Visualization of the sharp area in optical measurement systems with Scheimpflug correction
This paper describes the sharpness area visualization algorithm by contrast distribution in the image plane. The parameters of the optical system, simulating arm stereoscopic measurement system by correlation methods, for background images registration are given. The image registration system consists of a photographic lens, a Scheimpflug adapter and a CCD camera. Also the parameters of the optical system computer model with the image plane tilt are given. The simulation was performed using Zemax software. The Scheimpflug adapter allows you to combine the plane of the inclined image and the plane of the photodetector and, as a result, reduce the measurement error at the periphery of the research areas. It is not always possible to get a completely sharp. Visualizing the sharp image area allows you to select a frame region with higher measurement accuracy. Experimental background images for different combinations of viewing angles and matrix tilt and synthesized images are presented. The contrast distributions at the image plane are obtained. The influence of other factors on the contrast distribution, such as uneven illumination of the object, the structure of the background and the lens aberration is shown. The dynamics of PSF changes with the viewing angle increase for different field of view with and without Scheimpflug correction is analyzed by the model of optical system. The experimental results explanation in the approximation of a real optical system is proposed.