageConverterImplementationTest::info() {

src/Magnum/Trade/Test/ImageConverterTest.cpp

@@ -34,6 +34,7 @@
 #include <Corrade/Utility/Path.h>
 
 #include "Magnum/Trade/AbstractImporter.h"
+#include "Magnum/Trade/AbstractImageConverter.h"
 
 #include "configure.h"
 
@@ -51,21 +52,38 @@ const struct {
     const char* name;
     Containers::Array<Containers::String> args;
     const char* requiresImporter;
+    const char* requiresConverter;
     const char* expected;
 } InfoData[]{
+    {"importer", Containers::array<Containers::String>({
+        "--info-importer", "-i", "someOption=yes"}),
+        "AnyImageImporter", nullptr,
+        "info-importer.txt"},
+    {"converter", Containers::array<Containers::String>({
+        "-C", "AnyImageConverter", "--info-converter", "-c", "someOption=yes"}),
+        nullptr, "AnyImageConverter",
+        "info-converter.txt"},
+    {"converter, implicit", Containers::array<Containers::String>({
+        "--info-converter", "-c", "someOption=yes"}),
+        nullptr, "AnyImageConverter",
+        "info-converter.txt"},
+    {"importer, ignored input and output", Containers::array<Containers::String>({
+        "--info-importer", "a.png", "b.png", "out.jpg"}),
+        "AnySceneImporter", nullptr,
+        "info-importer-ignored-input-output.txt"},
     {"data", Containers::array<Containers::String>({
         "-I", "TgaImporter", "--info", Utility::Path::join(TRADE_TEST_DIR, "ImageConverterTestFiles/file.tga")}),
-        "TgaImporter",
+        "TgaImporter", nullptr,
         "info-data.txt"},
     {"data, map", Containers::array<Containers::String>({
         "--map", "-I", "TgaImporter", "--info", Utility::Path::join(TRADE_TEST_DIR, "ImageConverterTestFiles/file.tga")}),
-        "TgaImporter",
+        "TgaImporter", nullptr,
         /** @todo change to something else once we have a plugin that can
             zero-copy pass the imported data */
         "info-data.txt"},
     {"data, ignored output file", Containers::array<Containers::String>({
         "-I", "TgaImporter", "--info", Utility::Path::join(TRADE_TEST_DIR, "ImageConverterTestFiles/file.tga"), "whatever.png"}),
-        "TgaImporter",
+        "TgaImporter", nullptr,
         "info-data-ignored-output.txt"}
 };
 
@@ -122,8 +140,11 @@ void ImageConverterTest::info() {
     /* Check if required plugins can be loaded. Catches also ABI and interface
        mismatch errors. */
     PluginManager::Manager<Trade::AbstractImporter> importerManager{MAGNUM_PLUGINS_IMPORTER_INSTALL_DIR};
+    PluginManager::Manager<Trade::AbstractImageConverter> converterManager{MAGNUM_PLUGINS_IMAGECONVERTER_INSTALL_DIR};
     if(data.requiresImporter && !(importerManager.load(data.requiresImporter) & PluginManager::LoadState::Loaded))
         CORRADE_SKIP(data.requiresImporter << "plugin can't be loaded.");
+    if(data.requiresConverter && !(converterManager.load(data.requiresConverter) & PluginManager::LoadState::Loaded))
+        CORRADE_SKIP(data.requiresConverter << "plugin can't be loaded.");
 
     CORRADE_VERIFY(true); /* capture correct function name */
 

src/Magnum/Trade/Test/ImageConverterTestFiles/info-converter.txt

@@ -0,0 +1,11 @@
+Plugin name: AnyImageConverter
+Features:
+  Convert1DToFile
+  Convert2DToFile
+  Convert3DToFile
+  ConvertCompressed1DToFile
+  ConvertCompressed2DToFile
+  ConvertCompressed3DToFile
+  Levels
+Configuration:
+  someOption=yes

src/Magnum/Trade/Test/ImageConverterTestFiles/info-importer-ignored-input-output.txt

@@ -0,0 +1,6 @@
+Ignoring input files for --info: a.png b.png
+Ignoring output file for --info: out.jpg
+Plugin name: AnyImageImporter
+Features:
+  OpenData
+  FileCallback

src/Magnum/Trade/Test/ImageConverterTestFiles/info-importer.txt

@@ -0,0 +1,6 @@
+Plugin name: AnyImageImporter
+Features:
+  OpenData
+  FileCallback
+Configuration:
+  someOption=yes

src/Magnum/Trade/Test/configure.h.cmake

@@ -26,21 +26,28 @@
 #define TRADE_TEST_DIR "${TRADE_TEST_DIR}"
 #define TRADE_TEST_OUTPUT_DIR "${TRADE_TEST_OUTPUT_DIR}"
 #cmakedefine IMAGECONVERTER_EXECUTABLE_FILENAME "${IMAGECONVERTER_EXECUTABLE_FILENAME}"
+#cmakedefine ANYIMAGEIMPORTER_PLUGIN_FILENAME "${ANYIMAGEIMPORTER_PLUGIN_FILENAME}"
+#cmakedefine ANYIMAGECONVERTER_PLUGIN_FILENAME "${ANYIMAGECONVERTER_PLUGIN_FILENAME}"
+#cmakedefine TGAIMAGECONVERTER_PLUGIN_FILENAME "${TGAIMAGECONVERTER_PLUGIN_FILENAME}"
 
 #ifdef CORRADE_TARGET_WINDOWS
 #ifdef CORRADE_IS_DEBUG_BUILD
 #define MAGNUM_PLUGINS_INSTALL_DIR "${CMAKE_INSTALL_PREFIX}/${MAGNUM_PLUGINS_DEBUG_BINARY_INSTALL_DIR}"
 #define MAGNUM_PLUGINS_IMPORTER_INSTALL_DIR "${CMAKE_INSTALL_PREFIX}/${MAGNUM_PLUGINS_IMPORTER_DEBUG_BINARY_INSTALL_DIR}"
+#define MAGNUM_PLUGINS_IMAGECONVERTER_INSTALL_DIR "${CMAKE_INSTALL_PREFIX}/${MAGNUM_PLUGINS_IMAGECONVERTER_DEBUG_BINARY_INSTALL_DIR}"
 #else
 #define MAGNUM_PLUGINS_INSTALL_DIR "${CMAKE_INSTALL_PREFIX}/${MAGNUM_PLUGINS_RELEASE_BINARY_INSTALL_DIR}"
 #define MAGNUM_PLUGINS_IMPORTER_INSTALL_DIR "${CMAKE_INSTALL_PREFIX}/${MAGNUM_PLUGINS_IMPORTER_RELEASE_BINARY_INSTALL_DIR}"
+#define MAGNUM_PLUGINS_IMAGECONVERTER_INSTALL_DIR "${CMAKE_INSTALL_PREFIX}/${MAGNUM_PLUGINS_IMAGECONVERTER_RELEASE_BINARY_INSTALL_DIR}"
 #endif
 #else
 #ifdef CORRADE_IS_DEBUG_BUILD
 #define MAGNUM_PLUGINS_INSTALL_DIR "${CMAKE_INSTALL_PREFIX}/${MAGNUM_PLUGINS_DEBUG_LIBRARY_INSTALL_DIR}"
 #define MAGNUM_PLUGINS_IMPORTER_INSTALL_DIR "${CMAKE_INSTALL_PREFIX}/${MAGNUM_PLUGINS_IMPORTER_DEBUG_LIBRARY_INSTALL_DIR}"
+#define MAGNUM_PLUGINS_IMAGECONVERTER_INSTALL_DIR "${CMAKE_INSTALL_PREFIX}/${MAGNUM_PLUGINS_IMAGECONVERTER_DEBUG_LIBRARY_INSTALL_DIR}"
 #else
 #define MAGNUM_PLUGINS_INSTALL_DIR "${CMAKE_INSTALL_PREFIX}/${MAGNUM_PLUGINS_RELEASE_LIBRARY_INSTALL_DIR}"
 #define MAGNUM_PLUGINS_IMPORTER_INSTALL_DIR "${CMAKE_INSTALL_PREFIX}/${MAGNUM_PLUGINS_IMPORTER_RELEASE_LIBRARY_INSTALL_DIR}"
+#define MAGNUM_PLUGINS_IMAGECONVERTER_INSTALL_DIR "${CMAKE_INSTALL_PREFIX}/${MAGNUM_PLUGINS_IMAGECONVERTER_RELEASE_LIBRARY_INSTALL_DIR}"
 #endif
 #endif

src/Magnum/Trade/imageconverter.cpp

@@ -192,7 +192,8 @@ magnum-imageconverter [-h|--help] [-I|--importer PLUGIN]
     [-i|--importer-options key=val,key2=val2,…]
     [-c|--converter-options key=val,key2=val2,…]... [-D|--dimensions N]
     [--image N] [--level N] [--layer N] [--layers] [--levels] [--in-place]
-    [--info] [--color on|off|auto] [-v|--verbose] [--profile] [--] input output
+    [--info-importer] [--info-converter] [--info] [--color on|off|auto]
+    [-v|--verbose] [--profile] [--] input output
 @endcode
 
 Arguments:
@@ -221,6 +222,8 @@ Arguments:
     more
 -   `--levels` --- combine multiple image levels into a single file
 -   `--in-place` --- overwrite the input image with the output
+-   `--info-importer` --- print info about the importer plugin and exit
+-   `--info-converter` --- print info about the image converter plugin and exit
 -   `--info` --- print info about the input file and exit
 -   `--color` --- colored output for `--info` (default: `auto`)
 -   `-v`, `--verbose` --- verbose output from importer and converter plugins
@@ -231,9 +234,16 @@ tightly-packed square of pixels in given @ref PixelFormat. Specifying `-C` /
 `--converter raw` will save raw imported data instead of using a converter
 plugin.
 
-If `--info` is given, the utility will print information about all images
-present in the file, independently of the `-D` / `--dimensions` option. In this
-case no conversion is done and output file doesn't need to be specified.
+If the `--info-importer` or `--info-converter` option is given, the utility
+will print information about given plugin specified via the `-I` or `-C`
+option, including its configuration options potentially overriden with
+`-i` or `-c`. In this case no file is read and no conversion is done and
+neither the input nor the output file needs to be specified.
+
+If `--info` is given, the utility will print information about given data,
+independently of the `-D` / `--dimensions` option. In this case the input file
+is read but no no conversion is done and output file doesn't need to be
+specified.
 
 The `-i` / `--importer-options` and `-c` / `--converter-options` arguments
 accept a comma-separated list of key/value pairs to set in the importer /
@@ -258,6 +268,11 @@ using namespace Containers::Literals;
 
 namespace {
 
+bool isPluginInfoRequested(const Utility::Arguments& args) {
+    return args.isSet("info-importer") ||
+           args.isSet("info-converter");
+}
+
 template<UnsignedInt dimensions> bool checkCommonFormatFlags(const Utility::Arguments& args, const Containers::Array<Trade::ImageData<dimensions>>& images) {
     CORRADE_INTERNAL_ASSERT(!images.isEmpty());
     const bool compressed = images.front().isCompressed();
@@ -362,15 +377,21 @@ int main(int argc, char** argv) {
         .addBooleanOption("layers").setHelp("layers", "combine multiple layers into an image with one dimension more")
         .addBooleanOption("levels").setHelp("layers", "combine multiple image levels into a single file")
         .addBooleanOption("in-place").setHelp("in-place", "overwrite the input image with the output")
+        .addBooleanOption("info-importer").setHelp("info-importer", "print info about the importer plugin and exit")
+        .addBooleanOption("info-converter").setHelp("info-converter", "print info about the image converter plugin and exit")
         .addBooleanOption("info").setHelp("info", "print info about the input file and exit")
         .addOption("color", "auto").setHelp("color", "colored output for --info", "on|off|auto")
         .addBooleanOption('v', "verbose").setHelp("verbose", "verbose output from importer and converter plugins")
         .addBooleanOption("profile").setHelp("profile", "measure import and conversion time")
         .setParseErrorCallback([](const Utility::Arguments& args, Utility::Arguments::ParseError error, const std::string& key) {
-            /* If --in-place or --info is passed, we don't need the output
-               argument */
+            /* If --info for plugins is passed, we don't need the input */
             if(error == Utility::Arguments::ParseError::MissingArgument &&
-               key == "output" && (args.isSet("in-place") || args.isSet("info")))
+               key == "input" && isPluginInfoRequested(args))
+                return true;
+            /* If --in-place or --info for plugins or data is passed, we don't
+               need the output argument */
+            if(error == Utility::Arguments::ParseError::MissingArgument &&
+               key == "output" && (args.isSet("in-place") || isPluginInfoRequested(args) || args.isSet("info")))
                 return true;
 
             /* Handle all other errors as usual */
@@ -382,9 +403,14 @@ Specifying --importer raw:<format> will treat the input as a raw tightly-packed
 square of pixels in given pixel format. Specifying -C / --converter raw will
 save raw imported data instead of using a converter plugin.
 
-If --info is given, the utility will print information about all images present
-in the file, independently of the -D / --dimensions option. In this case no
-conversion is done and output file doesn't need to be specified.
+If the --info-importer or --info-converter option is given, the utility will
+print information about given plugin specified via the -I or -C option,
+including its configuration options potentially overriden with -i or -c. In
+this case no file is read and no conversion is done and neither the input nor
+the output file needs to be specified.
+
+If --info is given, the utility will print information about given data, independently of the -D / --dimensions option. In this case the input file is
+read but no conversion is done and output file doesn't need to be specified.
 
 The -i / --importer-options and -c / --converter-options arguments accept a
 comma-separated list of key/value pairs to set in the importer / converter
@@ -410,16 +436,26 @@ no -C / --converter is specified, AnyImageConverter is used.)")
         useColor = Debug::isTty() ? Debug::Flags{} : Debug::Flag::DisableColors;
 
     /* Generic checks */
+    if(const std::size_t inputCount = args.arrayValueCount("input")) {
+        /* Not an error in this case, it should be possible to just append
+           --info* to existing command line without having to remove anything.
+           But print a warning at least, it could also be a mistyped option. */
+        if(isPluginInfoRequested(args)) {
+            Warning w;
+            w << "Ignoring input files for --info:";
+            for(std::size_t i = 0; i != inputCount; ++i)
+                w << args.arrayValue<Containers::StringView>("input", i);
+        }
+    }
     if(args.value<Containers::StringView>("output")) {
         if(args.isSet("in-place")) {
             Error{} << "Output file shouldn't be set for --in-place:" << args.value<Containers::StringView>("output");
             return 1;
         }
 
-        /* Not an error in this case, it should be possible to just append
-           --info to existing command line without having to remove anything.
-           But print a warning at least, it could also be a mistyped option. */
-        if(args.isSet("info"))
+        /* Same as above, it should be possible to just append --info* to
+           existing command line */
+        if(isPluginInfoRequested(args) || args.isSet("info"))
             Warning{} << "Ignoring output file for --info:" << args.value<Containers::StringView>("output");
     }
 
@@ -450,7 +486,7 @@ no -C / --converter is specified, AnyImageConverter is used.)")
         Error{} << "The --levels option can't be combined with raw data output";
         return 1;
     }
-    if(!args.isSet("layers") && !args.isSet("levels") && args.arrayValueCount("input") > 1) {
+    if(!args.isSet("layers") && !args.isSet("levels") && args.arrayValueCount("input") > 1 && !isPluginInfoRequested(args)) {
         Error{} << "Multiple input files require the --layers / --levels option to be set";
         return 1;
     }
@@ -463,6 +499,35 @@ no -C / --converter is specified, AnyImageConverter is used.)")
         args.value("plugin-dir").empty() ? Containers::String{} :
         Utility::Path::join(args.value("plugin-dir"), Utility::Path::split(Trade::AbstractImageConverter::pluginSearchPaths().back()).second())};
 
+    /* Print plugin info, if requested */
+    if(args.isSet("info-importer")) {
+        Containers::Pointer<Trade::AbstractImporter> importer = importerManager.loadAndInstantiate(args.value("importer"));
+        if(!importer) {
+            Debug{} << "Available importer plugins:" << ", "_s.join(importerManager.aliasList());
+            return 1;
+        }
+
+        /* Set options, if passed */
+        if(args.isSet("verbose")) importer->addFlags(Trade::ImporterFlag::Verbose);
+        Implementation::setOptions(*importer, "AnyImageImporter", args.value("importer-options"));
+        Trade::Implementation::printImporterInfo(useColor, *importer);
+        return 0;
+    }
+    if(args.isSet("info-converter")) {
+        Containers::Pointer<Trade::AbstractImageConverter> converter = converterManager.loadAndInstantiate(args.arrayValueCount("converter") ? args.arrayValue("converter", 0) : "AnyImageConverter");
+        if(!converter) {
+            Debug{} << "Available converter plugins:" << ", "_s.join(converterManager.aliasList());
+            return 1;
+        }
+
+        /* Set options, if passed */
+        if(args.isSet("verbose")) converter->addFlags(Trade::ImageConverterFlag::Verbose);
+        if(args.arrayValueCount("converter-options"))
+            Implementation::setOptions(*converter, "AnyImageConverter", args.arrayValue("converter-options", 0));
+        Trade::Implementation::printImageConverterInfo(useColor, *converter);
+        return 0;
+    }
+
     const Int dimensions = args.value<Int>("dimensions");
     /** @todo make them array options as well? */
     const UnsignedInt image = args.value<UnsignedInt>("image");