Hi Richard,
We have implemented a new transform cache system in the AtrousWaveletTransform and MultiscaleMedianTransform tools. When these tools are applied to previews or to the Real-Time Preview window, they compute the wavelet or median transform for the whole image, and then store it in a memory cache. While the parameters of the transform are not changed in a way that invalidates the cache, it is reused when the process is applied to a preview or R-T preview of the same image.
The advantage of this cache system is twofold: you always get perfectly accurate previews on regular previews and on the Real Time Preview window (previously these previews were inaccurate, especially on R-T), and once the cache has been generated the process is very fast, allowing true real-time previews. The disadvantage is that this requires more memory to store the wavelet or median transform. This also requires you to be careful not to reset the tool, or change the number of layers unnecessarily, since these actions invalidate the cache.
With just 4 GB of RAM, your machine might require some memory swapping to disk, especially if you work with large images and have many background processes running. This could be the cause of these performance problems.
I have just made two quick tests on Windows:
- On a virtual Windows 7 x64 machine with 4 cores and 8 GB of RAM assigned (VMware running on a Core i7 990X Linux workstation), for a 5202x3465 RGB image (a Canon EOS 7D image), the cache computes in less than 8 seconds.
- On a physical Windows 7 x64 machine with a Core i5 processor (2 cores + hyperthreading = 4 logical cores) and 8 GB of RAM, for a 6000x4000 RGB image, the cache requires about 12 seconds.
Have you tried the new RC3 version on a more powerful machine? You may consider increasing the RAM on your notebook, especially since you're using a 64-bit operating system. I think 8 GB would be a reasonable upgrade.
