diff --git a/src/gui/image/qimage.cpp b/src/gui/image/qimage.cpp
index b1dcf6a9f8..9870e19cec 100644
--- a/src/gui/image/qimage.cpp
+++ b/src/gui/image/qimage.cpp
@@ -2120,6 +2120,44 @@ QImage QImage::convertToFormat(Format format, const QVector<QRgb> &colorTable, Q
     return image;
 }
 
+/*!
+    \since 5.9
+
+    Changes the format of the image without changing the data. Only
+    works between formats of the same depth.
+
+    Returns \c true if successful.
+
+    This function can be used to change images with alpha-channels to
+    their corresponding opaque formats if the data is known to be opaque-only,
+    or to change the format of a given image buffer before overwriting
+    it with new data.
+
+    \warning The function does not check if the image data is valid in the
+    new format and will still return \c true if the depths are compatible.
+    Operations on an image with invalid data are undefined.
+
+    \warning If the image is not detached, this will cause the data to be
+    copied.
+
+    \sa isDetached(), hasAlphaChannel(), convertToFormat()
+*/
+
+bool QImage::reinterpretAsFormat(Format format)
+{
+    if (!d)
+        return false;
+    if (d->format == format)
+        return true;
+    if (qt_depthForFormat(format) != qt_depthForFormat(d->format))
+        return false;
+    if (!isDetached()) // Detach only if shared, not for read-only data.
+        detach();
+
+    d->format = format;
+    return true;
+}
+
 /*!
     \fn bool QImage::valid(const QPoint &pos) const
 
diff --git a/src/gui/image/qimage.h b/src/gui/image/qimage.h
index fd2298561e..204e7a54b2 100644
--- a/src/gui/image/qimage.h
+++ b/src/gui/image/qimage.h
@@ -192,6 +192,7 @@ public:
     QImage convertToFormat(Format f, Qt::ImageConversionFlags flags = Qt::AutoColor) const Q_REQUIRED_RESULT;
 #endif
     QImage convertToFormat(Format f, const QVector<QRgb> &colorTable, Qt::ImageConversionFlags flags = Qt::AutoColor) const Q_REQUIRED_RESULT;
+    bool reinterpretAsFormat(Format f);
 
     int width() const;
     int height() const;
diff --git a/tests/auto/gui/image/qimage/tst_qimage.cpp b/tests/auto/gui/image/qimage/tst_qimage.cpp
index 65ee4a2188..21481e374d 100644
--- a/tests/auto/gui/image/qimage/tst_qimage.cpp
+++ b/tests/auto/gui/image/qimage/tst_qimage.cpp
@@ -206,6 +206,11 @@ private slots:
     void ditherGradient_data();
     void ditherGradient();
 
+    void reinterpretAsFormat_data();
+    void reinterpretAsFormat();
+
+    void reinterpretAsFormat2();
+
 #ifdef Q_OS_DARWIN
     void toCGImage_data();
     void toCGImage();
@@ -3303,6 +3308,64 @@ void tst_QImage::ditherGradient()
     QVERIFY(observedGradientSteps >= minimumExpectedGradient);
 }
 
+void tst_QImage::reinterpretAsFormat_data()
+{
+    QTest::addColumn<QImage::Format>("in_format");
+    QTest::addColumn<QImage::Format>("out_format");
+    QTest::addColumn<QColor>("in_color");
+    QTest::addColumn<QColor>("out_color");
+
+#if Q_BYTE_ORDER == Q_LITTLE_ENDIAN
+    QTest::newRow("rgb32 -> rgbx8888") << QImage::Format_RGB32 << QImage::Format_RGBX8888 << QColor(Qt::red) << QColor(Qt::blue);
+    QTest::newRow("rgba8888 -> argb32") << QImage::Format_RGBA8888 << QImage::Format_ARGB32 << QColor(Qt::red) << QColor(Qt::blue);
+    QTest::newRow("argb32pm -> rgba8888pm") << QImage::Format_RGBA8888_Premultiplied << QImage::Format_ARGB32_Premultiplied << QColor(Qt::green) << QColor(Qt::green);
+#endif
+    QTest::newRow("rgb32 -> argb32") << QImage::Format_RGB32 << QImage::Format_ARGB32 << QColor(Qt::cyan) << QColor(Qt::cyan);
+    QTest::newRow("argb32pm -> rgb32") << QImage::Format_ARGB32_Premultiplied << QImage::Format_RGB32 << QColor(Qt::transparent) << QColor(Qt::black);
+    QTest::newRow("argb32 -> rgb32") << QImage::Format_ARGB32 << QImage::Format_RGB32 << QColor(255, 0, 0, 127) << QColor(255, 0, 0);
+    QTest::newRow("argb32pm -> rgb32") << QImage::Format_ARGB32_Premultiplied << QImage::Format_RGB32 << QColor(255, 0, 0, 127) << QColor(127, 0, 0);
+}
+
+void tst_QImage::reinterpretAsFormat()
+{
+    QFETCH(QImage::Format, in_format);
+    QFETCH(QImage::Format, out_format);
+    QFETCH(QColor, in_color);
+    QFETCH(QColor, out_color);
+
+    QImage image(1, 1, in_format);
+    image.setPixelColor(0, 0, in_color);
+    QVERIFY(image.reinterpretAsFormat(out_format));
+    QCOMPARE(image.pixelColor(0, 0), out_color);
+}
+
+void tst_QImage::reinterpretAsFormat2()
+{
+    const uint imageData[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
+
+    {
+        QImage image(reinterpret_cast<const uchar*>(imageData), 4, 2, QImage::Format_RGB32);
+        QCOMPARE(image.pixelColor(0, 0), QColor(Qt::black));
+        QVERIFY(image.isDetached());
+        QVERIFY(image.reinterpretAsFormat(QImage::Format_ARGB32_Premultiplied));
+        QCOMPARE(image.constBits(), reinterpret_cast<const uchar*>(imageData));
+        QCOMPARE(image.pixelColor(0, 0), QColor(Qt::transparent));
+
+        QVERIFY(!image.reinterpretAsFormat(QImage::Format_Grayscale8));
+    }
+    {
+        QImage image(reinterpret_cast<const uchar*>(imageData), 8, 4, QImage::Format_Indexed8);
+        image.setColor(0, qRgb(255, 255, 255));
+        QCOMPARE(image.pixelColor(0, 0), QColor(Qt::white));
+        QVERIFY(image.reinterpretAsFormat(QImage::Format_Grayscale8));
+        QCOMPARE(image.pixelColor(0, 0), QColor(Qt::black));
+        QVERIFY(image.reinterpretAsFormat(QImage::Format_Alpha8));
+        QCOMPARE(image.pixelColor(0, 0), QColor(Qt::transparent));
+
+        QVERIFY(!image.reinterpretAsFormat(QImage::Format_RGB16));
+    }
+}
+
 #ifdef Q_OS_DARWIN
 
 void tst_QImage::toCGImage_data()