CN115775511A - Method and device for correcting brightness uniformity of display equipment - Google Patents
Method and device for correcting brightness uniformity of display equipment Download PDFInfo
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- CN115775511A CN115775511A CN202211481437.2A CN202211481437A CN115775511A CN 115775511 A CN115775511 A CN 115775511A CN 202211481437 A CN202211481437 A CN 202211481437A CN 115775511 A CN115775511 A CN 115775511A
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Abstract
The invention discloses a method for correcting the brightness uniformity of display equipment, which comprises the following steps: receiving and analyzing an image signal and acquiring a gray state in the image signal; calculating initial gray scale values of all display areas of the whole display image in the image signal according to the gray scale states; calculating a correction coefficient of each display area, wherein the correction coefficient is used for recording the one-to-one correspondence between the initial gray scale value and the reference gray scale value; carrying out gray correction on the initial gray-scale values of all the display areas by using the correction coefficients to obtain corresponding reference gray-scale values; outputting and displaying the image after the gray-scale value correction; the invention realizes the brightness uniformity of the display device without adding any external device.
Description
Technical Field
The invention relates to the technical field of image display, in particular to a method and a device for correcting brightness uniformity of display equipment.
Background
A projection device is a display device capable of generating a large-sized picture, and has been increasingly applied to the fields of offices, enterprises, businesses, research and education, entertainment venues, and the like. As the quality of the display image is required to be higher and higher, the color uniformity of the projection display system is also concerned. In a projection display system, because a light beam incident on an optical film is not a parallel light but a cone-shaped light beam with a certain divergence angle, and then passes through a heavy path of reflection and refraction to complete projection, a projection picture finally imaged on a projection surface has a phenomenon of uneven brightness. The most common phenomenon of uneven pictures is that the central area of a projected picture is brighter but the peripheral area of the projected picture is darker; in addition, the projection pictures projected by different projection devices have the phenomenon of brightness drop, so that when a plurality of projection devices are used for projection splicing, the splicing position of the projection pictures can obviously display the phenomenon of non-uniformity.
Disclosure of Invention
In order to solve the problems in the prior art, the invention aims to provide a method and a device for correcting the brightness uniformity of a display device.
In order to achieve the purpose, the invention adopts the technical scheme that: a method for correcting brightness uniformity of a display device comprises the following steps:
s10, receiving and analyzing the image signal and acquiring a gray state in the image signal;
s20, calculating initial gray-scale values of all display areas of the whole display image in the image signal according to the gray-scale state;
s30, calculating correction coefficients of all the display areas, wherein the correction coefficients are used for recording the one-to-one corresponding relation between the initial gray-scale values and the reference gray-scale values;
s40, carrying out gray scale correction on the initial gray scale values of all the display areas by using the correction coefficients to obtain corresponding reference gray scale values;
and S50, outputting and displaying the image after the gray-scale value correction.
As a further improvement of the present invention, in the step S30, the calculating the correction coefficient of each display area specifically includes the following steps:
s31, outputting test images with different initial gray scales by display equipment;
s32, detecting initial brightness values of different initial gray scale values in each display area;
s32, smoothing curves of the minimum brightness values in the plurality of display areas under different initial gray scale values to serve as the reference brightness values under the gray scale values;
s32, according to the reference brightness value of each display area, a gray level value corresponding to the reference brightness value is found out and is used as the reference gray level value under the reference brightness value; thereby obtaining the one-to-one correspondence between the initial gray-scale values and the reference gray-scale values of each display area.
As a further improvement of the present invention, the test image in step S31 is a white field signal of 0-255 gray scale.
As a further improvement of the present invention, when there are a plurality of display devices, the reference luminance value in step S32 is comprehensively selected from the plurality of display devices.
As a further improvement of the present invention, the method further comprises performing a gray maximum linear processing on the adjacent portion between the adjacent display areas to obtain a reference gray curve in which the adjacent portion gradually changes from the reference gray level value of one display area to the reference gray level value of the other display area, so as to prevent brightness between the adjacent display areas from suddenly changing.
As a further improvement of the present invention, the display apparatus is a projection apparatus or an apparatus that outputs RGB monochrome signals.
The invention also discloses a device for correcting the brightness uniformity of the display equipment, which comprises:
the image recognition module is used for receiving and analyzing the image signal and acquiring the gray state in the image signal;
the gray level calculation module is used for calculating the initial gray level value of each display area of the whole display image in the image signal according to the gray level state;
the correction coefficient module is used for calculating and storing correction coefficients of all the display areas, and the correction coefficients are used for recording the one-to-one correspondence relationship between the initial gray-scale values and the reference gray-scale values;
the gray correction module is used for carrying out gray correction on the initial gray values of all the display areas by using the correction coefficients to obtain corresponding reference gray values;
and the image output module is used for outputting and displaying the image after the gray-scale value correction.
The invention has the beneficial effects that:
the invention divides the display image area into a plurality of display areas, and the brightness change of each display area is realized by adjusting the gray scale value through the stored gray scale correction coefficient of each display area, thereby realizing the correction of the brightness uniformity. Projecting test images with different gray scales through a projection device, equally dividing the display images into a plurality of display areas, detecting the brightness value of each area under different initial gray scales, smoothing the minimum brightness curve of the areas under different initial gray scale values to be used as the reference brightness under the gray scales, and then back-checking the reference gray scale value of each area according to the reference brightness to obtain the reference gray scale value of different areas under different initial gray scale values, thereby obtaining the relation between the initial gray scale value and the reference gray scale value, namely a gray scale correction coefficient; compare in traditional projection luminance homogeneity and lean on the mode of adjustment ray apparatus structure to realize, labour saving and time saving, and luminance homogeneity is higher.
Drawings
FIG. 1 is a flow chart of an embodiment of the present invention;
FIG. 2 is a schematic diagram of a division structure of a display area according to an embodiment of the present invention;
FIG. 3 is a graph of a baseline luminance value in an embodiment of the present invention;
FIG. 4 is a graph of a reference gray scale value according to an embodiment of the present invention;
FIG. 5 is a diagram illustrating an initial frame of a display device according to an embodiment of the present invention;
FIG. 6 is a diagram illustrating a structure of a corrected frame of a display device according to an embodiment of the present invention;
FIG. 7 is a diagram illustrating brightness variations before correction of adjacent portions between adjacent display regions according to an embodiment of the present invention;
FIG. 8 is a schematic diagram illustrating gray scale variation after correction of neighboring portions between adjacent display regions according to an embodiment of the present invention.
Detailed Description
Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
Examples
As shown in fig. 1, a method for correcting luminance uniformity of a display device, which is described in this embodiment by taking a projection device as an example, includes the following steps:
s10, receiving and analyzing the image signal and acquiring a gray state in the image signal;
s20, calculating initial gray-scale values of all display areas of the whole display image in the image signal according to the gray-scale state;
s30, calculating correction coefficients of all the display areas, wherein the correction coefficients are used for recording the one-to-one correspondence relationship between the initial gray scale values and the reference gray scale values;
s40, carrying out gray correction on the initial gray-scale values of all the display areas by using the correction coefficients to obtain corresponding reference gray-scale values;
and S50, outputting and displaying the image after the gray-scale value correction.
As shown in fig. 2, taking 3 × 3 display regions as an example for correction, the calculation method of the correction coefficient is as follows:
1. the projection device projects test images of different initial gray levels (e.g., white field signals of 0-255 gray levels).
2. Detecting initial brightness values under different initial gray scales (0-255 gray scales) in 3 × 3 display areas;
that is, as in the display area of fig. 2, the display image is divided into 3 × 3 display areas, and one point test brightness value is selected in each of the nine display areas. And testing 256 brightness values (of 0-255) in each area to obtain the corresponding relation between the initial gray-scale value and the initial brightness value.
3. Smoothing the curve of the minimum brightness values of 3 x 3 regions under different initial gray scale values to be used as the reference brightness value under the gray scale;
namely: selecting the minimum brightness value in the 9 areas under each gray scale value, totally 256 data, and performing curve smoothing treatment to obtain the reference brightness under each gray scale value; as shown in fig. 3, the initial luminance values in the 2 display regions correspond to the reference luminance values;
the reference brightness value can be selected from the display frame of the device, or can be selected from several devices in a comprehensive way.
4. Reversely checking the reference gray scale value of each region according to the reference brightness value; obtaining a one-to-one corresponding relation between the initial gray scale value and the reference gray scale value of each correction area, namely a correction coefficient;
as shown in fig. 4, 5, and 6, when the actual luminance value of a certain region is a 255-level gray-scale white field signal, the luminance 400 is the reference luminance of the 255-level white field signal when the lowest luminance of 9 regions is 400 in the 255-level white field signal of the entire display image. When the luminance of the area is reduced to 400, and the corresponding relation between the initial gray-scale value and the luminance value is found that the actual luminance is closest to 400 when the 230-level gray-scale white field signal is detected, the 230-level gray-scale value is taken as the reference gray-scale value of the 250-level initial gray-scale value of the area. I.e., the initial gray scale value of 255 corresponds to the reference gray scale value of 230. Similarly, the initial gray scale values of 0-255 can be associated with the reference gray scale values one by one. The correction coefficient is the one-to-one correspondence of the initial gray scale value and the reference gray scale value. And when the whole image corresponds to the reference gray-scale value, the brightness uniformity of the displayed image is greatly improved.
As shown in fig. 7, in the initial picture, although there is a brightness difference in different regions, the brightness does not change abruptly, but the brightness at the region boundary is a relatively linear and gradual change process; as shown in FIG. 8, since the inter-region brightness abrupt change occurs when no process is performed between two calibration regions, the gray scale maximum value linear process is performed between different regions to obtain the intermediate reference gray scale curve, thereby preventing the inter-region brightness abrupt change from affecting the viewing effect.
The present embodiment can also perform gradation correction on RGB monochrome signals to achieve correction of color uniformity and luminance uniformity.
The embodiment also discloses a device for correcting the brightness uniformity of the display device, which comprises:
the image recognition module is used for receiving and analyzing the image signal and acquiring the gray state in the image signal;
the gray level calculation module is used for calculating the initial gray level value of each display area of the whole display image in the image signal according to the gray level state;
the correction coefficient module is used for calculating and storing correction coefficients of all the display areas, and the correction coefficients are used for recording the one-to-one correspondence relationship between the initial gray-scale values and the reference gray-scale values;
the gray correction module is used for carrying out gray correction on the initial gray scale values of all the display areas by using the correction coefficients to obtain corresponding reference gray scale values;
and the image output module is used for outputting and displaying the image after the gray-scale value correction.
The above-mentioned embodiments only express the specific embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that various changes and modifications can be made by those skilled in the art without departing from the spirit of the invention, and these changes and modifications are all within the scope of the invention.
Claims (7)
1. A method for correcting brightness uniformity of a display device is characterized by comprising the following steps:
s10, receiving and analyzing the image signal and acquiring a gray state in the image signal;
s20, calculating initial gray-scale values of all display areas of the whole display image in the image signal according to the gray-scale state;
s30, calculating correction coefficients of all the display areas, wherein the correction coefficients are used for recording the one-to-one corresponding relation between the initial gray-scale values and the reference gray-scale values;
s40, carrying out gray scale correction on the initial gray scale values of all the display areas by using the correction coefficients to obtain corresponding reference gray scale values;
and S50, outputting and displaying the image after the gray-scale value correction.
2. The method for correcting luminance uniformity of a display device according to claim 1, wherein the step S30 of calculating the correction coefficient of each display area specifically comprises the steps of:
s31, outputting test images with different initial gray scales by display equipment;
s32, detecting initial brightness values of different initial gray scale values in each display area;
s32, smoothing curves of the minimum brightness values in the plurality of display areas under different initial gray scale values to serve as the reference brightness values under the gray scale values;
s32, according to the reference brightness value of each display area, a gray level value corresponding to the reference brightness value is found out and is used as the reference gray level value under the reference brightness value; thereby obtaining the one-to-one correspondence between the initial gray scale value and the reference gray scale value of each display area.
3. The luminance uniformity correction method of a display device according to claim 2, wherein the test image in step S31 is a white field signal of gray scale 0-255.
4. The luminance uniformity correction method for a display device according to claim 2, wherein when there are a plurality of display devices, the reference luminance value in step S32 is comprehensively selected from the plurality of display devices.
5. The luminance uniformity correction method for a display device according to claim 2, further comprising subjecting the adjoining portion between the adjacent display regions to a gray maximum linear process to obtain a reference gray curve in which the adjoining portion is gradually changed from a reference gray level of one display region to a reference gray level of another display region for preventing a sudden luminance change between the adjacent display regions.
6. The luminance uniformity correction method for a display device according to any one of claims 1 to 5, wherein the display device is a projection device or a device outputting RGB monochrome signals.
7. A luminance uniformity correction apparatus for a display device, comprising:
the image recognition module is used for receiving and analyzing the image signal and acquiring the gray state in the image signal;
the gray level calculation module is used for calculating the initial gray level value of each display area of the whole display image in the image signal according to the gray level state;
the correction coefficient module is used for calculating and storing correction coefficients of all the display areas, and the correction coefficients are used for recording the one-to-one correspondence relationship between the initial gray scale values and the reference gray scale values;
the gray correction module is used for carrying out gray correction on the initial gray scale values of all the display areas by using the correction coefficients to obtain corresponding reference gray scale values;
and the image output module is used for outputting and displaying the image after the gray-scale value correction.
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| CN202211481437.2A CN115775511A (en) | 2022-11-24 | 2022-11-24 | Method and device for correcting brightness uniformity of display equipment |
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| CN202211481437.2A CN115775511A (en) | 2022-11-24 | 2022-11-24 | Method and device for correcting brightness uniformity of display equipment |
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