Am 21.12.2012 20:36, schrieb Pascal de Bruijn: > Hi, > > We (Tobias and me) just noticed our sharpen module fails at image > borders. This is particularly noticeable (at 200% zoom) with a radius > of 8 and amount of 2 and a threshold of 0. In more real-world > use-cases it's not so noticeable. > > Could this be a trivial issue? Or should I create a low priority > ticket for the long run? >
I think it's expected behavior. For the border pixels we can not apply the normal gaussian convolution filter as it would access pixels outside the image buffer. For that reason border pixels are just copied from input image without sharpening. At extreme parameter settings this leads to visible differences. So, if we would want to change that, we would need to make a special round of convolution taking the above mentioned restrictions into account, e.g. out of range pixels are replaced by edge values etc. I doubt if under real life conditions this really makes a difference and is worth the effort. BTW: our OpenCL path does not suffer from this issue as there is a hardware-enabled option to replace out-of-range pixels by edge values. Ulrich > Regards, > Pascal de Bruijn > ------------------------------------------------------------------------------ LogMeIn Rescue: Anywhere, Anytime Remote support for IT. Free Trial Remotely access PCs and mobile devices and provide instant support Improve your efficiency, and focus on delivering more value-add services Discover what IT Professionals Know. Rescue delivers http://p.sf.net/sfu/logmein_12329d2d _______________________________________________ darktable-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/darktable-devel
