📱 Perspective Animation

Example of perspective animation of a photo.

This is an implementation of how to detect a rectangle from a camera and animate a perspective.

Used frameworks

• AVFoundation for taking a photo.
• Vision for on the fly rectangle detection from the camera.
• CoreImage for filtering image.

Algorithm

1. Launch a camera and observe output for rectangles.
2. When a rectangle is detected, show it at the UI.
3. Take a picture and apply a perspective correction filter to get the resulting image.
4. Calculate the 4x4 transform matrix to animate from the initial image to the resulting image.

Implementation is simplified for clarity.

See also

• Core Animation Basics
• Perspective Mappings

Special thanks

• Alexander Khlebnikov for rectangle detection.
• Paul Zabelin for transform matrix calculator.
• Anton Glezman for the article resource.