WO2018086388A1

WO2018086388A1 - Image processing device and method, and a liquid crystal display device

Info

Publication number: WO2018086388A1
Application number: PCT/CN2017/095337
Authority: WO
Inventors: 王烨东; 刁玉洁
Original assignee: 青岛海信电器股份有限公司
Priority date: 2016-11-08
Filing date: 2017-07-31
Publication date: 2018-05-17
Also published as: CN106531092A; CN106531092B

Abstract

Disclosed are an image processing device and method, and a liquid crystal display device. The device comprises: at least one processor, and a memory. The memory stores instructions that can be executed by the at least one processor, and is used for reading the instructions for executing: obtaining gray scale values of all pixel points in a current image frame (S101); selecting a first gray scale value and a second gray scale value, which satisfy preset requirements, from the gray scale values of all the pixel points in the current image frame (S102); using the first gray scale value and the second gray scale value as input gray scale values, and determining, in a preset range according to a brightness adjustment relation, critical parameter values of a difference between output gray scale values respectively corresponding to the first gray scale value and the second gray scale value (S103); and adjusting the parameters in the brightness adjustment relation according to the critical parameter values, and adjusting the brightness and contrast ratio of all the pixel points in the current image frame according to the adjusted brightness adjustment relation (S104).

Description

Image processing device and method, liquid crystal display device

The present application claims the priority of the Chinese Patent Application, the entire disclosure of which is hereby incorporated by reference.

Technical field

The present disclosure relates to the field of image signal processing technologies, and in particular, to an image processing apparatus and method, and a liquid crystal display device.

Background technique

As shown in FIG. 1 , the liquid crystal display mainly includes a liquid crystal module 1 , a backlight module (not shown), a video processor 4 , and the like. The liquid crystal module 1 mainly includes a liquid crystal panel 2 and a thin film transistor-liquid crystal display ( a thin film Transistor-Liquid Crystal Display (TFT-LCD) driving circuit 3 is provided with a liquid crystal display unit 21 arranged in an array on the liquid crystal panel 2, and the TFT-LCD driving circuit 3 is electrically connected to the liquid crystal panel 2; On the back side of the liquid crystal panel 2, a backlight is provided for the liquid crystal display unit 21; the video processor 4 receives an image signal transmitted by the signal source, analyzes a digital signal such as a luminance signal and a chrominance signal in the image signal, and transmits the digital signal to the TFT- The LCD drive circuit 3, the TFT-LCD drive circuit 3 converts these digital signals into electrical signals, and drives the liquid crystal display unit 21 to display different brightness and chromaticity. Therefore, when the image processor 4 processes the image signal, by adjusting the image signal, the display brightness and chromaticity of the liquid crystal display unit 21 can be controlled, thereby ensuring the display effect of the liquid crystal display.

Summary of the invention

The present disclosure provides an image processing apparatus and method, and a liquid crystal display device.

In one aspect, some embodiments of the present disclosure provide an image processing apparatus, including:

At least one processor; and,

a memory communicatively coupled to the at least one processor; wherein

The memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to:

Obtaining the gray value of all pixels in the current image frame;

Selecting a first gray value and a second gray value from gray values of all pixels of the current image frame; wherein the first gray value is a maximum gray value, and the second gray value The second largest gray value; or the first gray level a value of a minimum gray value, and the second gray value is a second small gray value;

Taking the first gray value and the second gray value as input gray values, determining a first output gray value corresponding to the first gray value and the second gray value according to a brightness adjustment relationship a critical parameter value when a difference between the corresponding second output gray value is within a preset range; wherein the critical parameter value includes a critical contrast parameter value and/or a critical brightness parameter value;

Adjusting a parameter in the brightness adjustment relationship according to the critical parameter value, and adjusting brightness and contrast of all pixel points in the current image frame according to the adjusted brightness adjustment relationship, and outputting brightness and contrast adjustment The gray value of all subsequent pixels.

In a second aspect, some embodiments of the present disclosure provide an image processing method, including: acquiring gray values of all pixels in a current image frame;

Selecting a first gray value and a second gray value from gray values of all pixels of the current image frame; wherein the first gray value is a maximum gray value, and the second gray value a second largest gray value; or the first gray value is a minimum gray value; the second gray value is a second small gray value;

In a third aspect, some embodiments of the present disclosure provide a liquid crystal display device, including: a liquid crystal module, a backlight module, a video processor, and a memory storing instructions executable by the video processor, the video processor Electrically connecting with the liquid crystal module and the backlight module, and controlling display of the liquid crystal module and illumination of the backlight module; wherein

The instructions are executed by the video processor to enable the video processor to:

Obtaining the gray value of all pixels in the current image frame;

Taking the first gray value and the second gray value as input gray values, determining a first output gray value corresponding to the first gray value and the second gray value according to a brightness adjustment relationship Corresponding second output gray value difference a critical parameter value when in a preset range; wherein the critical parameter value comprises a critical contrast parameter value and/or a critical brightness parameter value;

The above general description and the following detailed description are intended to be illustrative and not restrictive.

DRAWINGS

The accompanying drawings, which are incorporated in the specification

In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings used in the embodiments or the prior art description will be briefly described below, and it will be apparent to those skilled in the art that In other words, other drawings can be obtained based on these drawings without paying for creative labor.

1 is a schematic structural view of a liquid crystal display provided by the related art;

FIG. 2 is a schematic flowchart diagram of an image processing method according to some embodiments of the present disclosure;

FIG. 3 is a schematic flowchart of a method for determining a critical contrast parameter value and/or a critical brightness parameter value according to some embodiments of the present disclosure;

4 is a schematic flowchart of a method for determining a first gray value and a second gray value according to some embodiments of the present disclosure;

FIG. 5 is a schematic flowchart of a method for determining a maximum gray value and a second largest gray value according to a gray histogram according to some embodiments of the present disclosure;

FIG. 6 is a schematic flowchart diagram of another method for determining a first gray value and a second gray value according to some embodiments of the present disclosure;

FIG. 7 is a schematic structural diagram of an image processing apparatus according to some embodiments of the present disclosure.

detailed description

The present disclosure will be further described in detail with reference to the accompanying drawings, in which FIG. Based on the embodiments in the present disclosure, those skilled in the art can make no creative work. All other embodiments obtained are within the scope of the disclosure.

Exemplary embodiments will be described in detail herein, examples of which are illustrated in the accompanying drawings. The following description refers to the same or similar elements in the different figures unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with aspects of the present disclosure as detailed in the appended claims.

Generally speaking, the liquid crystal panel is mainly composed of two glass substrates sandwiching a sandwich layer composed of a polarizing plate, a liquid crystal layer and a color filter, wherein the polarizing plate determines what kind of light can pass, and the liquid crystal layer determines how many Light can pass, and the color filter determines what color of light is generated. The liquid crystal is poured between two well-formed planes to form a liquid crystal layer. The two parallel planes are provided with grooves, and the grooves on the individual planes are all parallel, but the grooves on the two parallel planes are mutually vertical. The backlight module emits light and generates uniform light. The light passes through the liquid crystal panel. If a voltage is applied to the liquid crystal layer to stimulate the deflection of the liquid crystal molecules to generate images of dots, lines and surfaces, the liquid crystal molecules of different deflection states emit light to the backlight. different. Therefore, the TFT-LCD drive circuit controls the brightness of the pixel dots by controlling the voltage applied to the liquid crystal molecules.

In the related art, in order to enhance the display effect of the liquid crystal display, the video processor in the liquid crystal display uses the brightness adjustment relationship: Y(out)=Gain·Y(in)+Offset to process the image signal. Adjustment enhancement, wherein Gain refers to a contrast parameter, Offset refers to a brightness parameter, and Y(in) and Y(out) refer to an input gradation value and a brightness-adjusted output gradation value of each pixel of the image signal, respectively. When the video processor parses Y(in), the Y(in) is enhanced by the brightness adjustment relation to obtain the enhanced Y(out). The video processor sends Y(out) to the TFT-LCD driving circuit in the liquid crystal display, and the TFT-LCD driving circuit converts Y(out) into an electrical signal to drive the liquid crystal display unit, thereby enhancing the display brightness and contrast of the liquid crystal display. . Under normal circumstances, when the liquid crystal display is shipped from the factory, the default values of the contrast parameter Gain and the brightness parameter Offset are set, so that Y(in) does not appear saturated after the brightness is enhanced, thereby ensuring the integrity of the gray scale of the display screen.

However, each liquid crystal display unit in the liquid crystal display has a maximum gray value and a minimum gray value that can be achieved. Taking an 8-bit system as an example, the gray value of each pixel is enhanced after the brightness adjustment relationship is enhanced. The gray value is up to 255. When the output gray value is greater than 255, the output gray value is 255. Therefore, when the user adjusts the brightness or the contrast by the button on the remote controller or the liquid crystal display to increase the brightness parameter or the contrast parameter, the pixel of the high-intensity gray-scale portion may have a maximum gray value after the adjustment ( Exemplarily, the 245 grayscale before adjustment and the 235 grayscale before adjustment will take 255 grayscale after brightness enhancement. Similarly, in the dark field enhancement adjustment process, low-luminance grayscale values will exist. The dark field enhancement will achieve the lowest gray value (exemplary, the 5 gray scale before adjustment and the 15 gray scale before adjustment, will take 0 after the brightness adjustment Gray scale), so that the display screen appears high gray scale merge or low gray scale merge phenomenon, resulting in poor display layering.

Some embodiments of the present disclosure provide an image processing method, by which adjustment of image brightness and contrast can be realized, the problem of image gray scale loss is effectively solved, and the layering of the image is ensured, and the visual experience is enhanced.

Referring to FIG. 2, some embodiments of the present disclosure provide an image processing method.

In step S101, gray values of all pixel points in the current image frame are acquired.

When the video processor receives the video signal, it decodes the RGB signal in the video signal and converts the RGB signal into a YUV signal, where "Y" represents brightness, that is, gray level, and "U" and "V" indicate Chroma, used to describe image color and saturation. Therefore, after the video processor parses out the video signal, the gray value of all the pixels can be acquired. The gray value of all pixels is stored in memory or saved in the data node assigned by the processor.

In step S102, a first gray value and a second gray value are selected from gray values of all pixels of the current image frame; wherein the first gray value is a maximum gray value, the second The gray value is a second largest gray value; or the first gray value is a minimum gray value, and the second gray value is a second small gray value.

For example, when the brightness enhancement is performed by the brightness adjustment formula, since the brightness adjustment formula is a linear formula, the gray level value of the pixel point having a large gray value first reaches the high order saturation. In order to prevent the pixel points in the image frame from reaching high-order saturation after the brightness is enhanced, it is first necessary to ensure that the maximum gray scale value and the second largest gray scale value of all the pixel points cannot be saturated, thereby ensuring that the gray scale values of other pixel points are also not satisfied. The high-order saturation is achieved. Therefore, in the method provided by the embodiment of the present disclosure, the maximum gray value and the second largest gray value are selected from the gray values of all the pixel points, wherein the maximum gray value and the second largest gray level. The values can correspond to multiple pixels.

For another example, when the brightness of the image is weakened by the brightness adjustment formula, since the brightness adjustment formula is a linear formula, the pixel point having a small gray value first reaches low-order saturation (or dark field saturation). In order to prevent the pixel points in the image frame from reaching the dark field saturation after the brightness adjustment, firstly, it is necessary to ensure that the minimum gray scale value and the second small gray scale luminance value of all the pixel points cannot reach the dark field saturation, thereby ensuring dark pixels in the image frame. The dots are darker and the layering of the image is highlighted, making the display better.

In step S103, the first gray value and the second gray value are used as input gray values, and the first output gray value corresponding to the first gray value is determined according to the brightness adjustment relationship. a critical parameter value when a difference between the second output gray value corresponding to the second gray value is within a preset range; wherein the critical parameter value comprises a critical contrast parameter value and/or a critical brightness parameter value.

In some embodiments, the brightness adjustment relationship is:

Y(out)=Gain·Y(in)+Offset

Among them, Gain represents the contrast parameter, Offset represents the brightness parameter, and Y(in) and Y(out) represent the graph respectively. The input gray value of each pixel of the signal and the output gray value of the brightness adjustment.

The preset range may be set to be greater than 0 and less than or equal to 2, and determine a critical parameter value when a difference between the first output gray value and the second output gray value is within a preset range, That is, the critical parameter value when the first output gray value and the second output gray value are nearly equal are determined, thereby ensuring that the gray values of all the pixels in the image are not saturated.

For example, the first gray value and the second gray value of all the pixels are used as the input gray value, and the brightness adjustment relationship is input, and the first corresponding to the first gray value is calculated by the brightness adjustment relation. And outputting a second gray value corresponding to the gray value and the second gray value. When the first gray value is the maximum gray value and the second gray value is the second largest gray value, in order to ensure that the maximum gray value and the second largest gray value do not reach saturation, at the same time, the maximum gray is displayed. The brightness of the pixel points of the degree value and the second largest gray value can be enhanced, so that the displayed picture is brighter and the layering is stronger. Therefore, it is necessary to calculate the critical parameter value so that the maximum gray value and the second largest gray value value Nearly equal. When the first gray value is a minimum gray value, and the second gray value is a second small gray value, in order to ensure that the minimum gray value and the second small gray value do not reach saturation, the image frame is dark The pixel points are darker and the layering of the image is highlighted. Therefore, the critical parameter value needs to be calculated such that the output gray value corresponding to the minimum gray value is close to the output gray value corresponding to the second small gray value. equal.

In some embodiments, the first output gray value corresponding to the first gray value and the second gray value corresponding to the second gray value are adjusted to be equal, and the contrast parameter value may be separately adjusted. The brightness parameter value is kept at the default value, the critical contrast parameter value is calculated, or the brightness parameter value is separately adjusted, the contrast parameter value is kept at the default value, the critical brightness parameter value is calculated, or the contrast parameter value and the brightness parameter value are simultaneously adjusted. Calculate the critical contrast parameter value and the critical brightness parameter value. The specific adjustment method can be determined according to the actual application.

In step S104, the parameters in the brightness adjustment relationship are adjusted according to the critical parameter value, and the brightness and contrast of all the pixels in the current image frame are adjusted according to the adjusted brightness adjustment relationship, and the output is output. The gray value of all the pixels after the brightness and contrast adjustment.

For example, when the critical parameter value includes the critical contrast parameter value and the critical brightness parameter value, after the critical contrast parameter value and the critical brightness parameter value are calculated, the critical contrast parameter value and the critical brightness parameter value are substituted into the brightness adjustment relationship. , the contrast parameter value in the brightness adjustment relationship is adjusted to the critical contrast parameter value, and the brightness parameter value in the brightness adjustment relationship is adjusted to the critical brightness parameter value, and the adjusted brightness adjustment relationship is obtained, and then all the pixels are obtained. The brightness and contrast are adjusted by adjusting the brightness adjustment relationship to obtain the output gray value of all the pixels. The video processor converts the output gray value signal and other signals into RGB signals and sends them to the driving circuit of the liquid crystal module, and the driving circuit controls the liquid crystal panel to display the enhanced image. Like a picture.

It can be seen from the above description that the method provided by the embodiment of the present disclosure calculates the critical parameter value by adaptively adjusting the contrast parameter and/or the brightness parameter, so that the pixel in the image frame does not reach the saturated gray value, thereby avoiding the image frame. The phenomenon of gray scale loss ensures that the display of image frames is more layered and the display effect is better. For example, when the first gradation value is the maximum gradation value and the second gradation value is the second largest gradation value, the maximum gradation value and the sub-large gradation value are not achieved by the high-order saturation. All the pixels in the image frame do not exhibit high-order saturation, so that not only the gray level integrity of the image frame can be guaranteed, but also the requirement that the maximum gray value and the second largest gray value do not reach high-order saturation. Next, increase the brightness of all the pixels, so that the brightness of the entire image is enhanced, and the layering is good, thereby ensuring the display effect of the liquid crystal display. For another example, when the first gray value is a minimum gray value and the second gray value is a second small gray value, the image is made to be saturated by making the minimum gray value and the second small gray value not saturated. All the pixels of the frame do not reach the minimum gray value. When the pixel with the smallest gray value and the second small gray value does not reach the low-order saturation, all the pixels will not have low-order saturation. It ensures that the dark pixels in the display of the image frame are darker, which makes the picture more layered and the display effect is better.

In some embodiments, a method of determining a critical parameter value is shown in FIG.

In step S201, gray values of all the pixels in the current image frame are acquired.

In step S202, the first gray value and the second gray value are used as input gray values, and the contrast parameter value and/or the brightness parameter value in the brightness adjustment relationship are adjusted, and according to the adjustment And a brightness adjustment relationship determining a difference between the first output gray value and the second output gray value.

For example, the maximum gray value and the second largest gray value are used as the input gray value, and the gray value is enhanced by the brightness adjustment relation, so that the pixel points of the maximum gray value and the second largest gray value are brighter. Once the enhancement (ie, increasing the contrast parameter value and/or the brightness parameter value), the difference between the output gray value corresponding to the maximum gray value and the second largest gray value is calculated until the difference is satisfied. And obtaining a critical parameter value when the difference between the first output gray value corresponding to the maximum gray value and the second output gray value corresponding to the second largest gray value is within a preset range.

For another example, the minimum gray value and the second small gray value are used as the input gray value, and the gray value is weakened by the brightness adjustment relation, so that the pixel points of the minimum gray value and the second small gray value are darker. After a weakening (ie, reducing the contrast parameter value and/or the brightness parameter value), the difference between the output gray value corresponding to the minimum gray value and the second small gray value is calculated until the difference is satisfied. The value, in turn, obtains a critical parameter value when the difference between the output gray value corresponding to the minimum gray value and the output gray value corresponding to the second small gray value is within a preset range.

When calculating the critical parameter value, the video processor extracts the first gray value, the second gray value, and the brightness adjustment relation from the memory or the data node to calculate, and calculates the first output gray level corresponding to the first gray value. Value and second After the second output gray value corresponding to the gray value, the difference between the first output gray value and the second output gray value is calculated.

In step S203, it is determined whether the difference is within a preset range.

Taking an 8-bit system as an example, the gray value has 256 gray levels and is composed of 0-255 gray values. Each gray value represents a gray scale, and the magnitude of the difference of the output gray values determines the difference in luminance between the output gray values. In some embodiments, the preset range is set to be greater than 0 and less than or equal to 2, that is, the difference between the output gray values does not exceed two gray levels. When the difference between the output gray values is less than the preset difference, it is prescribed that the first output gray value and the second output gray value are nearly equal at this time.

In step S204, when the difference is within a preset range, it is determined that the adjusted contrast parameter value and/or the adjusted brightness parameter value is a critical parameter value.

For example, when the contrast parameter value is a and the brightness parameter value is b, the difference between the output gray value corresponding to the first gray value and the second gray value is within a preset range. At this time, it is determined that a is a critical value. Contrast parameter value, b is the critical brightness parameter value.

Of course, if the difference between the output values corresponding to the first gray value and the second gray value calculated based on the existing brightness adjustment relationship is already within the preset range, at this time, the critical parameter value does not need to be calculated again. The image is processed directly by the existing brightness adjustment relationship, and the output gray value of all the pixels is output.

It can be seen from the above description that the method for determining the critical parameter value provided by the embodiment of the present disclosure calculates the difference between the first gray value and the second gray value respectively corresponding to the output gray value within a preset range, and continuously adjusts The contrast parameter value and/or the brightness parameter value correct the difference of the output gray value within a preset range to determine the critical parameter value.

In some embodiments, another method of determining a critical parameter value is further provided, which is described in detail in three cases.

Case 1: The critical parameter value includes the critical contrast parameter value.

In this case, the method of determining the critical parameter value includes:

Using the first gray value and the second gray value as the input gray value, adjusting the contrast parameter value in the brightness adjustment relationship, and determining the first output gray according to the adjusted brightness adjustment relationship Corresponding contrast parameter value when the degree value and the second output gray value are equal;

The value obtained by subtracting the preset contrast value from the corresponding contrast parameter value when the first output gray value and the second output gray value are equal is determined as the critical contrast parameter value.

Case 2: The critical parameter value includes the critical brightness parameter value.

In this case: the method of determining the critical parameter value includes:

Adjusting the first gray value and the second gray value as input gray values to adjust the brightness adjustment relationship a brightness parameter value, and determining, according to the adjusted brightness adjustment relationship, a brightness parameter value corresponding to the first output gray value and the second output gray value being equal;

The value obtained by subtracting the preset brightness value from the corresponding brightness parameter value when the first output gray value and the second output gray value are equal is determined as the critical brightness parameter value.

Case 3: Critical parameter values include critical contrast parameter values and critical brightness parameter values.

In this case: the method of determining the critical parameter value includes:

Using the first gray value and the second gray value as the input gray value, adjusting the contrast parameter value and the brightness parameter value in the brightness adjustment relationship, and determining the relationship according to the adjusted brightness adjustment relationship a contrast parameter value and a brightness parameter value when the first output gray value and the second output gray value are equal;

When the difference between the first output gray value and the second output gray value is equal, the corresponding contrast parameter value and the brightness parameter value are respectively subtracted from the preset value, and the value is determined as the critical contrast parameter value and the critical brightness parameter value. .

It can be seen from the above description that the method for calculating the critical contrast parameter value and/or the critical brightness parameter value provided by the embodiment of the present disclosure has the contrast parameter value and/or the brightness parameter value as an unknown number, the first output gray value and the second output. The gray values are equal, so that the contrast parameter value and/or the brightness parameter value corresponding to the first output gray value and the second output gray value are equal, and then, in order to ensure that the output gray value of all the pixel points does not reach saturation The determined contrast parameter value is subtracted from the preset value to obtain a critical contrast parameter value, and the determined brightness parameter value is subtracted from the preset value to obtain a critical brightness parameter value.

In some embodiments, the method of determining the first gray value and the second gray value is further optimized, see FIG.

In step S401, gray values of all pixel points in the current image frame are acquired.

In step S402, all the pixel points are sorted from light to dark according to the gray value, and a gray histogram of all the pixel points is established.

After obtaining the gray value of all the pixels, all the pixels are sorted from light to dark, since each gray level corresponds to multiple pixels, that is, there are multiple pixels with the same gray value. Therefore, by counting all the pixels by the gray histogram, the number of pixels corresponding to each gradation can be determined. At the same time, according to the gray histogram, the maximum gray value and the second largest gray value can be quickly determined, and the minimum gray value and the second small gray value can be quickly determined.

In step S403, the first gray value and the second gray value are determined according to the gray histogram.

For example, when the first gray value is the maximum gray value and the second gray value is the second largest gray value, the gray value of all the pixel points is counted by the gray histogram, and the maximum gray level can be quickly determined. The value and the second largest gray value, and the number of pixels of each gray level can also be counted. The gray histogram can be sorted according to the gray value from large to small, or can be sorted according to the gray value from small to large, so the maximum can be quickly determined by the gray histogram. Gray value and second largest gray value.

Of course, the gray histogram is only a statistical method, and the pie chart or the line chart can also be used for statistics to determine the first gray value and the second gray value.

In some embodiments, a method of determining a first gray value and a second gray value from a gray histogram is provided, which is illustrated below in two cases.

Case 1: the first gray value is a maximum gray value, and the second gray value is a second largest gray value.

A method of determining the maximum gray value and the second largest gray value based on the gray histogram is shown in FIG.

In step S4031, the average gradation value of all the pixel points is determined based on the gradation histogram.

The grayscale histogram gives all the grayscale values of all the pixels, and the number of pixels corresponding to each grayscale value. Therefore, the sum of the product of the gray scale value and the number of pixel points is calculated, and then the sum value is compared with the number of pixel points to obtain an average gray value.

Therefore, when determining the critical parameter value, it is necessary to ensure that the maximum gray value and the second largest gray value are close to each other. Therefore, for the convenience of calculation, the pixel point smaller than the average gray value may be discarded in the determination process.

In step S4032, pixel points whose gradation values are larger than the average gradation value are selected, and the proportion of the pixel points of the different gradation values in the selected pixel points in the selected pixel points is determined.

In step S4033, the pixel points whose ratio is smaller than the preset scale value are discarded, and a reordered gray histogram is obtained.

If the maximum gray value or the second largest gray value corresponds to a relatively small number of pixels, when the output values corresponding to the maximum gray value and the second largest gray value are equal, the display image of the image frame is less affected. It can be ignored. Therefore, even if the output gray values corresponding to the maximum gray value and the second largest gray value are equal, it is visually difficult to detect, and the gray value saturation can be ignored at this time. Therefore, in this step S4033, it is necessary to discard the pixel points whose ratio is smaller than the preset scale value.

In step S4034, the maximum gray value and the second largest gray value are selected according to the reordered gray histogram.

Since the gray value of the small pixel is less affected by the visual effect of the screen, the pixel point with a smaller ratio can be ignored. Therefore, in this step, the pixel points whose ratio is less than the preset ratio value are not counted in the statistical range. In some embodiments, the preset ratio value is set to 3%-5%. After rounding off, the pre-position is complemented by the original sort to obtain a new sort, and the maximum gray value and the second largest gray value are determined according to the reordered gray histogram.

Case 2: the first gray value is a minimum gray value, and the second gray value is a second small gray value

A method for determining a minimum gray value and a second small gray value according to a gray histogram, including:

Determining an average gray value of all pixels according to the gray histogram;

Selecting a pixel point whose gray value is smaller than the average gray value, and determining different gray values in the selected pixel point The proportion of pixels in the selected pixel points;

Retrieving a pixel whose ratio is smaller than a preset scale value, and obtaining a reordered gray histogram;

A minimum gray value and a second small gray value are selected according to the reordered gray histogram.

In this method, the same or similar parts as those of the above embodiment will not be described herein.

It can be seen from the above description that the method provided by the embodiment of the present disclosure ensures that the proportion of the pixel points corresponding to the different gray values is less than the preset ratio by ensuring the ratio of the pixel points corresponding to the first gray value and the second gray value. The pixels are determined to determine the effective first gray value and the second gray value, thereby ensuring a better display effect.

Referring to Figure 6, some embodiments of the present disclosure provide another method of determining a first gray value and a second gray value.

In step S501, gray values of all the pixels in the current image frame are acquired.

In step S502, the gray values of the adjacent two pixel points are sequentially compared according to the array sorting order of all the pixel points until all the pixel points are compared.

In step S503, it is determined that the maximum and second largest values of the final compared gray value are the maximum gray value and the second largest gray value, or that the minimum and minimum values of the final compared gray value are the minimum gray value. And the second small gray value.

After parsing the video signal, the video processor obtains the order of the pixels on the display screen, and sequentially compares the gray values of the adjacent two pixels according to the order of the pixels. For example, when determining the maximum gray value and the second largest gray value, comparing the gray values of the first pixel point and the second pixel point, when the gray value of the second pixel point is greater than the first pixel point Comparing the gray values of the second pixel and the third pixel, and sequentially comparing until all the pixels are compared, thereby determining the maximum gray value and the second largest gray value. For another example, when determining the minimum gray value and the second small gray value, comparing the gray value of the first pixel point and the second pixel point, when the gray value of the first pixel point is smaller than the second pixel point When the gray values of the first pixel and the third pixel are compared, the pixels are compared in sequence until all the pixels are compared, thereby determining the minimum gray value and the second small gray value.

As can be seen from the above description, the embodiment of the present disclosure provides a method for determining a first gray value and a second gray value, according to the number of times of all pixel points when determining the first gray value and the second gray value. The gray values of the adjacent two pixels are compared in turn until all the pixels are compared. The method provided in this embodiment is simple and convenient to calculate, and the first gray value and the second gray value can be calculated in a short time.

In some embodiments, the first gray value is a maximum gray value, the second gray value is a second largest gray value, and the maximum gray value and the second largest gray value are used as input gray values, and the brightness adjustment relationship is adjusted. The value of the contrast parameter in the formula, when the difference between the output value corresponding to the maximum gray value and the second largest gray value is within a preset range, determining that the adjusted contrast parameter value is a critical contrast parameter value, and the critical contrast parameter is The value is substituted into the brightness adjustment relationship as the contrast parameter value, and the brightness parameter value is kept as the default value, thereby obtaining the adjusted brightness adjustment relationship, and all the pixels in the current image frame are adjusted by the adjusted brightness adjustment relationship. Adjust the brightness and contrast, The gray value of all the pixels after the brightness and contrast adjustment are output.

In some embodiments, the first gray value is a minimum gray value, the second gray value is a second small gray value, and the minimum gray value and the second small gray value are used as input gray values, when the minimum gray level is When the difference between the output value corresponding to the value and the second small gray value is within a preset range, it is determined that the adjusted brightness parameter value is a critical brightness parameter value, and the critical brightness parameter value is substituted as a brightness parameter value into the brightness adjustment relationship. At the same time, the contrast parameter value is kept as the default value, and the adjusted brightness adjustment relationship is obtained, and the brightness and contrast of all the pixels in the current image frame are adjusted by the adjusted brightness adjustment relationship, and the brightness and contrast are output. The adjusted gray value of all the pixels.

In some embodiments, when adjusting the brightness and contrast of the image, the critical brightness parameter value is first calculated according to the above embodiment, and then the critical contrast parameter value is calculated, and finally, the output of all the pixel points is calculated according to the adjusted brightness adjustment relationship. The gray value is used to adjust the brightness and contrast of the image frame.

The output gray value of the pixel point calculated by the above embodiment reduces the gray value of the pixel point with a low gray value, that is, makes the dark pixel point darker, and at the same time, makes the bright pixel point brighter, thereby making the bright pixel point brighter. The display of the image frame is more layered, which in turn makes the display of the picture better.

The embodiment of the present disclosure further provides a video processor, including a gray value acquiring unit, maximum and second large gray value selecting units, a threshold calculating unit, and an image brightness and contrast adjusting unit, wherein:

A gray value acquisition unit is configured to acquire gray values of all pixels in the current image frame. After decoding the image frame, the video processor acquires the gray values of all the pixels.

The maximum and second largest gray value selection units are configured to select a maximum gray value and a second largest gray value from gray values of all pixel points of the current image frame. The maximum and second largest gray value selection unit may be configured to calculate a gray histogram of all the pixels according to the gray value histogram, and then determine the maximum gray value and the second largest gray value, or configured to be based on the pixel. The order of the dots is sequentially compared with the gray values of the adjacent two pixels to determine the maximum gray value and the second largest gray value.

The threshold value calculation unit is configured to adjust a relationship according to a brightness adjustment, adjust a contrast parameter, and use the maximum gray value and the second largest gray value as an input gray value, and calculate the maximum gray value and the second largest gray level. The values of the critical contrast parameters when the values of the output gray values correspond to each other.

Meanwhile, the threshold value calculation unit is configured to adjust the relationship according to the brightness, adjust the brightness parameter, use the minimum gray value and the second small gray value as the input gray value, and calculate the minimum gray value and the second small gray value respectively. The value of the critical brightness parameter when the output gray values approach the same. When calculating the critical value, the threshold calculation unit first calculates the critical brightness parameter value and then calculates the critical contrast parameter value.

The image brightness and contrast adjustment unit is configured to adjust the critical contrast parameter value as a brightness The contrast parameter value in the system adjusts the brightness and contrast of all the pixels in the current image frame, and outputs the gray value of all the pixels after the brightness and contrast adjustment; meanwhile, the critical brightness parameter is used The value is used as the brightness parameter value in the brightness adjustment relationship, and the brightness and contrast of all the pixels in the current image frame are adjusted, and the gray values of all the pixels after the brightness and contrast adjustment are output.

The threshold value calculation unit inputs the calculated critical contrast parameter value and/or the brightness parameter value to the image brightness and contrast adjustment unit, and the image brightness and contrast adjustment unit uses the critical contrast parameter value and/or the critical brightness parameter value as the brightness adjustment relationship. Contrast parameters and/or brightness parameters in , and calculate the output gray value of all pixels.

The video processor converts the output gray value into an RGB signal and sends it to the liquid crystal module. The liquid crystal module adjusts the voltage of the driving circuit according to the RGB signal, thereby controlling the deflection of the liquid crystal molecules, and finally realizing the adjustment of the brightness and contrast of the image.

Referring to FIG. 7, some embodiments of the present disclosure provide an image processing apparatus by which adjustment of image brightness and contrast can be realized, the apparatus comprising:

At least one processor 71; and,

a memory 72 communicatively coupled to the at least one processor; wherein

The memory 72 stores instructions executable by the at least one processor 71, the instructions being executed by the at least one processor 71 to enable the at least one processor 71 to:

Obtaining the gray value of all pixels in the current image frame;

In some embodiments, the instructions are executed by the at least one processor 71 to enable the at least one processor 71 to:

Adjusting the first gray value and the second gray value as input gray values to adjust the brightness adjustment relationship a contrast parameter value and/or a brightness parameter value, and determining a difference between the first output gray value and the second output gray value according to the adjusted brightness adjustment relationship;

Determining whether the difference is within a preset range;

When the difference is within a preset range, determining that the adjusted contrast parameter value and/or the adjusted brightness parameter value is a critical parameter value.

In some embodiments, the critical parameter value includes a critical contrast parameter value, the instructions being executed by the at least one processor 71 to enable the at least one processor 71 to further:

Using the first gray value and the second gray value as input gray values, adjusting a contrast parameter value in the brightness adjustment relationship, and determining the first according to the adjusted brightness adjustment relationship Corresponding contrast parameter value when the output gray value and the second output gray value are equal;

In some embodiments, the critical parameter value comprises a critical brightness parameter value, the instructions being executed by the at least one processor 71 to enable the at least one processor 71 to further:

Using the first gray value and the second gray value as the input gray value, adjusting the brightness parameter value in the brightness adjustment relationship, and determining the first according to the adjusted brightness adjustment relationship Corresponding brightness parameter value when the output gray value and the second output gray value are equal;

In some embodiments, the critical parameter value comprises a critical contrast parameter value and a critical brightness parameter value, the instructions being executed by the at least one processor 71 to enable the at least one processor 71 to further:

When the first output gray value and the second output gray value are equal, the corresponding contrast parameter value and the brightness parameter value are respectively subtracted from the preset value, and the value is determined as the critical contrast parameter value and the critical brightness parameter value.

All the pixels are sorted according to the gray value from light to dark, and a gray histogram of all the pixels is established;

The first gray value and the second gray value are determined according to the gray histogram.

In some embodiments, the first gray value is a maximum gray value, and the second gray value is a second largest gray value. The instructions are executed by the at least one processor 71 to enable the at least one processor 71 to:

Selecting a pixel point whose gray value is greater than the average gray value, and determining a ratio of pixel points of different gray value values in the selected pixel point to the selected pixel point respectively;

According to the reordered gray histogram, the maximum gray value and the second largest gray value are selected.

In some embodiments, the first gray value is a minimum gray value, the second gray value is a second small gray value, and the instruction is executed by the at least one processor 71 to cause the At least one processor 71 is also capable of:

Selecting a pixel point whose gray value is smaller than the average gray value, and determining a ratio of pixel points of different gray value values in the selected pixel point to the selected pixel point respectively;

According to the array arrangement order of all the pixel points, the gray values of the adjacent two pixel points are sequentially compared until all the pixel points are compared;

The maximum and second largest values of the final comparison gray value are determined as the maximum gray value and the second largest gray value, or the minimum and second small values of the final comparison gray value are determined as the minimum gray value and the second small gray value. .

Some embodiments of the present disclosure further provide a liquid crystal display device including a liquid crystal module, a backlight module, a video processor, and a memory storing instructions executable by the video processor, the video processor and the liquid crystal respectively The module and the backlight module are electrically connected to send the parsed video signal to the liquid crystal module and the backlight module, and control the display brightness, contrast and color of the liquid crystal module, and control the brightness of the backlight module; ,

Obtaining the gray value of all pixels in the current image frame;

Taking the first gray value and the second gray value as input gray values, determining a first output gray value corresponding to the first gray value and the second gray value according to a brightness adjustment relationship a critical parameter value when a difference between the corresponding second output gray value is within a preset range; wherein the critical parameter value includes a critical contrast parameter value and/or Boundary brightness parameter value;

For the specific implementation of the adjustment of the brightness and the contrast of the image by the above-mentioned liquid crystal display device, refer to any of the above embodiments, and details are not described herein again.

Other embodiments of the present disclosure will be apparent to those skilled in the <RTIgt; The present disclosure is intended to cover any variations, uses, or adaptations of the present disclosure, which are in accordance with the general principles of the present disclosure and include common general knowledge or conventional technical means in the art that are not disclosed in the present disclosure. . The specification and examples are to be regarded as illustrative only,

It is to be understood that the present invention is not limited to the precise structures shown and described in the drawings, and various modifications and changes can be made without departing from the scope thereof. Thus, it is intended that the present invention cover the modifications and the modifications

Claims

An image processing apparatus, comprising: at least one processor;

a memory communicatively coupled to the at least one processor; wherein

The memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to:

Obtaining the gray value of all pixels in the current image frame;

Selecting a first gray value and a second gray value from gray values of all pixels of the current image frame; wherein the first gray value is a maximum gray value, and the second gray value a second largest gray value; or the first gray value is a minimum gray value; the second gray value is a second small gray value;

Taking the first gray value and the second gray value as input gray values, determining a first output gray value corresponding to the first gray value and the second gray value according to a brightness adjustment relationship a critical parameter value when a difference between the corresponding second output gray value is within a preset range; wherein the critical parameter value includes a critical contrast parameter value and/or a critical brightness parameter value;

Adjusting a parameter in the brightness adjustment relationship according to the critical parameter value, and adjusting brightness and contrast of all pixel points in the current image frame according to the adjusted brightness adjustment relationship, and outputting brightness and contrast adjustment The gray value of all subsequent pixels.
The apparatus of claim 1 wherein said instructions are executed by said at least one processor such that said at least one processor is further capable of:

Using the first gray value and the second gray value as input gray values, adjusting a contrast parameter value and/or a brightness parameter value in the brightness adjustment relationship, and adjusting a relationship according to the adjusted brightness Determining a difference between the first output gray value and the second output gray value;

Determining whether the difference is within a preset range;

When the difference is within a preset range, determining that the adjusted contrast parameter value and/or the adjusted brightness parameter value is a critical parameter value.
The apparatus of claim 1 wherein said critical parameter value comprises a critical contrast parameter value, said instructions being executed by said at least one processor to enable said at least one processor to further:

Using the first gray value and the second gray value as input gray values, adjusting a contrast parameter value in the brightness adjustment relationship, and determining the first according to the adjusted brightness adjustment relationship a contrast parameter value when the output gray value and the second output gray value are equal;

Subtracting the preset contrast parameter value when the first output gray value and the second output gray value are equal The value after the value is determined as the critical contrast parameter value.
The apparatus of claim 1 wherein said critical parameter value comprises a critical brightness parameter value, said instructions being executed by said at least one processor to enable said at least one processor to further:

Using the first gray value and the second gray value as the input gray value, adjusting the brightness parameter value in the brightness adjustment relationship, and determining the first according to the adjusted brightness adjustment relationship Corresponding brightness parameter value when the output gray value and the second output gray value are equal;

The value obtained by subtracting the preset brightness value from the corresponding brightness parameter value when the first output gray value and the second output gray value are equal is determined as the critical brightness parameter value.
The apparatus of claim 1 wherein said critical parameter value comprises a critical contrast parameter value and a critical brightness parameter value, said instructions being executed by said at least one processor to cause said at least one processor to further were able:

Using the first gray value and the second gray value as the input gray value, adjusting the contrast parameter value and the brightness parameter value in the brightness adjustment relationship, and determining the relationship according to the adjusted brightness adjustment relationship a contrast parameter value and a brightness parameter value when the first output gray value and the second output gray value are equal;

When the first output gray value and the second output gray value are equal, the corresponding contrast parameter value and the brightness parameter value are respectively subtracted from the preset value, and the value is determined as the critical contrast parameter value and the critical brightness parameter value.
The apparatus of claim 1 wherein said instructions are executed by said at least one processor such that said at least one processor is further capable of:

All the pixels are sorted according to the gray value from light to dark, and a gray histogram of all the pixels is established; and the first gray value and the second gray value are determined according to the gray histogram.
The apparatus according to claim 6, wherein said first gray value is a maximum gray value, said second gray value is a second largest gray value, said instruction being said at least one processor Executing to enable the at least one processor to also:

Determining an average gray value of all pixels according to the gray histogram;

Selecting a pixel point whose gray value is greater than the average gray value, and determining a ratio of pixel points of different gray value values in the selected pixel point to the selected pixel point respectively;

Retrieving a pixel whose ratio is smaller than a preset scale value, and obtaining a reordered gray histogram;

According to the reordered gray histogram, the maximum gray value and the second largest gray value are selected.
The apparatus according to claim 6, wherein said first gray value is a minimum gray value, said second gray value is a second small gray value, said instruction being said at least one processor Executing to enable the at least one processor to also:

Determining an average gray value of all pixels according to the gray histogram;

Selecting a pixel point whose gray value is smaller than the average gray value, and determining a ratio of pixel points of different gray value values in the selected pixel point to the selected pixel point respectively;

Retrieving a pixel whose ratio is smaller than a preset scale value, and obtaining a reordered gray histogram;

A minimum gray value and a second small gray value are selected according to the reordered gray histogram.
The apparatus of claim 1 wherein said instructions are executed by said at least one processor such that said at least one processor is further capable of:

According to the array arrangement order of all the pixel points, the gray values of the adjacent two pixel points are sequentially compared until all the pixel points are compared;

The maximum and second largest values of the final comparison gray value are determined as the maximum gray value and the second largest gray value, or the minimum and second small values of the final comparison gray value are determined as the minimum gray value and the second small gray level. value.
An image processing method, comprising:

Obtaining the gray value of all pixels in the current image frame;

Selecting a first gray value and a second gray value from gray values of all pixels of the current image frame; wherein the first gray value is a maximum gray value, and the second gray value a second largest gray value; or the first gray value is a minimum gray value; the second gray value is a second small gray value;

Taking the first gray value and the second gray value as input gray values, determining a first output gray value corresponding to the first gray value and the second gray value according to a brightness adjustment relationship a critical parameter value when a difference between the corresponding second output gray value is within a preset range; wherein the critical parameter value includes a critical contrast parameter value and/or a critical brightness parameter value;

Adjusting a parameter in the brightness adjustment relationship according to the critical parameter value, and adjusting brightness and contrast of all pixel points in the current image frame according to the adjusted brightness adjustment relationship, and outputting brightness and contrast adjustment The gray value of all the pixels.
The method according to claim 10, wherein the first gray value and the second gray value are used as input gray values, and the first gray value is determined according to the brightness adjustment relationship. A critical parameter value when a difference between the output value and the second output gray value corresponding to the second gray value is within a preset range, including:

Using the first gray value and the second gray value as input gray values, adjusting a contrast parameter value and/or a brightness parameter value in the brightness adjustment relationship, and adjusting a relationship according to the adjusted brightness Determining a difference between the first output gray value and the second output gray value;

Determining whether the difference is within a preset range;

Determining the adjusted contrast parameter value and/or the adjusted brightness when the difference is within a preset range The parameter value is a critical parameter value.
The method according to claim 10, wherein the critical parameter value comprises a critical contrast parameter value, and the first gray value and the second gray value are used as input gray values, and the relationship is adjusted according to the brightness. The determining the critical parameter value when the difference between the first output value corresponding to the first gray value and the second output gray value corresponding to the second gray value is within a preset range includes:

Using the first gray value and the second gray value as input gray values, adjusting a contrast parameter value in the brightness adjustment relationship, and determining the first according to the adjusted brightness adjustment relationship Corresponding contrast parameter value when the output gray value and the second output gray value are equal;

The value obtained by subtracting the preset contrast value from the corresponding contrast parameter value when the first output gray value and the second output gray value are equal is determined as the critical contrast parameter value.
The method according to claim 10, wherein the critical parameter value comprises a critical brightness parameter value, and the first gray value and the second gray value are used as input gray values, and the relationship is adjusted according to the brightness. The determining the critical parameter value when the difference between the first output value corresponding to the first gray value and the second output gray value corresponding to the second gray value is within a preset range includes:

Using the first gray value and the second gray value as the input gray value, adjusting the brightness parameter value in the brightness adjustment relationship, and determining the first according to the adjusted brightness adjustment relationship Corresponding brightness parameter value when the output gray value and the second output gray value are equal;

The value obtained by subtracting the preset brightness value from the corresponding brightness parameter value when the first output gray value and the second output gray value are equal is determined as the critical brightness parameter value.
The method according to claim 10, wherein the critical parameter value comprises a critical contrast parameter value and a critical brightness parameter value, and the first gray value and the second gray value are used as input gray values, according to The brightness adjustment relationship determines that the critical parameter value when the difference between the first output value corresponding to the first gray value and the second output gray value corresponding to the second gray value is within a preset range includes:

Using the first gray value and the second gray value as the input gray value, adjusting the contrast parameter value and the brightness parameter value in the brightness adjustment relationship, and determining the relationship according to the adjusted brightness adjustment relationship a contrast parameter value and a brightness parameter value when the first output gray value and the second output gray value are equal;

When the first output gray value and the second output gray value are equal, the corresponding contrast parameter value and the brightness parameter value are respectively subtracted from the preset value, and the value is determined as the critical contrast parameter value and the critical brightness parameter value.
The method according to claim 10, wherein selecting the first gray value and the second gray value from gray values of all pixels of the current image frame comprises:

All the pixels are sorted according to the gray value from light to dark, and a gray histogram of all the pixels is established;

The first gray value and the second gray value are determined according to the gray histogram.
The method according to claim 15, wherein said first gray value is a maximum gray value, and said second gray value is a second largest gray value, and said gray level histogram is used to determine The maximum gray value and the second largest gray value include:

Determining an average gray value of all pixels according to the gray histogram;

Selecting a pixel point whose gray value is greater than the average gray value, and determining a ratio of pixel points of different gray value values in the selected pixel point to the selected pixel point respectively;

Retrieving a pixel whose ratio is smaller than a preset scale value, and obtaining a reordered gray histogram;

According to the reordered gray histogram, the maximum gray value and the second largest gray value are selected.
The method according to claim 15, wherein said first gray value is a minimum gray value, and said second gray value is a second small gray value, and said gray level histogram is used to determine The minimum gray value and the second small gray value include:

Determining an average gray value of all pixels according to the gray histogram;

Selecting a pixel point whose gray value is smaller than the average gray value, and determining a ratio of pixel points of different gray value values in the selected pixel point to the selected pixel point respectively;

Retrieving a pixel whose ratio is smaller than a preset scale value, and obtaining a reordered gray histogram;

A minimum gray value and a second small gray value are selected according to the reordered gray histogram.
The method according to claim 10, wherein selecting the first gray value and the second gray value from gray values of all pixels of the current image frame comprises:

According to the array arrangement order of all the pixel points, the gray values of the adjacent two pixel points are sequentially compared until all the pixel points are compared;

The maximum and second largest values of the final comparison gray value are determined as the maximum gray value and the second largest gray value, or the minimum and second small values of the final comparison gray value are determined as the minimum gray value and the second small gray level. value.
The method of claim 10 wherein said brightness adjustment relationship is:

Y(out)=Gain·Y(in)+Offset;

Wherein Y(out) represents the output gradation value after the brightness adjustment of the pixel point in the image signal, Y(in) represents the input gradation value of the pixel point in the image signal, Gain represents the contrast parameter, and Offset represents the illuminance parameter.
A liquid crystal display device, comprising: a liquid crystal module, a backlight module, a video processor, and a memory storing instructions executable by the video processor, wherein the video processor and the liquid crystal mode respectively The group and the backlight module are electrically connected, and control the display of the liquid crystal module and the illumination of the backlight module; wherein

The instructions are executed by the video processor to enable the video processor to:

Obtaining the gray value of all pixels in the current image frame;

Selecting a first gray value and a second gray value from gray values of all pixels of the current image frame; wherein the first gray value is a maximum gray value, and the second gray value a second largest gray value; or the first gray value is a minimum gray value; the second gray value is a second small gray value;

Taking the first gray value and the second gray value as input gray values, determining a first output gray value corresponding to the first gray value and the second gray value according to a brightness adjustment relationship a critical parameter value when a difference between the corresponding second output gray value is within a preset range; wherein the critical parameter value includes a critical contrast parameter value and/or a critical brightness parameter value;

Adjusting a parameter in the brightness adjustment relationship according to the critical parameter value, and adjusting brightness and contrast of all pixel points in the current image frame according to the adjusted brightness adjustment relationship, and outputting brightness and contrast adjustment The gray value of all subsequent pixels.