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authorQt Forward Merge Bot <qt_forward_merge_bot@qt-project.org>2018-04-07 01:00:13 +0200
committerQt Forward Merge Bot <qt_forward_merge_bot@qt-project.org>2018-04-07 01:00:14 +0200
commit800119509837f4dfe3b4de1ecd88938ae6b18b71 (patch)
treea2d58870ac1d5a45c78e4da455d26b653758eee3 /src/gui/image/qimage_conversions.cpp
parent093cf19f1efdfbba3edb76547917a51e5b8cdba5 (diff)
parent28c9ad199c313444149471e854bfa6cc7c708549 (diff)
Merge remote-tracking branch 'origin/5.11' into dev
Diffstat (limited to 'src/gui/image/qimage_conversions.cpp')
-rw-r--r--src/gui/image/qimage_conversions.cpp12
1 files changed, 8 insertions, 4 deletions
diff --git a/src/gui/image/qimage_conversions.cpp b/src/gui/image/qimage_conversions.cpp
index 39d97f4bd9..16ad0a3edc 100644
--- a/src/gui/image/qimage_conversions.cpp
+++ b/src/gui/image/qimage_conversions.cpp
@@ -1331,14 +1331,18 @@ void dither_to_Mono(QImageData *dst, const QImageData *src,
} else {
bit--;
}
+ const int e7 = ((err * 7) + 8) >> 4;
+ const int e5 = ((err * 5) + 8) >> 4;
+ const int e3 = ((err * 3) + 8) >> 4;
+ const int e1 = err - (e7 + e5 + e3);
if (x < w)
- *b1 += (err*7)>>4; // spread error to right pixel
+ *b1 += e7; // spread error to right pixel
if (not_last_line) {
- b2[0] += (err*5)>>4; // pixel below
+ b2[0] += e5; // pixel below
if (x > 1)
- b2[-1] += (err*3)>>4; // pixel below left
+ b2[-1] += e3; // pixel below left
if (x < w)
- b2[1] += err>>4; // pixel below right
+ b2[1] += e1; // pixel below right
}
b2++;
}