WO2018035899A1 - 图像处理方法 - Google Patents

图像处理方法 Download PDF

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WO2018035899A1
WO2018035899A1 PCT/CN2016/098809 CN2016098809W WO2018035899A1 WO 2018035899 A1 WO2018035899 A1 WO 2018035899A1 CN 2016098809 W CN2016098809 W CN 2016098809W WO 2018035899 A1 WO2018035899 A1 WO 2018035899A1
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pixel
value
image
processing method
image processing
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French (fr)
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张源
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TCL China Star Optoelectronics Technology Co Ltd
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Shenzhen China Star Optoelectronics Technology Co Ltd
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Priority to US15/308,591 priority Critical patent/US10147368B2/en
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    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G09G3/3607Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00Details of television systems
    • H04N5/14Picture signal circuitry for video frequency region
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G09G3/3611Control of matrices with row and column drivers
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00Control of display operating conditions
    • G09G2320/02Improving the quality of display appearance
    • G09G2320/0233Improving the luminance or brightness uniformity across the screen
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00Control of display operating conditions
    • G09G2320/02Improving the quality of display appearance
    • G09G2320/029Improving the quality of display appearance by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2360/00Aspects of the architecture of display systems
    • G09G2360/16Calculation or use of calculated indices related to luminance levels in display data
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/03Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes specially adapted for displays having non-planar surfaces, e.g. curved displays

Definitions

  • the present invention relates to the field of liquid crystal display, and more particularly to an image processing method.
  • TFT-LCD thin film transistor-liquid crystal display
  • TFT-LCD thin film transistor-liquid crystal display
  • color ray In the production of TFT-LCD, a major quality defect is called color ray (Mura).
  • Mura color ray
  • the main manifestation of color smear is that some RGB pixels are displayed on the premise that all RGB pixels of TFT-LCD display the same gray value.
  • the gray value is significantly different from the gray value displayed by most of the surrounding RGB pigments, and the color spots may also exhibit a variety of different shapes, such as linear spots, spotted spots, and other irregular shapes.
  • the color spots In the prior art, there are many reasons for the occurrence of color spots, such as processing or mounting quality problems of a color filter, cell gaps generated during glass mounting, excessive spacing between pixels, and damage.
  • most of the existing color spot compensation methods require more color spot detection and compensation time, and the compensation effect is poor. Therefore, it is necessary to perform image processing on the screen displayed on the liquid crystal display.
  • the present invention provides an image processing method capable of performing color spot compensation on a display screen of a liquid crystal display, thereby reducing detection and compensation time of a stain, and improving display quality of the screen.
  • an embodiment of the present invention provides an image processing method for color spot detection and compensation of a flat panel display, the image processing method comprising the following steps:
  • step (a) To calculate an average of the gray value of each pixel of the global original image, where p i (i, j) represents the gray value of each pixel, and V lmean represents the average value of the gray value of each pixel.
  • step (b) comprises the following substeps:
  • step (b1) calculates the average and median values of the gray values of each pixel in each window, where V median represents the median value of the gray value of each pixel.
  • the patch compensation value for each window is calculated, where s(i,j) represents the patch value of each pixel of each window.
  • the standard deviation is calculated, where p n3 (i, j) is the gray value of each pixel of the last image obtained.
  • step (g) when the standard deviation is greater than the preset value, returning to the step (b).
  • step (f) the above steps (b) to (e) are repeated twice or three times.
  • the compressed color spot compensation table is stored in the timing controller of the display, and the timing controller can perform the lossless reduction on the compressed color spot compensation table in a wavelet manner.
  • the image processing method performs a window calculation on the image to calculate the color spot value of each window, thereby obtaining the color spot value of the entire image, according to the color spot value and the pixel of the current image.
  • the average value of the stain is calculated, and a corresponding compensation table is generated, which can compensate the color spot of the liquid crystal display, thereby reducing the detection and compensation time of the stain, and improving the display quality of the screen, and the compensation table is compressed by the wavelet method. Storage can improve the compensation effect and reduce the space required for storage.
  • FIG. 1 is a flow chart of an image processing method according to an embodiment of the present invention.
  • FIG. 2(a) is a schematic diagram showing a two-dimensional image of an original picture in an embodiment of the present invention.
  • Fig. 2(b) is a schematic diagram of a three-dimensional image generated from the original picture of Fig. 2(a).
  • Fig. 2(c) is a schematic view showing the effect of compensating the three-dimensional image of Fig. 2(b).
  • connection In the description of the present invention, it should be noted that the terms “installation”, “connected”, and “connected” are to be understood broadly, and may be fixed or detachable, for example, unless otherwise explicitly defined and defined.
  • the ground connection, or the integral connection may be a mechanical connection; it may be directly connected, or may be indirectly connected through an intermediate medium, and may be internal communication between the two elements.
  • the specific meaning of the above terms in the present invention can be understood in a specific case by those skilled in the art.
  • the color spot (Mura) of the flat panel display is detected and supplemented.
  • the CCD (Charge Coupled Device) camera According to the gradation data of the flat panel display collected by the CCD (Charge Coupled Device) camera, the point-to-point color spot recognition and compensation of the 4K or 8K flat panel display can be accurately performed; the collected gray scale data is utilized.
  • Use mathematical statistics methods such as mean square error, to find background data from the acquired grayscale data, and then generate a point-to-point color patch compensation table for 4K or 8K flat panel display based on background data and raw data;
  • the compensation table is 4K data of 4K or 8K, so the wavelet algorithm is used to compress the stain compensation table to 1/16 or 1/64 of the original data, and the compressed color patch compensation table is stored to TCON (Timing Controller, timing). Controller) to reduce the cost of hardware such as TCON; use the wavelet algorithm to reduce the compressed compensation table stored in TCON to 4K or 8K point-to-point color without loss in LCD (Liquid Crystal Display) display Spot compensation table for use in real-time reality.
  • FIG. 1 is a flowchart of an image processing method according to an embodiment of the present invention.
  • the image processing method can be used for image processing of a displayed screen of a liquid crystal display to compensate for the color spot thereof.
  • the image processing method can include at least the following steps:
  • step (a) To calculate an average of the gray value of each pixel of the global original image, where p i (i, j) represents the gray value of each pixel, and V lmean represents the average value of the gray value of each pixel.
  • step (b) includes the following sub-steps:
  • step (b1) calculates an average value and a median value of each pixel gray value in each window, wherein V median represents a median value of each pixel gray value;
  • a color spot compensation value of each pixel gray value of the local original image may be calculated
  • step (c) according to the formula:
  • the patch compensation value for each window is calculated; where s(i, j) represents the patch compensation value for each pixel gray value of each window.
  • the gray value of each pixel of the image obtained after the Nth update is p n3 (i, j), according to the formula:
  • the standard deviation can be calculated.
  • the preset value may be determined according to the quality of the desired display image.
  • the standard deviation is less than or equal to the preset value, performing step (h); and, when the standard deviation is greater than the preset value, returning to step (b).
  • the stain compensation table is compressed (for example, compressed 2 to 3 times) by a wavelet (Wavelet) compression method, and the compressed color patch compensation table is stored.
  • the timing controller of the LCD display stores the timing controller of the LCD display. It can be understood that, when actually used, the timing controller can perform the non-destructive reduction of the compressed color spot compensation table in a wavelet manner and display through the liquid crystal display, that is, the compression and losslessness of the color spot compensation table by using wavelet image compression technology. reduction.
  • V t represents the spot threshold
  • (2-3) calculating a patch compensation value of each pixel of the local original image according to the color patch threshold
  • the patch compensation value of each pixel gray value of the local original image is calculated according to the determined color patch threshold V t ;
  • the patch compensation value for each window is calculated; where s(i, j) represents the patch compensation value for each pixel gray value of each window.
  • step (7) comparing the calculated standard deviation with a preset value, wherein the preset value can be based on The quality of the image to be displayed is determined.
  • step (7) is performed; when the standard deviation is greater than the preset value, then returning to step (2).
  • the color patch threshold in each image window is established in an adaptive manner to identify the color spot, and the color spot of the liquid crystal display is recognized and the color spot compensation is established by an adaptive method. table.
  • the number of times the color patch compensation table is compressed may be 2 to 3 times, and the compressed color spot compensation table may be stored in a timing controller of the liquid crystal display. It can be understood that, when actually used, the timing controller can perform the lossless reduction of the compressed color spot compensation table in a wavelet manner and display through the liquid crystal display, that is, using the wavelet image compression technology to realize the compression of the stain compensation table. Lossless reduction.
  • FIG. 2( a ) is a schematic diagram of a two-dimensional image of an original picture in an embodiment of the present invention
  • FIG. 2( b ) is a diagram according to FIG. 2 ( a )
  • 2(c) is a schematic diagram of an image after compensating the three-dimensional image of FIG. 2(b).
  • the image can be clearly displayed at each coordinate.
  • the intensity of the image on the point (x, y), and the edges and interior of the picture are smooth and flat. For better picture display quality and display.
  • the image processing method of the embodiment of the present invention performs a window calculation on the image to calculate the color spot value of each window, thereby obtaining the color spot value of the entire image, and calculating the color spot according to the color spot value and the pixel average value of the current image.
  • Standard deviation and generate a corresponding compensation table, which can compensate the color spot of the liquid crystal display, thereby reducing the detection and compensation time of the stain, and improving the display quality of the screen
  • the compensation table is compressed and stored by the wavelet method, which can improve Compensation effect and reduce the space required for storage.

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Abstract

一种图像处理方法,包括以下步骤:计算全局原始图像的每个像素灰度值的平均值(a);计算每个局域图像的所有像素灰度值的平均值和中值(b1);计算每个窗口的色斑阀值(b2);计算出局域原始图像的每个像素的色斑补偿值(c);将局域原始图像的像素的灰度值加上色斑补偿值获得更新后的局域图像的每个像素的灰度值(d);将更新后的图像进行显示(e);将多次更新后的图像的灰度值与所有像素的平均值计算出标准差(f);将标准差与预设值进行比较(g);当该标准差大于预设值时,执行步骤(b1);当该标准差小于或者等于预设值时,根据所计算的标准差生成色斑补偿表,并将该色斑补偿表进行压缩后存储(h)。

Description

图像处理方法
本发明要求2016年08月25日递交的发明名称为“图像处理方法”的申请号201610724656.7的在先申请优先权,上述在先申请的内容以引入的方式并入本文本中。
技术领域
本发明涉及液晶显示领域,尤其是涉及一种图像处理方法。
背景技术
TFT-LCD(thin film transistor-liquid crystal display,薄膜晶体管液晶显示器)已经成为各个平板显示器制造厂家的主要产品,而且TFT-LCD正朝着大尺寸、曲面化的方向发展,所以TFT-LCD的品质直接关系到各个平板显示器制造厂家的生存。因此,在TFT-LCD的生产制造过程中,对TFT-LCD进行品质检测就显得尤为重要。
在TFT-LCD的生产中,一种主要的品质缺陷称为色斑(Mura),色斑的主要体现是在要求TFT-LCD所有RGB像素显示相同灰度值的前提下,一部分RGB像素所显示的灰度值与邻近周围大部分RGB色素所显示的灰度值有明显差异,而且色斑还可能呈现出多种不同的形状,比如线状色斑、点状色斑、和其他不规则形状的色斑。在现有技术中,产生色斑的原因有很多,例如,彩色滤光片(Color Filter)的加工或安装质量问题、玻璃安装过程中产生的单元隙缝、像素之间过多的间隔、受到损坏的面板基板、上下面板胶合后因为漏光而产生的对准问题等。然而,由于上述产生色斑的原因,现有的色斑补偿方法大多需要较多的色斑检测和补偿时间,而且补偿效果较差。因此,有必要对液晶显示器所显示的画面进行图像处理。
发明内容
针对现有技术中存在的问题,本发明提供一种图像处理方法,其可对液晶显示器显示画面进行色斑补偿,从而减少色斑的检测和补偿时间,并提高其画面显示质量。
为了实现上述目的,本发明实施方式提供一种用于平板显示器色斑检测和补偿的图像处理方法,该图像处理方法包括以下步骤:
(a)计算全局原始图像的每个像素灰度值的平均值;
(b)以自适应的方法,根据局域图像的像素灰度值的中值和平均值计算出局域原始图像的所有像素灰度值的色斑阀值;
(c)根据所述色斑阀值,计算出局域原始图像的每个像素的色斑补偿值;
(d)将局域原始图像的每个像素的灰度值加上计算出的色斑补偿值得到更新后的局域图像的每个像素的灰度值;
(e)将更新后的图像进行显示;
(f)对于更新后的图像,变换局域大小后重复上述步骤(b)至(e)若干次数,将最后得到图像的每个像素的灰度值与步骤(a)中得到的所有像素的平均值计算出标准差;
(g)将所述标准差与预设值进行比较;以及
(h)当该标准差小于或者等于所述预设值时,根据所计算的标准差生成色斑补偿表,并将该色斑补偿表以小波的压缩方式进行压缩后存储。
其中,在所述步骤(a)中,根据公式:
Figure PCTCN2016098809-appb-000001
来计算全局原始图像的每个像素灰度值的平均值,其中,pi(i,j)代表每个像素灰度值,Vlmean代表每个像素灰度值的平均值。
其中,所述步骤(b)包括以下子步骤:
(b1)将图像分为若干窗口,计算每个窗口内的每个局域图像的像素灰度值的平均值和中值;以及
(b2)计算每个窗口的色斑阀值。
其中,在所述步骤(b1)中,分别根据公式:
Figure PCTCN2016098809-appb-000002
以及Vmedian=med(pi(i,j))计算每个窗口内的每个像素灰度值的平均值和中值,其 中,Vmedian代表每个像素灰度值的中值。
其中,在所述步骤(b2)中,根据公式:Vt=a*Vmedian+β*Vlmean计算每个窗口的色斑阀值,其中,
Figure PCTCN2016098809-appb-000003
β=1-a,Vt代表色斑阀值。
其中,在所述步骤(c)中,根据公式:
Figure PCTCN2016098809-appb-000004
计算每个窗口的色斑补偿值,其中,s(i,j)代表每个窗口的每个像素的色斑值。
其中,所述的步骤(f)中,根据公式:
Figure PCTCN2016098809-appb-000005
计算出标准差,其中,pn3(i,j)为最后得到图像的每个像素的灰度值。
其中,在所述的步骤(g)中,当所述标准差大于所述预设值时,则返回至所述步骤(b)。
其中,所述的步骤(f)中,重复上述步骤(b)至(e)为2次或者3次。
其中,在所述的步骤(h)中,压缩后的色斑补偿表存储至显示器的时序控制器内,该时序控制器可将该压缩色斑补偿表以小波的方式无损还原。
相较于现有技术,本发明实施例所述的图像处理方法对图像进行分窗口计算每个窗口的色斑值,进而获得整幅图像的色斑值,根据色斑值及当前图像的像素平均值计算色斑标准差,并生成对应的补偿表,可对液晶显示器的色斑进行补偿,从而减少色斑的检测和补偿时间,并提高其画面显示质量,且该补偿表通过小波方式压缩存储下来,可提高补偿效果及减小存储所需空间。
附图说明
为了更清楚地说明本发明实施例或现有技术中的技术方案,下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍,显而易见地,下面描述中的附图仅仅是本发明的一些实施例,对于本领域普通技术人员来讲,在不付 出创造性劳动的前提下,还可以根据这些附图获得其他的附图。
图1为本发明的实施例的图像处理方法的流程图。
图2(a)为本发明的实施例中的原始图片的二维图像示意图。
图2(b)为根据图2(a)原始图片产生的三维图像示意图。
图2(c)为对图2(b)的三维图像进行补偿后的效果示意图。
具体实施方式
下面将结合本发明实施例中的附图,对本发明实施例中的技术方案进行清楚、完整地描述,显然,所描述的实施例仅仅是本发明一部分实施例,而不是全部的实施例。基于本发明中的实施例,本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例,都属于本发明保护的范围。
此外,以下各实施例的说明是参考附加的图示,用以例示本发明可用以实施的特定实施例。本发明中所提到的方向用语,例如,“上”、“下”、“前”、“后”、“左”、“右”、“内”、“外”、“侧面”等,仅是参考附加图式的方向,因此,使用的方向用语是为了更好、更清楚地说明及理解本发明,而不是指示或暗指所指的装置或元件必须具有特定的方位、以特定的方位构造和操作,因此不能理解为对本发明的限制。
在本发明的描述中,需要说明的是,除非另有明确的规定和限定,术语“安装”、“相连”、“连接”应做广义理解,例如,可以是固定连接,也可以是可拆卸地连接,或者一体地连接;可以是机械连接;可以是直接相连,也可以通过中间媒介间接相连,可以是两个元件内部的连通。对于本领域的普通技术人员而言,可以具体情况理解上述术语在本发明中的具体含义。
此外,在本发明的描述中,除非另有说明,“多个”的含义是两个或两个以上。若本说明书中出现“工序”的用语,其不仅是指独立的工序,在与其它工序无法明确区别时,只要能实现该工序所预期的作用则也包括在本用语中。另外,本说明书中用“~”表示的数值范围是指将“~”前后记载的数值分别作为最小值及最大值包括在内的范围。在附图中,结构相似或相同的单元用相同的标号表示。
在本发明中的实施例中,在对平板显示器的色斑(Mura)进行检测和补 偿时,根据CCD(Charge Coupled Device,电荷耦合器件)相机采集到的平板显示器的灰度数据,精确的做到4K或8K平板显示器的点对点的色斑辨识和补偿;利用采集到的灰度数据,使用数理统计的方法,比如均方差等方法,从采集到的灰度数据里找出背景数据,再根据背景数据和原始数据产生4K或8K平板显示器的点对点的色斑补偿表;因为色斑补偿表是4K或8K的12bit数据,所以使用小波的算法来压缩色斑补偿表到原始数据的1/16或1/64,并将压缩后的色斑补偿表存储至TCON(Timing Controller,时序控制器)中,以减少TCON等硬件的成本;在LCD(Liquid Crystal Display,液晶显示器)显示时利用小波算法将TCON里储存的压缩后的补偿表无损耗地还原成4K或8K的点对点的色斑补偿表,以便在实时现实中利用。
请参阅图1,图1为本发明的实施例的图像处理方法的流程图。该图像处理方法可用于液晶显示器的显示的画面进行图像处理,以对其色斑进行补偿,如图1所示,该图像处理方法可包括至少以下步骤:
(a)计算全局原始图像的每个像素灰度值的平均值;
具体地,在所述步骤(a)中,根据公式:
Figure PCTCN2016098809-appb-000006
来计算全局原始图像的每个像素灰度值的平均值,其中,pi(i,j)代表每个像素灰度值,Vlmean代表每个像素灰度值的平均值。
(b)以自适应的方法,根据局域图像的像素灰度值的中值和平均值计算出局域原始图像的所有像素灰度值的色斑阀值;
具体地,在本较佳实施例中,所述步骤(b)包括以下子步骤:
(b1)将原始图像分为若干窗口,计算每个窗口内的每个局域图像的像素灰度值的平均值和中值;
具体地,在所述步骤(b1)中,分别根据公式:
Figure PCTCN2016098809-appb-000007
以及Vmedian=med(pi(i,j))计算每个窗口内的每个像素灰度值的平均值和中值,其中,Vmedian代表每个像素灰度值的中值;
(b2)计算每个窗口的色斑阀值;
具体地,在所述步骤(b2)中,根据公式:Vt=a*Vmedian+β*Vlmean计算每个窗口的色斑阀值,其中,
Figure PCTCN2016098809-appb-000008
β=1-a,Vt代表色斑阀值。
(c)根据所述色斑阀值,计算出局域原始图像的每个像素的色斑补偿值;
具体地,在所述步骤(c)中,根据所述色斑阀值,可计算出局域原始图像的每个像素灰度值的色斑补偿值;
具体地,在所述步骤(c)中,可根据公式:
Figure PCTCN2016098809-appb-000009
计算每个窗口的色斑补偿值;其中,s(i,j)代表每个窗口的每个像素灰度值的色斑补偿值。
(d)将局域原始图像的每个像素的灰度值加上所述色斑补偿值得到更新后的局域图像的每个像素的灰度值;
具体地,在所述步骤(d)中,更新后的局域图像的每个像素的灰度值可为:pn1(i,j)=s(i,j)+pi(i,j)。
(e)将更新后的图像进行显示。
(f)对于所述更新后的图像,重复上述步骤(b)至(e)N次得到第N次更新后的图像的每个像素的灰度值,当输入第N次更新后的图像时,将第N-1次更新后的图像的每个像素的灰度值与步骤(a)中得到的所有像素的平均值计算出标准差;
具体地,在较佳实施例中,重复上述步骤(b)至(e)的次数N=2或3,则在所述的步骤(f)中,重复上述步骤(b)至(e)N次得到第N次更新后的图像的每个像素的灰度值为pn3(i,j),根据公式:
Figure PCTCN2016098809-appb-000010
可计算出标准差。
(g)将所计算的标准差与预设值进行比较;
具体地,在所述步骤(g)中,该预设值可根据所需显示图像的质量确定。当该标准差小于或者等于所述预设值时,进行步骤(h);以及,当该标准差大于所述预设值时,则返回至步骤(b)。
(h)根据所计算的标准差生成色斑补偿表,并将该色斑补偿表压缩后进行存储;
具体地,在所述步骤(h)中,所述色斑补偿表以小波(Wavelet)的压缩方式进行压缩后(例如,压缩2到3次),进行存储,该压缩后的色斑补偿表存储至液晶显示器的时序控制器内。可以理解,当实际运用时,该时序控制器可将该压缩色斑补偿表以小波的方式无损还原,并通过该液晶显示器进行显示,即利用小波图像压缩技术实现色斑补偿表的压缩和无损还原。
结合上述图像处理方法的流程图,下文对该图像处理方法进行举例说明。
(1)计算全局原始图像的每个像素灰度值的平均值;
根据公式:
Figure PCTCN2016098809-appb-000011
来计算全局原始图像的每个像素灰度值的平均值,其中,pi(i,j)代表每个像素灰度值,Vlmean代表每个像素灰度值的平均值。
(2)以自适应的方法,根据局域图像的像素灰度值的中值和平均值计算出局域原始图像的所有像素灰度值的色斑阀值,并根据所述色斑阀值计算局域原始图像的每个像素的色斑补偿值;当第一副采集灰度图像输入时,整副图像被分为16x16的多个窗口,比如1920x1080的输入图像被分为120x68个窗口,每个窗口要进行如下运算:
(2-1)将原始图像分为若干窗口,计算每个窗口内的每个局域图像的像素灰度值的平均值和中值;分别根据公式:
Figure PCTCN2016098809-appb-000012
以及Vmedian=med(pi(i,j))计算每个窗口内的每个像素灰度值的平均值和中值,其中,Vmedian代表每个像素灰度值的中值;
(2-2)计算每个窗口的色斑阀值;
根据公式:Vt=a*Vmedian+β*Vlmean计算每个窗口的色斑阀值,其中,
Figure PCTCN2016098809-appb-000013
β=1-a,Vt代表色斑阀值;以及
(2-3)根据所述色斑阀值,计算出局域原始图像的每个像素的色斑补偿值;
具体地,根据求出的色斑阀值Vt计算出局域原始图像的每个像素灰度值的色斑补偿值;
根据公式:
Figure PCTCN2016098809-appb-000014
计算每个窗口的色斑补偿值;其中,s(i,j)代表每个窗口的每个像素灰度值的色斑补偿值。
(2-4)将原始图像的每个像素的灰度值加上计算出的色斑值得到第一更新后的图像的每个像素的灰度值;
具体地,更新后的图像的每个像素的灰度值为:pn1(i,j)=s(i,j)+pi(i,j)。
(2-5)将每个像素点灰度值都更新的图像显示在液晶显示器上,以备下一步的图像采集。
(3)当输入在步骤(2)更新的灰度图像时,整副图像被分为32x32的多个窗口,比如1920x1080的输入图像被分为60x34个小窗口,则每个窗口重复进行上述步骤(2-1)至(2-5)的运算,并获得更新后的图像的每个像素的灰度值为:pn2(i,j)=s(i,j)+pn1(i,j),并将每个像素点灰度值都更新的图像显示在液晶显示器上,以备下一步的图像采集。
(4)当输入在步骤(3)更新的灰度图像时,整副图像被分为64x64的多个窗口,比如1920x1080的输入图像被分为30x17个小窗口,则每个窗口重复进行上述步骤(2-1)至(2-5)的运算,并获得更新后的图像的每个像素的灰度值为:pn3(i,j)=s(i,j)+pn2(i,j),并将每个像素点灰度值都更新的图像显示在液晶显示器上,以备下一步的图像采集。因此,通过采用不同尺寸的图像窗口,不仅考虑到局部的像素灰度值对色斑辨识的影响,也考虑到大范围的像素灰度值对色斑辨识的影响。
(5)当输入在步骤(4)更新的灰度值pn3(i,j)图像时,将步骤(3)更新后的图像的像素的灰度值与步骤(1)中得到的像素的平均值Vlmean运算得出标准差;具体地,在本在较佳实施例中,可根据公式:
Figure PCTCN2016098809-appb-000015
计算出标准差。
(6)将计算出的标准差与一预设值进行比较,其中,该预设值可根据所 需显示图像的质量确定。当该标准差小于或者等于所述预设值时,进行步骤(7);当该标准差大于所述预设值时,则返回至步骤(2)。
(7)将根据所计算的标准差生成色斑补偿表,并将上述色斑补偿表以小波(Wavelet)的压缩方式进行压缩后存储;
具体地,在所述步骤(7)中,以自适应的方法建立各个图像窗口里的色斑阀值,以辨识色斑,并以自适应的方法辨识液晶显示器的色斑和建立色斑补偿表。所述色斑补偿表压缩的次数可为2到3次,该压缩后的色斑补偿表可存储至液晶显示器的时序控制器内。可以理解,当实际运用时,该时序控制器可将该压缩色斑补偿表以小波的方式无损还原,并通过该液晶显示器进行显示,即,利用小波图像压缩技术实现色斑补偿表的压缩和无损还原。
请一并参阅图2(a)至图2(c),其中,图2(a)为本发明的实施例中的原始图片的二维图像示意图;图2(b)为根据图2(a)原始图片产生的三维图像示意图,为了直观地显示原始图片在每个坐标点(x,y)上的图像强度,根据原始图片产生的3维图像。图2(c)为对图2(b)的三维图像进行补偿后的图像示意图,由该图2(c)可知,经过上述图像处理方法的补偿处理后,可以清楚地显示图片在每个坐标点(x,y)上的图像强度,且图片的边缘和内部均光滑、平整。以获得较佳的画面显示质量和显示效果。
综上所述,本发明实施例图像处理方法对图像进行分窗口计算每个窗口的色斑值,进而获得整幅图像的色斑值,根据色斑值及当前图像的像素平均值计算色斑标准差,并生成对应的补偿表,可对液晶显示器的色斑进行补偿,从而减少色斑的检测和补偿时间,并提高其画面显示质量,且该补偿表通过小波方式压缩存储下来,可提高补偿效果及减小存储所需空间。
在本说明书的描述中,参考术语“一个实施例”、“一些实施例”、“示例”、“具体示例”或“一些示例”等的描述意指结合该实施例或示例描述的具体特征、结构、材料或者特点包含于本发明的至少一个实施例或示例中。在本说明书中,对上述术语的示意性表述不一定指的是相同的实施例或示例。而且,描述的具体特征、结构、材料或特点可以在任何的一个或多个实施例或示例中以合适的方式结合。
以上所揭露的仅为本发明一种较佳实施例而已,当然不能以此来限定本发 明之权利范围,本领域普通技术人员可以理解实现上述实施例的全部或部分流程,并依本发明权利要求所作的等同变化,仍属于发明所涵盖的范围。

Claims (20)

  1. 一种用于平板显示器色斑检测和补偿的图像处理方法,所述图像处理方法包括以下步骤:
    (a)计算全局原始图像的每个像素灰度值的平均值;
    (b)以自适应的方法,根据局域图像的像素灰度值的中值和平均值计算出局域原始图像的所有像素灰度值的色斑阀值;
    (c)根据所述色斑阀值,计算出局域原始图像的每个像素的色斑补偿值;
    (d)将局域原始图像的每个像素的灰度值加上所述色斑补偿值得到更新后的局域图像的每个像素的灰度值;
    (e)将更新后的图像进行显示;
    (f)对于更新后的图像,变换局域大小后重复上述步骤(b)至(e)若干次数,将最后得到图像的每个像素灰度值与步骤(a)中得到的所有像素的平均值计算出标准差;
    (g)将所述标准差与预设值进行比较;以及
    (h)当该标准差小于或者等于所述预设值时,根据所计算的标准差生成色斑补偿表,并将该色斑补偿表以小波的压缩方式进行压缩后存储。
  2. 如权利要求1所述的图像处理方法,其中,在所述步骤(a)中,根据公式:
    Figure PCTCN2016098809-appb-100001
    来计算全局原始图像的每个像素灰度值的平均值,其中,pi(i,j)代表每个像素灰度值,Vlmsan代表每个像素灰度值的平均值。
  3. 如权利要求2所述的图像处理方法,其中,所述步骤(b)包括:
    (b1)将图像分为若干窗口,计算每个窗口内的每个局域图像的像素灰度值的平均值和中值;以及
    (b2)计算每个窗口的色斑阀值。
  4. 如权利要求3所述的图像处理方法,其中,在所述步骤(b1)中,分别根据公式:
    Figure PCTCN2016098809-appb-100002
    以及Vmsdian=med(pi(i,j))计算每个窗口内的每 个像素灰度值的平均值和中值,其中,Vmsdian代表每个像素灰度值的中值。
  5. 如权利要求4所述的图像处理方法,其中,在所述步骤(b2)中,根据公式:Vt=a*Vmedian+β*Vlmean计算每个窗口的色斑阀值,其中,
    Figure PCTCN2016098809-appb-100003
    β=1-a,Vt代表色斑阀值。
  6. 如权利要求5所述的图像处理方法,其中,在所述步骤(c)中,根据公式:
    Figure PCTCN2016098809-appb-100004
    计算每个窗口的色补偿斑值,其中,s(i,j)代表每个窗口的每个像素的色斑补偿值。
  7. 如权利要求1所述的图像处理方法,其中,所述的步骤(f)中,根据公式:
    Figure PCTCN2016098809-appb-100005
    计算出标准差,其中,pn3(i,j)为最后得到图像的每个像素的灰度值。
  8. 如权利要求1所述的图像处理方法,其中,在所述的步骤(g)中,当所述标准差大于所述预设值时,则返回至步骤(b)。
  9. 如权利要求1所述的图像处理方法,其中,在所述步骤(f)中,重复上述步骤(b)至(e)为2次或者3次。
  10. 如权利要求1所述的图像处理方法,其中,在所述的步骤(h)中,压缩后的色斑补偿表存储至显示器的时序控制器内,该时序控制器将该压缩色斑 补偿表以小波的方式无损还原。
  11. 如权利要求2所述的图像处理方法,其中,所述的步骤(f)中,根据公式:
    Figure PCTCN2016098809-appb-100006
    计算出标准差,其中,pn3(i,j)为最后得到图像的每个像素的灰度值。
  12. 如权利要求3所述的图像处理方法,其中,所述的步骤(f)中,根据公式:
    Figure PCTCN2016098809-appb-100007
    计算出标准差,其中,pn3(i,j)为最后得到图像的每个像素的灰度值。
  13. 如权利要求4所述的图像处理方法,其中,所述的步骤(f)中,根据公式:
    Figure PCTCN2016098809-appb-100008
    计算出标准差,其中,pn3(i,j)为最后得到图像的每个像素的灰度值。
  14. 如权利要求5所述的图像处理方法,其中,所述的步骤(f)中,根据公式:
    Figure PCTCN2016098809-appb-100009
    计算出标准差,其中,pn3(i,j)为最后得到图像的每个像素的灰度值。
  15. 如权利要求6所述的图像处理方法,其中,所述的步骤(f)中,根据公式:
    Figure PCTCN2016098809-appb-100010
    计算出标准差,其中,pn3(i,j)为最后得到图像的每个像素的灰度值。
  16. 如权利要求2所述的图像处理方法,其中,在所述的步骤(h)中,压缩后的色斑补偿表存储至显示器的时序控制器内,该时序控制器将该压缩色斑补偿表以小波的方式无损还原。
  17. 如权利要求3所述的图像处理方法,其中,在所述的步骤(h)中,压缩后的色斑补偿表存储至显示器的时序控制器内,该时序控制器将该压缩色斑补偿表以小波的方式无损还原。
  18. 如权利要求4所述的图像处理方法,其中,在所述的步骤(h)中,压缩后的色斑补偿表存储至显示器的时序控制器内,该时序控制器将该压缩色斑补偿表以小波的方式无损还原。
  19. 如权利要求5所述的图像处理方法,其中,在所述的步骤(h)中,压缩后的色斑补偿表存储至显示器的时序控制器内,该时序控制器将该压缩色斑补偿表以小波的方式无损还原。
  20. 如权利要求6所述的图像处理方法,其中,在所述的步骤(h)中,压缩后的色斑补偿表存储至显示器的时序控制器内,该时序控制器将该压缩色斑补偿表以小波的方式无损还原。
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