Artifacts in Zerene Stacker D-map

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Big Pete
Posts: 62
Joined: Thu Dec 02, 2021 7:40 am
Location: Ulricehamn Sweden

Artifacts in Zerene Stacker D-map

Post by Big Pete »

This phenomenon causes a lot of frustration. In D-map, it looks like glue is running down between different color fields and details. What am I doing wrong?


https://flic.kr/p/2nhwi2h
[url=https://flic.kr/p/2nhwi2h][img]https://live.sta

rjlittlefield
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Re: Artifacts in Zerene Stacker D-map

Post by rjlittlefield »

In the image that you linked, I see two different sorts of DMap artifacts.

First, the blotchy appearance in out-of-focus regions is caused by having the contrast threshold slider set too far left. This forces DMap to fit a depth map to tiny contrast differences that are really due to random pixel noise.

The best attack on this problem is to push the slider farther right, so that all those areas currently filled with annoying blotches go "black in preview" while you're setting the slider.

Second, there are "loss of detail" halos on transitions between detailed areas that are at much different depths. I suspect these are the "glue" you' mention. This problem is caused by the depth map being unable to capture the sudden transition between depths. Instead, the depth map slews between front and back in a sort of ramp that passes through a lot of frames where nothing is in focus. DMap will never give a completely clean result in these areas, so the best solution is to retouch those areas from a PMax output that will have a better rendering of the background.

The Zerene Stacker website has relevant documentstion. See https://zerenesystems.com/cms/stacker/d ... _with_dmap for an overview of controlling the DMap slider. This is the "Stacking With DMap" section of the basic "How To Use Zerene Stacker" page. More details are provided at https://zerenesystems.com/cms/stacker/d ... utorial003 , in the "How To Use DMap" tutorial. Additional examples of how to use the slider in combination with retouching are provided in the two video tutorials on retouching, especially the "Advanced Retouching" tutorial. All of these materials are linked on the main Tutorials index page at https://zerenesystems.com/cms/stacker/d ... rialsindex .

If you want more information on why the front/back overlap transitions are troublesome, try the discussion at viewtopic.php?p=102557#102557 .

I hope this helps!

--Rik

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