PROPER ACQUISITION AND HANDLING OF SCANNING ELECTRON-MICROSCOPY IMAGES USING A HIGH-PERFORMANCE PERSONAL-COMPUTER

The modem high-performance personal computer (PC) has very recently ex panded the range of utilization of digital scanning electron microscop y (SEM) images, and the PC will be used increasingly with SEMs. Howeve r, the image quality of digital SEM images may be considerably influen ced by scanning and digitization conditions. In particular, the effect s of the aliasing error peculiar to digital data are often serious in the low-magnification acquisition (undersampling) of SEM images, and m oreover even a high-magnification image (oversampling) is disturbed by the undersampled noise (a sort of aliasing error). Furthermore, the s ignal-to-noise ratio of a digitized SEM image is closely related to th e performance of the analog-to-digital converter. To prevent a flood o f low-quality digital images with artifacts by the aliasing and additi onal noise, we propose a method using very high-density sampling (scan ning). In addition, we will discuss how to handle digital SEM images f rom the point of view of the sampling and quantization.