Bug 30740
| Summary: | [Qt] QtWebKit should consider using QImageReader::setQuality(49) | ||
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| Product: | WebKit | Reporter: | Holger Freyther <zecke> |
| Component: | Images | Assignee: | Nobody <webkit-unassigned> |
| Status: | RESOLVED FIXED | ||
| Severity: | Normal | CC: | laszlo.gombos, yael |
| Priority: | P2 | Keywords: | Qt |
| Version: | 528+ (Nightly build) | ||
| Hardware: | PC | ||
| OS: | OS X 10.5 | ||
Holger Freyther
ImageDecoderQt.cpp should use QImageReader::setQuality(49) to use JDCT_IFAST in the Qt JPEG Image Decoder. This change can give a 5% speedup on the image_cycling reduction.
JDCT_IFAST is supposingly not generating as good results as the other integer based method but it is not certain how bad these are. The Palm developers have opted to use this for the WebOS.
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| Add attachment proposed patch, testcase, etc. |
Yael
(In reply to comment #0)
> ImageDecoderQt.cpp should use QImageReader::setQuality(49) to use JDCT_IFAST in
> the Qt JPEG Image Decoder. This change can give a 5% speedup on the
> image_cycling reduction.
>
> JDCT_IFAST is supposingly not generating as good results as the other integer
> based method but it is not certain how bad these are. The Palm developers have
> opted to use this for the WebOS.
Sorry I did not get back to you in that. I was OOO until today. Will try to arrange testing during next week.
Yael
We collected a few JPG images and tested on N97. The colors of the images looked better after we applied this change.
Holger Freyther
I landed a patch to do this in r52086. Let us see if someone is noticing the difference.