A method and apparatus for improving the quality of a projector

Abstract

The application discloses a method for improving the picture quality of a projector, converts image data output by the projector into a contrast modulation signal of the image, and adjusts the light intensity according to the contrast modulation signal of the image. The application also discloses a device for improving the picture quality of the projector, which comprises a light source, a contrast modulation module, an image output control module, a processing module and an optical imaging module. The image output control module is used for inputting image data into the processing module. The processing module is used for calculating an image contrast modulation signal according to the image data, and the image contrast modulation signal is input into the contrast modulation module. The contrast modulation module is used for modulating the light of the light source according to the image contrast modulation signal, and projecting and imaging through the optical imaging module. The application can improve the picture quality, has a defogging effect, makes the picture clearer and more colorful, and can also speed up the image data calculation speed.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of projection technology, in particular to a method and device for improving the picture quality of a projector. BACKGROUND

[0002] The current household projector has low contrast, and is easily affected by the ambient light. When the ambient light is relatively strong, the image projected onto a white wall will have a low contrast, and the picture will not be clear, which will affect the viewing.

[0003] Only in the case of dark ambient light or when the projector has extremely high brightness, the picture of the projector can be clearly presented. Currently, the contrast is improved by simply improving the image algorithm of the projector or improving the contrast in the optical system. For example, the Epson company uses a high-efficiency light source to improve the light efficiency, uses a high-transmittance Lcos liquid crystal panel, and uses a comb filter to improve the contrast of the projector. All of these are to improve the picture quality by changing the performance of the light source or the performance of the Lcos liquid crystal panel or the picture algorithm. However, there is no improvement technology that combines hardware and algorithm to modulate light to improve contrast at the light source end. SUMMARY

[0004] The present application solves the technical problems of the prior art and provides a method and device for improving the picture quality of a projector, which improves the contrast and picture quality of the projector.

[0005] The present application solves the technical problems by adopting the following technical solutions:

[0006] According to the present application, a method for improving the picture quality of a projector is provided, which includes:

[0007] The image data output by the projector is converted into an image contrast modulation signal, and the light intensity is adjusted according to the image contrast modulation signal. There are two methods for obtaining the image contrast modulation signal, which are as follows:

[0008] The first method is to calculate the image data, convert the RGB signal of the image data into an LMS cone response signal, extract a visual brightness signal from the LMS cone response signal, the visual brightness signal is an L+M signal, perform Gaussian convolution calculation on the data matrix of the L+M signal to obtain a newly generated Gaussian convolution signal, and modulate the newly generated Gaussian convolution signal to obtain an image contrast modulation signal. Wherein, L is a long-wave cone response signal, and M is a medium-wave cone response signal.

[0009] The second method is to convert the RGB signal of the image data into an HSV signal, extract the brightness V signal from the HSV signal, and modulate and process the brightness V signal to obtain the image contrast modulation signal.

[0010] As a further optimization of the method for improving the image quality of a projector, the newly generated Gaussian convolution signal is modulated by a sigmoid function.

[0011] As a further optimization of the method for improving the image quality of a projector, the first method for obtaining the image contrast modulation signal is as follows:

[0012] The RGB signal is converted into an LMS signal: wherein, is the conversion matrix from RGB to LMS, p1-p9 are all constants, L is the long-wave cone response signal, M is the medium-wave cone response signal, S is the short-wave cone response signal, R, G, and B are the red channel signal, green channel signal, and blue channel signal of the projector output image data, respectively;

[0013] The brightness signal I is extracted, I = L + M;

[0014] The data matrix I(x, y) of I is subjected to Gaussian convolution calculation, P(x, y) = I(x, y) * G(x, y), wherein G(x, y) is a Gaussian matrix, and x and y are the horizontal and vertical pixel values of the RGB image data;

[0015] The P(x, y) is subjected to sigmoid function modulation to obtain the image contrast modulation signal Iz(x, y);

[0016]

[0017] wherein Imax is the maximum value of I(x, y), a, b, and c are parameters for adjustment, a ∈ (0, 5), b ∈ (0, 10), c ∈ (0, 50), and exp(*) is an exponential function.

[0018] As a further optimization of the method for improving the image quality of a projector, the second method for obtaining the image contrast modulation signal is as follows:

[0019] The second method is to convert the RGB signal of the image data into an HSV signal, extract the brightness V signal from the HSV signal, and modulate and process the brightness V signal to obtain the image contrast modulation signal.

[0020] The RGB signal of the image data is converted to an HSV signal. The luminance matrix V(x,y) of the luminance V signal is extracted. The V(x,y) data matrix is ​​decomposed into m*n submatrices E(i,j), where m is the number of horizontal groups and n is the number of vertical groups, m and n are constant integers, and i and j are the number of horizontal and vertical elements in each submatrix, respectively. The maximum value Max of each submatrix E(i,j) is calculated. The maximum values ​​Max of all submatrices E(i,j) are combined to form a new matrix Max(m,n). The Fourier transform of the convolution theorem is used to speed up the calculation. The Fourier transform of the new matrix Max(m,n) is used to obtain the Fourier transform matrix X(m,n) of Max(m,n).

[0021] X(m,n)=F{Max(m,n)}, F{*} is the Fourier transform;

[0022] The Gaussian Fourier matrix Y(m,n) is obtained by performing a Fourier transform on the Gaussian matrix G(m,n).

[0023] Y(m,n) = F{G(m,n)};

[0024] Using the convolution theorem, the dot product of X(m,n) and matrix Y(m,n) yields the convolution matrix Z(m,n).

[0025] Z(m,n) = X(m,n).*Y(m,n);

[0026] Performing an inverse Fourier transform on the Z(m,n) matrix yields the convolutional inverse Fourier matrix P(m,n).

[0027] P(m,n)=F -1 {Z(m,n)};

[0028] Modulating P(m,n) with the sigmoid function yields the modulated signal Vz(m,n).

[0029]

[0030] Where Pmax is the maximum value of P(m,n), and a, b, and c are parameters used for adjustment, where a∈(0,5), b∈(0,10), and c∈(0,50).

[0031] The image contrast modulation signal Vz(x,y) is obtained by amplifying Vz(m,n) through spline interpolation.

[0032] As a further optimization of the method for improving the image quality of a projector described in this invention, m is an integer between 2 and 16, and n is an integer between 2 and 9.

[0033] As a further optimization of the method for improving the picture quality of a projector, i is an integer between 1 and x / m, and j is an integer between 1 and y / n.

[0034] The device for the method for improving the picture quality of a projector comprises a light source, a contrast modulation module, an image output control module, a processing module and an optical imaging module, wherein,

[0035] The image output control module is configured to input image data to the processing module.

[0036] The processing module is configured to calculate an image contrast modulation signal according to the image data, and the image contrast modulation signal is input to the contrast modulation module.

[0037] The contrast modulation module is configured to modulate the light of the light source according to the image contrast modulation signal and project the modulated light through the optical imaging module.

[0038] As a further optimization of the device for the method for improving the picture quality of a projector, the contrast modulation module comprises a liquid crystal screen, which can adjust the intensity of light transmission of liquid crystals by adjusting the voltage of the electrode layer, and the contrast modulation module can adjust the intensity of the light emitted from different positions of the light emitting surface of the light source; the contrast modulation module is composed of a cholesteryl liquid crystal layer with a reflection wavelength existing in the visible light region and two transparent electrode layers.

[0039] As a further optimization of the device for the method for improving the picture quality of a projector, the light source is an LED light source, an OLED light source or a quantum light source.

[0040] As a further optimization of the device for the method for improving the picture quality of a projector, the optical imaging module is a light path module composed of an LCOS liquid crystal screen or a DMD reflection imaging module, and the optical imaging module comprises an LCOS or a DMD, an optical lens group and a polarizing plate.

[0041] Compared with the prior art, the above technical scheme has the following technical effects:

[0042] (1) The present application increases a contrast modulation module between the light source and the optical imaging module of a conventional projector, which can increase the contrast of a one-dimensional LED light source projector such as a DLP projector and improve the picture quality. Figure 1 The special liquid crystal screen in the contrast modulation module can display a contrast modulation signal, thereby increasing the contrast of the projector and improving the picture quality; specifically, a contrast modulation signal is calculated according to image data, and the modulation signal is input to the liquid crystal screen in the contrast modulation module; the liquid crystal changes the light transmission performance by changing the deflection of the liquid crystal through the voltage control of the two sides, thereby forming a contrast modulation signal picture; the light of the light source is modulated through the liquid crystal, thereby forming a modulated light plane.

[0043] (2) For two-dimensional lattice LED or OLED light source does not use liquid crystal modulation such as Figure 2 , the contrast modulation signal can be directly input to the two-dimensional LED, OLED light source panel, forming a modulated light source, and then projected and imaged through the optical imaging module, which can achieve a contrast ratio of 5% to 10%, or can improve the image quality, has a defogging effect, makes the picture clearer and the colors more vivid. In addition to increasing the contrast ratio, it can also speed up the image data calculation speed. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 is a schematic diagram of an embodiment of a device for improving the quality of a projector.

[0045] Figure 2 is a schematic diagram of an embodiment of a device for improving the quality of a projector. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the present application clearer, the present application will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0047] The present application is a module and algorithm for improving the contrast ratio of a projector. For a one-dimensional LED light source projector, as shown in Figure 1 , the image signal is transmitted to the algorithm system through the image output control module, the algorithm system calculates the contrast modulation signal according to the image signal, and then inputs the modulation signal to the liquid crystal screen in the contrast modulation module. After the light of the light source system is modulated, it is projected and imaged through the optical imaging module, achieving an increase in contrast ratio or image quality. For a two-dimensional light source projector, the contrast modulation module is the light source itself, and the contrast modulation signal is directly input to the two-dimensional LED or OLED light source.

[0048] A module and algorithm for improving the contrast ratio of a projector, a module for improving the contrast ratio of a projector includes a light source system, a contrast modulation module, an image output control module, an algorithm system, and an optical imaging module:

[0049] When the quality of the projector needs to be changed or the contrast ratio needs to be improved, the image signal is transmitted to the algorithm system through the image output control module, the algorithm system calculates the image modulation signal according to the image signal, and then inputs the modulation signal to the liquid crystal screen in the contrast modulation module. After the light of the light source system is modulated, it is projected and imaged through the optical imaging system, achieving an increase in contrast ratio or image quality. The light source system can be an LED light source or an OLED light source.

[0050] For the projector of one-dimensional LED light source, the contrast modulation module is a liquid crystal screen with a control system. The liquid crystal screen can adjust the intensity of the liquid crystal light transmission by adjusting the voltage of the electrode layer, and the intensity of the light emitted by the light source can be adjusted by the optical modulation module. The contrast modulation module is composed of a cholesteric liquid crystal layer with a reflection wavelength in the visible light region, and two transparent electrode layers above and below.

[0051] For the projector of two-dimensional LED or OLED light source, the contrast modulation module is the LED or OLED light source itself.

[0052] The optical imaging module can be an optical path module for LCOS liquid crystal screen or DMD reflection imaging. It includes LCOS, or DMD, optical lens group, polarizing plate and other optical components.

[0053] The algorithm system can convert the image signal into an image contrast modulation signal.

[0054] The specific implementation method of the contrast modulation algorithm is as follows,

[0055] Calculate the image data, and convert the RGB signal of the image data into the LMS signal,

[0056] Convert the RGB signal into the LMS signal: Wherein, is the conversion matrix from RGB to LMS, p1-p9 are all constants, L is the long-wave cone response signal, M is the medium-wave cone response signal, S is the short-wave cone response signal, R is the red channel signal of the projector output image data, G is the green channel signal, and B is the blue channel signal.

[0057] Extract the brightness signal I, I = L + M;

[0058] Perform Gaussian convolution calculation on the data matrix I(x, y) of I, P(x, y) = I(x, y) * G(x, y), G(x, y) is a Gaussian matrix, wherein x, y are the horizontal and vertical pixel values of the RGB image data;

[0059] Sigmoid function modulation is performed on P(x, y) to obtain the image contrast modulation signal Iz(x, y);

[0060]

[0061] Wherein, Imax is the maximum value of I(x, y), a, b, c are parameters for adjustment, a ∈ (0, 5), b ∈ (0, 10), c ∈ (0, 50), and exp(*) is an exponential function.

[0062] The second method for obtaining the image contrast modulation signal is as follows:

[0063] The image data is calculated, the RGB signal of the image data is converted into the HSV signal, the brightness V signal is extracted as a brightness matrix V(x, y), the V(x, y) data matrix is decomposed into m*n sub-matrices E(i, j), m is the number of groups in the horizontal direction, n is the number of groups in the vertical direction, m and n are constant integers, m can be an integer between 2 and 16, n can be an integer between 2 and 9, i is the number of horizontal elements contained in each sub-matrix, j is the number of vertical elements (i is an integer between 1 and x / m, and j is an integer between 1 and y / n), the maximum value Max of each sub-matrix E(i, j) is calculated, and the maximum values Max of all the sub-matrices E(i, j) form a new matrix Max(m, n),

[0064] The Fourier transform is used to speed up the calculation according to the convolution theorem, and the Fourier transform matrix X(m, n) of the new matrix Max(m, n) is obtained,

[0065] X(m, n) = F{Max(m, n)};

[0066] The Gaussian matrix G(m, n) is subjected to Fourier transform to obtain the Gaussian Fourier matrix Y(m, n),

[0067] Y(m, n) = F{G(m, n)};

[0068] According to the convolution theorem, the point multiplication of X(m, n) and Y(m, n) obtains the convolution matrix Z(m, n),

[0069] Z(m, n) = X(m, n).*Y(m, n);

[0070] The inverse Fourier transform of the Z(m, n) matrix is performed to obtain the inverse Fourier transform matrix P(m, n) of Z(m, n),

[0071] P(m, n) = F -1 {Z(m, n)};

[0072] The sigmoid function modulation is performed on P(m, n) to obtain the modulation signal Vz(m, n),

[0073]

[0074] Wherein, Pmax is the maximum value of P(m, n), a, b, c are parameters for adjustment, a ∈ (0, 5), b ∈ (0, 10), c ∈ (0, 50);

[0075] The modulation signal Vz(x, y) is obtained by spline interpolation amplification of Vz(m, n). The Vz(x, y) signal is input to the liquid crystal screen of the contrast modulation module to adjust the light intensity.

[0076] The application adds a contrast modulation module between the light source and the optical imaging module of a conventional projector, and is suitable for a projector with a one-dimensional LED light source such as Figure 1 The special liquid crystal screen in the contrast modulation module can modulate the contrast modulation signal by display, and finally increase the contrast of the projector and improve the picture quality; the specific method is to calculate the contrast modulation signal according to the image data, and then input the modulation signal to the liquid crystal screen in the contrast modulation module; the liquid crystal changes the light transmission performance by changing the deflection of the two sides of the electric level control, and forms the contrast modulation signal picture; after the light of the light source is modulated by the liquid crystal, the modulated light source light plane is formed. For a two-dimensional dot matrix LED or OLED light source, the liquid crystal modulation is not used, such as Figure 2 The contrast modulation signal can be directly input to the two-dimensional LED and OLED light source panel to form a modulated light source, and then the optical imaging module is used for projection imaging, so that the contrast is improved by 5% to 10%, or the picture quality is improved, the fog is removed, the picture is clearer, the color is more vivid, and in addition to increasing the contrast, the image data calculation speed can be accelerated.

[0077] The above is only a specific embodiment of the application, but the protection scope of the application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the application, which should be covered within the protection scope of the application.

Claims

1. A method for improving the quality of a projector, characterized by, The application relates to a contrast modulation method and device for image output. The image data output by the projector is converted into a contrast modulation signal of the image, and the light intensity is adjusted according to the contrast modulation signal of the image; wherein, The image data is calculated, the RGB signal of the image data is converted into an LMS cone response signal, a visual brightness signal is extracted from the LMS cone response signal, the visual brightness signal is an L+M signal, a data matrix of the L+M signal is subjected to Gaussian convolution calculation to obtain a newly generated Gaussian convolution signal, and the newly generated Gaussian convolution signal is modulated to obtain an image contrast modulation signal; wherein, L is a long-wave cone response signal, and M is a medium-wave cone response signal; The image contrast modulation signal is obtained by the following method: Converting the RGB signals to LMS signals: = wherein, is the conversion matrix from RGB to LMS, pi-p9 are constants, S is the short cone response signal, R, G, B are the red channel signal, green channel signal, blue channel signal of the projector output image data respectively. The brightness signal I is extracted, I=L+M; performing a Gaussian convolution calculation on the data matrix I(x,y) of I, where G(x,y) is a Gaussian matrix; The P(x, y) is modulated by a sigmoid function to obtain an image contrast modulation signal ; ； wherein is , , is a parameter for adjustment, ∈ (0, 5), ∈ (0, 10), ∈ (0, 50), is an exponential function.

2. An apparatus for improving the quality of a projection based on the method of claim 1, characterized in that, The application relates to a contrast modulation method and device for image output. The image output control module is used for inputting the image data into the processing module; The processing module is used for calculating the image contrast modulation signal according to the image data, and the image contrast modulation signal is input into the contrast modulation module; The contrast modulation module is used for modulating the light of the light source, and then the light is projected and imaged through the optical imaging module.

3. The apparatus for improving the quality of a projected image according to claim 2, wherein, The contrast modulation module comprises a liquid crystal screen, the liquid crystal screen can adjust the light transmission intensity of liquid crystal by adjusting the voltage of the electrode layer, the light intensity of the light emitted from different positions of the light emitting surface of the light source can be adjusted through the contrast modulation module; the contrast modulation module is composed of a choline chloride liquid crystal layer with a reflection wavelength existing in the visible light region and two upper and lower transparent electrode layers.

4. The apparatus for improving the quality of a projected image according to claim 2, wherein, The light source is an LED light source, an OLED light source or a quantum light source.

5. The apparatus for improving the quality of a projected image according to claim 2, wherein, The optical imaging module is a light path module composed of LCOS liquid crystal screen or DMD reflection imaging, and the optical imaging module comprises LCOS or DMD, an optical lens group and a polaroid.

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