title: Overall noise characteristics of reduced images on liquid crystal display and advantages of independent subpixel driving technology.
abstract: OBJECTIVE
  During soft-copy diagnoses, medical images with a large number of matrices often need to display reduced images on liquid crystal displays (LCDs) because of the spatial resolution limitation of LCDs. A new technology, known as independent subpixel driving (ISD), was recently applied to clinical uses aiming to improve the spatial resolution. The authors' study demonstrates the overall noise characteristics of images displayed on a LCD at various display magnifications, with and without ISD application.
  
  
  METHODS
  Measurements of the overall noise power spectra (NPS) of x-ray images displayed on LCD were performed at varying display magnifications, with and without ISD. The NPS of displayed images in several display situations were also simulated based on hypothetical noise factors.
  
  
  RESULTS
  The measured and simulated NPS showed that noise characteristics worsened when the display magnification was reduced, due to aliasing errors. The overall noise characteristics were attributed to luminance-value fluctuation converted from pixel values, image-interpolation effects, inherent noise, and blurring of the LCD. ISD improved the noise characteristics because it suppressed noise increments by aliasing errors.
  
  
  CONCLUSIONS
  ISD affected the noise-characteristic advantages of reduced images displayed on LCDs, particularly at low frequencies.
authors: Graduate School of Medical Sciences, Nagoya University, Higashi-Ku, Nagoya, Aichi, Japan. yamazakia@opho.jp
authors: Asumi
authors: A
authors: Yamazaki
authors: Katsuhiro
authors: K
authors: Ichikawa
authors: Yoshie
authors: Y
authors: Kodera
authors: Masao
authors: M
authors: Funahashi
mesh_terms: D003952:Diagnostic Imaging / Q000295:instrumentation*; D005583:Fourier Analysis; D050866:Liquid Crystals; D059629:Signal-To-Noise Ratio