KR100480166B1 - Apparatus And Method For Compensating Color Of Plasma Display Panel Using An Enlarging Method Of Dynamic Range - Google Patents

Abstract

The present invention relates to a color correction apparatus and method for a plasma display panel using a dynamic range magnification method for correcting a color conversion error by expanding a dynamic range when displaying a moving image to improve contrast of a display screen.

The color correction apparatus of the plasma display panel using the dynamic range expansion method according to the present invention includes a frame memory for storing moving image data input from an external input line in units of frames, and is connected in series with the frame memory to between the previous and current frames. The dynamic range is connected in series with a dynamic range adjusting unit which expands the dynamic range of the video data via the frame memory using the minimum distribution lower and upper gray levels when the amount of motion is larger than a preset threshold. A plasma display panel driver for controlling and supplying the corrected corrected image data signal to the panel, and between the input line and the dynamic range adjusting unit in parallel with the frame memory, so that the minimum and upper A minimum distribution lower and upper gray level detection unit for detecting a ray level, and a movement amount detection unit connected in parallel with the frame memory between an input line and a dynamic range adjusting unit to detect a movement amount between a previous and a current frame; do.

Description

Apparatus And Method For Compensating Color Of Plasma Display Panel Using An Enlarging Method Of Dynamic Range}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel, and more particularly, to a method of correcting a color of a plasma display panel and a driving apparatus using the same, to correct a color conversion error by expanding a dynamic range when displaying a moving image.

Plasma Display Panel (hereinafter referred to as "PDP") is a display device using visible light generated from a phosphor when ultraviolet light generated by gas discharge excites the phosphor. PDP is thinner and lighter than Cathode Ray Tube (CRT), which has been the mainstay of display means, and has the advantage of realizing high definition / large screen.

The PDP has an upper substrate and a lower substrate which are installed to face each other with partition walls therebetween. The upper substrate includes a scan electrode and a sustain electrode formed in a direction crossing the partition wall. The lower substrate includes an address electrode formed in a direction parallel to the partition wall, and a dielectric layer formed to cover the address electrode. The discharge cell is positioned at the intersection of the scan electrode, the sustain electrode and the address electrode.

The PDP is driven by dividing one frame into several subfields having different emission counts in order to realize gray levels of an image. Each subfield is divided into a reset period for uniformly causing discharge, an address period for selecting a discharge cell, and a sustain period for implementing gray scale according to the number of discharges.

In the address period, scan pulses are supplied to the scan electrodes, and data pulses synchronized with the scan pulses are supplied to the address electrodes. At this time, an address discharge occurs in the discharge cell supplied with the scan pulse and the data pulse. After the scan pulses are supplied to all the scan electrodes, the sustain pulses are alternately supplied to the scan electrodes and the sustain electrodes. When a sustain pulse is supplied to the scan electrode and the sustain electrode, sustain discharge occurs in the discharge cells in which the address discharge has occurred.

When the image is to be displayed in 256 gray levels, the frame period (16.67 ms) corresponding to 1/60 second is divided into eight subfields. Here, the reset period and the address period of each subfield are the same for each subfield, while the sustain period and the number of discharges thereof are 2 ⁿ (n = 0,1,2,3,4,5,6,7) in each subfield. , 8). As described above, since the sustain period is changed in each subfield, gray levels of an image can be realized.

The PDP is driven by enlarging the dynamic range of moving images in order to improve contrast.

1 is a block diagram showing a driving apparatus of a PDP using a dynamic range expansion method according to the prior art.

Referring to FIG. 1, a driving apparatus of a PDP using a dynamic range expansion method according to the related art includes a frame memory 14, lower and upper gray level histogram detectors 22A and 22B, minimum distribution lower and upper gray level value determination units. 24A and 24B, the dynamic range adjusting unit 16, and the PDP driving unit 18 are provided.

The frame memory 14 stores the data from the input line 12 in one frame unit and supplies the data to the dynamic range adjusting unit 16.

The lower and upper gray level histogram detectors 22A and 22B detect histograms of the lower and upper gray levels for each gray level based on data from the input line 12 in units of frames. This first obtains the overall distribution of each gray level for the input screen of one frame. The histogram H (I), which is a gray level distribution value of the input data, is detected based on the overall distribution. At this time, histograms are mainly detected at gray levels, such as about 0 to 20 gray and 220 to 255, to determine minimum and maximum gray levels (MIN and MAX).

The minimum distribution lower and upper gray level value determination units 24A and 24B determine an arbitrarily set reference ratio and determine lower and upper gray levels (MIN, MAX) having less gray level distribution through histograms of detected lower and upper gray levels. do.

The dynamic range adjusting unit 16 enlarges the dynamic range of the input data using the data input from the frame memory 14, the minimum distribution lower and upper gray level values. The dynamic range adjuster 16 supplies input data having an enlarged dynamic range to the PDP driver 18.

The PDP driver 18 corrects the digital signal input from the dynamic range adjuster 16 and supplies it to the panel. To this end, the PDP driver 18 includes the first inverse gamma correction unit 32A, the gain control unit 34, the error diffusion unit 36, the subfield mapping unit 38, and the data alignment unit 40 as shown in FIG. And a second inverse gamma correction unit 32B, an average picture value (APL) unit 44, a waveform generator 46, and a panel 48.

The first and second inverse gamma correction units 32A and 32B perform inverse gamma correction on the video signal input from the dynamic range adjusting unit 16 to linearly convert the luminance value according to the gray value of the image signal.

The APL unit 44 receives the video data corrected by the second inverse gamma correction unit 32B and generates an N-stage signal for adjusting the number of sustain pulses. The gain controller 34 amplifies the video signal corrected by the first inverse gamma correction unit 32A by the effective gain.

The error diffusion unit 36 finely adjusts the luminance value by diffusing an error component of a cell into adjacent cells. The subfield mapping unit 38 reallocates the video data corrected by the error diffusion unit 36 for each subfield.

The data aligner 40 aligns the video signal to be supplied to the panel 48, and supplies the video signal to an address driving integrated circuit (IC) not shown.

The waveform generator 46 generates a timing control signal based on the N-stage signal input from the APL unit 44, and converts the generated timing control signal into an address driver IC, a scan driver IC, and a sustain driver IC of the panel 48. Supply.

In detail, the second inverse gamma correction unit 32B first performs inverse gamma correction on the video signal input from the dynamic range adjustment unit 16 and supplies the inverse gamma correction unit to the APL unit 44. The APL unit 44 receiving the inverse gamma corrected video signal generates an N-stage signal for adjusting the number of sustain pulses, and supplies it to the waveform generator 46. The waveform generator 46 generates a timing control signal using the N-stage signal input from the APL unit 44, and supplies the generated control signal to the address driving IC, the scan driving IC, and the sustain driving IC.

The first inverse gamma correction unit 32A performs inverse gamma correction on the video signal input from the dynamic range adjustment unit 16 and supplies it to the gain control unit 34. The gain control unit 34 receiving the inverse gamma corrected video signal amplifies the corrected video signal by an effective gain and supplies it to the error diffusion unit 36. The error diffusion unit 36 error-spreads the video signal input from the gain control unit 34 to finely adjust the luminance value. The video signal output from the error diffusion unit 36 is input to the subfield mapping unit 38. The subfield mapping unit 38 reallocates the error-diffused video data for each subfield and supplies the data to the data alignment unit 40. The data aligner 40 aligns the video signal and supplies it to the address driver IC.

Thereafter, an image corresponding to the video signal is displayed on the panel 48 by the control of the address driving IC, the scan driving IC, the sustain driving IC, and the like. In the PDP driving apparatus according to the related art, a sharp image can be obtained by improving contrast through an enlarged dynamic range.

FIG. 3 is a flowchart illustrating the dynamic range expansion method described with reference to FIG. 1.

Referring to FIG. 3, first, input data RGB from the outside is input to the lower and upper gray level histogram detectors 22A and 22B.

The histogram H (I) of each gray level is detected (S12). This first obtains an overall distribution of gray levels for an input screen of one frame. Based on the overall gray level distribution, the ratio of the histogram, which is the number of distributions of 0 to 255 gray levels, can be known. For example, in a PDP with WVGA (853 * 480) resolution mode, if the number of histograms with 2 grays is 245, the distribution ratio is Becomes When the distribution ratio of each gray level is obtained, the histogram ratio with respect to the input data appears as shown in Tables 1 and 2.

Histogram % Of distribution Hist [0] 0.02 Hist [1] 0.04 Hist [2] 0.06 Hist [3] 0.0 … … Hist [17] 0.03 Hist [18] 0.09 Hist [19] 0.1 Hist [20] One

Histogram % Of distribution Hist [220] 1.0 Hist [221] 0.1 Hist [222] 0.06 Hist [223] 0.001 … … Hist [252] 0.03 Hist [253] 0.02 Hist [254] 0.09 Hist [255] 0.05

Here, the histogram distribution ratio (%) for each of these gray levels may vary depending on the input data for one frame.

Based on the histogram distribution ratio (%), the minimum distribution lower and upper gray levels (MIN, MAX) are determined. (S14) First, before determining the minimum distribution lower and upper gray level values, the threshold value of the histogram distribution ratio (%) is determined. Decide In Figure 3, 0.1% was set as the threshold. This sets the first gray level with 0.1% or more as the minimum distributed lower gray level (MIN) and the minimum distributed upper gray level (MAX). (S18) When the distribution ratio is 0.1% or less, the next histogram distribution ratio is continuously searched. (S16)

Accordingly, in the case of Table 1 and Table 2, the gray level is determined as the minimum distributed lower gray level MIN is 19 and the minimum distributed upper gray level MAX is 221.

The values of the minimum distribution lower and upper gray levels MIN and MAX determined as described above are input to the dynamic range adjusting unit 16. The dynamic range adjusting unit 16 rearranges the input image by using Equation 1 to input the minimum distribution lower and upper gray levels MIN and MAX.

Where X is the gray level of the input data before correction and Y is the gray level of the input data after correction. In addition, MAX is the value of the minimum distributed upper gray level, and MIN is the value of the minimum distributed lower gray level.

When X is 40, the minimum distribution lower and upper gray level values determined through Table 1 and Table 2 are applied to Equation 1. By Y, the minimum gray level value after correction for X becomes 26.5. This changes the input data of 40 to a lower value of 26.5. That is, in the present invention, as shown in FIG. 4, the histogram distribution I according to the gray level in the dotted line form may be obtained as the histogram distribution II according to the gray level in the solid line form in which the dynamic range is expanded. As a result, as the dynamic range is enlarged, the contrast of the screen is improved to obtain a clear screen. In other words, the bright part is displayed brighter and the dark part is displayed darker so that the contrast between the bright part and the dark part of the screen can be clearly displayed.

5A and 5B illustrate changes in the display image before and after applying the dynamic range enlargement method. As the contrast of the light and dark of the screen becomes clearer, the dynamic range is enlarged according to the prior art illustrated in FIG. 5B. It can be seen that the image is clearer than that of FIG. 5A.

FIG. 6 is a view for designating a predetermined area for comparing only a part of the display image shown in FIG. 5B, and FIGS. 7A and 7B are views showing a change in histogram distribution after the dynamic range expansion process according to the prior art. FIG. 8B is a diagram illustrating a change of a display image of a portion of FIG. 6.

7A and 7B, the distribution of the histogram according to the prior art of FIG. 7B is toward the gray level lower than the distribution of the histogram according to the prior art of FIG. 7A by expanding the dynamic range according to the minimum distribution lower and upper gray level values. You can see that it has been moved. As a result, as described above, the darker portions become darker and the brighter portions appear brighter.

Referring to the results of FIGS. 7A and 7B through FIGS. 8A and 8B, first, FIGS. 8A and 8B compare regions A of FIG. 6, and it can be seen that a dark portion of the sky becomes darker. Next, FIGS. 9A and 9B compare the area B of FIG. 6 and show a display screen in which a bright part and a dark part coexist. In this case as well, the contrast between the bright and dark areas can be seen that the contrast is improved.

For example using the dynamic range expansion method as described above, when each gray level of RGB (red cyan) is an image having 205, 20, 205 as shown in FIG. 10, the maximum gray level MAX is 205, and the minimum The gray level MIN has a value of 20.

Applying Equation 1, the maximum gray level (MAX) is Is converted to 255 by the minimum gray level (MIN) Is converted to 0 by As a result of this conversion, each image data before conversion on the left side is converted to each image after conversion on the right side. However, this dynamic range enlargement method may cause excessive color change compared to the original image as shown in FIG. 10 (c) when driving the PDP.

Accordingly, an object of the present invention is to provide a color correction apparatus and method for a plasma display panel using a dynamic range expansion method that can determine whether a still image or a moving image is compensated for color conversion errors when adjusting the dynamic range.

Another object of the present invention is to provide a color correction apparatus and method for a plasma display panel using a dynamic range enlargement method that can compensate for color conversion errors when adjusting the dynamic range by determining the degree of motion of an input image.

It is still another object of the present invention to provide a color correction apparatus and method for a plasma display panel using a dynamic range enlargement method that can compensate for color conversion errors when adjusting the dynamic range by using distribution degrees of the same gray range.

In order to achieve the above objects, the color correction apparatus of the plasma display panel using the dynamic range expansion method according to the present invention is connected to the frame memory and the frame memory for storing the moving image data input from an external input line by one frame unit; And a dynamic range adjusting unit for enlarging the dynamic range of the video data via the frame memory using the minimum distribution lower and upper gray levels when the amount of movement between the previous and current frames is greater than a preset threshold. A plasma display panel driver for controlling and supplying a corrected image data signal of which the dynamic range is expanded to a panel and connected in parallel with the frame memory between the input line and the dynamic range adjusting unit A minimum distribution lower and upper gray level detector for detecting a minimum distribution lower and upper gray level for one frame, and a parallel connection with the frame memory between the input line and the dynamic range adjusting unit to detect the amount of movement between previous and current frames And a movement amount detecting unit.

The motion detection unit according to the present invention compares the previous and current frame data to detect the degree of movement at the same point and determines the presence or absence of movement according to the degree of movement, and the motion for each image from the movement detection unit. And a motion degree determining unit for detecting whether information about the presence or absence from the input data is present and whether the degree of motion occurs on the entire screen between frames.

The minimum and lower gray level detectors of the present invention detect the histogram distribution ratio which is the number of distributions of the lower and upper gray levels after detecting each gray level of the video data during one frame input from the outside. And a level histogram detector and a minimum distributed lower and upper gray level determiner connected in series to the lower and upper gray level histogram detectors to determine a minimum distributed lower gray level.

A driving apparatus of a plasma display panel using another dynamic range expansion method according to the present invention is a frame memory for storing moving image data input from an external input line in units of frames, and is connected in series with the frame memory to between a previous and a current frame. A dynamic range adjusting unit for enlarging the dynamic range of the moving image data via the frame memory using the weighted minimum distribution lower and upper gray levels when the amount of motion is greater than a preset threshold, and serially connected to the dynamic range adjusting unit. A plasma display panel driver for controlling and supplying a corrected image data signal having an extended dynamic range to a panel, and being connected in parallel with the frame memory between the input line and the dynamic range adjusting unit for one frame. The minimum distribution lower and upper gray level detectors for detecting lower and upper gray levels, and the minimum and lower gray level detectors, and the dynamic range adjuster are connected between the minimum and upper gray level detectors, and the minimum distribution is less than the preset threshold. A weighting unit that applies weights to the minimum and lower gray levels so that lower gray levels are lower and the minimum distribution upper gray levels are higher, and the minimum distribution lower between the input line, frame memory, and weight applying unit And a motion amount determiner connected in parallel with a higher gray level detector to detect and determine a motion amount between a previous and current frame, and supply control information and a detected motion amount to the weight applying unit.

The motion amount determining unit according to the present invention includes a motion detection unit for comparing the previous and current frame data to detect the degree of movement, and a motion degree determining unit for detecting the amount of movement from the degree of movement and determining the degree of movement. It is done.

In the present invention, the motion determining unit determines a motion amount by comparing the calculated motion amount with a preset motion threshold and a motion calculating unit calculating a motion amount for one frame from the detected motion amount. It is characterized by comprising a part.

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The minimum and lower gray level detectors of the present invention detect the histogram distribution ratio which is the number of distributions of the lower and upper gray levels after detecting each gray level of the video data during one frame input from the outside. And a level histogram detector and a minimum distributed lower and upper gray level determiner connected in series to the lower and upper gray level histogram detectors to determine a minimum distributed lower gray level.

The motion detection unit according to the present invention is characterized by comprising a motion detection unit for detecting the degree of movement by comparing the previous and current frame data, and a motion degree determination unit for calculating the amount of motion from the movement degree.

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In the present invention, the plasma display panel driver includes an inverse gamma correction unit that inversely gamma corrects a video signal via the dynamic range adjustment unit and linearly converts luminance values according to grayscale values of an image signal, and the inverse gamma correction unit. A gain control unit for amplifying the corrected video signal by effective gain, an error diffusion unit for finely adjusting the luminance value by diffusing an error component of the cell into adjacent cells, and the video data corrected from the error diffusion unit for each subfield. And a data alignment unit for aligning the video signal to be supplied to the display panel.

In the present invention, an average image value (APL) unit for receiving the video data corrected by the inverse gamma correction unit and generating an N-stage signal for adjusting the number of sustain pulses, and an N-stage signal input from the average image value unit. And generating a timing control signal and supplying the generated timing control signal to a driving integrated circuit of the display panel.

The color correction method of the plasma display panel using the dynamic range expansion method according to the present invention includes detecting a minimum distribution lower and upper gray level of a moving image input image, and comparing the previous and current frames with respect to the moving image input image. Detecting the amount and the detected minimum distribution lower gray level is lower and the detected minimum distribution upper gray level is higher when the detected motion amount is less than or equal to a preset threshold. And converting the dynamic range of the input image using the converted minimum distribution lower and upper gray levels.

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Other objects and features of the present invention in addition to the above object will become apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 11 to 19.

11 is a block diagram illustrating a color correction apparatus of a plasma display panel using a dynamic range expansion method according to a first embodiment of the present invention.

Referring to FIG. 11, the color correction apparatus of the plasma display panel using the dynamic range expansion method according to the first embodiment of the present invention includes a frame memory 50, a motion detector 52, a motion degree determiner 54, and a lower part. And an upper gray level histogram detector 56, a minimum distribution lower and upper gray level value determiner 57, a dynamic range adjuster 58, and a PDP driver 60.

The frame memory 50 stores data from the input line in units of frames and supplies the data to the motion detector 52 and the dynamic range controller 58.

The motion detector 52 is connected in parallel with the frame memory 50 between the input line and the dynamic range adjuster 58, and has a frame delayed by one frame from the frame memory 50 and data of one frame inputted from the current input line. Compare data in units of frames. By comparing the current and delayed data, it is determined that the information difference at the same point is greater than or equal to a certain value, which is information with motion, which can be represented by Equation 2.

Here, x and y represent the coordinates of the image, and T represents the threshold setting value.

For example, if the difference between the gray level of the previous picture and the current picture for two identical points is 16 or more or 32 or more, at that point, it is determined that motion has occurred between the previous and current pictures. The part where the difference of the following values differs is judged that there is no movement.

The motion degree determining unit 54 is connected between the motion detecting unit 52 and the dynamic range adjusting unit 58 to receive the degree of movement of each image from the motion detecting unit 52 as input data, and to move between the frames. It is determined whether or not this occurs for the entire screen. Information on whether or not to be judged is connected to the dynamic range adjusting unit 58.

The lower and upper gray level histogram detector 56 is connected in parallel with the frame memory 50 between the input line and the dynamic range adjusting unit 58 so that the data from the input line is lower and upper gray level for each gray level in units of frames. It will detect the histogram for the level. This first obtains the overall distribution of each gray level for the input screen of one frame. The histogram H (I), which is a gray level distribution value of the input data, is detected based on the overall distribution. At this time, histograms are mainly detected at gray levels, such as about 0 to 20 gray and 220 to 255, to determine minimum and maximum gray levels (MIN and MAX).

The minimum distribution lower and upper gray level value determining unit 57 is connected between the lower and upper gray level histogram detector 56 and the dynamic range adjusting unit 58 to determine a randomly set reference ratio, and to detect the histogram of the detected lower and upper gray levels. The lower and upper gray levels (MIN, MAX) with less gray level distribution are determined by. The lower and upper gray levels (MIN, MAX) with less determined gray level distribution are supplied to the dynamic range adjusting unit 58.

The dynamic range adjusting unit 58 is commonly connected to the frame memory 50, the movement degree determining unit 54, and the minimum distribution lower and upper gray level value determining unit 57, so that the dynamic range of the input data via the frame memory 50 is increased. It serves to expand the range. The dynamic range adjusting unit 58 first determines whether the dynamic range is enlarged based on whether or not the movement degree is determined from the movement degree determining unit 54. For example, if it is determined that there is no motion degree, the input data is directly input to the PDP driver 60 without expanding the dynamic range, and when it is determined that the moving image is motion, the input data is the lowest and the lowest distribution. The dynamic range is expanded using the gray level values MIN and MAX and then supplied to the PDP driver 60.

The PDP driver 60 corrects the digital signal input from the dynamic range adjuster 58 and supplies it to the panel. To this end, the PDP driver 60 includes the first inverse gamma correction unit 62A, the gain control unit 64, the error diffusion unit 66, the subfield mapping unit 68, and the data alignment unit 70 as shown in FIG. And a second inverse gamma correction unit 62B, an average picture value (APL) unit 74, a waveform generator 76, and a panel 78.

The first and second inverse gamma correction units 62A and 62B inversely gamma correct the video signal input from the dynamic range adjusting unit 58 to linearly convert the luminance value according to the gray value of the image signal.

The APL unit 74 receives the video data corrected by the second inverse gamma correction unit 62B and generates an N-stage signal for adjusting the number of sustain pulses. The gain control unit 64 amplifies the video signal corrected by the first inverse gamma correction unit 62A by the effective gain.

The error diffusion unit 66 finely adjusts the luminance value by diffusing an error component of a cell into adjacent cells. The subfield mapping unit 68 reallocates the video data corrected by the error diffusion unit 66 for each subfield.

The data aligner 70 aligns the video signal to be supplied to the panel 78, and supplies the video signal to an address driving integrated circuit (IC) not shown.

The waveform generator 76 generates a timing control signal by the N-stage signal input from the APL unit 74, and converts the generated timing control signal into an address driving IC, a scan driving IC, and a sustain driving IC of the panel 78. Supply.

In detail, the second inverse gamma correction unit 62B first performs reverse gamma correction on the video data input from the dynamic range adjustment unit 58 and supplies the inverse gamma correction unit to the APL unit 74. The APL unit 74 receiving the inverse gamma corrected video signal generates an N-stage signal for adjusting the number of sustain pulses, and supplies it to the waveform generator 76. The waveform generator 76 generates a timing control signal using the N-stage signal input from the APL unit 74, and supplies the generated control signal to the address driving IC, the scan driving IC, and the sustain driving IC.

The first inverse gamma correction unit 62A performs inverse gamma correction on the video signal input from the dynamic range adjustment unit 58 and supplies it to the gain control unit 64. The gain control unit 64 receiving the inverse gamma corrected video signal amplifies the corrected video signal by the effective gain and supplies it to the error diffusion unit 66. The error diffusion unit 66 diffuses the video signal input from the gain control unit 64 to finely adjust the luminance value. The video signal output from the error diffusion unit 66 is input to the subfield mapping unit 68. The subfield mapping unit 68 reallocates the error-diffused video data for each subfield and supplies it to the data alignment unit 70. The data alignment unit 70 aligns the video signal and supplies it to the address driver IC.

Thereafter, the image corresponding to the video signal is displayed on the panel 78 by the control of the address driving IC, the scan driving IC, the sustain driving IC, and the like. In the driving apparatus of the PDP according to the first embodiment of the present invention having such a configuration, after determining whether the image is a still image, the dynamic range is enlarged to prevent excessive color change of the image and to improve contrast to obtain a clear image. do.

FIG. 13 is a block diagram illustrating a color correction apparatus of a plasma display panel using a dynamic range expansion method according to a second embodiment of the present invention, which shows a method of determining an amount of motion information and adjusting an error in color conversion.

Referring to FIG. 13, the color correction apparatus of the plasma display panel using the dynamic range expansion method according to the second embodiment of the present invention includes a frame memory 80, a motion detector 82, a motion degree determiner 84, and a lower part. And an upper gray level histogram detection unit 86, a minimum distribution lower and upper gray level value determination unit 88, a weight applying unit 90, a dynamic range adjustment unit 92, and a PDP driver 94.

The frame memory 80 stores data from an input line in units of frames and supplies the data to the motion detector 82 and the dynamic range adjuster 92.

The motion detection unit 82 is connected in parallel with the frame memory 80 between the input line and the dynamic range adjusting unit 92, and has one frame delayed from the frame memory 80 and one frame of data input from the current input line. Compare data in units of frames. The degree of movement is detected by comparing these current and delayed data.

The motion degree determining unit 84 is connected between the motion detector 82 and the dynamic range adjusting unit 92, and the motion amount calculating unit 95 for calculating the motion amount and the motion amount for determining the motion level as shown in FIG. The determination unit 96 is provided. The motion calculation unit 95 receives motion detection information from the motion detection unit 82 and calculates an amount of motion between frames. The motion amount determining unit 96 is connected to the motion amount calculating unit 95 to determine whether or not the magnitude is determined by comparing the calculated motion amount with a preset motion threshold. As a result, it is determined whether the calculated amount of motion is equal to or less than a threshold value and is supplied to the weight applying unit 90.

The lower and upper gray level histogram detector 86 is connected in parallel with the frame memory 80 between the input line and the dynamic range adjusting unit 92 so that the lower and upper gray levels for each gray level of the data from the input line in one frame unit. It will detect the histogram for the level. This first obtains the overall distribution of each gray level for the input screen of one frame. The histogram H (I), which is a gray level distribution value of the input data, is detected based on the overall distribution. At this time, histograms are mainly detected at gray levels, such as about 0 to 20 gray and 220 to 255, to determine minimum and maximum gray levels (MIN and MAX).

The minimum distribution lower and upper gray level value determining unit 88 is connected between the lower and upper gray level histogram detection unit 86 and the dynamic range adjusting unit 92 to determine a randomly set reference ratio, and to detect the histogram of the detected lower and upper gray levels. The lower and upper gray levels (MIN, MAX) with less gray level distribution are determined by.

The weight applying unit 90 is connected between the minimum distribution lower and upper gray level value determining unit 88 and the dynamic range adjusting unit 92 to receive the control information determined by the movement degree determining unit 84 and to provide the amount of movement. The weight setting information is stored. In this case, when the movement amount is greater than or equal to the threshold value by the movement degree determining unit 84, the dynamic range adjusting unit determines the lower and upper gray levels MIN and MAX having less gray level distribution determined by the minimum distribution lower and upper gray level value determining unit 88. If the amount of motion is less than or equal to the threshold value in the movement degree determining unit 84, the stored weight is supplied to the lower and upper gray levels having the smallest gray level distribution determined by the minimum distribution lower and upper gray level value determining unit 88. MIN, MAX) and then supply it to the dynamic range adjusting unit 92.

The dynamic range adjusting unit 92 is connected between the frame memory 80 and the PDP driver 94 to lower and upper gray level distributions having less gray level distribution derived from the weight applying unit 90 to the input data via the frame memory 80. Adjust the dynamic range by applying the gray level (MIN, MAX). Thereafter, the input data of which the dynamic range is adjusted is supplied to the PDP driver 94.

If these operations are described as an example, weights are applied to the lower and upper gray levels (MIN, MAX) with small detected gray level distributions of 15 and 230 and the amount of motion detected is below the detected threshold. . Because of this, the lower gray level (MIN) with less actual gray level distribution sets a value less than 15 as the minimum distributed lower gray level (MIN), and the upper gray level (MAX) with a low gray level distribution has a minimum value greater than 230. Set to the distribution upper gray level (MAX). If the minimum distribution lower and upper gray levels (MIN, MAX) detected by the minimum distribution lower and upper gray level determination units 90 are converted according to the factor that sets the weight according to the motion amount, the entire histogram of the final transformed image is converted. The application amount is changed.

The PDP driver 94 corrects the digital signal input from the dynamic range adjusting unit 92 and supplies it to the panel. To this end, the PDP driver 94 includes a first inverse gamma correction unit 102A, a gain control unit 104, an error diffusion unit 106, a subfield mapping unit 108, and a data alignment unit 110 as shown in FIG. And a second inverse gamma correction unit 102B, an average picture value (APL) unit 114, a waveform generator 116, and a panel 118.

The first and second inverse gamma correction units 102A and 102B linearly correct the video signal input from the dynamic range adjusting unit 92 to linearly convert luminance values according to grayscale values of the image signal.

The APL unit 114 receives the video data corrected by the second inverse gamma correction unit 102B and generates an N-stage signal for adjusting the number of sustain pulses. The gain control unit 104 amplifies the video signal corrected by the first inverse gamma correction unit 102A by the effective gain.

The error diffusion unit 106 finely adjusts the luminance value by diffusing an error component of a cell into adjacent cells. The subfield mapping unit 108 reallocates the video data corrected by the error diffusion unit 106 for each subfield.

The data aligning unit 110 aligns the video signal so as to be supplied to the panel 118 and supplies the video signal to an address driving integrated circuit (IC) not shown.

The waveform generator 116 generates a timing control signal based on the N-stage signal input from the APL unit 114, and converts the generated timing control signal into an address driving IC, a scan driving IC, and a sustain driving IC of the panel 118. Supply.

When the operation process is described in detail, first, the second inverse gamma correction unit 102B inversely gamma corrects the video data input from the dynamic range adjustment unit 92 and supplies the inverse gamma correction unit to the APL unit 114. The APL unit 114 receiving the inverse gamma corrected video signal generates an N-stage signal for adjusting the number of sustain pulses, and supplies it to the waveform generator 116. The waveform generator 116 generates a timing control signal using the N-stage signal input from the APL unit 114, and supplies the generated control signal to the address driving IC, the scan driving IC, and the sustain driving IC.

The first inverse gamma correction unit 102A performs inverse gamma correction on the video signal input from the dynamic range adjustment unit 92 and supplies it to the gain control unit 104. The gain control unit 104 receiving the inverse gamma corrected video signal amplifies the corrected video signal by an effective gain and supplies it to the error diffusion unit 106. The error diffusion unit 106 fine-tunes the luminance value by error diffusion of the video signal input from the gain control unit 104. The video signal output from the error diffusion unit 106 is input to the subfield mapping unit 108. The subfield mapping unit 108 reallocates the error-diffused video data for each subfield and supplies the data to the data arranging unit 110. The data alignment unit 110 aligns the video signal and supplies it to the address driver IC.

Thereafter, the image corresponding to the video signal is displayed on the panel 118 by the control of the address driving IC, the scan driving IC, the sustain driving IC, and the like. In the driving apparatus of the PDP according to the second embodiment of the present invention having such a configuration, it is possible to determine whether the image is a low movement and adjust the dynamic range to prevent excessive color change of the image and to improve contrast to obtain a clear image. It becomes possible.

16 is a block diagram illustrating a color correction apparatus of a plasma display panel using a dynamic range expansion method according to a third embodiment of the present invention.

Referring to FIG. 16, the color correction apparatus of the plasma display panel using the dynamic range expansion method according to the third embodiment of the present invention may include a frame memory 120, a motion detector 122, a motion degree determiner 124, and a minimum. The distribution lower and upper gray level detection unit 126, the same gray level distribution detection unit 128, the correction minimum distribution lower and upper gray level setting unit 130, the dynamic range adjusting unit 132, and the PDP driving unit 134 are provided.

The frame memory 120 stores the data from the input line in one frame unit and supplies the data to the motion detector 122 and the dynamic range adjuster 132.

The motion detector 122 is connected in parallel with the frame memory 120 between the input line and the dynamic range adjusting unit 132, and has a frame delayed by one frame from the frame memory 120 and one frame of data input from the current input line. Compare data in units of frames. These data are compared to detect the degree of motion during one frame.

The motion degree determining unit 124 is connected in series between the motion detector 122 and the dynamic range adjusting unit 132, and receives motion detection information from the motion detector 122 to calculate the amount of motion between frames.

The minimum distribution lower and upper gray level detector 126 is connected in parallel with the frame memory 120 between the input line and the dynamic range adjuster 132, and the minimum and upper gray level histogram detector 136 and the minimum are displayed as shown in FIG. 17. A distribution lower and upper gray level determiner 137 is provided. The lower and upper gray level histogram detection unit 136 detects histograms of the lower and upper gray levels for each gray level based on data from the input line by one frame. This first obtains the overall distribution of each gray level for the input screen of one frame. The histogram H (I), which is a gray level distribution value of the input data, is detected based on the overall distribution. At this time, histograms are mainly detected at gray levels, such as about 0 to 20 gray and 220 to 255, to determine minimum and maximum gray levels (MIN and MAX). The minimum distribution lower and upper gray level value determination unit 137 is connected to the lower and upper gray level histogram detection unit 136 to determine a randomly set reference ratio, and the lower gray level distribution having low gray level distribution through histograms of the detected lower and upper gray levels. And determine the upper gray level (MIN, MAX).

The same gray level distribution detection unit 128 is connected in parallel with the frame memory 120 between the input line and the dynamic range adjustment unit 132 and has the same distribution of red-green-blue (RGB) color in the data for one frame from the input line. The degree of gray level distribution is determined and the degree is detected.

The correction minimum distribution lower and upper gray level setting unit 130 includes a motion degree determining unit 124, a minimum distribution lower and upper gray level detection unit 126, and the same gray level distribution detection unit 128 and the dynamic range adjustment unit 132. And a correction value setting unit 136 and a correction minimum distribution lower and upper gray level determination unit 138, as shown in FIG. The correction value setting unit 136 determines whether the amount of motion calculated from the motion degree determining unit 124 and the data having the same gray level from the same gray level distribution detecting unit 128 are equal to or greater than a predetermined threshold, respectively, to determine the amount of motion. If it is less than the threshold and the same gray level is above the predetermined threshold, the correction value is determined so that the minimum distributed lower gray level is lower, and the correction value is determined so that the minimum distributed upper gray level is higher. This determined correction value is supplied to the correction minimum distribution lower and upper gray level determination sections 138.

The corrected minimum distribution lower and upper gray level determination unit 138 performs correction values input from the correction value setting unit 136 and the minimum distributed lower and upper gray levels MIN, input from the minimum distribution lower and upper gray level detection unit 126. The lower and upper gray levels (MIN, MAX) of the corrected minimum distribution derived by applying the MAX) are supplied to the dynamic range adjusting unit 132.

The dynamic range adjusting unit 132 is connected between the frame memory 120 and the PDP driver 134 to apply the correction minimum distribution lower and upper gray levels (MIN, MAX) to the input data via the frame memory 120. It serves to expand the dynamic range of the data. The dynamic range adjusting unit 132 adjusts the dynamic range of the input data using the corrected minimum distribution lower and upper gray levels (MIN, MAX), and then supplies the input data of which the dynamic range is adjusted to the PDP driver 134.

The PDP driver 134 corrects the data signal input from the dynamic range adjusting unit 132 and supplies it to the panel. To this end, the PDP driver 134 may include the first inverse gamma correction unit 142A, the gain control unit 144, the error diffusion unit 146, the subfield mapping unit 148, and the data alignment unit 150 as shown in FIG. 19. And a second inverse gamma correction unit 142B, an average picture level (APL) unit 154, a waveform generator 156, and a panel 158.

The first and second inverse gamma correction units 142A and 142B inversely gamma correct a video signal input from the dynamic range adjusting unit 132 to linearly convert luminance values according to grayscale values of the image signal.

The APL unit 154 receives the video data corrected by the second inverse gamma correction unit 142B and generates an N-stage signal for adjusting the number of sustain pulses. The gain controller 144 amplifies the video signal corrected by the first inverse gamma correction unit 142A by the effective gain.

The error diffusion unit 146 finely adjusts the luminance value by diffusing an error component of a cell into adjacent cells. The subfield mapping unit 148 reallocates the video data corrected by the error diffusion unit 146 for each subfield.

The data aligner 150 aligns the video signal to be supplied to the panel 158, and supplies the video signal to an address driving integrated circuit (IC) not shown.

The waveform generator 156 generates a timing control signal based on the N-stage signal input from the APL unit 154, and converts the generated timing control signal into an address driving IC, a scan driving IC, and a sustain driving IC of the panel 158. Supply.

When the operation process is described in detail, first, the second inverse gamma correction unit 142B inversely gamma corrects the video data input from the dynamic range adjustment unit 132 and supplies the inverse gamma correction unit to the APL unit 154. The APL unit 154 receiving the inverse gamma corrected video signal generates an N-stage signal for adjusting the number of sustain pulses, and supplies it to the waveform generator 156. The waveform generator 156 generates a timing control signal using the N-stage signal input from the APL unit 154, and supplies the generated control signal to the address driving IC, the scan driving IC, and the sustain driving IC.

The first inverse gamma correction unit 142A performs inverse gamma correction on the video signal input from the dynamic range adjustment unit 132 and supplies it to the gain control unit 144. The gain control unit 144 receiving the inverse gamma corrected video signal amplifies the corrected video signal by an effective gain and supplies it to the error diffusion unit 146. The error diffusion unit 146 error-spreads the video signal input from the gain control unit 144 to finely adjust the luminance value. The video signal output from the error diffusion unit 146 is input to the subfield mapping unit 148. The subfield mapping unit 148 reallocates the error-diffused video data for each subfield and supplies the data to the data alignment unit 150. The data alignment unit 150 aligns the video signal and supplies the video signal to the address driver IC.

Thereafter, the image corresponding to the video signal is displayed on the panel 158 by the control of the address driving IC, the scan driving IC, the sustain driving IC, and the like. In the driving apparatus of the PDP according to the third embodiment of the present invention having such a configuration, the color conversion can be recognized when the single gray is distributed and the same gray is concentrated. For this reason, the PDP driving apparatus of the present invention can increase the dynamic range by using the distribution degree of the same gray level, thereby preventing excessive color change of the image and improving the contrast to obtain a clear image.

As described above, the apparatus and method for color correction of a plasma display panel using the dynamic range expansion method according to the present invention is to detect the minimum and lower gray levels of the minimum distribution detected by the histogram distribution ratio with respect to the gray levels of the moving image input image. Can be converted by a predetermined amount depending on the degree of motion image and the same gray level distribution. As a result, the converted minimum distribution lower and upper gray levels are applied to the dynamic range of the moving image input image to enlarge the image, thereby preventing excessive color change of the image and improving contrast, thereby displaying a clear moving image.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

1 is a block diagram illustrating an apparatus for driving a plasma display panel using a dynamic range expansion method according to the related art.

FIG. 2 is a block diagram illustrating in detail the PDP driver shown in FIG. 1.

FIG. 3 is a flow chart for explaining the dynamic range expansion method described with reference to FIG. 1.

4 is a diagram showing a histogram distribution change with respect to a gray level according to the prior art.

5A and 5B illustrate changes in the display image before and after applying the dynamic range expansion method.

FIG. 6 is a diagram for comparing only a part of the display image illustrated in FIG. 5B.

7A and 7B illustrate changes in histogram distribution after dynamic range expansion according to the prior art.

8A and 8B illustrate changes in a display image of a portion of FIG. 6.

9A and 9B are diagrams illustrating changes of a display image with respect to another part of FIG. 6.

FIG. 10 is a diagram illustrating an example of color error conversion when driving a plasma display panel using a dynamic range expansion method according to the related art.

11 is a block diagram illustrating a color correction apparatus of a plasma display panel using a dynamic range expansion method according to a first embodiment of the present invention.

FIG. 12 is a detailed block diagram illustrating the plasma display panel driver illustrated in FIG. 11.

FIG. 13 is a block diagram illustrating a color correction apparatus of a plasma display panel using a dynamic range expansion method according to a second embodiment of the present invention.

14 is a view illustrating in detail the movement degree determining unit in FIG. 13.

FIG. 15 is a detailed block diagram illustrating the plasma display panel driver illustrated in FIG. 13.

16 is a block diagram illustrating a color correction apparatus of a plasma display panel using a dynamic range expansion method according to a third embodiment of the present invention.

FIG. 17 is a diagram illustrating in detail the lowest and lower gray level detectors shown in FIG. 16.

FIG. 18 is a detailed diagram illustrating the lower and upper gray level detectors of the corrected minimum distribution shown in FIG. 16.

FIG. 19 is a detailed block diagram illustrating the plasma display panel driver illustrated in FIG. 16.

<Description of Symbols for Main Parts of Drawings>

12: input line 14,50,80,120: frame memory

16,58,92,132: Dynamic Range Adjustment Unit

18,60,94,134: PDP driver

22,56,86: Gray level histogram detector

24,57,88: Minimum distribution gray level value determining unit

32,62,102,142: reverse gamma correction unit 34,64,104,144: gain control unit

36,66,106,146: Error diffusion unit 38,68,108,148: Subfield mapping unit

40,70,110,150: Data sorter 44,74,114,154: APL

46,76,116,156: Waveform generator 48,78,118,158: Panel

52, 82, 122: motion detection unit 54, 84, 124: motion degree determining unit

90: weight applying unit 128: same gray level distribution detection unit

130: correction minimum distribution lower and upper gray level setting unit

Claims (24)

A frame memory for storing video data input from an external input line in units of frames, A dynamic range adjusting unit which is connected in series to the frame memory and expands the dynamic range of the moving picture data via the frame memory by using the minimum distribution lower and upper gray levels when the amount of movement between the previous and current frames is greater than a preset threshold; , A plasma display panel driver connected in series to the dynamic range adjusting unit to control and supply a corrected image data signal having an enlarged dynamic range to a panel; A minimum distribution lower and upper gray level detection unit connected in parallel with the frame memory between the input line and the dynamic range adjusting unit to detect a minimum distribution lower and upper gray level during one frame; And a motion amount detecting unit connected in parallel with the frame memory between the input line and the dynamic range adjusting unit to detect a motion amount between a previous and a current frame. . The method of claim 1, The motion detection unit detects the movement degree at the same point by comparing the previous and current frame data, and determines the presence or absence of movement according to the movement degree; And a motion degree judging unit which receives a degree of motion for each image from the motion detection unit from input data and detects information on whether the degree of motion occurs on the entire screen between frames. A color correction device for a plasma display panel using an enlargement method. The method of claim 1, The minimum and lower gray level histogram detectors detect respective gray levels of the video data during one frame input from the outside, and then detect lower and upper gray level histogram detectors to detect histogram distribution ratios of distribution numbers of lower and upper gray levels; , And a minimum distribution lower and upper gray level determination unit connected in series to the lower and upper gray level histogram detectors to determine a minimum distribution lower gray level. The method of claim 1, The plasma display panel driver includes an inverse gamma correction unit that linearly converts a luminance value according to a gray value of an image signal by performing an inverse gamma correction on the video signal via the dynamic range adjusting unit; A gain controller for amplifying the video signal corrected by the inverse gamma correction unit by an effective gain; An error diffusion unit for finely adjusting the luminance value by diffusing an error component of the cell into adjacent cells; A subfield mapping unit for reallocating the video data corrected by the error diffusion unit for each subfield; And a data alignment unit for aligning the video signals to be supplied to the display panel. The method of claim 4, wherein An average image value (APL) unit receiving the video data corrected by the inverse gamma correction unit and generating an N-stage signal for adjusting the number of sustain pulses; And a waveform generator for generating a timing control signal based on the N-stage signal input from the average image value unit and supplying the generated timing control signal to a driving integrated circuit of the display panel. Color correction device of the plasma display panel. A frame memory for storing video data input from an external input line in units of frames, Dynamically expands the dynamic range of video data via the frame memory by using weighted minimum distribution lower and upper gray levels when the amount of movement between the previous and current frames is greater than the preset threshold, connected in series to the frame memory. With a range adjustment part, A plasma display panel driver connected in series to the dynamic range adjusting unit to control and supply a corrected image data signal having an enlarged dynamic range to a panel; A minimum distribution lower and upper gray level detection unit connected in parallel with the frame memory between the input line and the dynamic range adjusting unit to detect a minimum distribution lower and upper gray level during one frame; The minimum distribution lower gray level is lower and the minimum distribution upper gray level is higher than the minimum distribution lower and upper gray level detection unit and the dynamic range adjusting unit is connected to the dynamic range adjusting unit so that the movement amount is smaller than a preset threshold. And a weight applying unit to apply weights to the upper gray levels; The input line, the frame memory and the weight applying unit are connected in parallel with the minimum distribution lower and upper gray level detector to detect and determine the amount of motion between the previous and current frames, and control information and the detected amount of motion are added to the weight applying unit. A color correction apparatus for a plasma display panel using a dynamic range expansion method, characterized in that it comprises a movement amount determining unit for supplying. The method of claim 6, The motion amount determining unit compares the previous and current frame data with a motion detection unit for detecting a degree of movement; And a motion degree determining unit for detecting the amount of motion from the degree of motion and determining the degree of motion. The method of claim 7, wherein The motion degree determining unit calculating a motion amount for one frame from the detected motion degree; And a motion amount determiner configured to compare the calculated motion amount with a preset motion threshold to determine the magnitude of the motion. The method of claim 6, The plasma display panel driver includes an inverse gamma correction unit that linearly converts a luminance value according to a gray value of an image signal by performing an inverse gamma correction on the video signal via the dynamic range adjusting unit; A gain controller for amplifying the video signal corrected by the inverse gamma correction unit by an effective gain; An error diffusion unit for finely adjusting the luminance value by diffusing an error component of the cell into adjacent cells; A subfield mapping unit for reallocating the video data corrected by the error diffusion unit for each subfield; And a data alignment unit for aligning the video signals to be supplied to the display panel. The method of claim 9, An average image value (APL) unit receiving the video data corrected by the inverse gamma correction unit and generating an N-stage signal for adjusting the number of sustain pulses; And a waveform generator for generating a timing control signal based on the N-stage signal input from the average image value unit and supplying the generated timing control signal to a driving integrated circuit of the display panel. Color correction device of the plasma display panel. delete delete delete delete delete delete Detecting a minimum distribution lower and upper gray level for the moving image input image; Detecting a motion amount by comparing previous and current frames with respect to the moving image input image; Converting the detected minimum distributed lower and upper gray levels so that the detected minimum distributed lower gray level is lower and the detected minimum distributed upper gray level is higher when the detected motion amount is less than or equal to a preset threshold; And enlarging the dynamic range of the input image using the converted minimum distribution lower and upper gray levels. delete delete delete The method of claim 17, The detecting of the motion amount by comparing the previous and current frames with respect to the moving image input image may include detecting a histogram distribution ratio which is a distribution number of the detected gray levels; And determining a minimum distribution lower and an upper gray level by using the histogram distribution ratio. The method of claim 21, The detecting of the histogram distribution ratio may include determining a histogram number of each gray level; And dividing the number of the histograms by the resolution of the input image and displaying the result as a percentage. The method of claim 21, Determining the minimum distribution lower and upper gray levels comprises setting a threshold for the histogram distribution ratio; And setting the first gray level coming out of the threshold value to a minimum distribution lower and upper gray level as a minimum distribution. The method of claim 17, The step of enlarging the dynamic range of the input image may include determining a gray level of image data input from the outside; And determining a gray level of the image data corrected using the gray level, the minimum distribution lower and upper gray levels of the input image data.