Counter-scanned images
Encyclopedia
Counter-scanned images are a pair of images obtained during counter-scanning
. During the counter-scanning it is possible to obtain one or two pairs of CSIs (see Fig. 1). Each pair consists of a direct image and the image counter to it. First, a conventional image is obtained called the direct image, after that a counter image is obtained by reversing the movement direction along a raster line and the movement direction from line to line of the raster. The direct image of the second pair is formed by the retrace lines of the direct image of the first pair. The counter image of the second pair is formed by the retrace lines of the counter image of the first pair. CSIs are intended for correction of distortions caused by drift of the scanning microscope
probe relative to the surface under investigation. To implement correction, it is sufficient to have at least one common feature between the direct and the counter images. As compared to a single CSI pair, the use of two pairs requires twice as much memory and processing time but on the other hand it allows increasing precision of correction and reducing noise level in the corrected image.
Fig. 1. Counter-scanned images of porous alumina (AFM
, 128×128 pixels): (a) direct and (b) counter images of the first pair; (c) direct and (d) counter images of the second pair. Drift induced error makes 25%. (e) Corrected image, residual error makes 0.1%.
Counter-scanning
Counter-scanning is a scanning method that allows correcting raster distortions caused by drift of the probe of scanning microscope relative to the measured surface. During counter-scanning two surface scans, viz., direct scan and counter scan are obtained . The counter scan starts in the point...
. During the counter-scanning it is possible to obtain one or two pairs of CSIs (see Fig. 1). Each pair consists of a direct image and the image counter to it. First, a conventional image is obtained called the direct image, after that a counter image is obtained by reversing the movement direction along a raster line and the movement direction from line to line of the raster. The direct image of the second pair is formed by the retrace lines of the direct image of the first pair. The counter image of the second pair is formed by the retrace lines of the counter image of the first pair. CSIs are intended for correction of distortions caused by drift of the scanning microscope
Scanning probe microscopy
Scanning Probe Microscopy is a branch of microscopy that forms images of surfaces using a physical probe that scans the specimen. An image of the surface is obtained by mechanically moving the probe in a raster scan of the specimen, line by line, and recording the probe-surface interaction as a...
probe relative to the surface under investigation. To implement correction, it is sufficient to have at least one common feature between the direct and the counter images. As compared to a single CSI pair, the use of two pairs requires twice as much memory and processing time but on the other hand it allows increasing precision of correction and reducing noise level in the corrected image.
Fig. 1. Counter-scanned images of porous alumina (AFM
Atomic force microscope
Atomic force microscopy or scanning force microscopy is a very high-resolution type of scanning probe microscopy, with demonstrated resolution on the order of fractions of a nanometer, more than 1000 times better than the optical diffraction limit...
, 128×128 pixels): (a) direct and (b) counter images of the first pair; (c) direct and (d) counter images of the second pair. Drift induced error makes 25%. (e) Corrected image, residual error makes 0.1%.
External links
- Drift elimination based on counter-scanned images, Research section, Lapshin's Personal Page on SPM & Nanotechnology
- Counter-scanned images, Dictionary of Nanotechnological Terms, Russian Corporation of Nanotechnologies