* Sebastian <se...@sebix.at> [06-30-15 08:29]: > On 06/30/2015 02:07 PM, Patrick Shanahan wrote: > >>> > >>> I expect he thinks that DT will tell you if it's focused because that is > >>> what the linked article tells us and pressing ctrl-z does indeed zoom > >>> the image and over lays it with a grid of red dashed rectangles, which, > >>> according to the article, indicate infocus areas. I would like to add > >>> that there is no option "indicate focus regions" in gui settings so this > >>> may be the problem.Or perhaps the feature has been removed. > >> > >> Have you had a look at the provided screenshot, linked below? It shows > >> the red rectangles, indicating a good focus, all over the image. > >> The keyboard shortcuts can be looked up or modified in the settings > > >> shortcuts > views > lighttable. There are 4 options: > >> [sticky] preview [with focus detection] > > > > iianm, the red rectangles indicate the areas the camera *uses* to achieve > > focus and except for displaying them as provided by the camera image info, > > have nothing to do with the program editing or indicating anything else. > > Do you have a source for that? > Citing the dt blog at > https://www.darktable.org/2013/11/determining-focus-in-lighttable/ > > we do a two-scale decimated cdf 2,2 wavelet transform and use a > > threshold on the detail coefficients. the second scale is only computed > > if the first scale (the sharper one) doesn't yield any results. > > visually, these are displayed as red clusters (first scale, very sharp) > > and blue clusters (second scale, not quite as sharp).
Now you have made me curious. :) Paging thru a collection I am presently developing, I see photos with red rectangles, some which show very sharp focus, and photos with blue rectangles which indicate areas out-of-focus. But no photos with both colors of rectangles. And it seems the blue always indicate out-of-focus but sometimes there are greater that one red and not all red really show good focus, sometimes clustered away from center, usually bottom and this collection is center focus. That said, I believe the rectangles are meant as an aid rather than a determinant factor. I personally have rarely used this function. -- (paka)Patrick Shanahan Plainfield, Indiana, USA @ptilopteri http://en.opensuse.org openSUSE Community Member facebook/ptilopteri http://wahoo.no-ip.org Photo Album: http://wahoo.no-ip.org/gallery2 Registered Linux User #207535 @ http://linuxcounter.net ------------------------------------------------------------------------------ Don't Limit Your Business. Reach for the Cloud. GigeNET's Cloud Solutions provide you with the tools and support that you need to offload your IT needs and focus on growing your business. Configured For All Businesses. Start Your Cloud Today. https://www.gigenetcloud.com/ _______________________________________________ Darktable-users mailing list Darktable-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/darktable-users
