Abstract:
A spatial mask printer may be used in conjunction with an optical inspection tool. The tool can be used to obtain a Fourier image of an inspected object, and a filter mask image can be designed to block certain aspects of the object's image in the Fourier plane corresponding to repetitive aspects of the imaged object. The filter mask image can then be printed and used in the tool during the inspection process. The mask image may be designed by hand or by computer and may be stored for later use. Filters may be automatically placed into the optical path of the inspection tool by a filter wheel, or may be housed in other filter banks. The printer may be configured to operate in a clean room environment, and may be integrated into the optical inspection tool.
Abstract:
As multiple matched filter memories for optical correlators increase in size, their design, fabrication and alignment becomes increasingly complex and critical for proper operation of the optical correlator. The present invention places special alignment targets on the multiple matched filter memory to provide for proper alignment thereof to enable efficient correlator operation.
Abstract:
An image processing apparatus for generating a template image used for template matching relying on a frequency component of an image is provided. The image processing apparatus includes a setting portion accepting setting of a region in an input image as a template candidate image and an effectiveness degree calculation portion calculating, by analyzing the template candidate image itself set in the input image, a degree of effectiveness indicating appropriateness as the template image of the template candidate image. The effectiveness degree calculation portion calculates the degree of effectiveness based on a value associated with frequency distribution of the template candidate image.
Abstract:
An atmospheric aberration sensor that uses two optically correlated images of a scene and the Fourier transform capabilities of a lens or other focusing element. The sensor receives light via an f-number matching element from a scene or from an external optical system and transmits it through a focusing optical element to an updateable display element such as a spatial light modulator or micro mirror array, which modulates the real time image from the focusing element with previous template image of the same extended scene. The modulated image is focused onto an autocorrelation detection sensor, which detects a change in centroid position corresponding to a change of the tip/tilt in the optical path. This peak shift is detected by centroid detection and corresponds to the magnitude of global wavefront tip/tilt. With a lenslet array and detector array, the system can also measure local tip/tilt and higher order aberrations.
Abstract:
A real time digital correlation system is disclosed. Reference filters are constructed to define a region of filter space, and filters may be predictively selected based on a trajectory of selected filters through the filter space. In some instances, selected features of a spacecraft are selected for correlation to produce full 6DoF information. In other instances, portions of a correlation target are selected for correlation to produce 6DoF information. Digital filters of the invention are preferably 4-bit filters, and use unique mapping algorithms to map phase and intensity information from larger images, such as 12, 16, 32 and 64 bit images, to the 4-bit format.
Abstract:
A method for correlating or finding similarity between two data sets. The method can be used for correlating two images with common scene content in order to find correspondence points between the data sets. These correspondence points then can be used to find the transformation parameters which when applied to image 2 brings it into alignment with image 1. The correlation metric has been found to be invariant under image rotation and when applied to corresponding areas of a reference and target image, creates a correlation surface superior to phase and norm cross correlation with respect to the correlation peak to correlation surface ratio. The correlation metric was also found to be superior when correlating data from different sensor types such as from SAR and EO sensors. This correlation method can also be applied to data sets other than image data including signal data.
Abstract:
A pair of matched filters describing a pre-selected category of objects isade, each of the filters having a center located at a unique place in the filter. When incorporated into a MACE filter and used in an optical correlator, a line drawn through the correlation peaks caused by the centers of the matched filter pair and a pre-selected axis together produce an angle that is indigenous to that particular category of objects, thus identifying the category of objects.
Abstract:
Disclosed is a temperature distribution measuring device for measuring the temperature distribution or the heat generation distribution in a sample. An embodiment collects a reflection signal the reflectivity of which changes on the basis of a bias signal applied to a sample, detects a signal of interest, which has been reflected from a region of interest in the sample, from the reflected signal, converts the signal of interest to a frequency range signal, calculates the relative amount of change in reflectivity of the sample by using a direct current component extracted on the basis of filtering of the frequency range signal and a frequency component of the bias signal, and acquires a thermal image of the sample on the basis of the relative amount of change in reflectivity.
Abstract:
An optical detector (110) is disclosed, the optical detector (110) comprising: at least one spatial light modulator (114) being adapted to modify at least one property of a light beam (136) in a spatially resolved fashion, having a matrix (132) of pixels (134), each pixel (134) being controllable to individually modify the at least one optical property of a portion of the light beam (136) passing the pixel (134); at least one optical sensor (116) adapted to detect the light beam (136) after passing the matrix (132) of pixels (134) of the spatial light modulator (114) and to generate at least one sensor signal; at least one modulator device (118) adapted for periodically controlling at least two of the pixels (134) with different modulation frequencies; and at least one evaluation device (120) adapted for performing a frequency analysis in order to determine signal components of the sensor signal for the modulation frequencies.
Abstract:
An optical detector (110) is disclosed, the optical detector (110) comprising: at least one spatial light modulator (114) being adapted to modify at least one property of a light beam (136) in a spatially resolved fashion, having a matrix (132) of pixels (134), each pixel (134) being controllable to individually modify the at least one optical property of a portion of the light beam (136) passing the pixel (134); at least one optical sensor (116) adapted to detect the light beam (136) after passing the matrix (132) of pixels (134) of the spatial light modulator (114) and to generate at least one sensor signal; at least one modulator device (118) adapted for periodically controlling at least two of the pixels (134) with different modulation frequencies; and at least one evaluation device (120) adapted for performing a frequency analysis in order to determine signal components of the sensor signal for the modulation frequencies.