1 files changed, 117 insertions, 0 deletions
diff --git a/vcl/qa/cppunit/jpeg/JpegWriterTest.cxx b/vcl/qa/cppunit/jpeg/JpegWriterTest.cxx
new file mode 100644
index 0000000000..c20dd9e8bc
--- /dev/null
+++ b/vcl/qa/cppunit/jpeg/JpegWriterTest.cxx
@@ -0,0 +1,117 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ */
+
+#include <sal/config.h>
+
+#include <string_view>
+
+#include <unotest/bootstrapfixturebase.hxx>
+#include <vcl/graphicfilter.hxx>
+#include <vcl/BitmapReadAccess.hxx>
+#include <tools/stream.hxx>
+#include <graphic/GraphicFormatDetector.hxx>
+
+constexpr OUStringLiteral gaDataUrl(u"/vcl/qa/cppunit/jpeg/data/");
+
+class JpegWriterTest : public test::BootstrapFixtureBase
+{
+    OUString getFullUrl(std::u16string_view sFileName)
+    {
+        return m_directories.getURLFromSrc(gaDataUrl) + sFileName;
+    }
+
+    BitmapEx load(const OUString& aURL);
+    BitmapEx roundtripJPG(const BitmapEx& bitmap);
+    BitmapEx roundtripJPG(const OUString& aURL);
+
+public:
+    void testWrite8BitGrayscale();
+    void testWrite8BitNonGrayscale();
+
+    CPPUNIT_TEST_SUITE(JpegWriterTest);
+    CPPUNIT_TEST(testWrite8BitGrayscale);
+    CPPUNIT_TEST(testWrite8BitNonGrayscale);
+    CPPUNIT_TEST_SUITE_END();
+};
+
+BitmapEx JpegWriterTest::load(const OUString& aURL)
+{
+    GraphicFilter& rFilter = GraphicFilter::GetGraphicFilter();
+    Graphic aGraphic;
+    SvFileStream aFileStream(aURL, StreamMode::READ);
+    ErrCode bResult = rFilter.ImportGraphic(aGraphic, aURL, aFileStream);
+    CPPUNIT_ASSERT_EQUAL(ERRCODE_NONE, bResult);
+    return aGraphic.GetBitmapEx();
+}
+
+BitmapEx JpegWriterTest::roundtripJPG(const OUString& aURL) { return roundtripJPG(load(aURL)); }
+
+BitmapEx JpegWriterTest::roundtripJPG(const BitmapEx& bitmap)
+{
+    // EXPORT JPEG
+    SvMemoryStream aStream;
+    GraphicFilter& rFilter = GraphicFilter::GetGraphicFilter();
+    sal_uInt16 exportFormatJPG = rFilter.GetExportFormatNumberForShortName(JPG_SHORTNAME);
+    Graphic aExportGraphic(bitmap);
+    ErrCode bResult = rFilter.ExportGraphic(aExportGraphic, u"memory", aStream, exportFormatJPG);
+    CPPUNIT_ASSERT_EQUAL(ERRCODE_NONE, bResult);
+    //Detect the magic bytes - we need to be sure the file is actually a JPEG
+    aStream.Seek(0);
+    vcl::GraphicFormatDetector aDetector(aStream, "");
+    CPPUNIT_ASSERT(aDetector.detect());
+    CPPUNIT_ASSERT(aDetector.checkJPG());
+    // IMPORT JPEG
+    aStream.Seek(0);
+    Graphic aImportGraphic;
+    sal_uInt16 importFormatJPG = rFilter.GetImportFormatNumberForShortName(JPG_SHORTNAME);
+    bResult = rFilter.ImportGraphic(aImportGraphic, u"memory", aStream, importFormatJPG);
+    CPPUNIT_ASSERT_EQUAL(ERRCODE_NONE, bResult);
+    return aImportGraphic.GetBitmapEx();
+}
+
+void JpegWriterTest::testWrite8BitGrayscale()
+{
+    Bitmap bitmap = roundtripJPG(getFullUrl(u"8BitGrayscale.jpg")).GetBitmap();
+    BitmapScopedReadAccess access(bitmap);
+    const ScanlineFormat format = access->GetScanlineFormat();
+    // Check that it's still 8bit grayscale.
+    CPPUNIT_ASSERT_EQUAL(ScanlineFormat::N8BitPal, format);
+    CPPUNIT_ASSERT(bitmap.HasGreyPalette8Bit());
+    // Check that the content is valid.
+    CPPUNIT_ASSERT_EQUAL(BitmapColor(COL_WHITE), access->GetColor(0, 0));
+    CPPUNIT_ASSERT_EQUAL(BitmapColor(COL_WHITE), access->GetColor(0, access->Width() - 1));
+    CPPUNIT_ASSERT_EQUAL(BitmapColor(COL_WHITE), access->GetColor(access->Height() - 1, 0));
+    CPPUNIT_ASSERT_EQUAL(BitmapColor(COL_BLACK),
+                         access->GetColor(access->Height() - 1, access->Width() - 1));
+}
+
+void JpegWriterTest::testWrite8BitNonGrayscale()
+{
+    Bitmap bitmap = roundtripJPG(getFullUrl(u"8BitNonGrayscale.gif")).GetBitmap();
+    BitmapScopedReadAccess access(bitmap);
+    const ScanlineFormat format = access->GetScanlineFormat();
+    // Check that it's still 8bit grayscale.
+    CPPUNIT_ASSERT_EQUAL(ScanlineFormat::N8BitPal, format);
+    // The original image has grayscale palette, just with entries in a different order.
+    // Do not check for grayscale 8bit, the roundtrip apparently fixes that. What's important
+    // is the content.
+    CPPUNIT_ASSERT(bitmap.HasGreyPaletteAny());
+    // CPPUNIT_ASSERT(bitmap.HasGreyPalette8Bit());
+    // Check that the content is valid.
+    CPPUNIT_ASSERT_EQUAL(BitmapColor(COL_WHITE), access->GetColor(0, 0));
+    CPPUNIT_ASSERT_EQUAL(BitmapColor(COL_WHITE), access->GetColor(0, access->Width() - 1));
+    CPPUNIT_ASSERT_EQUAL(BitmapColor(COL_WHITE), access->GetColor(access->Height() - 1, 0));
+    CPPUNIT_ASSERT_EQUAL(BitmapColor(COL_BLACK),
+                         access->GetColor(access->Height() - 1, access->Width() - 1));
+}
+
+CPPUNIT_TEST_SUITE_REGISTRATION(JpegWriterTest);
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */