Abstract: A projection system comprises an image input element and an optical imaging element. The image input element is configured to input an original image or a processed image. The optical imaging element, an optical system with axisymmetrical structure and specific spherical aberration, is configured to generate an image with extended depth of field on an image projection surface in accordance with the original image or the processed image.

Abstract: A distance evaluation method for evaluating distances from an observation point to objects within an arbitrary detectable range in a scene is disclosed. The method includes the following steps. First, a focus distance is set to correspond to a lower or higher limit of a chosen detection range. Next, an image is then captured with an image acquisition system, wherein transfer function of the image acquisition system depends on the focus distance. The captured image of the scene is segmented. A blur metric is computed for each image segment of the captured image. The blur metric is associated with the distance of the objects from the observation point in each image segment.

Abstract: An image restoration method is disclosed. The method is used in an image restoration apparatus and configured to restore an image captured by an imaging system. The method includes capturing a scenery image by the imaging system and applying restoration processing to the scenery image using a plurality of restoration filters respectively corresponding to a plurality of depths, to generate a plurality of restored images respectively corresponding to the depths.

Abstract: A method and optical apparatus are utilized not only to increase the degree of the similarity of the point spread functions of different fields of view, but also to maintain the degree of the difference of point spread functions which are along the optical axis of the optical apparatus. Using the degree of the difference of on-axis point spread functions, the depth information of scenery can be extracted.

Abstract: A device and method for measuring and correcting eye aberrations integrate wavefront sensing, wavefront aberration correction and optometric testing into one another and configure the optical paths of wavefront sensing and optometric testing as aplanatic structures, such that under optometric testing conditions both wavefront sensing and aberration correction can be performed simultaneously, and final optometric testing is conducted on wavefront aberration-corrected optometric parameters to verify if the wavefront aberration-corrected optometric parameters fall within normal visual range, thus ensuring the accuracy and high repetition of the measured optometric parameters.

Abstract: A method and an apparatus for designing an image restoration filter and a method and an apparatus for restoring an image by using the image restoration filter are provided. A test image is captured by an imaging system to obtain image information of the test image. The image restoration filter is then calculated according to original image information of the test image and the image information obtained by the imaging system through a numerical method, such that the obtained image information after being processed by the image restoration filter has a better similarity to the original image information. Thereafter, an image captured by the imaging system is processed by using the image restoration filter as a kernel, so as to resolve the problems of image blur and distortion caused by the optical path and the imaging system.

Abstract: A device and method for measuring and correcting eye aberrations integrate wavefront sensing, wavefront aberration correction and optometric testing into one another and configure the optical paths of wavefront sensing and optometric testing as aplanatic structures, such that under optometric testing conditions both wavefront sensing and aberration correction can be performed simultaneously, and final optometric testing is conducted on wavefront aberration-corrected optometric parameters to verify if the wavefront aberration-corrected optometric parameters fall within normal visual range, thus ensuring the accuracy and high repetition of the measured optometric parameters.

Abstract: A device and method for measuring and correcting eye aberrations integrate wavefront sensing, wavefront aberration correction and optometric testing into one another and configure the optical paths of wavefront sensing and optometric testing as aplanatic structures, such that under optometric testing conditions both wavefront sensing and aberration correction can be performed simultaneously, and final optometric testing is conducted on wavefront aberration-corrected optometric parameters to verify if the wavefront aberration-corrected optometric parameters fall within normal visual range, thus ensuring the accuracy and high repetition of the measured optometric parameters.

Abstract: A technique for preparing stoichiometric group III-V compound semiconductor surfaces involves a repetitive anodizing and etching sequence in an aqueous solution of appropriate pH and a basic solution, respectively. Surfaces treated in the described manner evidence a correct surface stoichiometry and minimum carbon contamination.