Add support for the orientation of tiff images

The orientation tag was ignored for tiff images. The tag is now used
to rotate the image before providing it to the user.

The orientation of indexed an mono images is done completely manually.

The orientation of other type is done in conjunction to the mirroring
already performed by libtiff.

Task-number: 258526
Reviewed-by: Samuel Rødal

1 files changed, 106 insertions, 1 deletions

diff --git a/src/plugins/imageformats/tiff/qtiffhandler.cpp b/src/plugins/imageformats/tiff/qtiffhandler.cpp
index ec8a483..59edaf4 100644
--- a/src/plugins/imageformats/tiff/qtiffhandler.cpp
+++ b/src/plugins/imageformats/tiff/qtiffhandler.cpp
@@ -98,6 +98,43 @@ void qtiffUnmapProc(thandle_t /*fd*/, tdata_t /*base*/, toff_t /*size*/)
 {
 }
 
+// for 32 bits images
+inline void rotate_right_mirror_horizontal(QImage *const image)// rotate right->mirrored horizontal
+{
+    const int height = image->height();
+    const int width = image->width();
+    QImage generated(/* width = */ height, /* height = */ width, image->format());
+    const uint32 *originalPixel = reinterpret_cast<const uint32*>(image->bits());
+    uint32 *const generatedPixels = reinterpret_cast<uint32*>(generated.bits());
+    for (int row=0; row < height; ++row) {
+        for (int col=0; col < width; ++col) {
+            int idx = col * height + row;
+            generatedPixels[idx] = *originalPixel;
+            ++originalPixel;
+        }
+    }
+    *image = generated;
+}
+
+inline void rotate_right_mirror_vertical(QImage *const image) // rotate right->mirrored vertical
+{
+    const int height = image->height();
+    const int width = image->width();
+    QImage generated(/* width = */ height, /* height = */ width, image->format());
+    const int lastCol = width - 1;
+    const int lastRow = height - 1;
+    const uint32 *pixel = reinterpret_cast<const uint32*>(image->bits());
+    uint32 *const generatedBits = reinterpret_cast<uint32*>(generated.bits());
+    for (int row=0; row < height; ++row) {
+        for (int col=0; col < width; ++col) {
+            int idx = (lastCol - col) * height + (lastRow - row);
+            generatedBits[idx] = *pixel;
+            ++pixel;
+        }
+    }
+    *image = generated;
+}
+
 QTiffHandler::QTiffHandler() : QImageIOHandler()
 {
     compression = NoCompression;
@@ -223,7 +260,8 @@ bool QTiffHandler::read(QImage *image)
             if (image->size() != QSize(width, height) || image->format() != QImage::Format_ARGB32)
                 *image = QImage(width, height, QImage::Format_ARGB32);
             if (!image->isNull()) {
-                if (TIFFReadRGBAImageOriented(tiff, width, height, reinterpret_cast<uint32 *>(image->bits()), ORIENTATION_TOPLEFT, 0)) {
+                const int stopOnError = 1;
+                if (TIFFReadRGBAImageOriented(tiff, width, height, reinterpret_cast<uint32 *>(image->bits()), ORIENTATION_TOPLEFT, stopOnError)) {
                     for (uint32 y=0; y<height; ++y)
                         convert32BitOrder(image->scanLine(y), width);
                 } else {
@@ -262,6 +300,73 @@ bool QTiffHandler::read(QImage *image)
         }
     }
 
+    // rotate the image if the orientation is defined in the file
+    uint16 orientationTag;
+    if (TIFFGetField(tiff, TIFFTAG_ORIENTATION, &orientationTag)) {
+        if (image->format() == QImage::Format_ARGB32) {
+            // TIFFReadRGBAImageOriented() flip the image but does not rotate them
+            switch (orientationTag) {
+            case 5:
+                rotate_right_mirror_horizontal(image);
+                break;
+            case 6:
+                rotate_right_mirror_vertical(image);
+                break;
+            case 7:
+                rotate_right_mirror_horizontal(image);
+                break;
+            case 8:
+                rotate_right_mirror_vertical(image);
+                break;
+            }
+        } else {
+            switch (orientationTag) {
+            case 1: // default orientation
+                break;
+            case 2: // mirror horizontal
+                *image = image->mirrored(true, false);
+                break;
+            case 3: // mirror both
+                *image = image->mirrored(true, true);
+                break;
+            case 4: // mirror vertical
+                *image = image->mirrored(false, true);
+                break;
+            case 5: // rotate right mirror horizontal
+                {
+                    QMatrix transformation;
+                    transformation.rotate(90);
+                    *image = image->transformed(transformation);
+                    *image = image->mirrored(true, false);
+                    break;
+                }
+            case 6: // rotate right
+                {
+                    QMatrix transformation;
+                    transformation.rotate(90);
+                    *image = image->transformed(transformation);
+                    break;
+                }
+            case 7: // rotate right, mirror vertical
+                {
+                    QMatrix transformation;
+                    transformation.rotate(90);
+                    *image = image->transformed(transformation);
+                    *image = image->mirrored(false, true);
+                    break;
+                }
+            case 8: // rotate left
+                {
+                    QMatrix transformation;
+                    transformation.rotate(270);
+                    *image = image->transformed(transformation);
+                    break;
+                }
+            }
+        }
+    }
+
+
     TIFFClose(tiff);
     return true;
 }