I do not know of any option in Aperture that could do this.
Maybe one of the photobook plug-ins has such an option.
You can try to edit the edges of your images and make them transparent in an external editor like Photoshop.
- For this to work, e.g. in Photoshop, set the format for the external editor to "psd".
- Open your image with Photoshop as external editor.
- Then create a new, empty image with the same dimensions as your original image and set the background to "transparent".
- Then select all of your image to be edited and past it onto the transparent backdrop in the new image.
- In the new image again select all of the image, then go to the selection menu -> border and add a border of at least 10 pixels.
- Again in the "selection" menu set "invert selection". Now your border shuold be selected.
- Go "Selection"-> "Modify Selection" -> "Soft border". Set the border to a high value, e.g. 30.
- Now clear the border "Edit" -> "clear"
By now your image should have a soft, blurred, transparent border.
Save the image.
In Aperture you now should see a version of your image with a blurred border. Add it to your book. I tried this with Photoshop CS5.
The image below shows two versions of the same image: to the left theoriginal, to the right a version with the lower border made transparent like described above.
Yes, I just want to blur the edges kinda like a vingette. I just do not want the sharp edges of a picture that is on top of another picture. I don't want to merge the two pictures but simply put a faint blur on the edges to take off the contrast of edge of a picture.
Just didn't know if there was an easy way to do this within aperture without having to go through Photoshop.
Photoshop seems complicated to this novice.
BorderFX -- a free and worthy plug-in for Aperture -- has a few things to try. Here I've illustrated the "Soft Edge" effect:
The problem you'll encounter is that there will always remain a hard edge at the outside of the border, and this will show against any photos you overlay.
What you are asking for is something that blurs into an Alpha Channel. This can be done in PS, but not easily (see Léonie's reply above). You're best bet is to find a book template that _already_ does this. I don't know of any.
OT: My speculation ... Aperture is _rigorously_ photo-centered. As I put it, it is where you make your photographs as good as possible (and keep them organized and available). You then send them to another program to turn them into or use them as graphics elements in the creation of _graphics_ -- "graphics" being things like cards, books, posters, advertisements, etc -- things that are printed or displayed on screens that are composites of photographs and other graphics elements. I think it was you who recapitulated this recently as Aperture being the equivalent of a darkroom: you do all your development using it, and you end up with a photograph.
Aperture has mostly stuck to this. (The exception being books -- which must have presented a profit incentive big enough to make the exception. Books generate revenue -- alpha-channels do not.) My first thought on reading your suggestion to add an alpha-channel to Aperture was "That's a great idea!". On second thought, though, I think continuing to resist expanding Aperture's remit is a better plan. It would be all too easy to bloat the program with useful tools such as an alpha-channel and lose sight of the procedural rigor that, though it still needs much work, makes Aperture such a pleasure to use.
My pfennig, plus or minus.
On second thought, though, I think continuing to resist expanding Aperture's remit is a better plan.
d'accord, you are sooo right! Although going from RGB to RGBA (a for alpha) does not look like something adding new complexity, but that is an engineer's point of view.
And as to the darkroom metapher I recently used to express in different words what I learned from your posts - photographic negatives and transparencies used to be transparent, in the pre-digital age I never produced prints, all my early pictures are slides/transparencies (what's the correct word? I need a better dictionary), so to describe the darkroom process I would need alpha