108 results about "Focus measure" patented technology

The method of determining a focus measure from an image includes detecting one or more edges in the image by processing the image with one or more first order edge detection kernels adapted to reject edge phasing effects. A first measure of the strength of each of the edges, and the contrast of each of the edges may be determined. The method may include normalizing the first measure of the strength of each of the edges by the contrast of each of the edges to obtain a second measure of the strength of each of the edges, and resealing the second measure of the strength of each of the edges. The method may also include selecting one or more of the edges from the image in accordance with the second measure of their strengths, and calculating the focus measure from the second measure of the strengths of the selected edges.

A microscope apparatus 1A is formed with a CCD camera 30 that acquires an image of a sample S, a light guiding optical system 20 that guides an optical image of the sample S to the camera 30, an optical system driving section 25 that drives the camera 30 and the optical system 20 to change a focal position on the sample S in a z-axis direction, and a control device 50 that includes a focal point control section 51. The focal point control section 51 calculates a first focal point measurement value from a plurality of images acquired by a first focal point measurement that is executed while continuously changing the focal position in one direction, calculates a second focal point measurement value from a plurality of images acquired by a second focal point measurement that is executed while continuously changing the focal position in a direction opposite that of the first focal point measurement, and determines an in-focus position for the sample S based on the first and second focal point measurement values. This realizes an automatic focusing device that is capable of accurately determining an in-focus position in a short time and a microscope apparatus using the same.

An image based autofocus method and system that includes receiving image data; monitoring and analyzing the contrast between different portions of the image data in determining the location of a target wherein the different portions of the image data contain at least one type of image pixel information and the monitoring and analyzing are performed using at least one kernel filter to determine a focus measure; adjusting a focus mechanism that is focusing on the image data; observing an image quality of the image data that has been focused; and continuously outputting an image to support an image processing frame rate and adjusting the focus mechanism to obtain an improved focus image by adjusting the focus mechanism in a positive direction, a negative direction or a zero (0) direction based upon effectuating a desired change in the observed image quality of the image data.

A method for calibrating a focus point for a camera lens may include capturing a reflection of a focus point measuring device that is affixed to the camera. The method may include evaluating a captured image of the reflection to measure a calibration amount for a focus point, and adjusting a focus point of a lens of the camera by the calibration amount. The focus point measuring device may include a substantially planar target surface defining a plane, and a ruled target surface inclined at substantially 45° to the substantially planar target and extending through the plane thereof, marked to indicate respective distances in front of and behind the plane. The device may further include a fixture for holding the substantially planar target surface and the ruled target surface in a defined orientation to the camera, enabling performance of the method.

The method of determining a focus measure from an image includes detecting one or more edges in the image by processing the image with one or more first order edge detection kernels adapted to reject edge phasing effects. A first measure of the strength of each of the edges, and the contrast of each of the edges may be determined. The method may include normalizing the first measure of the strength of each of the edges by the contrast of each of the edges to obtain a second measure of the strength of each of the edges, and resealing the second measure of the strength of each of the edges. The method may also include selecting one or more of the edges from the image in accordance with the second measure of their strengths, and calculating the focus measure from the second measure of the strengths of the selected edges.

An image capturing apparatus includes an image sensor provided in the neighborhood of an image plane of a photographing optical system for forming the image of a subject; pupil dividing member for forming images of a pair of light beams that have passed through different pupil regions of the photographing optical system; focus detection sensors arranged two-dimensionally for photoelectrically converting images of the pupil dividing member; and a correlation calculation unit which, in order to obtain one focus measurement value from one pair of two-dimensional images generated by the focus detection sensors and extending in the pupil dividing direction of the pupil dividing member and in a direction perpendicular to the pupil dividing direction, calculates the correlation between the pair of two-dimensional images while shifting the pair of two-dimensional images in the pupil dividing direction.

A method of operation of a depth estimation system includes: calculating focus measures for positions on a two-dimensional image; generating a depth map for the two-dimensional image based on fitting the focus measure through a Gaussian function; generating a three-dimensional image from the depth map and the two-dimensional image; and processing the three-dimensional image on a storage unit for displaying on a device.

With respect to a charged particle beam device, the step size of focal point measure for executing autofocusing is optimized to a value that is optimal with respect to the spread of an approximation curve for a focal point measure distribution. The step size of focal point measure for executing autofocusing is corrected using an image feature obtained based on a layout image derived from an image obtained at a first magnification or from design data. Autofocusing is executed based on the obtained step size to carry out observation, measurement, or to image the sample under inspection.

An image display system and a method thereof are provided. A focal point of a user's eyes is measured by a focus measuring module. A distance between the user's eyes and a display unit is measured by a distance measuring module. At least two parallax image data are retrieved from a storage medium by an image forming module, and a distance between the at least two parallax image data is adjusted by the image forming module based on the focal point of the user's eyes and the distance between the eyes and the display unit, so as to display the adjusted parallax image data on an imaging point of the display unit. By the above system and method, a stereo image can be provided on the display unit without adjusting the focal point of the user.

A method, apparatus and computer program product are provided to facilitate scene segmentation from focal stack images. The method may include receiving a set of focal stack images, calculating a focal measure for each of a plurality of pixels of the set of focal stack images, and grouping each of a plurality of pixels for which the focal measure was calculated into a plurality of super pixels. The method may also include calculating a focal measure for each of the plurality of super pixels, segmenting a respective focal stack image based on the focal measure of each of the plurality of super pixels, calculating a color probability for each of the plurality of super pixels, and segmenting each focal stack image based on color probability of each of the plurality of super pixels.

A method for improving depth for field (DOF) in microscopic imaging, the method comprising combining a sequence of images captured from different focal distances to form an all-focus image, comprising computing a focus measure at every pixel, finding the largest peaks at each position in the focus measure as multiple candidate values and blending the multiple candidates values according to the focus measure to determine the all-focus image.

The invention discloses a compound differential type long-focus measuring device based on a Talbot effect. The light of a laser source runs through a polaroid, a lambda / 4 wave plate, a microscope objective and a collimating mirror, to be divided into two beams by a beam splitter prism, wherein one beam is incident to a standard lens, a first grating and a second grating, to form moire fringes on first ground glass, the first CCD (Charge Coupled Device) is used for collecting the fringes and inputting the fringes to a computer so as to calculate the angle alpha 1 of the fringes, to get a standard lens focus; the other beam is incident to a long-focus lens to be measured, reflected by a reflector and then incident to third and fourth gratings, to form moire fringes on second ground glass, and a second CCD is used for collecting the fringes and inputting the fringes to the computer so as to calculate the angle alpha 2 of the fringes; the alpha 1 and alpha 2 are subjected to differential treatment and the alpha 1 is corrected to obtain a long-focus value; and the standard lens focus and the known standard value thereof are subjected to differential treatment and the long-focus value to be measured is corrected to obtain a focus value of the long-focus lens to be measured finally. According to the device disclosed by the invention, the external interference is eliminated by adopting the two differential treatments, and the high precision measurement for the long-focus lens can be realized.

A microscope including an imaging optical unit, a sample stage for supporting a sample to be examined, a movement unit, by which the distance between sample stage and imaging optical unit can be altered, a focus measuring unit, which measures the present focus position and outputs a focus measurement signal, a control unit for maintaining a predetermined focus position for examinations of the sample that are separated from one another in time. The control unit receives the focus measurement signal and derives a deviation of the present focus position from the predetermined focus position. Dependent on the deviation derived the movement unit, changes the distance between sample stage and imaging optical unit so that the predetermined focus position is maintained. The control unit drives the movement unit (9) for maintaining the predetermined focus position only before and / or after at least one of the examinations, but never during the examinations.

The invention relates to a laser focusing device for a lens during the process of manufacturing a stage lamp, comprising a guide rail, a first slide carriage, a second slide carriage and a third carriage which are arranged on the guide rail; one side of each slide carriage is respectively provided with a fixing button, so that each slide carriage can slide and be fastened on the guide rail; the third slide carriage is provided with an L-shaped support having an upper end provided with a laser emitter module which is provided with a laser; the second slide carriage is provided with a lens support above which a lens is arranged; and the first slide carriage is provided with an L-shaped support having an upper end provided with a laser receiver module which is provided with a laser receiver. The device has the advantages of convenient and simple operation, accurate and direct measurement, low cost, simplified calculation during the designing process, reduced error, improved work efficiency, and accurate measurement for both spherical lens and non-spherical lens.

The invention discloses an attention focus measuring method, and the method comprises the steps: carrying out the real-time measurement of the offset data of the head part of a tested object, and estimating the position of the attention focus of the tested object according to the measurement data; removing a part of group attention focus measurement errors caused by the distraction of the attention of the tested object through abnormality discrimination and clustering. The method provided by the invention is used in a classroom environment for monitoring the class conditions, can provide reliable and visual data for knowing the learning states of students in the classroom, and is higher in value of monitoring the learning conditions of the students in the current classroom teaching.

A mask with a focus measurement pattern and a method for measuring a focus value in an exposure process using the same that are capable of improving the measurement of a focus change, wherein the mask includes an outer reference pattern which provides a position reference for focus measurement, and focus measurement patterns which are provided apart from the outer reference pattern and formed in a line shape extending in two different directions. Accordingly, the focus change caused in the exposure process can be measured by measuring the line shortening of the focus measurement patterns.

The invention discloses an integrated long-focus measuring device based on Talbot-moire technology. The integrated long-focus measuring device based on the Talbot-moire technology comprises a laser device, an aspheric surface collimator lens, a one-side anti-reflection one-side increase-reflection lens, a plane mirror, a semi-reflection and semi-anti-reflection mirror, a Talbot interferometer, an imaging lens, a first charge coupled device (CCD), a counter point system and a long-focus lens to be measured. The Talbot interferometer comprises first optical grating, a second optical grating and a first scatter plate. The counter point system comprises a convergent lens, a second scatter plate and a second CCD. When the long-focus lens to be measured is not placed to the device, system optical axes are adjusted into consistency by utilizing the counter point system. Then a moire fringe L1 collected by the first CCD is input to a computer. The moire fringe L1 is placed into the long-focus lens to be measured. A moire fringe L2 including focal distance collected by the first CCD is input to the computer together with the moire fringe L1. An included angle formed by the moire fringe L1 and the moire fringe L2 is calculated through the computer to obtain a focal length f of the lens to be measured. The counter point system is designed in the device, the consistency of the axes of the system is ensured, and long-focus measurement with high precision can be achieved.

Described is a low power surveillance camera system for intruder detection. The system observes a scene with a known camera motion to generate images with various viewing angles. Next, a background learning mode is employed to generate a low rank matrix for the background in the images. Background null space projections are then learned, which provide a foreground detection kernel. A new scene with known viewing angles is then obtained. Based on the foreground detection kernel and the new input image frame, low power foreground detection is performed to detect foreground potential regions of interest (ROIs), such as intruders. To filter out minimal foreground activity, the system identifies contiguous ROIs to generate the foreground ROI. Focus measures are then employed on the ROIs using foveated compressed sensing to generate foveated measurements. Based on the foveated measurements, the foreground is reconstructed for presentation to a user.

Provided is an underwater sound projector response time reversal focusing measuring method, comprising the steps of: 1) collecting probing signals; 2) generating time reversal transmitting signals; 3) measuring current and voltage signals; 4) calculating sending response; and 5) correcting sending response. The method is based on an acoustic wave equation time reversal invariance principle, and realizes standard hydrophone receiving signal spatial and temporal focusing through an underwater sound reciprocity principle, thereby restraining reverberation in measuring projector response within a limited space, and solving difficulties in measuring projector response time under limited space strong reverberation.

A digital image processing, in particular to the method of producing the output image with extended depth of field from a group of source images of the same scene, captured with a shift of depth of field. The method of producing the output image with extended depth of field form a group of at least two source images of substantially the same scene captured with a shift of depth of field, comprises determining focus measures of source image pixels; generation of a depth map with elements comprising source image indices; smoothing of the depth map in a way that the degree of smoothing of source image indices it contains is inversely proportional to the corresponding focus measure values; producing an output image using the smoothed depth map. A computer system that implements said method, and a computer readable medium comprising program instructions allowing for implementing said method.

In a focus measurement method and a method of manufacturing a semiconductor device relating to the present invention, a focus value is obtained by using a fluctuation where shrinkage of a resist pattern by an electron beam irradiation depends upon the focus value. In the case of obtaining the focus value, the shrinkage of the resist pattern for a focus measurement formed by exposure to be subject for a focus value measurement is measured. The focus value corresponding to the shrinkage is obtained from the pre-obtained focal dependency of the shrinkage. A focal shift length can be defined from a difference between the focus value and a predetermined best focus value.

An apparatus includes a stage configured to move a substrate, an optical system configured to project an image of a pattern on an original onto the substrate, an alignment detection system configured to detect an image of an alignment mark formed on the substrate and measure a position of the alignment mark, and a focus detection system having an index mark and configured to measure a height of the substrate by projecting an image of the index mark onto the substrate. The stage includes an alignment measurement mark and a focus measurement mark that has a positional relationship with the alignment measurement mark. The alignment detection system measures a position of the alignment measurement mark. The focus detection system measures a position of the image of the index mark by projecting the image of the index mark onto the focus measurement mark.

A method and system for auto-focusing is presented that receives an image at an image capture device, determines a focus measure of the image, and adjusts a focus of the image by moving a lens in the image capture device in a first direction until a maximum focus measure position is reached. The method and system then evaluates a noise level of the focus measure and continues to adjust the focus of the image by further moving the lens in the first direction until the focus measure is decreased by an adaptive threshold amount, wherein the adaptive threshold amount is based on the noise level of the focus measure. The method and system then adjusts the focus of the image by moving the lens in a second direction to the maximum focus measure position.

The invention discloses a method and a device for measuring minute amplitude vibration of a laser focused measuring head. The method is characterized by comprising the following steps: a vibrator to be measured is moved under the laser focused measuring head; a signal of the laser focused measuring head is acquired and transmitted to a data processor by a data acquisition card; after the data processor outputs a digital signal to the data acquisition card, the digital signal is converted into an analogue signal and output to an electric lifting platform controller; an electric lifting platform is driven to move near a focal plane of the laser focused measuring head by the electric lifting platform controller; when the vibrator to be measured starts vibrating, the distance between the surface of the vibrator and the surface of the laser focused measuring head is changed, and the signal of the laser focused measuring head is changed correspondingly; the frequency and the waveform of the signal of the laser focused measuring head reflect the vibration frequency and the waveform of the vibrator; and according to the linear relationship U=k*L+b between the displacement distance L and the signal U of the measuring head, b represents the output signal of the measuring head when the L is zero, and the amplitude is 1 / k time that of that of the signal of the measuring head.