Diffstat (limited to 'src/gui/image/qimagereader.cpp')
1 files changed, 15 insertions, 8 deletions
diff --git a/src/gui/image/qimagereader.cpp b/src/gui/image/qimagereader.cpp
index a1b9743209..a7a08a6fee 100644
@@ -877,15 +877,22 @@ QString QImageReader::fileName() const
- This is an image format specific function that sets the quality
- level of the image to \a quality. For image formats that do not
- support setting the quality, this value is ignored.
+ Sets the quality setting of the image format to \a quality.
- The value range of \a quality depends on the image format. For
- example, the "jpeg" format supports a quality range from 0 (low
- quality, high compression) to 100 (high quality, low compression).
+ Some image formats, in particular lossy ones, entail a tradeoff between a)
+ visual quality of the resulting image, and b) decoding execution time.
+ This function sets the level of that tradeoff for image formats that
+ support it.
- \sa quality()
+ In case of scaled image reading, the quality setting may also influence the
+ tradeoff level between visual quality and execution speed of the scaling
+ The value range of \a quality depends on the image format. For example,
+ the "jpeg" format supports a quality range from 0 (low visual quality) to
+ 100 (high visual quality).
+ \sa quality() setScaledSize()
void QImageReader::setQuality(int quality)
@@ -895,7 +902,7 @@ void QImageReader::setQuality(int quality)
- Returns the quality level of the image.
+ Returns the quality setting of the image format.