Abstract: A projector employing a linear array of light-emitting sources forms a super pixel in the form of a plurality of beams that are focused onto scanning optics that cause the beams to move across a viewing surface on a first axis for defining image lines along the first axis and on a second axis such that super pixel overwrites every addressable spot on the viewing surface thereby producing interleaved and staggered scan patterns that hide the effect of burned out, misdirected, or marginally operating light-emitting sources that would otherwise result in a degraded projected image. An alignment system that includes alignment electronics that is responsive to a charge-coupled device facilitate adjusting the scanning optics to allow precise alignment of individual ones of the light-emitting sources and to detect burnt out individual ones of the light-emitting sources.

Abstract: An image system includes a beam generator and a screen having a region with an adjustable brightness. The beam generator directs first and second electromagnetic beams onto the region. The first beam changes the brightness of the region according to a first polarity and the second beam changes the brightness of the region according to a second polarity. Such an imaging system can generate a video frame on a projection screen such that each pixel of the frame is “on” for the same or approximately the same amount of time as each of the other pixels. This technique prevents portions of the image from appearing visibly dimmer than other portions. It also allows the persistence of the screen regions to be relatively long, e.g., longer than the frame rate, and thus allows the screen to display/project relatively high-quality video frames.

Abstract: An optical image system includes an image projector and an image generator. The image projector has regions with adjustable brightness levels. The image generator generates an image received from a remote location on the image projector by directing first and second electromagnetic beams onto the regions of the image projector. The first beam changes the brightness levels of the regions in a direction, and the second beam generates the image by changing the brightness levels of predetermined ones of the regions in an opposite direction. Such an image system can capture, transmit, and display an image using an optical signal without converting the optical signal into an electrical signal and back again. Thus, the image system often provides a higher-quality image than conventional electro/optical image systems.

Abstract: An inexpensive projection lens unit in a rear projection type image display system, having a short focal distance (wide angle of viewing field), high focus and high contrast, and as well, including a power lens made of a glass material having a high refractive index in a range from 1.63 to 1.70 and an Abbe's number of not less than 50 with an optimized incident and emergent configuration in order to satisfactorily correct aberration with a enhanced focusing performance even with a shortened focal distance. Further, the power lens having a high refractive index can exhibit a high power, and accordingly, can carry out satisfactory aberration correction by optimizing the aspheric degree of a plastic lens even though the length of back focus is increased for enhancing the contrast.

Abstract: A registration correction apparatus having interpolation circuits. The interpolation circuits receives digital sampled pixel signals from at least one channel of a plurality of color signal channels. The digital sampled pixel signals have been obtained by sampling consecutive pixel signals. Each of the interpolation circuits generates a digital pixel signal in a desired position between adjacent two of the digital sampled pixel signals by interpolation processing. The desired position between the two adjacent digital sampled pixel signals is set in accordance with a registration discrepancy among the plurality of color signal channels by a control circuit.

Abstract: A projector employing a linear array of light-emitting sources forms a super pixel in the form of a plurality of beams that are focused onto scanning optics that cause the beams to move across a viewing surface on a first axis for defining image lines along the first axis and on a second axis such that super pixel overwrites every addressable spot on the viewing surface thereby producing interleaved and staggered scan patterns that hide the effect of burned out, misdirected, or marginally operating light-emitting sources that would otherwise result in a degraded projected image. An alignment system that includes alignment electronics that is responsive to a charge-coupled device facilitate adjusting the scanning optics to allow precise alignment of individual ones of the light-emitting sources and to detect burnt out individual ones of the light-emitting sources.

Abstract: An image distortion correcting apparatus is provided tat is capable of correcting keystone distortion and pincushion distortion in a video display device. The apparatus may include a reference image generating device for generating a reference image and setting a coordinate of the reference image. A displacement measuring device may display the reference image on a screen and measure a coordinate of the displayed image. A distortion information extracting device may extract distortion information on the basis of a coordinate value of the set reference image and a coordinate value of the measured image and generating inverse-distortion information. Still further, a distortion correcting device may generate an inverse-distorted (pre-warping) image of the reference image on the basis of the generated inverse-distortion information.

Abstract: Laser projection system suitable for commercial motion picture theaters and other large screen venues, including home theater, uses optical fibers to project modulated laser beams for simultaneously raster scanning multiple lines on screen. Emitting ends of optical fibers are arranged in an array such that red, green and blue spots are simultaneously scanned onto the screen in multiple lines spaced one or more scan lines apart. Use of optical fibers enables scanning of small, high resolution spots on screen, and permits convenient packaging and replacement, upgrading or modification of system components. Simultaneous raster scanning of multiple lines enables higher resolution, brightness, and frame rates with available economical components. Fiber-based beam coupling may be used to greatly enhance the flexibility of the system.

Abstract: A technique and system for detecting a radiometric variation/artifacts of a front-projected dynamic display region under observation by at least one camera. The display is comprised of one or more images projected from one or more of a plurality of projectors; the system is preferably calibrated by using a projective relationship. A predicted image of the display region by the camera is constructed using frame-buffer information from each projector contributing to the display, which has been geometrically transformed for the camera and its relative image intensity adjusted. A detectable difference between a predicted image and the display region under observation causes corrective adjustment of the image being projected from at least one projector.

Abstract: A technique, and associated system and computer executable program code on a computer readable storage medium, for automatically correcting distortion of a front-projected display under observation by at least one camera. The technique may be employed in a myriad of front-projected display environments, e.g., single or multiple projectors and cameras are used.

Abstract: The present invention provides a monitor system for a projection apparatus which system is suitable for detecting errors in a display on a projection screen. A projection apparatus 100 comprises a projection section 120 that projects an image on a screen 110, an image pickup element 130 into which the actual projected image projected by the projection section 120 is loaded, an error detection section 140 that detects errors in the projection section 120 on the basis of the actual projected image loaded into the image pickup element 130, and a notification section 150 that carries out a predetermined notification when the error detection section 140 detects an error. The error detection section 140 detects errors in the projection section 120 on the basis of an original projected image to be projected by the projection section 120 and an actual projected image loaded into the image pickup element 130.

Abstract: To provide an image processing system and the like which can correct image distortions and provide properly overlapped images when a plurality of projectors are used to project overlapped images, a projector includes: an image projection section projecting an image based on image signals to display the image in a manner to overlap another image projected from another projector at a projection target area; sensing section sensing an image and generating sensing information; overlap-area detecting section detecting projection areas for the projection target area, and detecting an overlap area at which the projection areas overlap, based on the sensing information; correction information generating section generating correction information indicating information for positions of the projection areas and a position of the overlap area; and projection area correction section correcting image signals, based on the correction information, to project an image onto a region corresponding to the overlap area.

Abstract: A projector includes a resin-made lamp case in which a light source lamp is fitted and a metal-made optical part holder in which an optical part is fitted. Preferably, the lamp case includes a positioning boss, the optical part holder includes a resin-made lamp case holder which accommodates the lamp case, a tubular light tunnel which shapes a form of light, a cylindrically shaped portion having a guide hole into which the positioning boss is inserted, and a resiliently deformable detent member, a metal-made light-tunnel fixing member, the detent member is substantially U-shaped and is provided integrally on the light-tunnel fixing member, the cylindrically shaped portion has a slot portion into which the detent member is inserted and which extends from an outer peripheral surface to the guide hole, and the positioning boss has a concave engaging portion which is engaged with the detent member.

Abstract: A projector includes a housing, an image module for projecting onto a screen toward a front side, a detecting module for detecting distances from the projector to the front side and from the projector to the back side, a processor for adjusting luminance of the projected image from the image module based on the distances from the projector to the front side and from the projector to the back side.

Abstract: An image projection apparatus is disclosed with which problems, caused by performing focusing control in a state in which the light amount of a light source is insufficient, can be avoided. The image projection apparatus comprises a controller, performing focusing control of a projection optical system, and a brightness detector which detects at least one of a brightness of the light source and a brightness of a reflected light on a projection surface. After turning the light source on, the controller restricts the focusing control until the brightness detected by the brightness detector reaches a predetermined value.

Abstract: A technique, associated system and computer executable program code, for projecting a superimposed image onto a target display surface under observation of one or more cameras. A projective relationship between each projector being used and the target display surface is determined using a suitable calibration technique. A component image for each projector is then estimated using the information from the calibration, and represented in the frequency domain. Each component image is estimated by: Using the projective relationship, determine a set of sub-sampled, regionally shifted images, represented in the frequency domain; each component image is then composed of a respective set of the sub-sampled, regionally shifted images. In an optimization step, the difference between a sum of the component images and a frequency domain representation of a target image is minimized to produce a second, or subsequent, component image for each projector.

Abstract: In measuring the angle of inclination of a liquid crystal projector with respect to the screen for automatically adjusting a trapezoidal distortion, the calculation of the angle of inclination by determining the distance from the screen using a distance sensor conventionally requires a high distance measurement accuracy and hence an expensive distance sensor. According to the invention, a distance sensor is rotated and the level of the wave reflected from it is observed. The angle of inclination with respect to the screen is detected from the rotational angle associated with the maximum value of the level of the reflected wave thereby to correct the trapezoidal distortion. In this way, the trapezoidal distortion can be adjusted automatically using an inexpensive distance sensor.

Abstract: A projection optical system is disclosed with which undistorted images can be obtained at any image position within a specification range, and whose projection angle can be changed. The projection optical system includes a plurality of optical elements and a first optical system constituted by at least one of the plurality of optical elements having the ability to form an image with light onto a predetermined surface different from the projection surface. A projection image of the original image can be moved by rotating a first optical element of the plurality of optical elements substantially around a center of an exit pupil position of the first optical system as the rotation center.

Abstract: A method of monitoring an illumination source including a reflector and a lamp. A reference orientation is defined where the reflector and a light producing luminary of the lamp are aligned to optimize light intensity reflected from the luminary to a desired target. The orientation of the lamp is monitored, and changes from the reference orientation are reported as an indication of a reduction in light intensity reflected from the luminary toward the desired target.

Abstract: A graphics system comprises pixel calculation units and a sample buffer which stores a two-dimensional field of samples. Each pixel calculation unit selects positions in the two-dimensional field at which pixel values (e.g. red, green, blue) are computed. The pixel computation positions are selected to compensate for image distortions introduced by a display device and/or display surface. Non-uniformities in a viewer's perceived intensity distribution from a display surface (e.g. hot spots, overlap brightness) are corrected by appropriately scaling pixel values prior to transmission to display devices. Two or more sets of pixel calculation units driving two or more display devices adjust their respective pixel computation centers to align the edges of two or more displayed images. Physical barriers prevent light spillage at the interface between any two of the display images. Separate pixel computation positions may be used for distinct colors to compensate for color distortions.

Abstract: A projection apparatus comprising a projection section for projecting an image corresponding to an input image signal, a distance measuring section for measuring each distance of several positions on an image projection plane made by the projection section, a focus control section for making keystone correction on an image projected by the projection section so that a projection image is formed into a rectangular shape having a proper aspect ratio based on each distance obtained by the distance measuring section while controlling a focus position of the image projected by the projection section, and a control section for instructing to carry out processing by the focus control section.

Abstract: A beam projector is aligned with a linear array of receptors. An alignment receptor is at each end of the linear array of receptors. A beam is projected from the projector. The beam is swept until the alignment receptors sense the beam. A signal is transmitted upon each of the alignment receptors sensing the beam. The position of the beam projector is recorded in response to the transmitted signals. The alignment position of the beam projector, to align with the linear array of receptors, is computed from the recorded positions. The beam projector is aligned with the linear array of receptors according to the alignment position.

Abstract: Convergence control apparatus of a projection television has: a pattern generator for generating a reference pattern; optical sensors for sensing the change of luminance of the reference pattern moving on a screen; and a convergence controller for compensating for the tilt of the reference pattern based on the output of the optical sensors. The optical sensors are respectively disposed at opposite sides on the screen. The convergence controller detects the angular error of the reference pattern distorted by earth's magnetic field, based on the difference between a standard position and a measured position of a maximum luminance of the reference pattern, and controls a deflection circuit to compensate for the angular error. When the image displayed on the screen is tilted by the influence of the earth's magnetic field, the tilt of the picture can be compensated. After completing the compensation for the angular error, a positional error of CRTs for R, G, and B colors is also compensated.

Abstract: A rear projection display device includes an image generator, a reflector, a screen and a light shield disposed between the reflector and the screen. The image engine emits image beams among which ineffective ones are blocked by the light shield while effective ones are reflected on the screen via the reflector, thereby increasing the image forming performance of the displace device. The light shield is mounted on an adjusting device having an adjusting element. After the rear projection display device has been assembled, an angle and position of the light shield can be adjusted by means of rotating the adjusting element to further help the light shield to block the ineffective beams.

Abstract: With respect to a display device having a high-resolution display panel, It makes possible to prevent to deteriorate the display quality by a dot defect. A display panel having a dot defect is identified and coordinates of the defective pixel are determined. The brightnesses of pixels adjacent to the defective pixel and/or the brightnesses of pixels of other display panels having the corresponding coordinates as the dot defect are increased to reduce the apparent perceptibility of the dot defect.

Abstract: Disclosed is a projection image display apparatus, specified in a convergence adjusting apparatus employing a spline interpolation scheme.

Abstract: An attitude of a measurement reference surface of a positioning master is adjusted using an auto-collimator, the positioning master being disposed so that the adjusted measurement reference surface is located on a designed position, and the light beam irradiated from the measurement reference surface is detected by a CCD camera to set the reference position. A calibrated position relative to the designed position is set based on average optical characteristics obtained by a projection lens inspection apparatus as an initializing process and the CCD camera is moved to the calibrated position. An optical device is mounted and a position of a liquid crystal panel is adjusted while detecting the light beam irradiated from the light-irradiating surface of a cross dichroic prism of the optical device by the CCD camera and the liquid crystal panel is fixed with ultraviolet curing adhesive.

Abstract: A method is provided to smooth photometric variations across multi-projector displays. Photometric calibration is performed to generate a luminance attenuation map (LAM) for each projector. An image for each projector is modified using the luminance attenuation map (LAM) for each projector to provide image correction in real time. In the photometric calibration step a digital camera is used to measure the color response of the multi-projector display. Using the generated luminance attenuation map (LAM) for each projector for image correction in real time smoothes out distracting color variations across the multi-projector display while maximizing a perceived dynamic range of the display.

Abstract: In a color display device, apparatus and method are provided to produce a convergence correction signal based on digital convergence correction values. The data rate by which the data is supplied to the apparatus varies, depending on the area of the display corresponding to the digital convergence correction values being supplied.

Abstract: A projection display comprises three cathode ray tubes each having a deflection yoke and convergence yoke and each tube generating a raster for projection. One of the three cathode ray tubes has the convergence yoke coupled for current flow in a direction opposite to that of the other two convergence yokes. An amplifier is respectively coupled to each convergence yoke for convergence correction of each raster. A convergence circuit supplies correction signal values that are coupled to each respective amplifier such that convergence correction by the other two convergence yokes is responsive to a difference between the correction signal value coupled to the one convergence yoke and the correction signal values coupled to the other two convergence yokes.

Abstract: An analog-to-digital converting apparatus for rapidly processing a plurality of analog input signals at a high rate and a display device using the same. The apparatus includes a clock signal generator that generates a clock signal with a predetermined frequency; a control signal generator that generates a switching control signal using the clock signal; a multiplexer (MUX) that receives and selectively outputs signals of the plurality of analog input signals according to the switching control signal; and an analog-to-digital converter (ADC) that converts an analog signal selected and output by the MUX to a digital signal.

Abstract: To provide an image processing system and the like which can perform an image distortion correction and focus adjustment approximately at the same time without changing a projecting position intended by a user, a projector includes: a distortion correcting section which corrects image signals to adjust the distortion in an image; an image projection section which includes a lens unit having a focus adjustment function, the lens unit projecting an image based on the corrected image signals; a control section and a focus lens driving section which control the driving of the lens unit so that the focal length of the lens unit to an image projection area changes; a sensing section which senses the projected image; and a distortion correction amount deriving section which derives the focal length to the center of the image projection area and also an amount of distortion correction for the distortion correcting section, based on sensing information.

Abstract: A focus control apparatus for a display is provided. The focus control apparatus adjusts the focus of a lens through a simple manipulation of an adjusting knob which adjusts a position of a connection tube connecting an image engine and a lens of the apparatus. The focus control apparatus adjusts the focus of the lens by the backward and forward movement of the connection tube, thereby simplifying the structure of the apparatus, improving productivity, and reducing the production cost.

Abstract: A system determines correspondence between locations on a display surface and pixels in an output image of a projector. The display surface can have an arbitrary shape and pose. Locations of known coordinates are identified on the display surface. Each location is optically coupled to a photo sensor by an optical fiber installed in a throughhole in the surface. Known calibration patterns are projected, while sensing directly an intensity of light at each location for each calibration pattern. The intensities are used to determine correspondences between the locations and pixels in an output image of the projector so that projected images can be warped to conform to the display surface.

Abstract: A method and system that objectively measures the convergence and focus of a 2 or 3 spatial light modulator (SLM) projection display. The system uses five (5) CCD cameras and a frame grabber to store red, green, and blue (R-G-B) data from selected pixels located in the corners and center of the projector's field-of-view. The horizontal and vertical locations for the R-G-B pixels at each of the five locations is determined and the delta (?) displacement of the green and blue pixels, relative to the reference red pixel, is calculated and used to converge the image. The optical focus of the system is also determined using a Fast Fourier Transform (FFT). The FFT is performed on this same data and a power spectrum summation beyond the first mimima is determined. The focus is then adjusted to maximize this value.

Abstract: A video projector including a network adapter, a microprocessor physically and electrically coupled to the network adapter, a graphics adapter physically and electrically coupled to the microprocessor, a light valve physically and electrically coupled to the graphics adapter, and a light source physically coupled to the light valve. The video projector is operable to receive video data in digital form and the network adapter and the video projector is operable to transfer the video data to the microprocessor, the graphics adapter, and the light valve in digital form.

Abstract: A projection type image display device includes a plurality of image display elements that perform modulation of light rays in accordance with an image signal, a color synthesizing optical element for synthesizing light rays having mutually different wavelength ranges that have been modulated by these image display elements by use of a dichroic membrane, lens groups having a positive refractive power as a whole that are disposed between the image display element and the color synthesizing optical element, and a projection optical system for projecting an image synthesized by the color synthesizing optical element. The projection type image display device further includes a storage circuit for storing data used to correct the brightness irregularity of a projected image, and a brightness irregularity correcting circuit for correcting brightness irregularity of a projected image on the basis of the data stored in the storage circuit.

Abstract: A projection television and a convergence control method thereof are provided.

Abstract: The need is met according to the present invention by providing a method of correcting pixel by pixel variations in a display, the method including the steps of creating a defect map of pixel intensity offsets for the display; correcting an input signal according to the defect map; and displaying the corrected input signal on the display, wherein the offset defect map is created by modulating a pixel in the display at a predetermined rate at a predetermined intensity; sensing the display with a photosensor to generate a sensed signal; demodulating the signal with a synchronous demodulator at the predetermined rate to produce a demodulated signal representing a sensed intensity; and employing the sensed intensity and the predetermined intensity to generate a correction offset.

Abstract: A graphics system comprises pixel calculation units and a sample buffer which stores a two-dimensional field of samples. Each pixel calculation unit selects positions in the two-dimensional field at which pixel values (e.g. red, green, blue) are computed. The pixel computation positions are selected to compensate for image distortions introduced by a display device and/or display surface. Non-uniformities in a viewer's perceived intensity distribution from a display surface (e.g. hot spots, overlap brightness) are corrected by appropriately scaling pixel values prior to transmission to display devices. Two or more sets of pixel calculation units driving two or more display devices adjust their respective pixel computation centers to align the edges of two or more displayed images. Physical barriers prevent light spillage at the interface between any two of the display images. Separate pixel computation positions may be used for distinct colors to compensate for color distortions.

Abstract: A display apparatus includes first and second IR or other light sources that produce light at respective first and second non-visible wavelengths. The light is modulated according to a desired image. The modulated light is then applied to a wavelength selective phosphor that converts each component of the light to a respective visible wavelength. In one embodiment, the image source is a scanned light beam display that scans an IR light beam onto a screen that carries the phosphor.

Abstract: The method combines a plurality of images. The images each have associated meta-data comprising meta-data element(s) having merging attribute tag(s). The merging attribute describes an action to be taken with the corresponding meta-data element when the images are combined. The method first reads (104) the attribute(s) of the images to identify the action(s) and then combines the meta-data elements of the images in accordance with said action(s) In another embodiment, the method transforms an image.

Abstract: A multi channel video engine (10) for accepting, dividing, modifying and recombining light to project an image. A housing (12) encloses an optical assembly (28) having a dichroic mirror assembly (58) and a color cube (60). A plurality of LCD assemblies (30) accept light from the dichroic mirror assembly (58), modifies it, and reflects it to the color cube (60). A lens assembly (16) is affixed to a bulkhead (24) of the housing (12) using a lens cradle (14) and lens retainer (18). An output prism (54) aligns light onto a second plane (70) to coincide with an optical axis (72) of the lens assembly (16).

Abstract: A graphics system comprises pixel calculation units and a sample buffer which stores a two-dimensional field of samples. Each pixel calculation unit selects positions in the two-dimensional field at which pixel values (e.g. red, green, blue) are computed. The pixel computation positions are selected to compensate for image distortions introduced by a display device and/or display surface. Non-uniformities in a viewer's perceived intensity distribution from a display surface (e.g. hot spots, overlap brightness) are corrected by appropriately scaling pixel values prior to transmission to display devices. Two or more sets of pixel calculation units driving two or more display devices adjust their respective pixel computation centers to align the edges of two or more displayed images. Physical barriers prevent light spillage at the interface between any two of the display images. Separate pixel computation positions may be used for distinct colors to compensate for color distortions.

Abstract: A lens assembly adapted to be connected to a CRT and affixed to mounting structure in a projection television cabinet. The lens assembly includes a tubular lens mount having a longitudinal axis and at least a first optical lens element mounted along the longitudinal axis. A tubular focus mount extends along the longitudinal axis and fastening and locking structure connects the lens mount to the focus mount after a focus mount position is obtained. A CRT coupler is formed integrally with the focus mount and includes structure for securing a CRT and for securing the coupler to the mounting structure within the television cabinet. A second optical lens element is mounted to the CRT coupler. A flexible bladder may be used to contain coolant fluid between the CRT and the coupler.

Abstract: A passive focus device including a support rod, an optical assembly translatably mounted on the support rod, and a sealed drive assembly containing a substance that physically changes in response to a temperature change, wherein the drive assembly is configured to move the optical assembly along the support rod based on a physical change of the substance.

Abstract: In an illumination optical system and a color combining optical system of a projection apparatus using three image display elements, the object of the present invention is to reduce misconvergence of enlarged images displayed on a screen. The present invention provides a projection apparatus including light-detecting elements provided outside of an effective screen display area. An active region of image display elements for each color beam is controlled respectively based on results of the light-detecting elements in order to adjust display position of each color beam on the screen.

Abstract: An adjusting apparatus comprises a base, and a supporting frame, a fixed plate, a sliding stand, and a carrier, which are sequential stacked on the base. An optical engine is fixed on the carrier. By rotating the adjusting device, the axis position of optical engine can be adjusted along sliding slots guided by bulges. By using arc surfaces of the sliding stand and the carrier, the adjusting apparatus clips and pushes the blocks of the carrier to adjust the left and right angle of inclination of optical engine. Therefore, the light beam provided by optical engine could project on a screen precisely and reach the optimum projection performance.

Abstract: A high throughput, compact image display apparatus comprises a source unit to generate a spatially uniform light beam that propagates along a first beam path in a first direction. The image display apparatus also comprises an imaging unit to collect and focus the light beam. The imaging unit includes a first refractive optical element disposed in the first beam path, a second refractive optical element disposed in the first beam path, a first reflecting mirror disposed in the first beam path, and a second reflecting mirror, having a concave reflecting surface, disposed in a second beam path defined by the first reflecting mirror and the second reflecting mirror. The second beam path is oriented in a second direction different from the first direction. The image display apparatus also comprises a digital micromirror device (“DMD”) to receive the light beam reflected by the second reflecting mirror. The DMD is disposed in a third beam path defined by the second reflecting mirror and the DMD.

Abstract: An apparatus and a method for correcting a distorted image is capable of correcting an optical distortion of an image and misconvergence by prewarping an inputted image without using a convergence yoke, and an image displayer using the same. The apparatus for correcting an image distortion for an image displayer in which an image signal is inputted to display an image on a screen and an image distortion is corrected, includes: a reference image generator for generating a predetermined reference image; a camera for inputting the reference image and photographing an image outputted on the screen; and a distortion information extracting unit for comparing the photographed image outputted from the camera and the reference image outputted from the reference image generator, and generating distortion correction information to correct a distortion of the photographed image in case that the image has been distorted.