121 results about "Luminance meter" patented technology

The invention discloses a marine radiance meter immersion factor measurement method, which belongs to the technical field of radiation value measurement, and comprises the following steps: controlling a stable halogen tungsten lamp to irradiate towards a calibration container below the calibration container, the bottom of the calibration container is a diffuse transmission plate to generate a uniform light field, and the calibration container is filled with ultrapure water; the method comprises the following steps: firstly, measuring the radiance value of the optical window of the radiance meter just immersed under the water surface, then discharging ultrapure water in a calibration container in sequence, and obtaining the radiance value when the distance between the optical window of the radiance meter and the water surface is zi; performing water attenuation correction on a measured value in the air of the radiance meter, and extrapolating to calculate radiance when zi is equal to 0; the refractive index of the water body is calculated, and the immersion factor of the to-be-measured radiometer is calculated. According to the marine radiance meter immersion factor measuring device, the problem that in theoretical calculation, only the radiance meter optical window refractive index is considered, and different radiance meter light path design influences are ignored, so that the deviation between a theoretical calculation result and an actual value is large is solved.

The invention relates to the technical field of intelligent control, and discloses an ultra-low power consumption miniature LED visible light intensity self-adaptive regulation and control method and system, and the method comprises the steps: obtaining an analog light intensity signal, and carrying out the smoothing processing of the analog light intensity signal, and obtaining an environment light intensity value; calculating a light intensity change rate, and if the light intensity change rate exceeds a dynamic threshold value, marking an environment state and outputting a light intensity difference value; generating a preliminary adjustment instruction according to the state matching control parameter and the difference value quantization mapping, and calculating target light intensity in combination with the basic brightness; after executing the instruction, calculating actual and target deviation, and iteratively correcting to obtain a light intensity control signal; if the power consumption exceeds the limit, optimizing the signal amplitude; the input driving circuit analyzes the synthesized pulse current, excites pixels to emit light and gathers to obtain adjustment data; and if the visual contrast is lower than a threshold value, the change rate is adjusted again to realize closed-loop refining, and the light intensity adjustment accuracy is improved. The method can improve the real-time sensing capability of ambient light.

The invention relates to the technical field of automobile testing, and discloses a method and system for evaluating and testing visual field glare of a driver in a cabin, and the method comprises the following steps: starting from the position of the eyes of the driver, capturing a brightness distribution image of the whole visual field, and dividing the image into a plurality of sub light source regions around a glare source; dividing the visual field into a main sight area and a residual light sight area according to the attention distribution of the driver, and endowing sub light source areas falling into different areas with different weight values; calculating a unified glare index according to the weighted sum of the glare intensity of each sub light source area and the background brightness in the cabin; and finally, comparing the index with a preset threshold value, and outputting an evaluation result. According to the method, the large-area light source is divided into the sub-light sources, weighted calculation is carried out in combination with the attention of the driver, the problem that a traditional glare evaluation model is not suitable for a close-range non-point light source scene of the automobile cabin is solved, a scientific evaluation system matched with the automobile cabin is established, and the glare evaluation result is more accurate.

An unevenness measuring device for a sheet-shaped material, the device including: a light irradiation unit configured to irradiate a measurement target with illumination light such that the illumination light is partially blocked at the measurement target; a time-delay integration type imaging unit arranged to face the light irradiation unit and configured to receive the illumination light that is irradiated from the light irradiation unit and that is not blocked at the measurement target; a luminance-profile calculation unit configured to calculate a luminance profile in a main-scanning direction from a captured image generated by the imaging unit; an unevenness determination unit configured to determine, based on the luminance profile, whether the sheet-shaped material has a recessed portion and / or a projecting portion; and an unevenness calculation unit configured to estimate, based on the luminance profile, a depth of the recessed portion and / or a height of the projecting portion.

A video recording control device includes an imaging data obtaining unit that obtains imaging data; a luminance calculating unit that divides the imaging data into regions and calculates luminance for each divided region; a light source region setting unit that sets, as light source regions, the regions for which the luminance calculated by the luminance calculating unit is equal to or higher than a luminance threshold value; a luminance adjusting unit that adjusts the luminance of the light source regions either to the average value of luminance of other regions excluding the light source regions or to a predetermined value, and obtains post-adjustment data; and a recording control unit that records, in a recording unit, the imaging data along with the post-adjustment data having the luminance adjusted by the luminance adjusting unit.

The invention discloses a self-adaptive enhancement method for a non-uniform illumination image, and the method comprises the steps: firstly, calculating a Y channel of an input image in an RGB color space in a YUV color space, and carrying out the low-pass filtering of the Y channel, and enabling the Y channel to serve as an initial brightness channel; secondly, according to the local brightness of the image, a pixel-level threshold value is calculated and used for judging the exposure degree of each pixel; then, taking the threshold value as a center, and adaptively adjusting local brightness through a symmetrical brightness remapping function, so as to eliminate the problems of overexposure and insufficiency; and finally, combining the adjusted brightness channel with the original image, reconstructing an RGB channel of the color image, and optimizing the local contrast to obtain an enhancement result. The adaptive enhancement method of the invention can obtain an effective enhancement result for an image with complex illumination change, especially an image with small-area extreme illumination.

A luminance compensation method of a display device includes a first luminance for a reference grayscale at a first operating frequency and a second luminance for the reference grayscale at a second operating frequency are measured. A first reference value is calculated based on the first luminance and the second luminance, a first duty ratio of the initialization control signal is changed into a second duty ratio depending on a comparison result of the first reference value and a threshold value After the first duty ratio is changed into the second duty ratio, a third luminance for the reference grayscale is measured, and a second reference value is calculated based on the first luminance and the third luminance. A final duty ratio corresponding to the threshold value is calculated depending on a comparison result of the second reference value and the threshold value.

A device performs ambient light sensing using an image sensor. The device includes an image sensor and a receiver configured to receive image data from the image sensor. The device also includes a luminance calculator configured to calculate a code corresponding to the luminance value of the image data based on the image data. The device further includes an image sensor controller configured to change the setup condition of the image sensor in response to the code having a minimum value or a maximum value, among values capable of being assumed by the code. The device additionally includes a brightness measurer configured to output a brightness value in the vicinity of the image sensor, which is identified using the changed setup condition and the code.

The application relates to a face brightness calculation method, device, medium and equipment, the method comprises the following steps: acquiring a first region of interest in an image, the first region of interest comprising a face; determining a target brightness difference value between a central region and an edge region of the first region of interest; adjusting the size of the first region of interest according to the target brightness difference value to obtain a second region of interest; and determining the brightness of the second region of interest as the face brightness of the image. The brightness difference value between the edge region and the central region of the region of interest is calculated, the size of the region of interest is adjusted through the brightness difference value, the size of the face region is converged to an ideal size, the face brightness is calculated, the accuracy of face brightness statistics is improved, different shooting scenes are adapted to, and a good portrait shooting effect is realized.

The utility model discloses an LED lamp detection device which comprises a detection table, the top of the detection table is fixedly connected with a detection box, the top of the detection box is covered with a fixing cover, the top of the fixing cover is connected with a brightness meter in a penetrating mode, the bottom of the fixing cover is fixedly connected with a hanging bracket, the hanging bracket is fixedly connected with an LED installation base, and the LED installation base is fixedly connected with a light source. The beneficial effects of the utility model are that the LED lamp to be detected is firstly installed on the LED installation seat, then the lifting mechanism drives the fixed cover to close the detection box, the LED lamp on the LED installation seat extends into the detection box to carry out darkroom detection, then the LED installation seat is controlled to be electrified, and the LED lamp can be conveniently and rapidly detected. During illumination, the brightness meter can detect the brightness, the heat dissipation mechanism can dissipate heat generated by the LED lamp in the detection process, the structure is reasonable, the brightness of the darkroom can be conveniently detected, and operation is convenient.

A vehicle drawing device draws a figure on a road surface with a light. When a luminance of the figure is assumed as a road surface drawing luminance, and a luminance in a surrounding environment of a driving vehicle is assumed as a background luminance, the light is irradiated such that a luminance contrast calculated by the road surface drawing luminance and the background luminance is 0.2 or more, and an angle formed by an inclination direction at a tip end of the figure with respect to a light irradiation direction is less than 120 degrees.

The application provides an image brightness adjusting method, a light adjusting device and an endoscope. The image brightness adjusting method is applied to the light adjusting device of the endoscope. The light adjusting device comprises a CMOS exposure time adjusting interval, a light source brightness adjusting interval and a CMOS gain adjusting interval. The image brightness adjusting method comprises the following steps: acquiring the average brightness of a current frame image and a preset target brightness; judging the current adjusting interval; calculating the adjusting proportion coefficient of the current adjusting interval according to the average brightness of the current frame image and the target brightness; and adjusting the image brightness in the current adjusting interval according to the adjusting proportion coefficient. Compared with the prior art, the application realizes dynamic adjustment of the image brightness by setting the adjusting proportion coefficient, widens the adjusting range, and improves the image quality as much as possible under the premise of achieving the same target brightness.

The invention provides a novel target and background contrast ratio measuring method, and belongs to the field of precise instrument manufacturing. When an image gray value is used for measuring the contrast ratio of a target and a background, imaging parameters of a detector and parameters of an optical system need to be calibrated, so that brightness information of the target and the background is truly reflected. The method comprises the following steps: respectively carrying out contrast measurement calibration on standard target plates with different contrast values under different illuminations by using a brightness meter, measuring the contrast values of the standard target plates by using an image gray value, fitting the contrast measured by the image gray value with the contrast measured by the brightness value in software by using a mathematical fitting algorithm, and calculating the contrast value of the standard target plates. The purpose of measuring the target background contrast value by using the image gray value is achieved. And establishing relational mapping between brightness and a gray value, defining a rule of a sampling sample, selecting a target and a background, and finally calculating a contrast ratio between the target and the background.

The utility model discloses a spectrum correction type imaging chrominance meter, which is used for improving the test precision and shortening the test time. The color and brightness meter comprises a lens, a color and brightness meter main body and a shaping lens group, the lens is connected to the color and brightness meter main body, and the lens is used for transmitting a light beam into the color and brightness meter main body; a wheel rotating disc and a built-in spectrograph are arranged in the chrominance meter main body, an optical fiber is arranged on the chrominance meter main body, the optical fiber is connected with the built-in spectrograph, a reflecting prism is arranged on the wheel rotating disc, and the wheel rotating disc is controlled to rotate so that the reflecting prism can be arranged at the position corresponding to the lens. The reflecting prism is used for reflecting the light beam; the shaping lens group is arranged on a light path of the light beam path and used for converging the light beams into parallel light beams, and the parallel light beams irradiate the end face of the optical fiber.

A method, system, terminal device, and storage medium for image metering and exposure processing, comprising: obtaining image information output by an endoscope's image sensor to obtain an original image corresponding to the current frame; partitioning the original image to obtain multiple sub-images; performing brightness calculations on the sub-images to obtain first brightness data corresponding to each sub-image; calculating third brightness data of the original image based on the first brightness data; and determining whether the third brightness data satisfies a preset brightness range. This application performs partitioning and brightness calculations on each frame of the original image to obtain third brightness data for evaluating the current brightness of the original image. Based on a comparison of the third brightness data with the preset brightness range, real-time adjustments are made to the image for reflections, excessive darkness, or excessive brightness, so that the details of the image captured by the endoscope are well presented, solving the problem of underexposure or overexposure.

The present application discloses a method, device and storage medium for screen brightness correction extraction, which is used to improve the accuracy of pixel brightness extraction. An image of a standard light source is collected by a sampling camera to generate a light source captured image; the screen is lit using the lit image, and an image is collected by the sampling camera to generate a screen captured image; the light source captured image and the screen captured image are subjected to region segmentation; a luminance meter is used to detect the luminance of the segmented regions on the light source captured image and the screen captured image; the grayscale mean data of the segmented regions on the light source captured image and the screen captured image is calculated; a correction coefficient is generated according to the luminance data and the grayscale mean data of the segmented regions; the screen captured image is corrected using the correction coefficient; pixel position correction is performed on the screen captured image after grayscale correction; pixel brightness information extraction is performed on the screen captured image after position correction is completed to generate a brightness extraction result image.

The present disclosure relates to a technology for measuring luminance to control tunnel lighting, wherein an area ratio of luminance-calculated areas included in a tunnel entrance image is corrected on the basis of an installation position of an optical device, and a reference position luminance value for controlling tunnel lighting is calculated by reflecting a correction coefficient set on the basis of the installation position, surrounding environmental factors, and the like, in luminance measurement values of the corrected luminance-calculated areas.

The utility model relates to a horizontal visual angle measuring device for a display, and the device comprises a workbench which is used for placing the display; the adjusting assembly comprises a connecting arm, an adjusting rod and a clamping piece, the adjusting rod and the clamping piece are vertically installed on the connecting arm, the connecting arm can drive the adjusting rod and the clamping piece to rotate in the horizontal direction under the action of external force, the brightness meter is driven to rotate, and the adjusting rod can move in the height direction relative to the connecting arm under the action of the external force; the measuring assembly comprises a mounting base mounted above the connecting arm, a protractor and an indicating piece, the protractor can rotate relative to the indicating piece along with the connecting arm so as to show the rotating angle of the connecting arm, and the measuring device is simple and compact in structure, small in occupied space and capable of being suitable for displays of different models and sizes; and the protractor can rotate relative to the indicating piece along with the connecting arm, so that a worker can conveniently indicate the scales on the protractor through the indicating piece to know the rotation angle of the brightness meter, and the measurement precision of the visual angle of the display in the horizontal direction is improved.

The utility model relates to the technical field of spectral radiometric calibration, and discloses a high-precision spectral radiometric calibration device. Comprising a machine shell and a base, the base is fixedly connected to the bottom of the machine shell, a conical reflecting cover is fixedly connected to the inner wall of the left side of the machine shell, a pipe body and a protective reflecting cylinder are fixedly connected to the side wall of the conical reflecting cover, the protective reflecting cylinder is arranged on the inner wall of the pipe body, and a plurality of optical fibers are arranged on the inner wall of the protective reflecting cylinder in a surrounding mode. The plurality of optical fibers are in close contact, and a gap is arranged between the tube body and the protective reflective cylinder. The light-emitting surface of the light source is attached to the inner wall of the conical reflecting cover, then the threaded rotating rod is rotated to rotate along the inner wall of the threaded ring so that the clamping plates can be pushed to be clamped on the side wall of the light source, the light source can be kept stable, follow-up calibration treatment is facilitated, the light source irradiates light beams to the ends of the optical fibers, and therefore the light source is more stable. The optical fiber can completely refract the light beam to the spectral radiance meter, and calibration processing can be carried out.

Embodiments of the present application disclose a method and device for calculating image brightness, electronic equipment and storage medium. The method comprises: performing face detection on a target image to determine a face rectangular region in the target image; determining a face region in the face rectangular region; calculating a proportion of the face region in the face rectangular region; determining an exposure weight table corresponding to the face rectangular region according to the proportion; and calculating the brightness of the face rectangular region based on the exposure weight table. The embodiments can improve the accuracy of image brightness calculation.

The present application relates to the technical field of projectors, and particularly relates to a method for adjusting the brightness of a projector, including: obtaining in real time the reflectivity distribution data of the surface of the projection area and calculating the local reflectivity gradient; non-uniformly partitioning the projection area according to the magnitude of the local reflectivity gradient; for each partition, calculating the compensation brightness based on the reflectivity distribution data and the target brightness; driving the projection light source to output according to the compensation brightness, and updating the reflectivity distribution data in real time. The present application has the effect of solving the problem of uneven brightness and darkness of the picture caused by changes in reflectivity.

This application provides a method and system for measuring the performance of a light source, which improves the convenience of measuring optical performance. The method includes: acquiring a first image; the first image is an image of the brightness detection area when a first attenuator and a first filter are placed directly in front of the lens; performing brightness analysis based on the first image to obtain a brightness calculation result; acquiring a second image, a third image, and a fourth image; the second image is an image of the chromaticity detection area when the first filter and the second attenuator are placed directly in front of the lens; the third image is an image of the chromaticity detection area when the second filter and the second attenuator are placed directly in front of the lens; the fourth image is an image of the chromaticity detection area when the third filter and the second attenuator are placed directly in front of the lens; performing chromaticity analysis based on the second image, the third image, and the fourth image to obtain a chromaticity calculation result; and combining the brightness calculation result and the chromaticity calculation result to obtain a light source performance measurement result.

The invention discloses a method for testing the brightness uniformity of a direct type backlight display screen. The method comprises the following steps of: shooting the brightness distribution of the whole surface of a display screen to be tested by using a brightness meter or a colorimeter to obtain a brightness distribution diagram; on the basis of the obtained brightness distribution diagram, on the basis of the original data, shrinking inwards by 1 / 4 to obtain an effective value range as shown in figure 3; identifying the minimum value and the maximum value of the brightness in the determined effective value range, and calculating the ratio of the minimum value and the maximum value to evaluate the brightness uniformity of the display screen; in the effective value range, dividing the brightness distribution diagram into a plurality of partitions according to the partition number, the arrangement mode and the screen resolution of the backlight source of the display screen, and calculating the length and the width of each partition; a plurality of vertical and horizontal sectioning lines are drawn according to the number and the arrangement mode of the partitions, as shown in figure 4, the brightness value of each point on the lines is measured, a brightness distribution curve is drawn, and then the characteristic parameters of the curve, namely the wave height, the half-wave width and the wavelength, are calculated so as to evaluate the severity of the lamp shadow effect. Compared with an existing uniformity testing method, the method has the advantages that the uniformity of the display screen can be directly revealed from the data level, and the defects of a mainstream testing method that errors are increased and testing objectivity is reduced due to the fact that the mainstream method cannot directly reflect the uniformity only through numerical values and depends on human eye observation and subjective judgment are effectively overcome. According to the method, the accuracy and reliability of the brightness uniformity test of the display screen are remarkably improved by reducing the intervention of human factors.

The invention relates to the field of video analysis, in particular to an intelligent video analysis method and system adaptive to environment change, and the method comprises the steps: obtaining a current frame image, and calculating a brightness mean value of the current frame image; calculating an illumination abrupt change factor based on the brightness; extracting feature point motion vectors between the current frame image and the previous frame image based on a Lucas-Kanade optical flow method to obtain a motion vector sequence; the average amplitude of high-frequency components with the frequency larger than a set threshold value in the motion vector sequence is obtained; obtaining a high-frequency vibration entropy based on the information entropy of the modulus length in the motion vector sequence and the average amplitude of the high-frequency component; combining the illumination abrupt change factor and the high-frequency vibration entropy to obtain a comprehensive environment complexity index; performing enhancement processing on the current frame image to obtain an enhanced image; inputting the enhanced image into a target detection model for detection; and giving out an early warning prompt in response to the existence of the detection target. The accuracy of the detection result is improved.

A duplex screen backlight optical detection device belongs to the technical field of backlight detection and comprises a detection table and a baffle fixed on the top surface of the detection table, a moving assembly is fixed on the inner side wall of the baffle, a mounting frame is fixed on the moving assembly, an imaging brightness meter is fixed on the mounting frame, and a plurality of guide rods are fixed on the top surface of the detection table. The multiple guide rods are jointly in sliding connection with a carrying table assembly, two lightening assemblies are symmetrically installed on the top face of the detection table relative to the carrying table assembly, plungers are fixedly connected to the outer walls of the two sides of the moving assembly, and the movable end of each plunger is fixedly connected with the side wall of the installation frame. According to the invention, the plunger and the lightening assembly are arranged, so that the collaboration of the imaging brightness meter and the lightening assembly is enhanced, more complex time sequence control is not needed, and the conditions of missing detection and false detection caused by the fact that the backlight source is not correctly lightened when the imaging brightness meter moves to one side are avoided.

The present application relates to a kind of high dynamic range image fusion method and device of ToF system.The present application judges whether the four phase data of high gain / long exposure time image are all luminance non-saturation first, if all are luminance non-saturation, then high gain / long exposure time image is used to carry out luminance calculation, otherwise low gain / short exposure time image is used to carry out luminance calculation, can only need to calculate the image of ToF system infrared thermal imager, need not simultaneously calculate two images, save the ToF system MCU operation time, can quickly carry out high dynamic range image fusion, can increase the dynamic range of ToF system infrared thermal imager image, avoid the phenomenon that only use low gain / short exposure time image causes the noise of image to be large, improve the image quality of ToF system infrared thermal imager.

The invention relates to the technical field of absolute response calculation of in-orbit optical remote sensing satellites, in particular to an in-orbit satellite response calculation method based on a point light source, which comprises the following steps of: calculating entrance pupil radiance and a response value of a remote sensing camera; calculating a spectral response function and a spectral response bandwidth of the remote sensing camera; equivalent entrance pupil radiance is calculated through wavelength infinitesimal elements; performing least square fitting calculation through the equivalent entrance pupil radiation brightness and the response value to obtain an absolute radiation calibration coefficient; calculating the absolute radiation brightness under the equivalent extended light source; the atmospheric upper bound absolute radiation brightness is calculated through the atmospheric transmittance and the absolute radiation brightness under the equivalent extended light source, and the equivalent radiation brightness is calculated through the spectral response bandwidth; and the output response value of the remote sensing camera is calculated according to the equivalent spectral radiation brightness. According to the method, on-orbit satellite response calculation based on the point light source is realized by utilizing a point source target radiation transmission principle and combining a basic principle of optical remote sensing camera radiation calibration.

The invention belongs to the field of infrared thermal imaging temperature correction, and particularly relates to a curved surface infrared thermal imaging detection temperature correction device and method based on a laser array. The correction method comprises the steps of establishing a correction device system, measuring a laser array, calculating an included angle between a normal direction of each measurement point and a radiation source direction, calculating a correction factor, measuring radiation brightness by a radiation emission method, calculating an uncorrected emissivity and a real emissivity, and calculating a real temperature. According to the correction device and method, a set of efficient, accurate and high-adaptability curved surface object temperature measurement system is formed by integrating a laser array scanning technology, radiation reflection method measurement and a computer processing technology, and efficient, accurate and high-adaptability detection of the surface temperature of the curved surface object is achieved; a traditional complex algorithm and a large amount of calculation processes are simplified, the influence of the curved surface shape on temperature measurement is effectively solved through the dynamic correction factor, and the measurement precision and reliability are remarkably improved.

The present invention discloses an absolute radiometric calibration method for a color area array CCD camera based on a Bayer array. By using a highly stable LED light source combined with an integrating sphere to generate a stable and energy-adjustable uniform surface light source, and transferring the spectral radiance at the exit of the integrating sphere to the pixels of the area array CCD detector through a standard radiance meter, absolute radiation response calibration is achieved. In the present invention, by setting the magnitude of the LED light source current and setting the minimum value, typical value, and maximum value of the spectral radiance, an absolute radiation response calibration experiment of the color area array CCD camera is carried out under the condition of a single light source to determine the corresponding absolute radiation response coefficient, thereby eliminating the calibration uncertainty caused by detector response aliasing and effectively improving the accuracy of absolute radiometric calibration.

Aspects of the present invention relate to a phototherapy system, comprising at least one radiative source configured to produce electromagnetic radiation (EMR) in one or more spectral bands, one or more sensors, and a controller that performs operations comprising calculating a point of gaze, calculating a distance between the subject and the at least one radiative source, setting a brightness to a brightness threshold when the calculated gaze of the subject is directed toward the at least one radiative source and the calculated distance is within an operational range, calculating an exposure time of the subject based on the calculated point of gaze and the brightness, and setting the brightness to a second brightness threshold when the exposure time exceeds a treatment duration, wherein the brightness of the at least one radiative source has a radiated power above a power threshold within a circadian wavelength range.