Flatten vs Merge

[jonk]

Hi All!

Can anyone answer what is the difference between Flattening an image vs Merging Visible? I really do not know what the difference between them are.

Thanks Again!
Jon

[venivedi]

As far as I know, Merge Visible can be used when 'Background' layer's eye-icon is on.

[Doug Nelson]

Flattening merges all layers. If they're not visible they're deleted. Merge visible merges just the visible layers, and doesn't delete the invisible layers.

[Gary Richardson]

As an addendum to what Doug posted.

Use Merge Visible when you only want to merge just a few of your layers.

Switch off the layers you don't want to merge, then use Merge Visible.

After the merge you can then switch the layers you did'nt want to merge back on.

Use Flatten Image when you want to merge all layers.

[byRo]

There is another subtle difference.

If (for some strange reason) you have deleted the Background layer then a merge of all layers will result in a "normal" layer whereas Flatten All will create a new Background layer.

One place I've seen that this is important is when you are going to use the FFT filter which only works on a Background layer.

Rô

[jonk]

Thanks!

Thank you guys! I learned something new!

Jon

[Ken Fournelle]

Ro,

Isn't file size increased when using Merge Visible? Is is treated like duplicating a layer?

K

[byRo]

Merging (advanced)

Isn't file size increased when using Merge Visible? Is is treated like duplicating a layer?

Hold on this is going to get complicated.........

There are 4 types of "Merge" that you can use.

Two of them will discard the layers after use and the other two will leave the layers intact. Those that discard the layers, the Adobe folks call Merging and those that leave the layers they call Stamping.

Two of them work only on adjacent layers and two work on all visible layers.

So we have:

1) <ctrl><E>: Merge adjacent (aka Merge Down) Takes the selected layer and merges with the underlying layer - both must be visible and the underlying layer cannot be an adjustment layer;

2) <ctrl><alt><E> : Stamp adjacent - Merge to the underlying layer, leaving the upper layer intact (*) (**);

3) <ctrl><shift><E> : Merge all visible to the selected layer (obs: If the Background layer is visible it will always merge to the Background);

4) <ctrl><alt><shift><E> : Stamp all visible to the selected layer, leave all other layers untouched (***).

(*) If the upper layer is an adjustment layer then you can repeatedly apply the adjustment this way.
(**) The 7.0 Help says it stamps to the upper layer - don't believe it!
(***) A quick way to stamp to a new layer, thus leaving all of your layers untouched is to hold <ctrl><alt><shift> and press <N> and then <E>

So finally replying to the question if you Stamp all Visible to an adjustment layer (or to a new layer) you will increase the file size otherwise, no.

Rô