A multi-frequency gamma correction parameter calculation method and device

Abstract

The application discloses a multi-frequency gamma correction parameter calculation method and device. The method steps are as follows: according to the gamma parameter value of gamma0 at different frequencies compared with the gamma parameter value at a reference frequency, a look-up table (LUT) of RGB ratio coefficients at different frequencies is respectively established; the gamma parameter setting of the reference frequency and the luminance relationship gain of gamma0 are inputted, and a new gamma parameter binding point gray scale is generated according to the luminance relationship gain; the ratio coefficient of the corresponding binding point is calculated by look-up table interpolation according to the new gamma parameter binding point gray scale; and the new gamma parameter is calculated and generated according to the obtained ratio coefficient, and the gamma correction parameter setting is outputted.

Description

Technical Field

[0001] This invention belongs to the field of image display technology and relates to a method and apparatus for calculating multi-frequency gamma correction parameters. Background Technology

[0002] Most high-end brand mobile phones or laptops on the market support multiple display frequencies and switching. On the one hand, this is to achieve the best picture display effect according to different application scenarios. On the other hand, switching from high frequency to low frequency display can reduce power consumption and improve battery life.

[0003] Switching frequencies means changing the charging and discharging time of the pixel driving circuit. With the same data voltage, different charging and discharging times will result in different final display brightness and different degrees of impact on the three primary colors of RGB. Thus, changes in brightness and chromaticity can be seen during frequency switching. Therefore, each frequency usually has an independent set of gamma parameters to correct display brightness and chromaticity.

[0004] If there are 10 sets of gamma parameters at each frequency, then there will be 80 sets of gamma parameters that need to be adjusted across 8 frequencies. This will greatly affect the production efficiency of the production line and reduce capacity.

[0005] Based on the above-mentioned technical problems, this invention proposes a method and apparatus for calculating multi-frequency gamma correction parameters. Summary of the Invention

[0006] This invention proposes a method for calculating multi-frequency gamma correction parameters, characterized by the following steps:

[0007] Step 1: Calculate the scaling factor of the gamma parameter relative to the reference frequency at different frequencies of gamma0, and establish LUTs for the RGB coefficients respectively; where, assuming there are multiple sets of gamma parameters at each frequency, gamma0 represents the first set of gamma parameters.

[0008] Step 2: Based on the input gamma parameter and the brightness relationship gain with gamma0, generate new gamma parameter binding points;

[0009] Step 3: Based on the new bound point grayscale and the input frequency frr, find the corresponding scaling factor list such as LUT1, and calculate the scaling factor corresponding to the bound point grayscale of the gamma parameter at the frequency frr.

[0010] Step 4: Based on the coefficient list LUT4 obtained in Step 3, combine it with LUT2 to generate the input gamma parameter LUT5.

[0011] Furthermore, step one includes:

[0012] Based on the ratio of the gamma parameter at different frequencies to the gamma parameter at the reference frequency, a table LUT1 is created for each of the three RGB channels at each frequency:

[0013] The gamma parameter D at the reference frequency referer k_refer and grayscale Gr k The corresponding relation is represented as f r :D k_refer =f r (Gr k ), where k is a natural number.

[0014] [D 0_refer D 1_refer D 2_refer ...,D k_refer ]

[0015] =[f r (Gr0),f r (Gr1),f r (Gr2)……,f r (Gr k )]

[0016] The gamma parameter D at any frequency frr k_frr and grayscale Gr k The corresponding relation is represented as f f :D k_frr =f f (Gr k ), where k is a natural number,

[0017] [D 0_frr D 1_frr D 2_frr ...,D k_frr ] = [f f (Gr0),f f (Gr1),f f (Gr2)……,f f (Gr k )]

[0018] Coef k =D k_frr / D k_refer The gamma parameter, frr, is the scaling factor for the frequency relative to the reference frequency.

[0019] The LUT1 corresponding to frequency frr is established as follows:

[0020] LUT1:[coef0,coef1,coef2,…coef k]=[L1(Gr0),L1(Gr1),L1(Gr2),...L1(Gr k )]

[0021] Among them, [Gr0,Gr1,Gr2……Gr k [coef0,coef1,coef2,……coef] represents the grayscale sequence of bound points in LUT1; k ] represents the sequence of proportional coefficients for the gray levels of each binding point in LUT1 at the frequency frr.

[0022] Furthermore, step three includes:

[0023] Each set of input gamma parameters has a corresponding binding point and parameter value, with a LUT2 correspondence. The gamma parameters and binding points of other sets are converted to gamma0 to generate new binding points.

[0024] LUT2:[D0,D1,D2……,D n ]=[L2(G0),L2(G1),L2(G2)……,L2(G n )]

[0025] Where [G0, G1, G2, ..., G] n [D0, D1, D2, ..., D] represents the bound-point grayscale sequence of the input gamma parameter. n ] represents the sequence of input gamma parameter values. Any input gray level can be obtained by linear interpolation through LUT2 lookup table;

[0026] A new method for calculating the grayscale of bound points based on the input gamma parameter.

[0027]

[0028] G n ′=G n *gain

[0029] Lv gamma0 This is the maximum brightness at gamma0, Lv other These are the maximum brightness values ​​corresponding to the gamma parameters of other groups; these brightness values ​​are known. n It is the original grayscale of the bound points, G n ′ is the new grayscale of the binding point.

[0030] Map the gamma parameter values ​​corresponding to the original binding point grayscale to the new binding point grayscale.

[0031] [D0,D1,D2……,D n ]=[f(G′0),f(G′1),f(G′2)……,f(G′n )]

[0032] Where [G′0,G′1,G′2……G′] n ] represents the new grayscale sequence of the gamma parameter.

[0033] Furthermore, step three includes

[0034] First, find the list of proportional coefficients (LUT1) corresponding to the frequency frr.

[0035] LUT1:[coef0,coef1,coef2,…coef k ]=[L1(Gr0),L1(Gr1),L1(Gr2),...L1(Gr k )]

[0036] Then, based on the new binding points, the scaling factor corresponding to each new binding point is calculated using linear interpolation on LUT1 to generate LUT3.

[0037] LUT3:[coef′0,coef′1,coef′2,…coef′ n ]=[L3(G′0),L3(G′1),L3(G′2),…L3(G′ n )]

[0038] Where [coef′0,coef′1,coef′2,……coef′] n [] indicates the proportional coefficient corresponding to the new binding point.

[0039] The linear interpolation method is as follows:

[0040] If Gr0 < G′0 < Gr1, then

[0041]

[0042] The scaling factors calculated using the new binding point interpolation are mapped one-to-one onto the original binding points to generate a LUT4.

[0043] LUT4:[coef′0,coef′1,coef′2,…coef′ n ]=[L4(G0),L4(G1),L4(G2),…L4(G n )]

[0044] The corresponding ratio coefficient is calculated by linear interpolation based on the LUT4 lookup table for any input gray level.

[0045] Furthermore, step four includes

[0046] LUT5:[D′0,D′1,D′2……,D′n ]=[L5(G0),L5(G1),L5(G2)……,L5(G n )]

[0047] Where D′ n =D n *coef′ n [G0,G1,G2……G n [] represents the bound-point grayscale sequence of the input gamma parameter, [D′0,D′1,D′2……,D′] n ] represents the sequence of correction parameter values ​​for the input gamma parameter.

[0048] Furthermore, the present invention also discloses a multi-frequency gamma correction parameter calculation device, including...

[0049] New binding point calculation unit: The binding point grayscale of the input gamma parameter is converted to gamma0 according to the input gain value to obtain a new set of binding point grayscale. The new binding point grayscale is used as the basis for looking up the table to calculate the ratio coefficient.

[0050] Ratio coefficient calculation unit: Based on the gray level of the new binding point and the input frequency frr, the ratio coefficient of the gray level of each binding point is calculated by LUT interpolation from the table.

[0051] New gamma parameter calculation unit: Calculates the correction parameter value of the input gamma parameter based on the input gamma parameter value and the ratio coefficient obtained from the table. Attached Figure Description

[0052] Figure 1 The diagram shown is a flowchart of the correction calculation method of the present invention;

[0053] Figure 2 The diagram shown is a structural diagram of the correction calculation device of the present invention. Detailed Implementation

[0054] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] Please see Figure 1-2 A method for calculating multi-frequency gamma correction parameters includes the following steps:

[0056] Step 1: Calculate the scaling factor of the gamma parameter relative to the reference frequency at different frequencies of gamma0, and establish LUTs for the RGB coefficients respectively; where, assuming there are multiple sets of gamma parameters at each frequency, gamma0 represents the first set of gamma parameters.

[0057] Step 2: Based on the input gamma parameter and the brightness relationship gain with gamma0, generate new gamma parameter binding points;

[0058] Step 3: Based on the new bound point grayscale and the input frequency frr, find the corresponding scaling factor list such as LUT1, and calculate the scaling factor corresponding to the bound point grayscale of the gamma parameter at the frequency frr.

[0059] Step 4: Based on the coefficient list LUT4 obtained in Step 3, combine it with LUT2 to generate the input gamma parameter LUT5.

[0060] Step one includes:

[0061] Based on the ratio of the gamma parameter at different frequencies to the gamma parameter at the reference frequency, a table LUT1 is created for each of the three RGB channels at each frequency:

[0062] The gamma parameter D at the reference frequency referer k_refer and grayscale Gr k The corresponding relation is represented as f r :D k_refer =f r (Gr k ), where k is a natural number,

[0063] [D 0_refer D 1_refer D 2_refer ...,D k_refer ]

[0064] =[f r (Gr0),f r (Gr1),f r (Gr2)……,f r (Gr k )]

[0065] The gamma parameter D at any frequency frr k_frr and grayscale Gr k The corresponding relation is represented as f f :D k_frr =f f (Gr k ), where k is a natural number,

[0066] [D 0_frr D 1_frr D 2_frr ...,D k_frr ] = [f f (Gr0),f f (Gr1),f f (Gr2)……,f f (Gr k )]

[0067] Coef k =D k_frr / D k_refer The gamma parameter, frr, is the scaling factor for the frequency relative to the reference frequency.

[0068] The LUT1 corresponding to frequency frr is established as follows:

[0069] LUT1:[coef0,coef1,coef2,…coef k ]=[L1(Gr0),L1(Gr1),L1(Gr2),...L1(Gr k )]

[0070] Among them, [Gr0,Gr1,Gr2……Gr k [coef0,coef1,coef2,……coef] represents the grayscale sequence of bound points in LUT1; k ] represents the sequence of proportional coefficients for the gray levels of each binding point in LUT1 at the frequency frr.

[0071] Step three includes:

[0072] Each set of input gamma parameters has a corresponding binding point and parameter value, with a LUT2 correspondence. The gamma parameters and binding points of other sets are converted to gamma0 to generate new binding points.

[0073] LUT2:[D0,D1,D2……,D n ]=[L2(G0),L2(G1),L2(G2)……,L2(G n )]

[0074] Where [G0, G1, G2, ..., G] n [D0, D1, D2, ..., D] represents the bound-point grayscale sequence of the input gamma parameter. n ] represents the sequence of input gamma parameter values. Any input gray level can be obtained by linear interpolation through LUT2 lookup table;

[0075] A new method for calculating the grayscale of bound points based on the input gamma parameter.

[0076]

[0077] G n ′=G n *gain

[0078] Lv gamma0 This is the maximum brightness at gamma0, Lv other These are the maximum brightness values ​​corresponding to the gamma parameters of other groups; these brightness values ​​are known. n It is the original grayscale of the bound points, G n ′ is the new grayscale of the binding point.

[0079] Map the gamma parameter values ​​corresponding to the original binding point grayscale to the new binding point grayscale.

[0080] [D0,D1,D2……,D n ]=[f(G′0),f(G′1),f(G′2)……,f(G′ n )]

[0081] Where [G′0,G′1,G′2……G′] n ] represents the new grayscale sequence of the gamma parameter.

[0082] Step three includes

[0083] First, find the list of proportional coefficients (LUT1) corresponding to the frequency frr.

[0084] LUT1:[coef0,coef1,coef2,…coef k ]=[L1(Gr0),L1(Gr1),L1(Gr2),...L1(Gr k )]

[0085] Then, based on the new binding points, the scaling factor corresponding to each new binding point is calculated using linear interpolation on LUT1 to generate LUT3.

[0086] LUT3:[coef′0,coef′1,coef′2,…coef′ n ]=[L3(G′0),L3(G′1),L3(G′2),…L3(G′ n )]

[0087] Where [coef′0,coef′1,coef′2,……coef′] n [] indicates the proportional coefficient corresponding to the new binding point.

[0088] The linear interpolation method is as follows:

[0089] If Gr0 < G′0 < Gr1, then

[0090]

[0091] The scaling factors calculated using the new binding point interpolation are mapped one-to-one onto the original binding points to generate a LUT4.

[0092] LUT4:[coef′0,coef′1,coef′2,…coef′ n ]=[L4(G0),L4(G1),L4(G2),…L4(G n )]

[0093] Any input grayscale can be used to calculate the corresponding ratio coefficient through linear interpolation based on a LUT4 lookup table.

[0094] Step four includes

[0095] LUT5:[D′0,D′1,D′2……,D′ n ]=[L5(G0),L5(G1),L5(G2)……,L5(G n )]

[0096] Where D′ n =D n *coef′ n [G0,G1,G2……G n [] represents the bound-point grayscale sequence of the input gamma parameter, [D′0,D′1,D′2……,D′] n ] represents the sequence of correction parameter values ​​for the input gamma parameter.

[0097] A multi-frequency gamma correction parameter calculation device, comprising:

[0098] New binding point calculation unit: The binding point grayscale of the input gamma parameter is converted to gamma0 according to the input gain value to obtain a new set of binding point grayscale. The new binding point grayscale is used as the basis for looking up the table to calculate the ratio coefficient.

[0099] Ratio coefficient calculation unit: Based on the gray level of the new binding point and the input frequency frr, the ratio coefficient of the gray level of each binding point is calculated by LUT interpolation from the table.

[0100] New gamma parameter calculation unit: Calculates the correction parameter value of the input gamma parameter based on the input gamma parameter value and the ratio coefficient obtained from the table.

[0101] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0102] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is limited by the appended claims and their equivalents.

Claims

1. A method of multi-frequency gamma correction parameter calculation, characterized in that, Includes the following steps: Step 1: Calculate the scaling factor of the gamma parameter relative to the reference frequency at different frequencies of gamma0, and establish LUTs for the RGB coefficients respectively; where, assuming there are multiple sets of gamma parameters at each frequency, gamma0 represents the first set of gamma parameters. Step 2: Based on the input gamma parameter and the brightness relationship gain with gamma0, generate new gamma parameter binding points; Step 3: Based on the new bound point grayscale and the input frequency frr, find the corresponding scaling factor list such as LUT1, and calculate the scaling factor corresponding to the bound point grayscale of the gamma parameter at the frequency frr. Step 4: Based on the coefficient list LUT4 obtained in Step 3, combine it with LUT2 to generate the input gamma parameter LUT5; Step two includes: Each set of input gamma parameters has a corresponding binding point and parameter value, with a LUT2 correspondence. The gamma parameters and binding points of other sets are converted to gamma0 to generate new binding points. ， wherein represents the sequence of the input gamma parameters, represents the sequence of the input gamma parameters, and the corresponding gamma parameter value of any input gray level is obtained by linear interpolation through LUT2; A new method for calculating the grayscale of bound points based on the input gamma parameter. ， ； wherein is the maximum luminance of gamma0, is the maximum luminance of other sets of gamma parameters, which luminance values are known, is the original tie point gray scale, is the new tie point gray scale Map the gamma parameter values ​​corresponding to the original binding point grayscale to the new binding point grayscale. ， wherein represents a new binding point gray scale sequence of the gamma parameter.

2. The method of claim 1, wherein, Step one includes: Based on the ratio of the gamma parameter at different frequencies to the gamma parameter at the reference frequency, a table LUT1 is created for each of the three RGB channels at each frequency: gamma parameter value at reference frequency refer and the tie point gray scale The corresponding relationship is expressed as k is a natural number, ， gamma parameter value at any frequency frr and grayscale of binding points The corresponding relationship is represented as k is a natural number. ， count The gamma parameter, frr, is the scaling factor for the frequency relative to the reference frequency. The LUT1 corresponding to frequency frr is established as follows: ， in, This represents the grayscale sequence of bound points in LUT1; This represents the sequence of proportional coefficients for the grayscale of each binding point in LUT1 at that frequency frr.

3. The method for calculating multi-frequency gamma correction parameters according to claim 2, characterized in that, Step three includes First, find the list of proportional coefficients (LUT1) corresponding to the frequency frr. ； Then, based on the new binding points, the scaling factor corresponding to each new binding point is calculated using linear interpolation on LUT1 to generate LUT3. ， in This indicates the proportional coefficient corresponding to the new binding point. The linear interpolation method is as follows: like ,but ， The scaling factors calculated using the new binding point interpolation are mapped one-to-one onto the original binding points to generate a LUT4. ， The corresponding ratio coefficient is calculated by linear interpolation based on the LUT4 lookup table for any input gray level.

4. The method for calculating multi-frequency gamma correction parameters according to claim 3, characterized in that, Step four includes ， in, , This represents the grayscale sequence of the bound points for the input gamma parameter. This represents the sequence of correction parameter values ​​for the input gamma parameter.

5. A multi-frequency gamma correction parameter calculation device, comprising any one of the multi-frequency gamma correction parameter calculation methods according to claims 1-4, characterized in that, include New binding point calculation unit: The binding point grayscale of the input gamma parameter is converted to gamma0 according to the input gain value to obtain a new set of binding point grayscale. The new binding point grayscale is used as the basis for looking up the table to calculate the ratio coefficient. Ratio coefficient calculation unit: Based on the gray level of the new binding point and the input frequency frr, the ratio coefficient of the gray level of each binding point is calculated by LUT interpolation from the table. New gamma parameter calculation unit: Calculates the correction parameter value of the input gamma parameter based on the input gamma parameter value and the ratio coefficient obtained from the table.

Images