Development of NMIJ CRM 5207-a tungsten dot-array for the image sharpness evaluation in scanning electron microscopy – structure evaluation and determination of dot-pitch

We have developed a new certified reference material (CRM) for image sharpness evaluation and magnification calibration for scanning electron microscopy (SEM). Designed to be suitable for the image sharpness evaluation by the derivative method, the CRM has nanoscale tungsten dot-array structure fabricated on silicon substrate, which gives steep contrast transition from the dot to the substrate in SEM image. The pitch of the dot-array was SI-traceably measured as a specified value with relative expanded uncertainty ($k=2$) of ~1.3%, which can be utilized for the magnification calibration of SEM. Since specimens, as one of the image formation parameters, easily affect image sharpness value, our CRM, as a ‘pinned specimen’, will play an important role to achieve robust and stable image sharpness measurement system.

Pre-processing Technique for Wireless Capsule Endoscopy Image Enhancement

<span>Wireless capsule endoscopy (WCE) is used to examine human digestive tract in order to detect abnormal area. However, it has been a challenging task to detect abnormal area such as bleeding due to poor quality and dark images of WCE. In this paper, pre-processing technique is introduced to ease classification of the bleeding area. Anisotropic contrast diffusion method is employed in our pre-processing technique as a contrast enhancement of the images. There is a drawback to the method proposed B. Li in which the quality of WCE image is degraded when the number of iteration increases. To solve this problem, variance is employed in our proposed method. To further enhance WCE image, Discrete Cosine Transform is used with anisotropic contrast diffusion. Experimental results show that both proposed contrast enhancement algorithm and sharpening WCE image algorithm provide better performance compared with B. Li’s algorithm since SDME and EBCM value is stable whenever number of iterations increases, and sharpness measurement using gradient and PSNR are both improved by 31.5% and 20.3% respectively.</span>

Pre-processing Technique for Wireless Capsule Endoscopy Image Enhancement

<span>Wireless capsule endoscopy (WCE) is used to examine human digestive tract in order to detect abnormal area. However, it has been a challenging task to detect abnormal area such as bleeding due to poor quality and dark images of WCE. In this paper, pre-processing technique is introduced to ease classification of the bleeding area. Anisotropic contrast diffusion method is employed in our pre-processing technique as a contrast enhancement of the images. There is a drawback to the method proposed B. Li in which the quality of WCE image is degraded when the number of iteration increases. To solve this problem, variance is employed in our proposed method. To further enhance WCE image, Discrete Cosine Transform is used with anisotropic contrast diffusion. Experimental results show that both proposed contrast enhancement algorithm and sharpening WCE image algorithm provide better performance compared with B. Li’s algorithm since SDME and EBCM value is stable whenever number of iterations increases, and sharpness measurement using gradient and PSNR are both improved by 31.5% and 20.3% respectively.</span>