Use Instant Alpha to Remove the Backgrounds of Images on iPad

A recent new and relatively little-known feature was added to the Keynote and Pages apps that makes removing the background of any image an easy task.

The other day I showed one of my classes a picture of me jumping in front leaning tower of Pisa from a few years ago. Since this was a group that I had introduced green screening (in video editing) to, some of them thought that I had just superimposed myself onto a “fake” background.

 

The photo is real, but using this tool, called Instant Alpha, you could essentially recreate anyone jumping in front of any famous landmark.

How to use Instant Alpha:

  • Open Keynote or Pages. In Keynote, use a non-white background at first to practice
  • Insert any image from your albums. Tap an that image to highlight it.
  • Tap the Paintbrush at the top right, and choose “Image”
  • The Instant Alpha feature will appear: tap it
  • Now go to your image and slowly tap and drag areas around the it to make the background transparent. You can do this several times. If you make a mistake and remove some of the original image, you can press Undo (multiple times even)
  • Once you are satisfied with the image, you can resize, and even flip and place it over other existing photos/images

That's it! Give it a try and it will become second nature.

This will also work very well for text over images as well.

Obviously the results will not be perfect and not comparable to what you can do on more robust programs like Photoshop, but for the average person, it will be just fine. You may be able to notice in my video below that the images still have a tiny bit of white around them. After spending a little more time afterwards, I was able to remove more of it.

Here is a short video I created showing the process:

Instant Alpha will work great especially if you want to place your cropped image on top of another.

One thing we are not able to do is save the cropped image as an actual image. You can copy it onto your clipboard and paste it onto another app though. I was able to successfully crop an image in Pages, copy it, and paste it into a Keynote presentation.

I completed the steps in Pages (on the left), and directly copied it to Keynote on the right:

I think this can be a powerful presentation tool to easily make great graphics, both for Keynote presentations, Pages documents and other apps as well. Students, once taught this, will be able to create both digital and physical presentations. The ideas for posters for projects are limitless. Remember, once you create a good “slide”, you can take a screenshot of it and proceed to crop it afterwards.

Special thanks to my good friend and colleague Matt Przybylski (@iphysed) for introducing me to this feature and encouraging me to share it on teachingwithipad.org.

Have you tried this feature yet? Can you think of how this will be useful for you?

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3 Comments Add yours

  1. hopy says:

    it’s a great thing about Alpha, I prefer the application of Alpha:
    great graphics and many powerful new features launched.

  2. I enjoy what you guys are up too. This type of clever work and exposure!
    Keep up the very good works guys I’ve incorporated you guys
    to my own blogroll.

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