Symmetric Overlay feature?

[Lordpenguin]

I have searched this forum, and nobody seems to have mentioned a symmetric overlay function, so I thought I would: I find it highly useful and would love for it to be implemented, though whether as an effect plugin or a proper combine mode I don't know.

In case you don't know, a symmetric overlay is an overlay that is identical irrelevant of layer order, which I find quite useful.

It is just an average, like (overlay(a,+overlay(b,a))/2

I suppose symmetric implementations for other combine modes are possible too, though I have only ever seen overlay elsewhere.

[usedHONDA]

Actually, this can be achieved pretty quick, without the use of a plugin or feature (see attachment). I did that in less than 2 minutes

Now what's the first thing that comes to your mind when you load the image?

[Lordpenguin]

Possibly you misunderstood me. Symmetric overlay is a combine mode, and nothing to do with image symmetry.

[Ash]

Myabe post some before and after images so easier for others to try to help.

[david.atwell]

There are several blend modes available in the Layer Properties dialog box...perhaps it's known by a different name?

[Lordpenguin]

No, I do know what I am talking about. And if I could generate example images, I wouldn't be requesting the feature.

Sorry if that sounded short, but I get the feeling that you don't understand me: In all combine modes, pixels from that layer and the composite of the layers below are subjected to a function - for example, in Multiply mode, the pixel values are multiplied. For overlay mode, the value is obtained via a slightly more complex formula; usually something like:

if a < 128 then

result := (a*

else

result := 255 - ((255-a) * (255-

However, this will return different images based on which layer, a or b, is placed on top. A Symmetric overlay is calculated by generating the image both ways round and averaging them. I could do this in CodeLab, except for the fact it _should_ be a combine mode rather than an effect.

[david.atwell]

Calm down, please. Sorry if it seemed like we were brushing you off...we get many people requesting features that are already in the program, so we wanted to make sure we covered that base.

No slight intended. You obviously know what you're talking about. Our apologies. :-)

[Hellfire010]

Calm down, please.

I don't believe he's "hyped up."

If I understand correctly, this can be achieved.

If layer a is on layer b, you can change the blending mode of a to something and leave b as normal. Alternatively, you could move b over a and change the blending mode of b and leave a as normal. Depending on the blending mode, both will achieve the same or different results. However, there doesn't seem to be a realistic reason for doing this when all you have to do is switch the layers - being such, I may not be understanding you properly.

[david.atwell]

I don't believe he's "hyped up."

You never can tell. I was just trying to cover the bases if s/he were. :-)