188 results about "High spatial frequency" patented technology

A camera acquires a 4D light field of a scene. The camera includes a lens and sensor. A mask is arranged in a straight optical path between the lens and the sensor. The mask including an attenuation pattern to spatially modulate the 4D light field acquired of the scene by the sensor. The pattern has a low spatial frequency when the mask is arranged near the lens, and a high spatial frequency when the mask is arranged near the sensor.

A method of reducing artifacts in an image previously processed by block transform encoding may comprise the steps of:

• • determining block boundaries;
  • determining an approximate metric of artifact visibility;
  • optionally interpolating across block boundaries;
  • adaptively filtering luminance;
  • optionally adaptively filtering chrominance;
  • adaptively adjusting local saturation variation; and
  • adaptively simulating high spatial frequency image detail;

wherein the adaptive steps are executed to an extent or in an amount depending on the metric or standard or measurement of artifact visibility.

A technique of reconstructing a high resolution image from at least one image sequence of temporally related high and low resolution image frames wherein each of said high resolution image frames includes a low spatial frequency component and a high spatial frequency component is described. The high-resolution image reconstruction technique uses spatial interpolation to generate a low spatial frequency component from a low-resolution image frame of the image sequence. The technique is adapted to generate a high spatial frequency component from at least one high resolution image frame of the image sequence which is closely related to the low resolution image frame, and to remap the high spatial frequency component to a motion-compensated high spatial frequency component estimate of the low resolution image frame. The motion-compensated high spatial frequency component estimate is added to the generated low spatial frequency component to form a reconstructed high-resolution image of the low-resolution image frame.

An image display method includes dividing one frame into a plurality of sub-frames by multiplying a frame frequency of an input image signal, reducing a high-spatial frequency component of an image signal which is used for image display in at least one predetermined sub-frame among the plurality of sub-frames in comparison with that of an image signal which is used for image display in another sub-frame, and displaying an image in each sub-frame.

A system and method for tracking an airborne target including an illumination source (e.g., a diode laser array) is used to enhance a target signature and a detector (e.g., a passive high-speed camera) is used to detect to electromagnetic radiation (e.g., infrared radiation) reflected off the target. The received electromagnetic radiation may be processed by a digital computer and passed through a spatial filter that implements a band limited edge detection operation in the frequency domain. The filter may remove low spatial frequencies that attenuate soft edged clutter such as clouds and smoke as well as filter out artifacts and attenuated medium to high spatial frequencies to inhibit speckle noise from the detector as well as speckle from the laser return off the target.

A method for producing a high-dynamic-range image, comprising: receiving a low-resolution image of a scene having a first resolution and captured at a first exposure level; receiving a first high-resolution image of the scene having a second resolution and captured at a second exposure level different from the first exposure level, the second resolution being greater than the first resolution; forming a residual image corresponding to high spatial frequency content in the first high-resolution image; forming a second high-resolution image having the second resolution and the first exposure level by combining the low-resolution image and the residual image; producing the high-dynamic-range image by combining the first high-resolution image and the second high-resolution image; and storing the high-dynamic-range image in a processor accessible memory.

An integrated imaging element for an interferometer generates at least one interference image that includes multiple interference portions with different relative phase shifts interleaved in a pattern having a high spatial frequency in the image. The interleaved pattern is at least partially determined by the pattern of a high density relative retarder array used in the integrated imaging element. In various embodiments, the multiple interference portions are interleaved in a checkerboard-like pattern across the entire surface of a detector device. As a result, various non-common mode errors present in various interferometers that generate separate non-interleaved images for each relative phase are reduced or eliminated.

In the conventional methods for enhancing defect detection sensitivity by improving the resolving power, if a microscopic pattern, which is a high spatial-frequency structure as is the case with a microscopic defect, has become the brightest portion, the gray-scale contrast of the microscopic defect will be enhanced. At the same time, however, the gray-scale contrast of the microscopic pattern will also be enhanced simultaneously. Consequently, there has existed a problem that it is impossible to enhance the microscopic-defect detection sensitivity further than that. In the present invention, an aperture stop which is divided into a plurality of small apertures is located on an illumination pupil plane. Then, light-shield/light-transmission for each small aperture is controlled independently of each other. This control allows an inspection-target object to be illuminated at only an incident angle at which the gray-scale contrast of the microscopic defect will be emphasized more sharply.

A dual function detector device operates in either a normal operating mode or in an EMI correction mode to suppress effects of EMI within the detector. The detector device may be a flat panel x-ray detectors used in x-ray imaging systems. The device has a pixel architecture and panel read-out technique that enables real-time, high spatial frequency measurement of noise induced by electromagnetic radiation on a digital x-ray detector. The measurement can be used to calibrate the detector in real-time to attain artifact-free imaging in all environments, including those that contain temporally and spatially changing electromagnetic fields.

A combination of active and passive force actuators provide adjustments to the shape of an optical element to reduce or compensate for aberrations in an optical system. Passive actuators at a high spatial frequency are capable of correcting higher order steady state components of shape error while dynamic corrections of higher frequency, operationally dependent is provided allowing the number of active actuators and the power supplied to each active actuator to be reduced; reducing heating of the optical element by the active actuators and increasing stability of the system. Compound actuators including a combination of an active actuator portion with a passive actuator portion (which provides a mechanical force bias to the active actuator portion) allows increased spatial flexibility of application of forces to the optical element and other advantages.

An exemplary embodiment of the present invention provides an interference projection exposure system comprising a beam-providing subsystem and an objective lens subsystem that can provide a plurality of light beams which intersect and interfere at an image plane to produce a high spatial frequency periodic optical-intensity distribution. The interference projection system can further comprise a pattern mask that can alter the periodic optical-intensity distribution so as to incorporate functional elements within the periodic optical-intensity distribution. The beam providing subsystem can comprise a beam generating subsystem, a beam conditioning subsystem and a beam directing subsystem. Another exemplary embodiment of the present invention provides for a method of producing a high spatial frequency periodic optical-intensity distribution using a interference projection exposure system.

This invention relates to a method, a computer program, a computer program product, and a device for reducing motion blur of images of a video signal shown on a hold-type display (101), comprising estimating (1102) motion vectors of moving components in said images of said video signal; band-pass filtering (1100, 1101) said video signal with respect to a spatial frequency domain, wherein said band-pass filtering at least partially depends on said estimated motion vectors, and wherein with increasing length of said estimated motion vectors, the passband of said band-pass filtering adaptively shifts from high spatial frequencies to medium spatial frequencies; and combining (1104) said video signal and said band-pass filtered video signal to produce an input video signal for said hold-type display.

A method and apparatus are presented for acquiring MR cardiac images in a time equivalent to a single breath-hold. MR data acquisition is segmented across multiple cardiac cycles. MR data acquisition is interleaved from each phase of a first cardiac cycle with MR data from each phase of a subsequent cardiac cycle. Preferably, low spatial frequency data are interleaved between multiple cardiac cycles, and the subsequent cardiac cycle acquisition includes sequential acquisition of high spatial frequency data towards the end of the acquisition window. An MR image can then be reconstructed with data acquired from each of the acquisitions that reduce ghosting and artifacts. Volume images of the heart can be produced within a single breath-hold. Images can be acquired throughout the cardiac cycle to measure ventricular volumes and ejection fractions. Single phase volume acquisitions can also be performed to assess myocardial infarction.

This invention relates to double wave pre-corrector self-adapting optical system, which comprises incline reflection lens, two before wave correctors, before wave sensor, splitter lens, before wave processor, two before wave correctors, which separately realize the low and high picture difference correction as needed. The before wave corrector needs large journey to correct the low picture difference and the before wave corrector has larger space frequency.

A sampling system adapts the sampling rate for sampling analog signals and/or the stored number of samples to the fixed or video image content, such that a higher rate, and equivalently a larger number of samples, are acquired for an image or video segment containing higher spatial frequencies while a lower number of samples (lower sampling rate) are retained for image or video segments containing lower spatial frequencies. The Nyquist theorem may still be satisfied for each individual image segment, while information necessary for edge enhancement is retained.

Defect mitigation in display panels. Defects in a display panel are mapped, and the defect information is associated with the display system or associated with the panel. During panel operation, the values of pixels neighboring defective pixels are altered to minimize their visibility to the observer. In a first model, luminance error caused by a defect is compensated by adjust neighboring pixels. In a second model, Error in luminance and one of the two chrominance channels is compensated by adjusting neighboring pixels. The defect mitigation methods seek to shift the errors introduced by defective pixels into high spatial frequency elements and chromatic elements, which the human eye is not sensitive to.