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tkImgPhoto.c - Patch for better performance
Description:
This patch adds a new option to the image command (-dither 1|0),
so you can specify, if you want dithering take place or not.
Switching dithering off reduces image display time significantly,
especially on 16 bit displays, without loosing much image quality.
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Notes:
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This patch is based on patch/bug # 224066.
See
http://charm.cs.uiuc.edu/users/olawlor/tmp/tkImgPhoto.patch
for the original patch.
I applied some changes to make it work correctly on Windows.
(Patch2)
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It works only for Tk 8.3 or 8.4.
The patch also applies a modification - already integrated into 8.4 -
which eliminates calling the dither code twice (Patch1).
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Now the bad thing: It adds platform-dependent code
(with #ifdefs) into a file located in the generic directory.
Could surely be eliminated, if a day had more than 24 hours.
Here are some timing results (in seconds): PIII, 333 MHz, 16-bit depth
Timed command: .label configure -image $myImg (image size is 1024x1024)
SuSE Linux 6.3:
With Patch1
Original 1.50 0.80
Patch2 dither=1 1.30 0.68
Patch2 dither=0 0.35 0.20
Windows 98:
With Patch1
Original 1.80 Not tested
Patch2 dither=1 1.40 0.70
Patch2 dither=0 0.40 0.22
So, if you don't bother too much about image quality (dither=0), you
are able to display images 7-8 times faster. If dithering is on, it's still
more than 2 times faster.
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Downloads:
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File name |
Description |
tkImgPhoto.zip |
Patched Tk source files for T 8.3.2 |
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