fdo#66006 Convert to PNG for JPEG that can't be losslessly rotated

If a JPEG image has a width or height which is not a multiple of 16
(width/heigh % 16 != 0) then it can't be completelly lossleessly
rotated (the last uncomplete MCUs can't be rotated) and the image
is cropped on the lower size. To prevent this such JPEG images
must be rotated to PNG to prevent loss. Afterwards image can still
be compressed with "Compress Graphic Dialog".

Change-Id: Ie2803512a93bba55573bf66c547f132f37cba711
Reviewed-on: https://gerrit.libreoffice.org/5159
Reviewed-by: Luboš Luňák <l.lunak@suse.cz>
Tested-by: Luboš Luňák <l.lunak@suse.cz>

1 files changed, 35 insertions, 30 deletions

diff --git a/vcl/source/filter/GraphicNativeTransform.cxx b/vcl/source/filter/GraphicNativeTransform.cxx
index 261ad90c3ce5..69a10bdc65c2 100644
--- a/vcl/source/filter/GraphicNativeTransform.cxx
+++ b/vcl/source/filter/GraphicNativeTransform.cxx
@@ -141,45 +141,50 @@ bool GraphicNativeTransform::rotateGeneric(sal_uInt16 aRotation, OUString aType)
 
 bool GraphicNativeTransform::rotateJPEG(sal_uInt16 aRotation)
 {
-    GfxLink aLink = mrGraphic.GetLink();
-
-    SvMemoryStream aSourceStream;
-    aSourceStream.Write(aLink.GetData(), aLink.GetDataSize());
-    aSourceStream.Seek( STREAM_SEEK_TO_BEGIN );
-
-    Orientation aOrientation = TOP_LEFT;
+    BitmapEx aBitmap = mrGraphic.GetBitmapEx();
 
-    Exif exif;
-    if ( exif.read(aSourceStream) )
+    if (aBitmap.GetSizePixel().Width()  % 16 != 0 ||
+        aBitmap.GetSizePixel().Height() % 16 != 0 )
     {
-        aOrientation = exif.getOrientation();
+        rotateGeneric(aRotation, OUString("png"));
     }
+    else
+    {
+        GfxLink aLink = mrGraphic.GetLink();
 
-    SvMemoryStream aTargetStream;
-    JpegTransform tranform(aSourceStream, aTargetStream);
-    tranform.setRotate(aRotation);
-    tranform.perform();
+        SvMemoryStream aSourceStream;
+        aSourceStream.Write(aLink.GetData(), aLink.GetDataSize());
+        aSourceStream.Seek( STREAM_SEEK_TO_BEGIN );
 
-    aTargetStream.Seek( STREAM_SEEK_TO_BEGIN );
+        Orientation aOrientation = TOP_LEFT;
 
-    // Reset orientation in exif if needed
-    if ( exif.hasExif() && aOrientation != TOP_LEFT)
-    {
-        exif.setOrientation(TOP_LEFT);
-        exif.write(aTargetStream);
-    }
+        Exif exif;
+        if ( exif.read(aSourceStream) )
+        {
+            aOrientation = exif.getOrientation();
+        }
 
-    aTargetStream.Seek( STREAM_SEEK_TO_END );
-    sal_uInt32 aBufferSize = aTargetStream.Tell();
-    sal_uInt8* pBuffer = new sal_uInt8[ aBufferSize ];
+        SvMemoryStream aTargetStream;
+        JpegTransform tranform(aSourceStream, aTargetStream);
+        tranform.setRotate(aRotation);
+        tranform.perform();
 
-    aTargetStream.Seek( STREAM_SEEK_TO_BEGIN );
-    aTargetStream.Read( pBuffer, aBufferSize );
+        aTargetStream.Seek( STREAM_SEEK_TO_BEGIN );
 
-    BitmapEx aBitmap = mrGraphic.GetBitmapEx();
-    aBitmap.Rotate(aRotation, COL_BLACK);
-    mrGraphic = aBitmap;
-    mrGraphic.SetLink( GfxLink( pBuffer, aBufferSize, aLink.GetType(), sal_True ) );
+        // Reset orientation in exif if needed
+        if ( exif.hasExif() && aOrientation != TOP_LEFT)
+        {
+            exif.setOrientation(TOP_LEFT);
+            exif.write(aTargetStream);
+        }
+
+        aTargetStream.Seek( STREAM_SEEK_TO_BEGIN );
+
+        Graphic aGraphic;
+        GraphicFilter& rFilter = GraphicFilter::GetGraphicFilter();
+        rFilter.ImportGraphic( aGraphic, OUString("import"), aTargetStream );
+        mrGraphic = aGraphic;
+    }
 
     return true;
 }