This tip comes in handy for graphic designers who need a quick way to get pedestrian-free photographs of their signage or environmental projects.

There is a classic digital photography technique for removing unwanted people: Take several shots of the same scene using a tripod — then layer those photos in Photoshop. People move around between shots, so you can use parts of one photo to erase an unwanted person from another. A good tutorial is available for this technique:

How to remove tourists from your photos. [dsphotographic.com]

Our own twist is to use Photoshop CS3’s improved Photomerge feature to automate this task. Simply shoot a collection of photos, erase the unwanted people in Photoshop, and let Photomerge stitch together a finished image.

Step 1: Take multiple shots of your subject.

In this example, there were rarely less than 7 people in the frame at any given time. We didn’t have a tripod with us — but that’s okay because we’ll be using Photoshop’s Photomerge feature to stich all the photos together.

Note: While only 6 photos are shown here, we shot about 25 individual photos in three minutes.

Step 2: Erase unwanted people from each photo.

Open your photos in Photoshop. Before you erase your unwanted people it is important your resulting image supports transparency. So, in the layers palette, double-click on the background layer and give it a name.

Then quickly erase unwanted people using any of Photoshop’s eraser tools. Unlike other retouching techniques, you don’t need a lot of finesse here — just do a rough erase, making sure to remove all unwanted people from your collection of photos.

Note: Save your finished photos in a Photoshop (PSD) format to maintain transparency.

Step 3: Use Photoshop CS3’s Photomerge to stitch the photos together.

In Photoshop CS3, choose File > Automate > Photomerge… Pick your collection of images with the people erased. Check the “Blend images together” option and click OK.

Photoshop will churn for a while. This process takes some time depending on how many photos you are working with and the speed of your computer.

In the end, the Photomerge feature combines your many photos into a single composite image — filling in the erased areas using parts from other photos in your collection.

In this example, we successfully removed all the people milling around this play structure. However we were not able to remove the long-term squatters on the two benches because they didn’t move during our three minutes of shooting photos.

Crop your resulting image, and save the completed masterpiece.

Do experiment with this technique — It can quickly become addictive.

Source: This tip inspired some time ago by a tip on the lifehacker blog.