Photoshop CC 2015.5.1: Sometimes does the color management doubly (macOS)

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  • Problem
  • Updated 2 years ago
  • (Edited)
My environment
Mac : Mac Pro (Mid2010)
OS : OS X El Capitan 10.11.6
Photoshop : CC 2015.5
Color Picker : Digital Color Meter.app

Steps to reproduce(To simplify the problem, I describe the difference of color space only with gamma)
Prepare ICC profileA(gamma:2.2) and ICC profileB(gamma:1.4).
Apply the monitor profile(gamma:2.2).
Launch Photoshop.
Open the color patch image(e.g. (32, 32, 32)) which has gamma 2.2 profile on Photoshop.

At this timing, monitor gamma and image gamma are the same.
Therefore, color management doesn't work, and color picker indicates the patch color as (32, 32, 32).
This is correct behavior.

Change monitor profile to ICC profileB(gamma:1.4).

If the focus is on Photoshop, color management works correctly and displays the color patch as (10, 10, 10).
The "10" is calculated with "POWER(32/255, 2.2/1.4) * 255".
This means the color management from 2.2 image to 1.4 monitor color space. So, it's correct.

But, If focus was not on Photoshop at the time of , the problem will happen.

Move the focus to Photoshop.

At the timing of focus on, displaying colors(RGB values) are changed once more.
It seems that (unnecessary) second color management is applied.
Because, the patch displays as (2, 2, 2) at this timing.
This values equals to "POWER(32/255, (2.2*2.2)/(1.4*1.4))".
Of course, this is the same for other tone.

For example, (64, 64, 64) is changed as follows
(64, 64, 64) -> change gamma -> (29, 29, 29) -> focus on -> (8, 8, 8). 
 
I think this is a bug.
The necessary color management is first one only.
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Takao

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Posted 2 years ago

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Photo of Jeffrey Tranberry

Jeffrey Tranberry, Sr. Product Manager, Digital Imaging

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(Edited)
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Takao

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Thanks for the replay.
But, I think suggested post is for other problem.

My Photoshop has already been updated to 2015.5.1(201607722.r.156).
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Pete Green, Customer Advocate

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Is it possible to record a video of the issue you're describing above?
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Takao

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Sure, please refer to the attached video (with caption).

At start, each color patch RGB values are as below.
0, 16, 32, 48, 64, 80, 96, 112, 128, 144, 160, 176...

At the time gamma was changed to 1.4:
0, 4, 9, 18, 29, 41, 55, 70, 86, 103, 123, 143...
These are approximately equal to POWER(x/255, 2.2/1.4)*255.
So, it seems to do correct color management (gamma 2.2 -> 1.4).

At last RGB values become as follows.
0, 1, 3, 5, 8, 15, 23, 33, 47, 62, 81, 102...
These are approximately equal to POWER(x/255, (2.2*2.2)/(1.4*1.4))*255.

These are not correct color, and I think Photoshop did the color management doubly. 
(Edited)