JP4823981B2 - Video resolution evaluation device for display device - Google Patents

Description

  The present invention relates to an apparatus for evaluating the resolution performance of a moving image displayed on a display device.

  Conventionally, as this type of evaluation apparatus, for example, there is an apparatus shown in the following (Patent Document 1). This (Patent Document 1) describes a conventional dynamic characteristic measuring apparatus. The dynamic characteristic measuring device of (Patent Document 1) is composed of an image signal generator, a camera, a display, a computing device using a computer, and the like. A repetitive pattern of a sine waveform of a test image is moved and displayed on this apparatus, and this display is photographed by following the camera to perform arithmetic processing. As the calculation processing by the computer, the dynamic characteristic is to be measured by using the ratio of the level of the fundamental wave and the other high frequency components by Fourier transform.

For (Non-Patent Document 1), the moving image response characteristic is evaluated using only the step pattern.
JP 2001-54147 A J. Someya, Y. Igarashi "A Review of MPRT Measurement Method for Evaluating Motion Blur of LCDs"IDW'04 VHF6 / LCT7-1

  However, in the conventional configuration, there is no description of the waveform that serves as a reference for the amplitude of the sine waveform, and the waveform distortion is reduced by taking the ratio of the level of the fundamental wave and the other high-frequency components by waveform analysis of Fourier transform. Although it can be calculated as a numerical value, it does not show a means to explicitly show the change in amplitude compared to the case of a still image, and it is not sufficient to know the change in resolution in the moving image, not the waveform distortion It has become.

  In addition, it is not clear which part of the entire captured image the specific range of Fourier transform in the sine wave of the image displayed on the display. In detail, page 7 in (Patent Document 1) and FIG. 3 show only a part of the sine waveform portion, and although it is recognized that it is a sine waveform, it is clearly described as a burst waveform. In addition, it is not clear which part is subject to the Fourier transform, and this means that information is somewhat lacking in order to perform the Fourier transform with high accuracy.

  In addition, (Non-Patent Document 1) uses only step patterns to evaluate moving image response characteristics, and does not evaluate response characteristics for patterns that repeat light and dark with higher frequency. It was not always enough to evaluate the performance of

  In order to solve the above problems, the present invention provides a step waveform that serves as a reference for amplitude, a repeating pattern that repeats a waveform having a predetermined cycle an integer number of times, and a burst pattern that is formed before and after the repeating pattern. Is used in the test pattern, and the information obtained by performing Fourier transform on the captured data divided by the length corresponding to the repeated pattern is used. Can be calculated in more detail and accurately.

In order to solve the above-described conventional problems, a moving image resolution evaluation apparatus of a display device according to the present invention uses a burst pattern having a flat portion before and after a periodic pattern composed of N repeated patterns and a reference for the amplitude of the burst pattern. A signal generating means for generating a step pattern having a level to represent as an image signal that moves at a predetermined speed in a predetermined direction on the display device, and a means for following the image displayed on the display device to obtain image data And a means for detecting a length of a section corresponding to the periodic pattern on the image data, and a means for calculating the image data, and a data sequence corresponding to the burst pattern on the image data a frequency component obtained by Fourier analysis, separated for each length of section corresponding to the pattern, corresponding to the step pattern To provide a moving resolution evaluation device for a display device characterized by evaluating the video resolution by using the frequency components obtained by Fourier analysis from over data column.

Further, the present invention provides a burst pattern having a flat portion before and after a periodic pattern composed of N repeated patterns and a step pattern having a level indicating a reference of the amplitude of the burst pattern on a display device. Corresponding to the period pattern on the image data, signal generating means for generating an image signal that moves in a direction at a predetermined speed, means for taking an image displayed on the display device and taking it as image data A periodic pattern detecting means for detecting a portion; a means for correcting image data of a portion corresponding to the burst pattern on the image data based on an output of the periodic pattern detecting means; and calculating the corrected image data. A data sequence corresponding to the burst pattern on the corrected image data. Evaluating the video resolution by using the frequency component obtained by Fourier analysis, separated for each length of section corresponding to over emissions, and a frequency component obtained by Fourier analysis of the data string corresponding to the step pattern A moving image resolution evaluation apparatus for a display device characterized by the above is provided.

  Further, according to the present invention, in the above-described moving picture resolution evaluation apparatus, a method of dividing and calculating a data string corresponding to the burst pattern for each length of a section corresponding to the periodic pattern is a portion corresponding to the burst pattern. Provided is a moving image resolution evaluation apparatus for a display device, which is a method for performing an operation on a data string extracted by changing a start position sequentially.

  In addition, the present invention provides a moving image resolution evaluation apparatus for a display device, wherein the calculation includes a calculation for obtaining an average value of data of a length of a section corresponding to the periodic pattern.

  In addition, the present invention provides a moving image resolution evaluation device for a display device, wherein the calculation is a calculation including a Fourier transform.

  In addition, the present invention provides a moving image resolution evaluation apparatus for a display device, wherein the calculation including Fourier transform is a calculation including a method for obtaining a frequency component corresponding to a repetition period of the repetitive pattern.

  In addition, the present invention provides a moving image resolution evaluation apparatus for a display device, in which the evaluation method is an evaluation method based on a relationship between a position where the photographed data is extracted and a result obtained by performing an operation on a data string.

  Further, the present invention provides the moving image resolution evaluation of a display device, wherein the means for correcting a portion corresponding to the burst pattern on the image data is a means for correcting so as to suppress a change in a position corresponding to before and after the repeated pattern. Providing equipment.

  The present invention also provides a moving image resolution evaluation apparatus for a display device, wherein the periodic pattern is a waveform obtained by sampling a rectangular waveform or a sine waveform.

The present invention also provides a moving image resolution evaluation apparatus for a display device in which N is 4, that is, the number of repetitions is 4.

  As described above, according to the moving image resolution evaluation apparatus of the display device of the present invention, it is composed of a burst pattern having flat portions before and after a periodic pattern, and a step pattern having a level representing a reference of the amplitude of the burst pattern. The displayed image is moved and displayed in a predetermined direction on the display device at a predetermined speed, and on the image data obtained by following the image, the data string corresponding to the burst pattern has a length corresponding to the period pattern. Evaluation is performed using information obtained by dividing and calculating for each step and information obtained by calculating a data string corresponding to a step pattern. The amplitude and shape of the periodic pattern portion generally changes in accordance with the speed of movement of the pattern and reflecting the response performance of the display device.

  In addition, the level of the flat portion of the step pattern is not easily affected by the movement of the pattern. Since it is set as such a structure, the moving image response performance of a display apparatus can be evaluated in detail by analyzing the part of a periodic pattern. The period pattern portion provides important information for knowing the reference amplitude level.

  Further, in the configuration of the present invention, for example, the range of data when performing periodic pattern analysis, such as dividing the captured data by a length corresponding to the periodic pattern and performing Fourier transform, is defined. Therefore, it is possible to analyze the periodic pattern with high accuracy.

  In addition, a means for correcting the portion corresponding to the burst pattern on the captured data is provided, and this correction data is used so that when the Fourier transform is performed, there is a waveform disturbance on the burst pattern. Therefore, it is possible to calculate the resolution performance in a moving image with high accuracy without the influence of the above.

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1A is a diagram showing the luminance level of an image for evaluation generated by a signal generating means in the moving picture resolution evaluation apparatus of the display device according to (Embodiment 1) of the present invention. As shown in (b).

  In FIG. 1A, regions A and C are flat portions, and are formed before and after the periodic pattern of region B to form a burst pattern. The region C and the region E constitute a step pattern together with the region D, and the original amplitude of the periodic pattern region B, that is, the amplitude information of the periodic pattern region B when there is a sufficient sampling multiple and there is no image movement. It is a pattern that gives.

  FIG. 2 is a block diagram showing a flow of calculation in the moving picture resolution evaluation apparatus of the display apparatus according to (Embodiment 1) of the present invention. In FIG. 2, reference numeral 1 denotes a follow-up camera, which is an image obtained by moving an image including a periodic pattern as a test image and a burst pattern or step pattern including a flat portion on a display (not shown) to be evaluated. Follow-up shooting.

  An image memory 2 stores image data for performing calculations. Reference numeral 3 denotes a pixel correspondence calculating means for calculating a correspondence relationship between the pixels of the image sensor of the follow-up camera and the pixels of the display to be evaluated. Reference numeral 4 denotes pattern position detecting means for detecting the position of a burst pattern or a periodic pattern from the captured image data. Reference numeral 5 denotes a reference level detecting means for detecting a level serving as a reference by analyzing the data corresponding to the step pattern.

Reference numeral 6 denotes data correction means for correcting the captured image as necessary. For example, when a ringing phenomenon or the like occurs before and after the periodic pattern of the burst pattern, the disturbance in the signal before and after the periodic pattern is suppressed to reduce an error when performing an analysis such as Fourier analysis. Reference numeral 7 denotes data selection means for determining a data range necessary for analyzing a periodic pattern portion. As a result, when analyzing data by Fourier transform or the like at a later stage, it can be expected to avoid the inclusion of unnecessary data and perform accurate evaluation.

  Reference numeral 8 denotes Fourier analysis means for performing calculations for analyzing and detecting periodic components of the burst pattern. A determination unit 9 comprehensively determines the detected reference level and the analyzed periodic pattern component, and determines whether the captured image pattern has sufficient amplitude and the frequency component satisfies a predetermined condition. For example, it is determined whether or not the amplitude of the periodic pattern portion of the captured image data portion is a sufficient level compared to the reference level detected from the analysis of the step pattern.

  As described above, in the moving picture resolution evaluation apparatus of the display device according to the first embodiment of the present invention shown in FIG. 2, the image data obtained by the follow-up shooting is detected as necessary while detecting and referring to the data serving as the level reference. Provided is a means that can accurately and accurately evaluate the moving image characteristics of the display device, in particular, the moving image resolution, in order to perform corrections and perform operations on necessary data.

  FIG. 3 is a block diagram showing a configuration example of the Fourier analysis means 8 of FIG. Reference numeral 81 denotes image data selected by the data selection means 7 and receives a data string to be analyzed for a periodic pattern. Reference numeral 82 denotes pattern position information, and reference numeral 83 denotes pixel correspondence information, which are required as parameters for frequency analysis.

  Reference numeral 84 denotes Fourier transform absolute value calculation means for calculating the absolute value of the component of the periodic pattern portion. Reference numeral 85 denotes Fourier transform phase calculation means for calculating the phase component of the periodic pattern portion. Reference numeral 86 denotes a peak level detecting means for calculating the peak level of the absolute value of the component of the calculated periodic pattern portion. Reference numeral 87 denotes a peak position detecting means for calculating the peak position of the absolute value of the component of the calculated periodic pattern portion.

  When the data selection position of the data selection means 7 in FIG. 2 changes, the level calculated by the Fourier transform absolute value calculation means 84 changes accordingly, and this is detected by the peak level detection means 86, This is a peak position detecting means 87.

  The detected information on the peak of the Fourier transform component is determined by 88 Fourier analysis shape determination means together with the phase component by Fourier transform, and it is determined whether or not it has a shape close to the original shape. Note that the final Fourier analysis determination is performed not only by the shape but also by 89 Fourier analysis comprehensive determination means whether there is a sufficient level. The shape can be determined from, for example, the relative relationship between the peak position and the peak height. Also, even if the burst pattern part of the follow-up image has a shape similar to the original image, it is not recognized that it was displayed correctly when observing the displayed image if its level is low, It is practical to determine the level by setting an appropriate threshold value.

  In the present embodiment, the image captured by the data correction unit 6 is corrected. However, when the waveform distortion is not so great, this data correction can be omitted.

  Further, in FIG. 1A, one step pattern is associated with one periodic pattern. Usually, a plurality of periodic patterns with different periods are provided as an evaluation pattern image for one step pattern. be able to.

  The moving image resolution evaluation apparatus for a display device according to the present invention simultaneously evaluates a step pattern having a reference level of information and a periodic pattern as a reference for evaluation of resolution performance. It is possible to accurately evaluate the so-called moving image resolution of how much the display resolution changes.

  In the present invention, in particular, when analyzing a periodic pattern, a range of data to be calculated can be appropriately selected, so that advanced frequency analysis such as Fourier transform is performed while suppressing the occurrence of errors. be able to. In general, the waveform of image data captured following tracking often has a complicated shape depending on the pixel structure and driving method, and when trying to determine the time-series waveform directly from its shape, etc., regardless of frequency analysis. In general, it is difficult to accurately perform the determination. When an easy low-pass filter or the like is used to simplify the waveform, the waveform carrying the original information is often distorted, and correct results are often not guaranteed.

  Therefore, according to the present invention, analysis processing such as Fourier transformation can be applied to captured image data, and as a result, evaluation close to the observer's appearance can be performed quantitatively and accurately, and as a standard method for measuring video resolution An extremely reliable evaluation means can be provided.

The figure which shows the example of the luminance level of the image for evaluation in Embodiment 1 of this invention. 1 is a block diagram of a moving image resolution evaluation device for a display device according to Embodiment 1 of the present invention. The block diagram which shows the structural example of the Fourier-analysis means in Embodiment 1 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tracking imaging camera 2 Image memory 3 Pixel correspondence detection means 4 Pattern position detection means 5 Reference level detection means 6 Data correction means 7 Data selection means 8 Fourier analysis means 9 Judgment means 81 Selection image data 82 Pattern position information,
83 Pixel correspondence information 84 Fourier transform absolute value calculation means 85 Fourier transform phase calculation means 86 Peak level detection means 87 Peak position detection means 88 Fourier analysis shape determination means 89 Fourier analysis comprehensive determination means

Claims (2)

A burst pattern having a flat portion before and after a periodic pattern composed of N repeated patterns and a step pattern having a level indicating a reference of the amplitude of the burst pattern are moved in a predetermined direction on the display device at a predetermined speed. Signal generating means for generating as an image signal, means for taking an image displayed on the display device and making it image data, means for detecting a length of a section corresponding to the periodic pattern on the image data, Means for calculating the image data;
On the image data, a frequency component obtained by performing Fourier analysis by dividing a data sequence corresponding to the burst pattern into lengths of sections corresponding to the periodic pattern, and Fourier analysis from the data sequence corresponding to the step pattern A moving image resolution evaluation apparatus for a display device, wherein the evaluation is performed using a frequency component obtained in this manner. A burst pattern having a flat portion before and after a periodic pattern composed of N repeating patterns and a step pattern having a level indicating a reference of the amplitude of the burst pattern at a predetermined speed on a display device. A signal generating means for generating a moving image signal; a means for following the image displayed on the display device to obtain image data; and a periodic pattern for detecting a portion corresponding to the periodic pattern on the image data Detecting means and means for correcting image data of a portion corresponding to the burst pattern on the image data based on the output of the periodic pattern detecting means, and means for calculating the corrected image data. On the obtained image data, the data string corresponding to the burst pattern is a section corresponding to the periodic pattern. A frequency component obtained by Fourier analysis, separated for each length, video resolution evaluation of the display device and evaluating by using the frequency components obtained by Fourier analysis of the data string corresponding to the step pattern apparatus.

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