LED screen energy saving method and system based on FPGA image processing

Abstract

The invention relates to an LED screen energy-saving method and system based on FPGA image processing, and the method comprises the following steps: converting an image into a YCbCr format, and extracting a brightness component; counting a brightness value of a complete image frame, and calculating a brightness mean value of the complete image frame based on the brightness value during vertical synchronization of the image; normalizing the brightness component of the image, and generating a brightness adjustment curve based on a brightness mean value and a set brightness adjustment parameter; performing sharpening calculation on the brightness component of the image in the horizontal direction to obtain a brightness value of the sharpened image; according to the brightness adjustment curve, adjusting the sharpened brightness value to obtain a new brightness component; recombining into a new image; according to the method, sharpening and brightness adjustment of the image are comprehensively considered, the brightness of all pixels in the image can be adjusted, meanwhile, the calculation load pressure of hardware is small, few hardware resources are consumed, and the application scene that the image brightness is reduced and the image display effect is guaranteed can be well met.

Description

Technical Field

[0001] The present invention relates to the field of LED screen display control technology, and more specifically, to an LED screen energy-saving method and system based on FPGA image processing. Background Art

[0002] In the field of LED screen display control, it is often necessary to involve outdoor use scenarios, such as commercial advertising display screens, bulletin display screens, etc. Maintaining the high brightness state of the LED screen for a long time will cause it to generate high heat. High temperature will cause the LED lamp beads to age faster. In addition, keeping the screen in high brightness during the evening when there are fewer people will also waste electricity.

[0003] In some existing designs, a single image sharpening method is usually used to solve the above problems without considering the image brightness processing at the same time. The actual effect is not ideal. For example:

[0004] A Chinese application, application number CN110796626A, discloses a method for image sharpening. This method applies Gaussian low-pass and high-pass filtering to image pixels to avoid Gaussian noise after sharpening. A gain coefficient is calculated based on the image's brightness texture map and the just noticeable difference (JND). The high-frequency component of the original image's brightness, Y, is then amplified based on the gain coefficient to achieve the sharpening effect. However, this method only sharpens the high-frequency brightness component and does not cover all pixels in the image. Furthermore, this method only enhances brightness, making it unsuitable for scenarios where brightness reduction is desired.

[0005] The Chinese application, application number CN113450272A, discloses a method for image sharpening, which normalizes the three RGB components of the image and then performs a sinusoidal adjustment on them. The adjusted image conforms to the characteristics of the sine function. The edge image is then obtained by performing convolution calculations in the horizontal and vertical directions, and the edge image is Gaussian filtered. Finally, the sine-adjusted image and the Gaussian-filtered image are exponentially calculated to obtain a sharpened image. The image effect finally achieved by this solution presents a certain sinusoidal characteristic, that is, the brightness of the image has both enhanced and weakened parts, which cannot meet the needs of scenes where the brightness needs to be reduced. In addition, this solution requires three convolution calculations in the horizontal and vertical directions, as well as Gaussian filtering, and deployment on an FPGA consumes a lot of hardware resources.

[0006] A Chinese application, application number CN115330637A, discloses a method for image sharpening. This method calculates the horizontal and vertical edges of the image's Y component to obtain an initial gradient value for each pixel. Based on this initial gradient value, the edge pixel is convolved with a sparse matrix in four directions. A sharpening coefficient is determined based on the parameter with the largest absolute value. The brightness value after sharpening is calculated based on the sharpening coefficient, the target parameters for the sharpening direction, and the original brightness value. This solution only sharpens the edges of the image and cannot adjust the brightness of all pixels in the image.

[0007] A method is needed to reduce the brightness of the LED screen while retaining the details of the image, so as to save energy, extend the use time of the LED screen, and minimize the impact on the image effect viewed by the user. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide an LED screen energy-saving method based on FPGA image processing and an LED screen energy-saving system based on FPGA image processing in response to the above-mentioned defects of the prior art.

[0009] The technical solution adopted by the present invention to solve its technical problem is:

[0010] Construct an LED screen energy-saving method based on FPGA image processing, which includes the following steps:

[0011] Convert the received image into YCbCr format and extract the brightness component of the converted image;

[0012] Counting the brightness values ​​of a complete image frame, and calculating the brightness mean of the complete image frame based on the brightness values ​​during the vertical synchronization period of the image;

[0013] Normalize the brightness component of the image and generate a brightness adjustment curve based on the brightness mean and the set brightness adjustment parameters;

[0014] Sharpening the brightness component of the image in the horizontal direction to obtain the brightness value of the image after sharpening;

[0015] According to the brightness adjustment curve, the brightness value after sharpening is adjusted to obtain a new brightness component;

[0016] The new brightness component is recombined with the Cb component and Cr component of the original image to form a new image, and the image is converted into RGB format.

[0017] In the LED screen energy-saving method based on FPGA image processing of the present invention, the brightness value of a complete image frame is calculated using the formula:

[0018]

[0019] Where SUM is the brightness value of the complete image frame, and (x, y) is the pixel coordinate point.

[0020] The LED screen energy saving method based on FPGA image processing of the present invention, wherein, during the vertical synchronization of the image, the brightness mean of the complete image frame is calculated based on the brightness value using the formula:

[0021] K = SUM / WIDTH / HEIGHT;

[0022] Where SUM is the brightness value of the complete image frame, K is the average brightness value of the complete image frame, WIDTH is the width value of the image, and HEIGHT is the height value of the image.

[0023] The LED screen energy saving method based on FPGA image processing of the present invention, wherein the brightness component of the image is normalized, and a brightness adjustment curve is generated based on the brightness mean and the set brightness adjustment parameters using the formula:

[0024] A=a+0.2c;

[0025] B = a + 0.73c;

[0026] f1=A*(1-c)+B*(c)=0.53c^2+0.2c+a;

[0027] f2=-0.2c+b;

[0028] F(c)=(1-K)*f1+K*f2;

[0029] Where A, B, f1, and f2 are intermediate variables, a and b are brightness adjustment parameters, F(c) is the brightness adjustment curve, K is the mean brightness of the complete image frame, and c is the normalized pixel brightness value, c∈[0,1].

[0030] The LED screen energy saving method based on FPGA image processing of the present invention, wherein the brightness value after sharpening is adjusted according to the brightness adjustment curve to obtain a new brightness component using the formula:

[0031] Y_adj=Y_sharp*F(c);

[0032] Where F(c) is the brightness adjustment curve, Y_sharp is the brightness value after sharpening, and Y_adj is the new brightness component.

[0033] In the LED screen energy-saving method based on FPGA image processing described in the present invention, a is taken as 0.6 and b is taken as 0.8.

[0034] In the LED screen energy-saving method based on FPGA image processing of the present invention, the brightness component of the image is sharpened in the horizontal direction to obtain the brightness value of the sharpened image using:

[0035] sharp_core=[-1,-2,6,-2,-1];

[0036]

[0037] Where sharp_core is the convolution kernel for sharpening the image brightness value. is the convolution symbol, and Y_sharp is the image brightness value after convolution calculation.

[0038] An LED screen energy-saving system based on FPGA image processing, wherein the system comprises: an image receiving unit, an image processing unit and an LED screen driving unit;

[0039] The image receiving unit is used to receive an image and send the image to the image processing unit;

[0040] The image processing unit is used to execute the LED screen energy-saving method based on FPGA image processing as described above, and send the generated new image to the LED screen driving unit.

[0041] The beneficial effect of the present invention is that: by applying the method of the present application, the sharpening and brightness adjustment of the image are comprehensively considered, and the brightness of all pixels in the image can be adjusted. At the same time, the computing load pressure on the hardware is small, and the hardware resources are consumed less, which can well meet the application scenarios of reducing the image brightness and ensuring the image display effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the present invention will be further described below with reference to the accompanying drawings and embodiments. The drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive efforts.

[0043] Figure 1 This is a flow chart of the LED screen energy saving method based on FPGA image processing in a preferred embodiment of the present invention;

[0044] Figure 2 This is a schematic diagram of dark image curve adjustment of an LED screen energy-saving method based on FPGA image processing according to a preferred embodiment of the present invention;

[0045] Figure 3 This is a schematic diagram of adjusting the bright image curve of an LED screen energy-saving method based on FPGA image processing according to a preferred embodiment of the present invention;

[0046] Figure 4 This is a principle block diagram of an LED screen energy-saving system based on FPGA image processing in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0047] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the following will be a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work shall fall within the scope of protection of the present invention.

[0048] The LED screen energy saving method based on FPGA image processing in the preferred embodiment of the present invention is as follows: Figure 1 See also Figure 2 and Figure 3 , including the following steps:

[0049] S01: Convert the received image into YCbCr format and extract the brightness component of the converted image;

[0050] S02: counting the brightness values ​​of a complete image frame, and calculating the average brightness value of the complete image frame based on the brightness values ​​during the vertical synchronization period of the image;

[0051] The formula for counting the brightness value of a complete image frame is:

[0052]

[0053] Where SUM is the brightness value of the complete image frame, (x, y) is the pixel coordinate point;

[0054] The formula for calculating the average brightness of the complete image frame based on the brightness value is:

[0055] K = SUM / WIDTH / HEIGHT;

[0056] Where SUM is the brightness value of the complete image frame, K is the average brightness value of the complete image frame, WIDTH is the width value of the image, and HEIGHT is the height value of the image.

[0057] S03: normalizing the brightness component of the image, and generating a brightness adjustment curve based on the brightness mean and the set brightness adjustment parameters;

[0058] The specific formula can be used:

[0059] A=a+0.2c;

[0060] B = a + 0.73c;

[0061] f1=A*(1-c)+B*(c)=0.53c^2+0.2c+a;

[0062] f2=-0.2c+b;

[0063] F(c)=(1-K)*f1+K*f2;

[0064] Where A, B, f1, and f2 are intermediate variables, a and b are brightness adjustment parameters, F(c) is the brightness adjustment curve, K is the brightness mean of the complete image frame, and c is the normalized pixel brightness value, c∈[0,1].

[0065] In a preferred embodiment, the value of a is 0.6 and the value of b is 0.8.

[0066] S04: performing horizontal sharpening calculation on the brightness component of the image to obtain a brightness value of the image after sharpening;

[0067] The specific formula can be used:

[0068] sharp_core=[-1,-2,6,-2,-1];

[0069]

[0070] Where sharp_core is the convolution kernel for sharpening the image brightness value. is the convolution symbol, and Y_sharp is the image brightness value after convolution calculation.

[0071] S05: According to the brightness adjustment curve, adjust the brightness value after sharpening to obtain a new brightness component;

[0072] The specific formula can be used:

[0073] Y_adj=Y_sharp*F(c);

[0074] Where F(c) is the brightness adjustment curve, Y_sharp is the brightness value after sharpening, and Y_adj is the new brightness component.

[0075] S06: Recombining the new brightness component with the Cb component and Cr component of the original image into a new image, and converting the image into RGB format;

[0076] The method and approach of this application comprehensively considers image sharpening and brightness adjustment. After sharpening all pixels in the entire image, the details in the image are highlighted, effectively eliminating the problem of detail loss after the image brightness is reduced. It can also adjust the brightness of all pixels in the image. The brightness adjustment suppresses the brightness of the highlighted parts of the image to the original 0.6 and the brightness of the low-brightness parts to the original 0.8, effectively reducing the brightness of the entire image and achieving the purpose of energy saving. At the same time, it puts less pressure on the hardware computing load and consumes less hardware resources, which can well meet the application scenarios of reducing image brightness and ensuring image display quality.

[0077] Specifically, the key points of the present invention are the following three points:

[0078] 1. Use the sharpening algorithm to improve the contrast of the original image, so as to reduce the LED brightness while minimizing the loss of image details.

[0079] 2. Use the average brightness of the image to control the overall brightness of the image.

[0080] 3.According to the brightness adjustment curve, the brightness of each pixel can be accurately adjusted.

[0081] like Figure 3 As shown in the figure, for the highlighted part of the image, after adjustment, the brightness becomes the original 0.6;

[0082] like Figure 2 As shown in the figure, for the low-light part, after adjustment, the brightness becomes the original 0.8.

[0083] An energy-saving system for LED screens based on FPGA image processing, such as Figure 4 As shown, the system includes: an image receiving unit 100, an image processing unit 101 and an LED screen driving unit 102;

[0084] The image receiving unit 100 is configured to receive an image and send the image to the image processing unit 101;

[0085] The image processing unit 101 is used to execute the LED screen energy saving method based on FPGA image processing as described above, and send the generated new image to the LED screen driving unit 102;

[0086] The method and approach of this application comprehensively considers image sharpening and brightness adjustment, and can adjust the brightness of all pixels in the image. At the same time, it puts little pressure on the hardware's computational load and consumes less hardware resources, and can well meet the application scenarios of reducing image brightness and ensuring image display effects.

[0087] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A LED screen energy saving method based on FPGA image processing, characterized in that: The following steps are involved: Convert the received image into YCbCr format and extract the brightness component of the converted image; Counting the brightness values ​​of a complete image frame, and calculating the brightness mean of the complete image frame based on the brightness values ​​during the vertical synchronization period of the image; Normalize the brightness component of the image and generate a brightness adjustment curve based on the brightness mean and the set brightness adjustment parameters; Sharpening the brightness component of the image in the horizontal direction to obtain the brightness value of the image after sharpening; According to the brightness adjustment curve, the brightness value after sharpening is adjusted to obtain a new brightness component; The new brightness component is recombined with the Cb component and Cr component of the original image to form a new image, and the image is converted into RGB format.

2. The LED screen energy saving method based on FPGA image processing according to claim 1 is characterized in that: The formula for counting the brightness value of a complete image frame is: Where SUM is the brightness value of the complete image frame, and (x, y) is the pixel coordinate point.

3. The LED screen energy saving method based on FPGA image processing according to claim 2 is characterized in that: During the vertical synchronization of the image, the brightness mean of the complete image frame is calculated based on the brightness value using the formula: K = SUM / WIDTH / HEIGHT; Where SUM is the brightness value of the complete image frame, K is the average brightness value of the complete image frame, WIDTH is the width value of the image, and HEIGHT is the height value of the image.

4. The LED screen energy saving method based on FPGA image processing according to claim 1 is characterized in that: The brightness component of the image is normalized, and a brightness adjustment curve is generated based on the brightness mean and the set brightness adjustment parameters using the formula: A=a+0.2c; B = a + 0.73c; f1=A*(1-c)+B*(c)=0.53c^2+0.2c+a; f2=-0.2c+b; F(c)=(1-K)*f1+K*f2; Where A, B, f1, and f2 are intermediate variables, a and b are brightness adjustment parameters, F(c) is the brightness adjustment curve, K is the mean brightness of the complete image frame, and c is the normalized pixel brightness value, c∈[0,1].

5. The LED screen energy saving method based on FPGA image processing according to claim 4 is characterized in that: According to the brightness adjustment curve, the brightness value after sharpening is adjusted to obtain a new brightness component using the formula: Y_adj=Y_sharp*F(c); Where F(c) is the brightness adjustment curve, Y_sharp is the brightness value after sharpening, and Y_adj is the new brightness component.

6. The LED screen energy saving method based on FPGA image processing according to claim 4 is characterized in that: The value of a is 0.6 and the value of b is 0.

8.

7. The LED screen energy saving method based on FPGA image processing according to claim 1 is characterized in that: The brightness component of the image is sharpened in the horizontal direction to obtain the brightness value of the sharpened image using: sharp_core=[-1,-2,6,-2,-1]; Where sharp_core is the convolution kernel for sharpening the image brightness value. is the convolution symbol, and Y_sharp is the image brightness value after convolution calculation.

8. An LED screen energy-saving system based on FPGA image processing, characterized in that: The system includes: an image receiving unit, an image processing unit and an LED screen driving unit; The image receiving unit is used to receive an image and send the image to the image processing unit; The image processing unit is used to execute the LED screen energy-saving method based on FPGA image processing as described in any one of claims 1-7, and send the generated new image to the LED screen driving unit.

Images