Generating images from non-raster data in AFM

Non-raster methods in atomic force microscopy utilize high-level feedback control to steer the tip in order to sample only regions of interest. Although the non-raster method can reduce the scanning time by gathering fewer samples, the measurement locations are no longer uniformly distributed. As a result, the production of accurate images from the data is a non-trivial problem. This paper presents a method of generating images that faithfully represent the sample from the non-raster data based on Kriging spatial interpolation theory. The method is modified to work well with a particular non-raster method developed previously by one of the authors. One of the primary drawbacks of Kriging, however, is its computational cost. As the algorithm is too slow for real time use, we also describe the use Delaunay triangulation for image generation. While less accurate than Kriging, triangulation is fast enough to produce images in real time, providing visual feedback to the user during the image process.