Canvas resize: How to set image margin to canvas in pixel/percent?

[H5T7P4]

Thank you for your last inspiration. Yes it works if I change it a little bit.
I do two canvas resizes:

At the first Canvas resize I do the height smaller then I really want (4400)
as output and set the position to top.

Then I do a second resize and set the height to the height I really want (5400)
and set the position to center. And I set the Alpha to 0.

Now I have the margin to the top that I want:

zweimal canvas resize.jpg

Thank you for all your tipps!

But I have a last question: Is a color with Alpha=0 the same as a transparent area?
Because it's not possible to set a Background color to "transparent".
In the preview it seems to be so.
If not, I don't know if I would get problems with this solution.

[cday]

You have advanced to the next step, and seem to have the result you need without using the watermark action, excellent!

The significance, as you probably recognise, is that you should now be able to process all your images directly, whereas the watermark solution in fact could only process one image each time.

But I have a last question: Is a color with Alpha=0 the same as a transparent area?

I'm afraid I don't know, my knowledge of transparency is still quite limited, you could find out more about transparency online, but there are two types to complicate matters

Because it's not possible to set a background color "transparent".
In the preview it seems to be so.
If not, I don't know if I would get problems with this solution.

If you are now able to process one image successfully I would think, and hope, that there shouldn't be a problem.

[H5T7P4]

For test I placed the XnConvert png output image in Illustrator top to a colored rectangle.
And the rectangle is shining through where is no ellipse area in the png.
So I think it's really transparent. Thanks again for your help.

[cday]

For test I placed the XnConvert png output image in Illustrator top to a colored rectangle.
And the rectangle is shining through where is no ellipse area in the png.
So I think it's really transparent. Thanks again for your help.

That is what you need, or you have an unexpected problem?