Decided to go into Krita development, and this time, I am aiming to add filters aimed to improve editing which can be helpful not only to photographers, but also to game artists, and texture artists. I want to speed Krita development as I find it useful, and has potential to rival Affinity or Photoshop with a few more features that’s needed like high pass, and lazy selection as it already has many color spaces, adjustment layers, adjustment masks, clone layers, and some very interesting features like Color Transfer (easily can work as adjustment layer/mask with only changing a very small part of the code). I have managed to add a new basic selection mode which is symmetric difference, and over 25 new blending modes (I found Super Light is actually good for high pass, and Fog modes are good for cloning).
Now the two filters I am working on are High Pass - https://phabricator.kde.org/D20475 , and now converting @patdavid Luminosity Mask tutorial into an actual filter. For now, I am making the second part as I couldn’t figure out how to get mix op to work which is needed to extract details from the guassian blur. High Pass in Krita is color-independent i.e you can do high pass in any space.
On the second part, it’s going to be an adjustment layer where only thing different is that the alpha is based on existing alpha multiplied by the LAB L*. The reason is simple, this enable one to apply filter masks under a new luminosity mask filter layer which goes above the source image or using many clone layer with filter mask over the source image.