New feature ‘Adjust lightness of indistinguishable text’ - how it works?

[foal]

How does the new feature work? For example I have the following color combination for total size of selected files (see screenshot). It is completely unreadable and I do not see any different while this option is turned on.

ConEmu build: 160428 x64

[Maximus5]

You may easily check the effect of the option yourself by running

ConEmu.exe -basic -run {Show ANSI Colors}

and playing with checkbox.

As for your screenshot - the distance between colors make them distinguishable for human eyes.

[foal]

As for your screenshot - the distance between colors make them distinguishable for human eyes.

Exactly! I hoped that you use some of a delta-E formula to implement it.
As evaluation I suggest to add a selector for different delta-E formulas and allows to setup a custom threshold,

[Maximus5]

The current implementation uses latest available DeltaE (2000). So I don't think you exact color combination, which you dislike, can be processed by feature. If ConEmu uses larger threshold - entire palette would be affected, which it's not suitable.

[foal]

Yes, you are right, the color distance in my example is too big to handle it by threshold parameter.

[foal]

I find out another parameter that influence on the text representation. Perhaps it will interest you.

It is contrast ration. In my example it is much bellow under recommended level 1.3 vs 4.5.

There is you can see it: http://leaverou.github.io/contrast-ratio/#rgb%28181%2C137%2C0%29-on-rgb%2849%2C130%2C164%29

More information:
https://www.w3.org/TR/WCAG/#visual-audio-contrast

I do not know how to exactly correct such things, but the first idea is dynamically shift the text color to increase the contract value.

e.g. (my case)
bg: rgb(49,130,164), text: rgb(181,137,0), contrast-ratio is 1.3
text
rgb(181,137,0) -> hsl(45,100%,35%),
shift the h to reach the maximum contrast-ratio for the current bg,
hsl(63,100%,35%) -> rgb(170,179,0)
result
bg: rgb(49,130,164), text: rgb(170,179,0), contrast-ratio is 1.9 (not a good, but much more better)

http://leaverou.github.io/contrast-ratio/#rgb%28170%2C179%2C0%29-on-rgb%2849%2C130%2C164%29

[foal]

Hi, How about new feature "Adjust contrast of indistinguishable text"? :)

[m0n]

I do not open a new issue because my notes maybe too minor:

I spent a hour to figure out why my white text turned to gray when I downloaded a fresh version which introduced this feature months ago...

I using a semi-light-gray texture background which replaces a light-gray color (#DDDDDD). After this feature appeared white text turned gray. I'm unsure in that this option must to be enabled by default. At least this fooled me when I updated my ConEmu months after this feature introduced.

Proposal 2: let add a checkbox "Use this feature on bitmap backgrounds", unchecked by default. You force this feature by default but since bitmap hides background color this could leads problems (see above)

Proposal 3: on bitmap-backgrounds calculate an average background color for each character (of course You need to do this only when a new background image used then cache it).

Proposal 4: cast a contrast-shadow around characters - that would be make ANY text readable on ANY background 👍 ( I know the technical difficulties 😃 )

OFF-TOPIC: congrats for (the long-time-not-seen) stable releases! 😃

[Maximus5]

• https://www.w3.org/TR/2008/REC-WCAG20-20081211/#relativeluminancedef
• https://www.w3.org/TR/2008/REC-WCAG20-20081211/#contrast-ratiodef

And note about bad experience in the zsh prompt, there should be no contrast triangle...

Normal image, but text is unreadable

The text: zsh-prompt.txt