Hello,
As you may have guessed, I like using this tool A LOT. In fact I use it all the time and that led me to discover several flaws in it. I have thought about how to fix them (from a user viewpoint) and here are my suggestions.
I have made another thread about that same thing (https://forum.kde.org/viewtopic.php?f=139&t=138777) but it was met with lukewarm attention. Maybe it was too hard to read and packed, and/or not clear enough, so I will try it again in this subforum (which I believe is better for this post), but this time I will format it better to make it much easier to read and understand.
I believe these changes would be very easy to implement and would make it much easier to use. You are of course free to agree/disagree with any proposed change and/or tweak any of my ideas.

On the fuzziness slider
Observations
Currently, you can select how sensitive the Contiguous Area Selection is. there is a slider ("Fuzziness") that goes from 0 to 200.
1. Any value above 100 (even just 101) will select the entire document, regardless of what is in it.
2. The little arrows to increase/decrease the fuzziness value increment it by 10 units.

Solutions

Observation 1
A. Make the maximum value (currently 200, but as stated before, 101-200 just selects all) be 101.

Reasons are :
- Sensible change (values between 101-200 do the same thing. Can't we just have it stop at 101?)
- Makes it easier to select a precise value with the mouse without having to use the keyboard to input it.
- I do not know exactly how the algorithm works, but as a user, I can very imagine that 0 selects "0%" and 101 (since 0 selects nothing) selects "100%". It is, IMO, more intuitive than "0-100 works normally, and 101-200 just selects everything".

OR ALTERNATIVELY

B. Adjust the selection algorithm to work within the 1-200 bounds, instead of just 1-100

Observation 2
A. The little increment/decrement arrows should change the value by just (IMO) 5 units.

Reasons are :
- Sensible change (slider is half as long, and so, so should be the unit incrementation).
- Easier to select a value with the mouse.

On performance
Observations
This tool is not particularly fast. it takes a good 1.5-2 second to select an area in an empty document with only a single layer with a black pixel in it. To be fair, AFAIK, having more things on a document does not add much more time to select areas (it stays around 2 seconds between the mouse click and the time the area is effectively selected), but it is still relatively slow.
I apologize for comparing it with SAI (I often do it unfortunately, as I use SAI and Krita), but SAI's selection is instant, regardless of document size, amount of layers and things on them. (for comparison, I run W7 in virtualbox and have SAI in it, and selections in it are instant - it is not my computer being slow).
I of course realize if it were up to you, you'd make everything lightning fast or instant, but I just wanted to let you know that if there is a possibility to improve this tool's performance, it'd be greatly appreciated.



I apologize for the long post, but it only looks long. Most of it's length is from formatting to make it easy to read.
I hope my suggestions will be helpful in the development of Krita.
Thank you for reading!

I'm agree with this. I don't use contiguous area selection much though so it doesn't bother me but I made little patch to "fix" fuzziness slider.
I changed values to 1-100 and made it exponential. Also I made slider step (arrows and mouse wheel step) to 1, I think it's better to have more control.
Not sure how soon it will be added to stable build.

I agree with performance too but I don't have enough programming skills to make it better.

radian wrote:I'm agree with this. I don't use contiguous area selection much though so it doesn't bother me but I made little patch to "fix" fuzziness slider.
I changed values to 1-100 and made it exponential. Also I made slider step (arrows and mouse wheel step) to 1, I think it's better to have more control.
Not sure how soon it will be added to stable build.

I agree with performance too but I don't have enough programming skills to make it better.

That's great! I extensively use contiguous selection tool as well as the similar color selection tool, especially the latter. Pretty neat tools for localized edits on color regions, or lighting. Great to know it's been worked on. Thanks.