| 摘要 |
A system for quantitatively evaluating resolution and image quality of devices which produce images or images produced by such devices. A charge coupled device (CCD) camera is disposed in a position to view a standard resolution test pattern displayed or produced by an imaging device and generates a video signal in response to the images viewed by the CCD camera. The video signal is modified by a custom image analysis circuit to provide 1) a video signal with a blanked region of interest and 2) triggering pulses to measure light intensity variations of this region using an oscilloscope. The easily moved, highlighted region of interest within the video image viewed on a monitor is digitized by the oscilloscope to provide quantitative data representing the imaging device's ability to faithfully reproduce detail at various spatial scales. A series of standard resolution patterns are measured and a modulation transfer function is fitted to the level of light modulation of individual resolution targets. Large modulation values correspond to the enhanced ability of the imaging system to record detail as the fineness of the patterns increase. The Simplex Algorithm is applied to the data to uniquely fit a cumulative log normal distribution as an approximation of the modulation transfer function of the device.
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