Microscanning is a method for increasing resolution of digital cameras. With the

color co-site sampling Colour co-site sampling is a system of photographic colour sensing, wherein 4, 16 or 36 images are collected from the sensor and merged to form a single image. Each subsequent image physically moves the sensor by exactly one pixel, in order to col ...

identically colored pixels in several frames of the specimen, obtained by moving the sensor with a piezo mechanism in a regular

raster Raster may refer to: * Raster graphics, graphical techniques using arrays of pixel values * Raster graphics editor, a computer program * Raster scan, the pattern of image readout, transmission, storage, and reconstruction in television and compu ...

, are combined to a sharp resulting image. The detector, however, can also be translated by a fraction of the pixel pitch: this way also the interstitial space between sensor pixels gets scanned and the number of pixels in the final image is increased. Three positions on the x and y axes increase the image size by a factor of 9, for instance from the common 1388 x 1040 pixels to 4164 x 3120 pixels (se
Sony ICX285 series
. The

used at the same time ensures correct reproduction of colors at the

pixel density Pixels per inch (ppi) and pixels per centimetre (ppcm or pixels/cm) are measurements of the pixel density of an electronic image device, such as a computer monitor or television display, or image digitizing device such as a camera or image scanner. ...

produced. Whether the spatial resolution will increase accordingly, depends on the

optical resolution Optical resolution describes the ability of an imaging system to resolve detail, in the object that is being imaged. An imaging system may have many individual components, including one or more lenses, and/or recording and display components. ...

of the complete system. The relevant parameter is the resolving power, i.e. how many lines per mm can be resolved. It increases with the aperture of the optical system and is inversely proportional to its magnification. As a result, a low-resolution camera with 500 lines would be enough for an 100X objective with 0.9 aperture. On the other hand, low-magnification objectives profit most from micro scanning: for instance for a 2,5X objective with N.A.=0.12 cameras with as high as 2500 lines resolution could be used.

References

* European patent EP0396687 (1989-10-26), Reimar Lenz
Optoelectronic image sensor

External links

Microscanning: how does it work?

Digital photography