Expert: LizaL - 1/23/2006

Question
Hi Liza,

Thanks again for your assistance with the copying DVD to still photo's.

I have another question for which I need your help again. Using PhotoShop, how do I combine a photograph with another using layers? For instance, I have a photo of a construction site as a background, and I want to include/add a certain group of people from another photograph so that it appears as one photograph. How, in easy baby steps, do I accomplish this? Do I use layers, or do I have to clone them in and retouch out the attached background? Thank you for any help you can offer, Regards, Ken.

Answer
Hi Ken,

Ha, I like that: "easy baby steps!" My favorite way to do stuff.

To answer your question, there's no need to clone pictures into an existing picture or anything like that. You're right, you can use layers to accomplish this. Also, work on copies of your original photos -- you might need to go back to the originals if you're not satisfied with your results.

1. Open both pictures. It's advisable for both images to have the same resolution and color space. So make sure, under the Image pulldown menu, that both are, for instance, RGB and 72dpi -- whatever is needed for your end result.

2. Choose the picture you're going to use for the foreground. This is the one we'll tweak, in order to add it to the second picture (the background).

3. If you're just doing a simple file, like a joke for a friend, and all you want to do is delete the background of the top picture, you can do a quick job of editing and call it a day (details below). But if you want a very precise image, maybe something you're going to submit to a site or print, you'd want to be more accurate (details forthcoming if you need them).

I've answered this question for other people in the past, so in order to avoid having this huge long answer typed out here on this (unreliable) site, or trying to refer you back to those previous answers, I cobbled some of the information together and stuck it on a page and uploaded it to my Web site.

Here's the link:
http://www.little-works.com/all_experts/backgrounds.html

You can see that I mention three very basic means of deleting backgrounds: Quick Mask, Magic Wand tool, and the Extract Filter. Each has a little screen capture movie with it. Note that I've used the term "cleanup" several times, and what I mean by this is erasing any rough edges you might have as a result of using Quick Mask, Magic Wand or Extract. It's pretty easy to do this using your eraser tool, set to a brush. You can see me doing just that after I've used the Extract filter.

4. Once you have the background removed from your top image, just select your Move tool from the tool box. Now simply drag the top picture, the one you've just edited, onto the other. This will automatically create two layers in the second file (the "background" picture).

I did that here -- I just dragged the top picture onto the bottom one, and then used the Magic Wand to cut away the excess from the top picture. Consider this a "down and dirty" method, not 100% precise, but it should show you how to drag one file onto another.
http://www.little-works.com/all_experts/quick_combine.mov

5. At this point you might see what I mean about it being advisable to have both images the same resolution and color space. You might run into the colors looking dissimilar. If this happens, go back to your originals, make more copies of them, and edit them so that they're similar in color and tone. Then perform the technique you're comfortable with to edit the top picture, and drag it back onto the bottom one.

6. This also applies to size and scale. If, for instance, your foreground picture contains people, and when you get it edited and drag it onto the background picture, you might find that they're too big or too small, etc. Again, how you fix this depends on how crucial the outcome. If it's a simple little file that doesn't have to be 100% accurate in terms of resolution, you can select the top layer of your file in the Layers palette, go to the Edit pulldown menu and select Free Transform. Grab a corner of the bounding box you see around your top layer, and stretch.

If you need to be more precise, do any scaling on the foreground picture *before* you attempt to delete its background. Then when you move it onto the background picture, it should be the right size.

Not so bad, huh? Let me know if you have problems, or further questions. There are other ways of doing what you ask, and I do know a mother lode of an answer that's very involved and meant for very precise file combinations, but hopefully these are the baby steps you need!

Lisa