A new United States Patent & Trademark Office patent application from Apple entitled “Image Capture Device Having Tilt and/or Perspective Correction” has surfaced this morning, detailing how Apple is actively seeking to improve image taking and camera capabilities on mobile devices. According to Apple, future iPhones could automatically compensate for tilt or perspective distortion during image capture or later, by determining a device orientation relative to the object.
The correction could occur on the fly – using dynamic crop lines or a virtual level (a bit akin to the grid lines in the iOS 5 Camera app) - prior to storing the image in the memory and even afterwards, in which case the orientation and distance data would be embedded in the image itself, using custom tags withing the EXIF file. As a result, you’d get perfectly aligned snaps that require little or no post-processing in image editing programs in order to compensate for perspective distortion. And how would the iPhone’s camera figure out whether or not your shots are perfectly aligned with the horizon?
Easy. Apple writes that some embodiments of the patent “may include an image sensor, a memory coupled to the image sensor, an orientation measurement device coupled to the image sensor, and a distance measurement device coupled to the image sensor, where the image data may be stored in the memory along with a measurement from the accelerometer and along with a measurement from the distance measurement device”. In short, the idea is to use the phone’s many sensors to determine the phone’s position relative to the subject, including gyroscope and accelerometer to measure “the Earth’s gravitational pull along the X, Y and Z axes” and “the velocity or acceleration” of your device (when capturing images from a car or while on a train, for example). Apple even mentions “inertial reference sensors” and GPS (to record relative GPS orientation of the object and your device). Unfortunately, the iPhone currently lacks ultrasonic and infrared sensors that capture the orientation and distance data. Of course, there’s nothing preventing the company from building those into future devices, even if such capabilities are usually associated with dedicated point-and-shoot digital cameras. The patent application credits Apple engineers Jason Hau-Ping Chen and others. To browse the document yourself, enter the patent application number 20110149094 into the USPTO search engine.