On 13/05/2013 22:01, Richard Hughes wrote: > I'm trying to make my transform go fast. I've got a 1920x1080 RGB > image being transformed from sRGB to the display profile. I've got a > quad core processor on my development box, no shaders or GPU, and I'm > trying to do the transform as quickly as possible.
Before you dive into the complexities of multithreading etc, it would seem sensible to ensure you are getting the best possible performance out of the transform routine in the first place. LCMS has various different transform routines built in; by using a cunning scheme, it can pick the appropriate one at runtime. If there happens to be one in its repertoire that exactly fits your needs, it can run considerably faster than if it has to use a generic one. To speed ghostscripts use of lcms2, I wanted to optimise the transforms that we use as much as possible. But we use quite a lot of them, and I didn't want to have to hand write optimised ones for all of the different cases. So I implemented a system that uses a chameleonic header; set a few options with #defines, and include the header, and it makes the optimised transform function for you. You can find this as part of the copy of lcms2 in the Ghostscript source, or on my git repository: https://github.com/robinwatts/Little-CMS/tree/artifex I offered this code back to Marti for inclusion in stock lcms2, so that people could easily add their own optimised transforms, but he wasn't keen on taking it as is. He did however point out that I could recast the code slightly as a plugin for lcms 2. This gives the same benefits without polluting the internals of the library itself. I plan to do this at some point, but I have not got round to it yet. In the meantime, if anyone has any use for the existing code, please feel free. Robin ------------------------------------------------------------------------------ AlienVault Unified Security Management (USM) platform delivers complete security visibility with the essential security capabilities. Easily and efficiently configure, manage, and operate all of your security controls from a single console and one unified framework. Download a free trial. http://p.sf.net/sfu/alienvault_d2d _______________________________________________ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
