PI has published a paper on image resolution enhancement and image stabilisation for electronic imaging sensors.
The paper describes basic techniques and explains different piezoelectric motion principles such as flexure mechanisms and ultrasonic motors.
In order to increase the resolution of common imaging detectors such as CCDs or CMOS, either the chip size can be increased or the pixel size be reduced; both solutions have undesirable side effects.
The first case requires a larger recording device and different imaging optics.
In the second case, light sensitivity decreases with the pixel size, also reducing the signal/noise ratio.
With pixel sub-stepping, the recording area is moved on predefined paths with a defined frequency.
This 'dithering', where the travel is less than the size of a pixel, causes the pixel to be exposed several times on the recording area, producing a virtual 'pixel multiplier' that can improve the resolution without negative side effects.
Today, small and cost-efficient piezo devices (in-plane scanners or tip/tilt mechanisms) are available to handle the task.
In addition to image resolution enhancement, these devices are also fast enough to remove jitter induced by vibration from images and video.
