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Layer mode overlay formula is different from normal

PostPosted: 13 Jan 2020, 05:17
by com
I want it to behave the same as photoshop. Is this a bug?

Re: Layer mode overlay formula is different from normal

PostPosted: 13 Jan 2020, 09:03
by u2bleank
it should be the same ( do you have a sample ? )

The possible difference is the color space in which the Blending occur. Black Ink works in Linear Color space while Photoshop use the color space of the current document by default.
Image

Re: Layer mode overlay formula is different from normal

PostPosted: 13 Jan 2020, 10:14
by com
The color values ​​are clearly different.
My photoshop color space is linear.

For example, if you draw gray B (128,128,128) on gray A (128,128,128) in photoshop with overlay

The formula for photoshop is
1-2 * (1-0.5 (Gray A)) * (1-0.5 (Gray B))

The drawing result is
(128,128,128)

But

blackink drawing results
(119,119,119)

sample
https://15.gigafile.nu/0120-d41817fbd27 ... c7b6b5edd8

The same is true for hard lights, which are the inverse of calculations for overlays.

Re: Layer mode overlay formula is different from normal

PostPosted: 13 Jan 2020, 11:52
by u2bleank
hum it's what I was explaining.
The Overlay equation take place in linear space and the 128 gray isn't 0.5 in linear but 0.21..
BUT we will make the overlay behave the same way as in Photoshop in the next update.

Re: Layer mode overlay formula is different from normal

PostPosted: 13 Jan 2020, 13:03
by com
Thank you!!!

Re: Layer mode overlay formula is different from normal

PostPosted: 09 Mar 2020, 13:19
by cathiss47
u2bleank wrote:it should be the same ( do you have a sample ? )

The possible difference is the color space in which the Blending occur Rachat de crédit meilleurs taux. Black Ink works in Linear Color space while Photoshop use the color space of the current document by default.
Image

I didn't realize there was so much difference between image processing tools.