[KimDaBa] performance improvements - patch
marcel.wiesweg at gmx.de
Sat Jun 12 22:24:19 CEST 2004
when I started to work with KimDaBa, I noticed first that it is an excellent
piece of work, and second a few major performance hits:
1. Thumbnail creation. A 64x64 thumbnail from a 3.2 Megapixel image took ~1.2
seconds on my machine. Imagine me sitting in front of 1000+ images to
2. The "one-at-a-time" ImageConfig dialog took veeery long to appear (3 s)
3. Switching to the next image in the same dialogue also took a good time.
I traced all the problems in last consequence down to the thumbnail creation.
The patch attached does the following:
- make use of libjpeg and its scale-while-decoding capability wherever
possible (now thumbnail takes ~0.2s => factor 6)
- use the excellent ImageManager/ImageLoader infrastructure in the ImageConfig
dialogue - if necessary, the preview appears after a short delay
- use a preloading mechanism in this dialogue: The next image is preloaded,
the last is kept in cache. This has the effect that in 'normal' operation the
preview always appears instantly.
You will see that I added the libjpeg decoding and a central function
getThumnailName(QString filename) to util.cpp
-------------- next part --------------
A non-text attachment was scrubbed...
Size: 18014 bytes
Desc: not available
Url : http://sulaco.hrhansen.dk/pipermail/kimdaba/attachments/20040612/14ca4ec3/kimdaba-performance.bin
More information about the KimDaBa