vkdt dev diary pt 6

today: an illustration of the focus stack blend mode.

consider this older playraw here (sorry since the thumbnails in the PlayRaw category don’t work any more i find it hard to keep track of the original reference… it’s somewhere here…):

beautiful lighting, but not easy to expose. with the blend module, you can now put graphs like this together to try and emulate the mertens/focus stack way of merging images:

this is just one path through the graph, for the ground:

this is the other path, for the sky:

and this is the merged version, i also applied a third curve after the merge (with quite a bit of bias to bring back negative values to the visible range, have to think about whether i want to clamp wavelet coefficients to positive range):

not sure i’m super happy with the result, i’d probably tweak a few values for a while:

i found the expressive power of this kind of combining pixel data quite fun to use!


Oh nice, looks like effectively a two-exposure Mertens fusion followed by an additional postprocessing curve?

This is a challenging input given that the shadow region is pretty heavily washed out in the input region, and the sky is pretty badly blown too.

yes that was my motivation trying to click this together… it’s close, but different. the blending is just a wavelet transform combining the coefficients with maximum absolute value (take sharper/more high frequency of the two images). i coded that to try and merge one of andabata’s bug stacks. without all the dedicated saturation/colour shielding i’d expect there are cases where this produces extremely weird colour, especially because it involves three curves now. seems though that the building block is generic enough for reuse here.