How much are you feathering it? A pixel is probably all you need. Usually some kind of cleanup is necessary when doing this, depending on what the original background was.
There are lots of other variables like size, resolution, etc that come into play, but you can’t expect this to be a simple process.
A technique I use very successfully to place parts of one image on another is to first start with as tight a selection of the object to be moved that I can create. Once moved to the new image it is on a separate layer. When in place, command clicking on the layer gives me the selection of the moved item. I’ll then Select > Modify > Contract the selection and save the result as an alpha channel. The amount Contracted depends on the resolution of the image. A screen rez usually gets contracted by two pixels, a print rez gets 4 or 5, for example. Then I use the Select > Modify > Expand option on the selection and expand the selection one or two pixels outside of the original selection. (For screen rez expand 3 pixels, for print 6 or 7. I’ll save that selection as an alpha channel just in case I need it again but with that selection still active I go into the Channels palette, click on my smaller selection-saved-as-alpha-channel and, while holding down the option key click on the button at the bottom of the Channels palette which loads the selected alpha channel as selection.
The result is that I get a thin border of selection slightly inside and outside the edge of the moved image. Then I use the Blur Tool with "Use all layers" selected and usually one of the three blend modes, Normal, Lighten, or Darken. With a huge brush go around my image in a single pass and the thin border of the moved image is blended with the background on which it now resides.
Once you get used to the technique it takes less time to do than it does to write it!
Cheers!
Welles, I’m surely missing something, but why can’t you achieve the same by loading the moved image as a selection, then using the Select/Modify/Border command set to the number of pixels appropriate for screen or print? This command (feathered or not) places the selection’s outer edge outside the originally selected image and its inner border inside… "straddling" the image in (what I think is) the same way your alphas allow.
Doug,
At first reading your suggestion, I slapped myself on the forehead and wondered why I’d never thought of that. Then I went and tried it out. I found that the Border command splits the pixel amount entered, with half inside and half outside the original selection. My experiment yielded more of a blur than I wanted when I was able to specify a proportion of two pixels inside to one outside. Drat. However, for a quick fix, your concept will work quite well if you choose just a 2 pixel border selection for screen and perhaps four for print.
I’ll stick with my original technique, though because my experiment with the Border technique isn’t quite what I’m after. I don’t really want to blur the outline so much as to merge the fringe color with the new background. A one pixel transparent space outside the original selection, when blurred, just acts as a sort of anti-aliasing, where more transparent pixels showed the blur effect too much.
Nice idea, though. I’m going to have to review all the selection menu options as my techniques have gotten a bit too routine.
Just to clarify:
I set a border with the border command, not to blur the boundary between background and composited image, but to do whatever it takes to "merge," as you say. Sometimes it’s applying a Curve to darken or lighten that slender area, sometimes a little dodging or burning, sometimes it’s using the clone tool to fill the area with edge pixels from the composited image. Sometimes it IS blurring, but sometimes it’s actually SHARPENING. Sometimes it’s erasing at a low opacity, sometimes picking up colors from the background layer and painting them into the selection in Color mode. And sometimes it’s painting from history into the border selection… a technique inspired by Ann Shelbourne, the History Lady. Whatever it takes. But the border command seems to set me up pretty well to do whatever it takes.
Whatever works! I’ll keep your idea in mind as another possibility.
Cheers!
