Bug 345501

Summary:	improve color to alpha filter
Product:	[Applications] krita	Reporter:	goco9
Component:	Filters	Assignee:	Krita Bugs <krita-bugs-null>
Status:	CONFIRMED ---
Severity:	wishlist	CC:	halla, tamtamy.tymona
Priority:	NOR
Version First Reported In:	2.9
Target Milestone:	---
Platform:	Microsoft Windows
OS:	Microsoft Windows
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description goco9 2015-03-25 06:32:06 UTC

using create filter mask in color to alpha make the result difference from the preview and the final result when use color to alpha alone, it seems to be krita fill something in to layer mask make it opaque than preview, 

but use undo history to go back to "add layer" get the right result.

wish list
1. if color to alpha can  seperate threshold to R/G/B or C/M/Y/K threshold
2. pick multiple sample point (like select > color range in photoshop)
3. something like GIMPS > threshold alpha to remove some noise that hard  to  see in preview

Reproducible: Always

Steps to Reproduce:
1. load file 
2. apply filter > Color to alpha > pick  a background color
3. click create filter mask 



krita 2.9 (Feb 27), Windows 7 Pro 64 bit + Nvidia Quadro 2000
(i did not see this bug fix in 2.91 (Mar 16) list)

Comment 1 Halla Rempt 2015-03-25 08:16:30 UTC

The way filters, filter layers and filter masks work means that the issue isn't that easy to solve: to get the exact effect of running the filter destructively on the layer, you need to add a filter layer, not a filter mask to the stack. 

For the rest, good points, that would make the filter much more useful.

Comment 2 Halla Rempt 2016-01-24 15:34:24 UTC

These are the bits we can work on:

 1. if color to alpha can seperate threshold to R/G/B or C/M/Y/K threshold
 2. pick multiple sample point (like select > color range in photoshop) 
3. something like GIMPS > threshold alpha to remove some noise that hard to see in preview

WISHGROUP: Larger Usability Fixes

Comment 3 Tiar 2020-04-03 00:00:07 UTC

It needs some GUI mockups.