Perspective Correction Comes To The iPad

For a long time I’d been hoping for a basic perspective correction tool for the iPhone or iPad. I’d shown one way to do this on the iPhone in the past, but a new app has arrived for the iPad called AndifTouch.

AndifTouch GUI

The main GUI of AndifTouch on the iPad.

The description from iTunes is very minimalistic. “AndifTouch is an app to interactively adjust radial and perpspective distortions in pictures. Radial distortions are typical for wide angle photography. Perspective distortions (keystone effect or in german: Stuerzende Linien) occur often in architectural photography.”

I explored the app and found it does exactly what it says. Overall I really like the app, although in this version 1, there are some things that need improvement.

Pros:

  • Allows for easy movement (scale, rotation, and shift), perspective, and distortion using just dragging gestures on the photo
  • Grid is helpful
  • Exported images are at full resolution (at least up to iPhone 4S resolution)
  • Help is very straightforward

Cons/Quirks:

  • The GUI for the cropping tool needs improvement.
  • Not sure why the “spinning” logo is always visible.
  • On a few occasions I got a “not enough memory” message when trying to save an image. It seems to have always exported, but the region in the app that showed the image is now black.
  • The grid is visible on the exported image if you leave it turned on. Not sure if this is a bug or not, but I can’t think of a reason for it.

Things I’d love to see in the future:

  • Ability to increase number of grid lines (such as is done in Image Straightener)
  • Change the crop tool so that you have an autocrop button, and also a more traditional view as in Camera+
  • A preference for whether you want everything to reset when you import a new image (currently all settings are saved).
  • A numerical display of the current settings.
  • A reset all button (move, perspective, and distortion)

Here are a few before/after samples which I used in my video walkthrough on YouTube (note: no audio, this is just raw recording from my iPad).

Before/After photos using AndifTouch

Using AndifTouch. The photo on the left is uncorrected. The photo on the right is corrected. Notice that posts are vertical and parallel to each other in the final image.

Before/After photos using AndifTouch

I used AndifTouch on the upper photo. The final output is the lower photo. Note the building now has “right angles” where it should and the umbrella and phone pole are vertical.

I really like this app and hope that the developer continues to improve it!

Currently AndifTouch for the iPad is $0.99 on iTunes. [download]

3 thoughts on “Perspective Correction Comes To The iPad

  1. peter beeson

    this app is ok, just, however it reduces the image clarity by about 80% after minimal correction i.e. a 15meg image comes out at 3meg!

    Reply

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