252 results about "Quality of vision" patented technology

The present invention discloses a system and method for rate control of MPEG video streams to achieve a target bit rate in a transcoder at the best visual quality possible. The invention monitors video buffer fullness for selecting the amount of rate reduction necessary to achieve a target bit rate. The invention also utilizes a method for selective requantization of DCT coefficients to assure visual quality.

Techniques related to vision correction are disclosed. The techniques involve establishing a visual model associated with a patient. The visual model includes data related to a quality of the patient's vision. A boundary is established as a function of the data associated with the visual model. The boundary is indicative of an area to be corrected within the patient's vision. A retinal map is established as a function of the boundary. An image from a camera associated with the patient is captured and corrections are applied to the image based on the retinal map to generate a corrected image. The corrected image is presented to the eye of the patient.

An apparatus for determining the refraction of a patient's eye includes a wavefront measurement device that determines aberrations in a return beam from the patient's eye viewing a target through a corrective test lens in the apparatus. The wavefront measurement device preferably outputs an display representative of the quality of vision afforded the patient through the test lens. The display may be, e.g., a representation of a Snellen chart convolved with the optical characteristics of the patient's vision, an overall quality of vision scale, or the optical contrast function, all of which are based on the wavefront measurements of the patient's eye. The examiner may use the display information to conduct a refraction examination or other vision tests without the subjective response from the patient.

Near infra-red images of natural scenes usually have better contrast and contain rich texture details that may not be perceived in visible light photographs. The contrast and rich texture details form a NIR image corresponding to a visible light image are useful for enhancing the visual quality of the visible light image. To enhance the visual quality of a visible light image using its corresponding near infra-red image, a computer-implemented method computes a weight region mask from the visible light image, transfers contrast data and texture data from the near infra-red image to the visible light image guided by the weighted region mask. The contrast data is computed from the low frequency subbands of the visible light image and corresponding infra-red image after a wavelet transform by matching the histogram of gradient magnitude. The texture data is computed from the high frequency subbands of both images after wavelet transform.

A method of measuring eye refraction to achieve desired quality according to a selected vision characteristics comprising the steps of selecting a characteristic of vision to correlate to the desired quality of vision from a group of vision characteristics comprising acuity, Strehl ratio, contrast sensitivity, night vision, day vision, and depth of focus, dynamic refraction over a period of time during focus accommodation, and dynamic refraction over a period of time during pupil constriction and dilation; using wavefront aberration measurements to objectively measure the state of the eye refraction that defines the desired vision characteristic; and expressing the measured state of refraction with a mathematical function to enable correction of the pre-selected vision characteristic to achieve the desired quality of vision. The mathematical function of expression may be a Zernike polynomial having both second order and higher order terms or a function determined by spline mathematical calculations. The pre-selected desired vision characteristics may be determined using ray tracing technology.

A vision metric, called the sharpness metric, indicates the subjective sharpness of a patient's vision by taking into account both the wavefront aberration and the retinal response to the image. A retinal image quality function such as the point spread function is convolved by a neural quality function, and the maximum of the convolution over the retinal plane provides the sharpness metric. The sharpness metric can be used to control eye surgery or the fabrication of a lens.

Techniques related to vision correction are disclosed. The techniques involve establishing a visual model associated with a patient. The visual model includes data related to a quality of the patient's vision. A boundary is established as a function of the data associated with the visual model. The boundary is indicative of an area to be corrected within the patient's vision. A retinal map is established as a function of the boundary. An image from a camera associated with the patient is captured and corrections are applied to the image based on the retinal map to generate a corrected image. The corrected image is presented to the eye of the patient.

The invention relates to a method of preventing the induction of aberrations in laser refractive surgery systems. Standard laser refractive surgery systems successfully correct low-order refractive errors (myopia, hypermetropia and astigmatism), but induce spherical aberration and, by extension, other high-order aberrations, which result in a worsening of vision quality. Said increase in spherical aberration is due to the shape of the cornea, and not inherent in the theoretical ablation profile, and, as a result, the problem is, in principle, common to all laser systems. The invention relates to a systematic method which can be used with any system and ablation profile in order to obtain a profile correction factor. The correction factor, which is specific to each system, can be applied in order to prevent the induction of spherical aberration and, in this way, improve the optical and visual quality of patients following surgery compared to surgery performed with standard systems. Moreover, the inventive method can be used to improve the production of lenses with controlled high-order aberrations using laser systems.

An method for providing an objective manifest refraction of a patient's eye includes obtaining at least fourth-order Zernike wavefront aberration information, fitting a second-order only polynomial to the at least fourth-order data, and using this information to predict the patient's manifest refraction with an accuracy approaching the patient's subjective manifest refraction. A method is also described for prescribing an accurate vision correction based upon the objective manifest refraction. A display according to the invention includes higher-order wavefront aberrations, lower order wavefront aberrations, numerical indicia of predicted manifest refraction, and images of qualitative assessments of a patient's vision quality. A device for obtaining an objective manifest refraction is described.

Eye refraction is measured to achieve desired quality via a selected vision characteristics. A characteristic of vision is selected to correlate to the desired quality of vision from a group of vision characteristics comprising acuity, Strehl ratio, contrast sensitivity, night vision, day vision, and depth of focus, dynamic refraction over a period of time during focus accommodation, and dynamic refraction over a period of time during pupil constriction and dilation. Wavefront aberration measurements are used to objectively measure the state of the eye refraction that defines the desired vision characteristic. The measured state of refraction is expressed with a mathematical function enabling correction of the pre-selected vision characteristic to achieve the desired quality of vision. The mathematical expression function may be a Zernike polynomial having both second order and higher order terms or a function determined by spline mathematical calculations. Pre-selected vision characteristics may be determined using ray tracing technology.

The present invention relates generally to the restoration or improvement of the quality of human vision and, more particularly to a self-adapting system and method for achieving automatic sharp vision by the human eye of objects for instance at distances between 25 cm and more than 10 meters away. The invention can be situated in at least four technological domains: 1. ophthalmology, in particular the implantation of intraocular lenses. 2. Non-contact biometric signal recording and processing. 3. Electro-optic control of refractive lens power. 4. Wireless energy transfer.

The parameters of an optical code are optimized to achieve improved signal robustness, reliability, capacity and / or visual quality. An optimization program can determine spatial density, dot distance, dot size and signal component priority to optimize robustness. An optical code generator employs these parameters to produce an optical code at the desired spatial density and robustness. The optical code is merged into a host image, such as imagery, text and graphics of a package or label, or it may be printed by itself, e.g., on an otherwise blank label or carton. A great number of other features and arrangements are also detailed.

Tear film stability has an important role in the quality of vision. A system and method for performing Fluctuation Analysis of Spatial Image Correlation (FASIC) provides for a non-invasive system and method for evaluating the dynamics of the tear film surface using spatial autocorrelation analysis. With FASIC, a series of images are obtained using illumination and a camera. The spatial autocorrelation is calculated for image frames produced by the camera. A sinusoidal background appears in this correlation together with other features. The changes in the sinusoidal background of the spatial autocorrelation is extracted and monitored over time. The spatial period of this sinusoidal background correlates with the thickness of the tear film. In this regard, one is able to derive the tear film thickness from the period of this sinusoidal background.

An apparatus for determining the objective refraction of a patient's eye includes a transparent window and a wavefront measurement device that determines aberrations in a return beam from the patient's eye after the beam passes through a corrective test lens in the apparatus. The wavefront measurement device outputs an instant display representative of the quality of vision afforded the patient through the test lens. The display can be a representation of a Snellen chart, convoluted with the optical characteristics of the patient's vision, an overall quality of vision scale or the optical contrast function, all based on the wavefront measurements of the patient's eye. The examiner may use the display information to conduct a refraction examination and other vision tests without the subjective response from the patient.

An apparatus for determining spherical and cylinder components of subjective refraction of a patient's vision includes a wavefront measurement device that can produce a measure of quality of vision in a return beam from the patient's eye viewing a target through a corrective test lens in the apparatus. The corrective lenses may be varied and a plurality of measurements of quality of vision may be obtained and analyzed to determine the spherical and cylinder components. Accordingly, the eye examiner may conduct a refraction examination without a subjective response from the patient.

The invention carries out process in frame for image; then carries out process inter frame for continuous three frames of image, which are processed in frame. The method includes following steps: using Laplace operator to carry out edge detection for image so as to obtain edge information of each pixel; if a pixel is an edge pixel or its more than two neighbor pixels in four pixels around are as edge pixels, then value of the pixel is saved; otherwise, carrying out filtering process for the pixel by using median filter; based on difference between adjacent frames, movement detection is carried out to determine whether pixel in the current frame is moved; if yes, the value is saved; if no, then result of median filter for corresponding points in three frames is as result of filtering the pixel. The invention protects details of image and sharpness furthest so as to raise vision quality of output image.

A method and apparatus for selecting a quantizer scale for each object within a frame to optimize the coding rate is disclosed. A quantizer scale is selected for each region or “object” within each frame such that the target bit rate for the frame is achieved while maintaining a uniform visual quality over the entire frame.

A preliminary guidance data is determined for the vehicle during an evaluation time window. A vision module collects vision data from a vision module during the evaluation time window. Vision guidance data is determined from the collected vision data. A vision quality estimator estimates vision quality data for at least one of the vision data and the vision guidance data during the evaluation time window. The vision quality data is based on a cross correlations and an r-squared value. An adjuster adjusts the preliminary guidance data to a revised guidance data based on the vision guidance data such that the revised guidance data is registered with or generally coextensive with the vision guidance data, if the vision quality data exceeds a minimum threshold.

The invention discloses a method for achieving global illumination drawing of an animation three-dimensional scene with virtual point light sources, and belongs to the technical field of three-dimensional animation drawing. According to the method, geometric objects in the scene are divided into the static geometric objects and the dynamic geometric objects, and organization and management are respectively carried out with different scene graphs. On the basis that light sampling is carried out on illumination emitting space of the light sources, intersection points of light and the geometric objects in the scene are solved, the virtual point light sources are created at the positions of the intersection points to illuminate the animation three-dimensional scene, and indirect illumination drawing of the animation three-dimensional scene is further achieved. By means of the method, the large number of virtual point light sources can be reused between continuous frames, and global illumination drawing of the animation three-dimensional scene with viewpoints and geometric object movement can be supported at the same time. The method is used for producing three-dimensional animations, and the visual quality of the three-dimensional animations can be improved.

The embodiments herein provide a pupil centered and fovea focused optics assembly comprising a ring platform provided inside a capsular bag of a mammalian eye to support an intraocular lens. The optical center of the intraocular lens is decentered with respect to the geometric center of the intraocular lens to align the optical centre of the lens with a visual axis of a pupil of the mammalian eye to improve the visual quality and to prevent an aberration. A plane of the intraocular lens is turned and tilted through a preset angle to point an optic axis of the intraocular lens to the Fovea.

Optical code signal components are generated and then transformed into signal bearing art that conveys machine readable data. The components of an optical code are optimized to achieve improved signal robustness, reliability, capacity and / or visual quality. An optimization program can determine spatial density, dot distance, dot size and signal component priority to optimize robustness. An optical code generator transforms tiles of an optical code or image embedded with the optical code into signal-bearing art using stipple, Voronoi, Delaunay or other graphic drawing methods so as to retain prioritized components of the optical code. The optical code is merged into a host image, such as imagery, text and graphics of a package or label, or it may be printed by itself, e.g., on an otherwise blank label or carton. A great number of other features and arrangements are also detailed.

The present invention describes a multi-focal intraocular lens for the human eye. The intraocular lens of the present invention provides improved vision quality over a range of object distances without producing glare or halos. It also provides non-symmetric, or nearly symmetric, optical zones about the lens optical axis.

The invention relates to a reading desk lamp evaluation method based on an ergonomic experiment. The reading desk lamp evaluation method comprises the steps of performance evaluation of average illumination and correlated color temperature, comfort level evaluation of average illumination and correlated color temperature, illumination uniformity evaluation, reflected glare evaluation, direct glare evaluation and color rendering property evaluation; an evaluation system is formed by outputs of respective evaluation scores of the six aspects and the weighted average of the evaluation scores; the establishment of performance evaluation of average illumination and correlated color temperature is based on a visual performance experiment; the establishment of comfort level evaluation of average illumination and correlated color temperature is based on a Christopher illumination-color temperature comfort curve; the establishment of illumination uniformity evaluation is based on a national standard; the establishment of reflected glare evaluation is based on a veiling reflected glare reception evaluation experiment; the establishment of direct glare evaluation is based on a national standard; and the establishment of color rendering property evaluation is based on quality factor (QF) indexes in a color quality grade drafted by American national standard institute. By adopting the reading desk lamp evaluation method, the relation between physical parameters and vision quality is established, a quality evaluation result can be output only by measuring the physical parameters of the reading desk lamp, the assessment routine is simplified, and the objectivity and the accuracy are higher.

The invention relates to a reversible video frequency watermark method based on interframe forecast error histogram modification, comprising watermark embedding and watermark detection. The watermarkembedding process is carried out according to a video frequency negative sequence: firstly, utilizing the previous frame to carry out motion estimation to obtain an interframe forecast error, and thencarrying out the histogram modification on the interframe forecast error so as to embed a watermark. An extracting process is carried out according to a video frequency sequence mode: similarly, utilizing the previous frame to carry out the motion estimation to obtain a forecast error, and then extracting a watermark from the forecast error, and modifying a histogram to carry out the frame imagerecovery. The invention uses the mode of negative sequence embedding and sequence extracting, thereby an embedded video frequency frame can be recovered after the watermark is extracted, and the reversibility of the video frequency watermark is realized; the motion estimation is used according to the content relation of adjacent interframes to carry out prediction so as to enable the forecast error histogram to have the height centrality, and realize the bigger embedding content; in the embedding process, using the histogram modification enables that the influence on the frame image is small,and a watermark-embedded video frequency has high visual quality.

A binocular vision apparatus allows a patient to view objects through the apparatus with polychromatic light and monochromatic aberration correction, such that the chromatic aberration of the eye can be combined with the monochromatic aberration correction, so as to provide a more accurate determination of vision quality. The binocular vision apparatus provides left and right viewing optics that can substantially maintain the line of sight of each eye, such that objects can be viewed in a room with 3D depth perception corresponding to the distance of the object from the patient. As both near and far objects can be viewed with binocular aberration correction, the patient can alternate binocular viewing between near and far vision with chromatic aberration so as to evaluate a proposed treatment such as a presbyopia correction.

The invention relates to a drug sustained-release microsphere capable of being embedded in intraocular lens loop and a preparation method of the drug sustained-release microsphere. The drug sustained-release microsphere prepared by the provided method can be used for effectively preventing and treating microorganism infection and antagonistic inflammatory reaction after a cataract surgery, reducing the occurrence rate of intraocular inflammation infection after the cataract surgery, and preventing and inhibiting after-cataract, so as to improve visual quality after the surgery. The technical scheme is that according to the drug sustained-release microsphere capable of being embedded in the intraocular lens loop, the drug sustained-release microsphere is formed by mixing drugs and a carrier at the ratio of 1 to (10000-1), and the drug sustained-release microsphere is 100-800mm in diameter. The preparation method of the drug sustained-release microsphere capable of being embedded in the intraocular lens loop sequentially comprises the following steps: (1) mixing the drugs and the carrier according to the ratio and stirring to obtain mixed liquid; (2) condensing fog-like materials in a collecting room to obtain microspheres; and (3) collecting the microspheres and screening the microspheres by virtue of a screen to obtain the microspheres with required diameters; disinfecting, sealing and packaging the microspheres.

A real-time low frame-rate video compression system and method that allows the user to perform face-to-face communication through an extremely low bandwidth network. The system and method employs image cropping and morphing to reduce frame rates. At the encoder side, the system is able to automatically select only a few good faces from the original sequence with high visual quality and compress and transmit them. At the decoder side, the system use image-morphing based rendering method to generate a normal frame-rate video. Experimental results show that the system is superior to more traditional video codecs for low bit-rate face-to-face communication.