I did another test: sharpening in darkroom or sharpening using a style in the "export selected" panel gives identical results. Instead, exporting a downscaled image, reopening this smaller image and then applying sharpening gives different, better, results.
So my advice was wrong or not ideal at least. It was based on this part <http://www.darktable.org/usermanual/ch02s03s12.html.php#d0e3405> of the manual that I find quite confusing/ambiguous: About export styles: "*You can use this feature to add processing steps and parameters that you want to be applied specifically to images before export, e.g. you may define a style that adds a stronger level of sharpening when you produce scaled-down JPEG files for the internet or add a certain level of exposure compensation to all of your output images.*" But sharpening gets softened a lot during downscale so it doesn't seem a good example, more like a workaround. So it seems like some separate post processing is needed. Bye Lorenzo 2017-03-29 10:31 GMT+02:00 Sascha Oleszczuk <[email protected]>: > Hello All, > > thank you for your feedback. > The initial idea of my questions was to get insights of your workflows. > How do you prepare images for web. > > I know that this can be done with darktable ( have read the manual ;-) ). > But as Roman mentioned the styles (during export) are not applied to the > downscaled image they are added to the history stack. > > Let me summarize your feedback: (not all have replied to mailing list > that's why I summarize it) > - Export with Darkktable full resolution as TIFF and downscale with Digikam > - Export and downscale with Darktable and append a style to sharpen. > Create styles for export like 640-sharpen, 1280-sharpen, 2048-sharpen > etc. > - Export full resolution with Darktable and use mogrify as part of > Imagemagick to create imgaes for web > e.g. mogrify -quality "85%" -resize 900x900 -unsharp 1.5x1+0.7+0.2 *.jpg > > > Let's see what others recommend. > > Thx > > 2017-03-28 0:26 GMT+02:00 <[email protected]>: > >> On Mon, 27 Mar 2017 23:58:19 +0200 >> Lorenzo Bolzani <[email protected]> wrote: >> >> >I just did a quick test: one export with no style applied and another >> >export with a custom style containing sharpening set to max >> >settings. The two exported files are clearly different. >> > >> >So I think the best option for downscale is to create a few styles >> >(like 640-sharpen, 1280-sharpen, 2048-sharpen, etc.) and use the >> >best one. >> > >> >About what kind of sharpening to use, I use all the ones you >> >mentioned (local contrast, highpass, etc.) often more the one at the >> >same time. They are different. I usually use the basic "sharpen" >> >with these settings: 1600, 0.800, 250. The threshold value depends >> >on how much noise is there in the picture as sharpening enhance the >> >noise. I rarely use the equalizer for simple sharpening only. High >> >pass with different settings and blend modes (e.g. softlight) gives >> >very different results as does local contrast. >> >> I have also gone the route of try this, try that: local contrast, >> sharpening and high pass. >> >> I ended up with mogrify which is part of imagemagick which is >> available for both mac and linux >> >> I export the jpegs to a temp directory and use: >> >> > mogrify -quality "85%" -resize 900x900 -unsharp 1.5x1+0.7+0.2 *.jpg >> >> It's extremely fast and I find it the sharpening more pleasing >> >> -- >> sknahT >> >> vyS >> ____________________________________________________________ >> ________________ >> darktable user mailing list >> to unsubscribe send a mail to darktable-user+unsubscribe@lis >> ts.darktable.org >> >> > > ____________________________________________________________________________ > darktable user mailing list to unsubscribe send a mail to > [email protected] > ____________________________________________________________________________ darktable user mailing list to unsubscribe send a mail to [email protected]
