Microscanning is a method for increasing resolution of
digital camera
A digital camera, also called a digicam, is a camera that captures photographs in Digital data storage, digital memory. Most cameras produced today are digital, largely replacing those that capture images on photographic film or film stock. Dig ...
s. With the
color co-site sampling identically colored pixels in several frames of the specimen, obtained by moving the sensor with a
piezo mechanism in a regular
raster, are combined to a sharp resulting image. The detector, however, can also be
translated by a fraction of the
dot 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
color co-site sampling 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 scan ...
produced.
Whether the
spatial resolution
In physics and geosciences, the term spatial resolution refers to distance between independent measurements, or the physical dimension that represents a pixel of the image. While in some instruments, like cameras and telescopes, spatial resoluti ...
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. E ...
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