Have you ever been somewhere where you wanted a nice “people free” photograph but there always seems to be someone walking through the scene? This article describes a method for getting that photograph despite there being a constant flow of people through the scene.
To utilise this method, you will need to have your camera on a tripod because it involves taking a number of images of the same scene, then combining them together to “remove” the people.
How many images will you need to take? That really depends upon the scene and how many people there are but usually 10-20 will work, with maybe 30 seconds between shots. It does depend upon the people moving through the scene, if you have people standing in the same spot for long periods, you will need to wait longer or maybe take more photos.
For the example image, I took eight photos in Hosier Lane (see Figure 1).
Fig 1 - The eight original images
The final resultant image is shown in Figure 2.
Fig 2 - The final resultant image
To combine the images, first open them all in Photoshop.
Then use the File / Scripts / Load Files into Stack command, the dialog box shown in Figure 3 will be displayed.
Fig 3 - Load Layers dialog
Click the Add Open Files button, and make sure the images to be combined are the only ones showing in the dialog box.
Make sure that both the Attempt to Automatically Align Images and Create Smart Object after Loading Layers check boxes are both ticked and press OK.
Photoshop will now create a new file and will take a few minutes to process the files. When finished you will have a file with a single layer that contains a Smart Object that contains all of your images in an aligned layer stack.
With that Smart Object selected choose the Layer / Smart Objects / Stack Mode / Median command (see Figure 4), and hopefully those pesky people will disappear.
Fig 4 - Stack Mode Median
It’s possible, that if you haven’t taken quite enough images, or if the people were not moving enough, you may still see some ghosts, but you may be able to clean these up with the healing brushes and clone stamp tools or content-aware fill.
Another use for this process is to remove noise.
If you have to shoot at a high ISO, resulting in noise, and you are able to take multiple images of the scene, try using the above method to remove the noise. As the noise appears at random positions in each different version of the image, the median stacking method can do a very effective method of removing it.
This article was first published in the December 2019 issue of Artists Down Under magazine.