CN100455029C - Method and device for color conversion and color gamut expansion in laser display - Google Patents

Abstract

The invention belongs to the field of laser video display, and relates to a method and device for color conversion and color gamut expansion in laser display. The conversion relationship between laser video modulation signal and phosphor video modulation signal is established according to the principle of colorimetric color conversion, and the phosphor video The modulation signal is converted into a laser video modulation signal, realizing the use of the laser three primary colors to reproduce the color gamut of the three primary colors of the phosphor, achieving the goal of correct color restoration; Carry out the outer edge to the boundary of the laser color gamut, and expand the small color gamut of the three primary colors of the phosphor to the large color gamut of the three primary colors of the laser, fully showing the purer saturated colors in the laser color gamut beyond the phosphor pink gamut.

Description

Colour switching and color domain expanding method and device in the laser display

Technical field

The invention belongs to laser video and show the field, relate to and a kind ofly correctly reappear the color video frequency image that the fluorescent material three primary colors are synthesized with the laser three primary colors, and the method that is the big colour gamut of laser three primary colors with the trichromatic little gamut extension of fluorescent material further.

Background technology

The color rendition of coloured image is based on red, green, blue three look composition principles in the color TV.The international broadcasting television standard committee has been formulated multiple different coloud codings and modulation systems such as Phase Alternation Line system, TSC-system and Sequential Color and Memory system according to different fluorescent material three primary colors and different modulation systems, forms international colored radio and television standard.Present various videos show information source, video input-output apparatus all with this standard design manufacturing, thereby make color video display standardization, standardization.

Develop today with practicability rapidly at all solid state three primary colors laser, utilizing three one-wavelength lasers of red, green, blue to realize as three primary colors that the laser color video shows has become research direction very popular in the present color video demonstration field.Because the laser three primary colors are different with traditional fluorescent material three primary colors colour gamut, therefore directly utilize existing vision signal modulated laser three primary colors certainly will cause the deviation of color reproduction; In addition, the trichromatic gamut range of laser (as selects for use the three primary colors Wavelength of Laser to be: R～671nm, G～532nm, B～457nm) than the trichromatic gamut range of fluorescent material is big a lot of usually.Only go to reappear the trichromatic colour gamut of fluorescent material with the laser three primary colors, though can reach the purpose of the correct reduction of color, the characteristics of the trichromatic high saturation of laser, big colour gamut do not show.

Summary of the invention

The object of the invention provides colour switching and color domain expanding method and device in a kind of laser display, according to colorimetry colour switching principle the fluorescent material video modulation signal is converted to the laser video modulation signal, realizes going to reappear the trichromatic colour gamut of fluorescent material with the laser three primary colors; Criterion according to " tone is constant " is carried out the outer to the color colour gamut on the fluorescent material gamut boundary, the outer is to the laser border, with the trichromatic little gamut extension of fluorescent material is the big colour gamuts of laser three primary colors, has reached the purpose of the correct reduction of color and has represented the higher color of saturation in the fluorescent material colour gamut laser colour gamut in addition.

The present invention is characterised in that the following step:

A, receive the video signal and be broken down into TV RGB standard signal and it carried out coffee is anti-to be proofreaied and correct by decoding circuit 1;

B, according to colorimetry colour switching principle, establish fluorescent material three primary colors and laser three primary colors and the corresponding relation of modulation signal separately, and then set up the transformational relation of laser video modulation signal and fluorescent material video modulation signal;

C, TV RGB standard signal is converted to laser RGB standard signal by the transformational relation of laser video modulation signal and fluorescent material video modulation signal;

D, judge TV RGB standard signal whether on the edge of colour gamut triangle, if color signal not on the edge of fluorescent material colour gamut triangle, promptly fluorescent material three primary colors psychrometric colour specification Rp, Gp, Bp are non-vanishing, then change step I; If color signal on the edge of fluorescent material colour gamut triangle, promptly has one or two among fluorescent material three primary colors psychrometric colour specification Rp, Gp, the Bp be zero, then change step e;

The total brightness of e, calculating laser RGB standard signal, and compare laser RGB standard signal laser three primary colors psychrometric colour specification R _L, G _L, B _LIn minimum one, establishing its value is Em;

F, with laser three primary colors psychrometric colour specification R _L, G _L, B _LDeduct Em respectively;

The total brightness and the laser three primary colors psychrometric colour specification R of g, calculating laser RGB standard signal _L, G _L, B _LDeduct the multiple K between the laser RGB standard signal brightness behind the Em respectively;

H, with laser three primary colors psychrometric colour specification R _L, G _L, B _LThe numerical value that deducts respectively behind the Em multiply by K respectively again, and making laser RGB standard signal luminance recovery is the total brightness of former laser RGB standard signal;

I, laser RGB standard signal carried out coffee is anti-to be proofreaied and correct;

J, in TV RGB standard signal, extract synchronizing signal and to its time-delay, coding circuit 3 is being encoded to the laser RGB standard signal after anti-correction the through coffee under the synchronization pulse after the time-delay and exported the video signal.

Realize circuit of the present invention as shown in Figure 3, comprise decoding circuit 1, programmable logic device 2, control circuit 4, coding circuit 3; Decoding circuit 1 output connects programmable logic device 2 inputs, and decoding circuit 1 is TV RGB standard signal with the video signal decomposition that receives and carries out the anti-correction of coffee, is transferred to programmable logic device 2 then; Programmable logic device 2 is converted to TV RGB standard signal laser RGB standard signal, judges that whether TV RGB standard signal is whether one or two is arranged among Rp, Gp, the Bp is zero, finishes the anti-correction of coffee that signal after virtual color expansion and the expansion amplifies, realizes laser RGB standard signal again on the edge of colour gamut triangle; The output of programmable logic device 2 connects the input of coding circuit 3, will send into coding circuit 3 through the anti-laser RGB standard signal of proofreading and correct of coffee; Programmable logic device 2 extracts synchronizing signal and time-delay from decoding circuit 1, make coding circuit 3 under the synchronization pulse after the time-delay to laser RGB standard signal recompile and export the video signal; Control circuit 4 is connected with decoding circuit 1, programmable logic device 2, coding circuit 3 respectively; Decoding circuit 1 is finished the video signal decoding under the signal controlling of control circuit 4 output, and the output control signal is given that programmable logic device 2 finishes that TV RGB standard signal is converted to that the coffee of laser RGB standard signal, laser RGB standard signal is instead proofreaied and correct, the signal after virtual color expansion and the expansion amplifies again; Coding circuit 3 is finished laser RGB standard signal recompile and is exported the video signal.

Beneficial effect: the present invention sets up the transformational relation of laser video modulation signal and fluorescent material video modulation signal according to colorimetry colour switching principle, and the fluorescent material video modulation signal is converted to the laser video modulation signal, realized going to reappear fluorescent material three primary colors colour gamut, reached the purpose of the correct reduction of color with the laser three primary colors; And the judgment criterion according to " tone is constant " is carried out the outer to the laser gamut boundary to the color on the fluorescent material gamut boundary, with the trichromatic little gamut extension of fluorescent material is the big colour gamuts of laser three primary colors, has fully represented purer heavy shade in the fluorescent material colour gamut laser colour gamut in addition.

Description of drawings

Fig. 1 is a laser display color virtual extended principle schematic of the present invention.2 is the colour triangle of laser among the figure, and 1 is the colour triangle of the fluorescent material of EBU TV, and the zone that curve 3 constitutes is the nature colour gamut.

Fig. 2 is a circuit design principle schematic diagram of the present invention.

Fig. 3 is an electrical block diagram of the present invention, also is Figure of abstract.Decoding circuit 1 among the figure, programmable logic device 2, control circuit 4, coding circuit 3, matrixer 5, NAND gate 6, the first switching circuits 7, second switch circuit 8, comparator 9, computing kernel 10,11 delay circuits.

Embodiment

Programmable logic device 2 internal structures comprise matrixer 5, NAND gate 6, the first switching circuits 7, second switch circuit 8, comparator 9, computing kernel 10, delay circuit 11; The output of decoding circuit 1 is connected with the input of NAND gate 6, matrixer 5 respectively; The output of matrixer 5 is connected with first switching circuit 7, second switch circuit 8 respectively; The output of NAND gate 6 is connected with first switching circuit 7, second switch circuit 8 respectively; Second switch circuit 8 is connected with intrinsic computing kernel 10 in comparator 9 and the programmable logic device 2 respectively, and computing kernel 10 intrinsic in first switching circuit 7 and the programmable logic device 2 is connected, and delay circuit 11 is connected with coding circuit 3 with decoding circuit 1.

Control circuit 4 adopts single-chip microcomputer, and its model is PLC2046; It is the chip of AD9884 that decoding circuit 1 adopts model; It is the chip of FPGA100F that programmable logic device 2 adopts model; It is the chip of TDA8501 that coding circuit 3 adopts model.Single-chip microcomputer is connected with the corresponding interface of decoding circuit 1, programmable logic device 2, coding circuit 3.

Because it is different that laser three primary colors and traditional fluorescent material three primary colors exist chroma point, their gamut range is also different, and therefore according to the colorimetry principle, two trichromatic color systems of difference can carry out color conversion by the matrix of a linear transformation.XYZ system is desirable Mathematical Modeling in the color system, and the RGB system is the actual physical model.Can set up following conversion relational expression between two systems:

$\left[\begin{array}{c}X\\ Y\\ Z\end{array}\right]={\left[\mathrm{Ar}\right]}^{-1}\left[\begin{array}{c}R\\ G\\ B\end{array}\right]---\left(1\right)$

When selecting different three primary colors for use as the primary colours of color system, corresponding different conversion relational expressions (1), i.e. [Ar] ^-1Different.But corresponding XYZ is constant, thus two kinds select for use the color system of different base colors can use XYZ system to set up the equation relation, and then set up two transformational relations between system.Transformational relation with Phase Alternation Line system and TSC-system fluorescent material and laser is an example, and its conversion relational expression is as follows.

${\left[\mathrm{Br}\right]}^{-1}\left[\begin{array}{c}{R}_p\\ G_p\\ B_p\end{array}\right]={\left[L_{\mathrm{Nr}}\right]}^{-1}\left[\begin{array}{c}{R}_L\\ G_L\\ B_L\end{array}\right]---\left(2\right)$

${\left[\mathrm{Cr}\right]}^{-1}\left[\begin{array}{c}{R}_p\\ G_p\\ B_p\end{array}\right]={\left[L_{\mathrm{Pr}}\right]}^{-1}\left[\begin{array}{c}{R}_L\\ G_L\\ B_L\end{array}\right]---\left(3\right)$

Top two equatioies (2), (3) be multiply by [B respectively _r] and [C _r] after have following equation to set up:

The color system transformational relation of laser color system and Phase Alternation Line system fluorescent material:

$\left[\begin{array}{c}{R}_p\\ G_p\\ B_p\end{array}\right]={\left[C_r\right]\left[L_{\mathrm{Pr}}\right]}^{-1}\left[\begin{array}{c}{R}_L\\ G_L\\ B_L\end{array}\right]---\left(4\right)$

$\left[{\mathrm{}}_r\right]{\left[L_{\mathrm{Pr}473}\right]}^{-1}=\left[\begin{array}{ccc}1.531& 0.4143& 0.8512\\ 1.085& 0.9377& 1.356\\ 0.00& 0.2128& 1.129\end{array}\right]---\left(5\right)$

$\left[C_r\right]{\left[L_{\mathrm{Pr}460}\right]}^{-1}=\left[\begin{array}{ccc}0.4451& 0.4558& 3.537\\ 0.1818& 1.032& 3.24\\ 56.16& 0.2341& 0.00\end{array}\right]---\left(6\right)$

$\left[C_r\right]{\left[L_{\mathrm{Pr}457}\right]}^{-1}=\left[\begin{array}{ccc}0.4412& 0.4672& 3.381\\ 0.1455& 1.057& 3.101\\ 52.85& 0.24& 0.0000\end{array}\right]---\left(7\right)$

The color system transformational relation of laser color system and TSC-system fluorescent material:

$\left[\begin{array}{c}{R}_p\\ G_p\\ B_p\end{array}\right]={\left[B_r\right]\left[L_{\mathrm{Nr}}\right]}^{-1}\left[\begin{array}{c}{R}_L\\ G_L\\ B_L\end{array}\right]---\left(8\right)$

$\left[B_r\right]{\left[L_{\mathrm{Nr}473}\right]}^{-1}=\left[\begin{array}{ccc}1.116& 0.7949& 0.8262\\ 0.8289& 1.103& 0.9209\\ 0.00& 0.4092& 1.036\end{array}\right]---\left(9\right)$

$\left[B_r\right]{\left[L_{\mathrm{Nr}460}\right]}^{-1}=\left[\begin{array}{ccc}0.3309& 0.897& 3.12\\ 1.386& 1.244& 2.003\\ 0.00& 0.4614& 0.00\end{array}\right]---\left(10\right)$

$\left[B_r\right]{\left[L_{\mathrm{Nr}457}\right]}^{-1}=\left[\begin{array}{ccc}0.3409& 0.9082& 3.08\\ 0.1178& 1.26& 1.977\\ 0.000& 0.4675& 0.0000\end{array}\right]---\left(11\right)$

More than be with 473nm, 532nm, 672nm; 460nm, 532nm, 672nm; 457nm, 532nm, 672nm are that conversion relational expression (9), (10), (11) between pal mode conversion relational expression (5), (6), (7) and TSC-system formula in laser RGB standard and the existing TV RGB standard are set up in three groups of laser displaies of primary colours.

(4) Rp, Gp, Bp represent fluorescent material three primary colors psychrometric colour specification, R respectively in formula, (8) formula _L, G _L, B _LRepresent laser three primary colors psychrometric colour specification respectively.

Can distinguish design matrix change-over circuit 5 according to conversion relational expression (9), (10), (11) between pal mode conversion relational expression (5), (6), (7) and TSC-system formula in laser RGB standard and the existing TV RGB standard, input signal is resolved into the energy ratio of the laser laser beam of corresponding R, G, three kinds of primary colours of B voltage signal control, synthesize correct color effects thereby reach, realize correctly reappearing the fluorescent material three primary colors with the laser three primary colors.

The course of work of the present invention: the video signal of input enters programmable logic device 2 after decoding circuit 1 resolves into TV RGB standard signal and the anti-correction of coffee sign indicating number, be converted to laser RGB standard signal by the matrixer in the programmable logic device 25; 6 couples of TV RGB of NAND gate standard signal is judged, if color signal is in fluorescent material colour gamut triangle, be that Rp, Gp, Bp are non-vanishing, gating first switching circuit 7 then, laser RGB standard signal are undertaken by computing kernel intrinsic in the programmable logic device 2 10 that coffee is anti-to be proofreaied and correct; Supply with coding circuit 3 by the synchronizing signal that decoding circuit 1 extracts through delay circuit 11 time-delays, make coding circuit 3 under synchronization pulse after the time-delay, carry out recompile and export the video signal laser RGB standard signal; If color signal is on the edge of fluorescent material colour gamut triangle, promptly one or two is arranged is zero for Rp, Gp, Bp, and then gating second switch circuit 8 goes out laser color tristimulus values R by the comparison circuit ratio _L, G _L, B _LMiddle minimum.Suppose B _LValue is minimum, in the intrinsic computing kernel 10 of programmable logic device 2, all tristimulus values is deducted B _LValue, the laser color tristimulus values becomes (R _L-B _L), (G _L-B _L), 0; Calculate the total brightness of laser color; Total brightness and laser color tristimulus values (R according to laser color _L-B _L), (G _L-B _L), 0 calculating needs laser color tristimulus values amplification multiple K again; With laser color tristimulus values (R _L-B _L), (G _L-B _L), 0 amplifies K again becomes K (R after doubly _L-B _L), K (G _L-B _L), 0, finish laser signal virtual extended function thus; Laser RGB standard signal is carried out the anti-correction of coffee, and output at last expands to the laser RGB standard signal of the big colour gamut of laser three primary colors.By the laser RGB standard signal of intrinsic computing kernels 10 outputs of programmable logic device 2 by coding circuit 3 under synchronization pulse after the time-delay, carry out recompile and export the video signal.

Claims (4)

1, colour switching and color domain expanding method in a kind of laser display is characterized in that the following step:

A, receive the video signal and be broken down into TV RGB standard signal and it carried out coffee is anti-to be proofreaied and correct by decoding circuit;

B, according to colorimetry colour switching principle, establish fluorescent material three primary colors and laser three primary colors and the corresponding relation of modulation signal separately, and then set up the transformational relation of laser video modulation signal and fluorescent material video modulation signal;

C, TV RGB standard signal is converted to laser RGB standard signal by the transformational relation of laser video modulation signal and fluorescent material video modulation signal;

D, judge TV RGB standard signal whether on the edge of colour gamut triangle, if color signal not on the edge of fluorescent material colour gamut triangle, promptly fluorescent material three primary colors psychrometric colour specification Rp, Gp, Bp are non-vanishing, then change step I; If color signal on the edge of fluorescent material colour gamut triangle, promptly has one or two among fluorescent material three primary colors psychrometric colour specification Rp, Gp, the Bp be zero, then change step e;

The total brightness of e, calculating laser RGB standard signal, and compare laser RGB standard signal laser three primary colors psychrometric colour specification R _L, G _L, B _LIn minimum one, establishing its value is Em;

F, with laser three primary colors psychrometric colour specification R _L, G _L, B _LDeduct Em respectively;

The total brightness and the laser three primary colors psychrometric colour specification R of g, calculating laser RGB standard signal _L, G _L, B _LDeduct the multiple K between the laser RGB standard signal brightness behind the Em respectively;

H, with laser three primary colors psychrometric colour specification R _L, G _L, B _LThe numerical value that deducts respectively behind the Em multiply by K respectively again, and making laser RGB standard signal luminance recovery is the total brightness of former laser RGB standard signal;

I, laser RGB standard signal carried out coffee is anti-to be proofreaied and correct;

J, in TV RGB standard signal, extract synchronizing signal and to its time-delay, coding circuit 3 is being encoded to the laser RGB standard signal after anti-correction the through coffee under the synchronization pulse after the time-delay and exported the video signal.

2, colour switching and gamut extension device in a kind of laser display is characterized in that comprising decoding circuit (1), programmable logic device (2), control circuit (4), coding circuit (3); Decoding circuit (1) output connects programmable logic device (2) input, and decoding circuit (1) is TV RGB standard signal with the video signal decomposition that receives and carries out the anti-correction of coffee, is transferred to programmable logic device (2) then; Programmable logic device (2) is converted to TV RGB standard signal laser RGB standard signal, judges that whether TV RGB standard signal is whether one or two is arranged among Rp, Gp, the Bp is zero, finishes the anti-correction of coffee that signal after virtual color expansion and the expansion amplifies, realizes laser RGB standard signal again on the edge of colour gamut triangle; The output of programmable logic device (2) connects the input of coding circuit (3), will send into coding circuit (3) through the anti-laser RGB standard signal of proofreading and correct of coffee; Programmable logic device (2) extracts synchronizing signal and time-delay from decoding circuit (1), make coding circuit (3) under the synchronization pulse after the time-delay to laser RGB standard signal recompile and export the video signal; Control circuit (4) is connected with decoding circuit (1), programmable logic device (2), coding circuit (3) respectively; Decoding circuit (1) is finished the video signal decoding under the signal controlling of control circuit (4) output, and the output control signal is given that programmable logic device (2) finishes that TV RGB standard signal is converted to that the coffee of laser RGB standard signal, laser RGB standard signal is instead proofreaied and correct, the signal after virtual color expansion and the expansion amplifies again; Coding circuit (3) is finished laser RGB standard signal recompile and is exported the video signal.

3, colour switching and gamut extension device in the laser display according to claim 2, it is characterized in that programmable logic device (2) internal structure comprises matrixer (5), NAND gate (6), first switching circuit (7), second switch circuit (8), comparator (9), computing kernel (10), delay circuit (11); The output of decoding circuit (1) is connected with the input of NAND gate (6), matrixer (5) respectively; The output of matrixer (5) is connected with first switching circuit (7), second switch circuit (8) respectively; The output of NAND gate (6) is connected with first switching circuit (7), second switch circuit (8) respectively; Second switch circuit (8) is connected with intrinsic computing kernel (10) in comparator (9) and the programmable logic device (2) respectively, computing kernel (10) intrinsic in first switching circuit (7) and the programmable logic device (2) is connected, and delay circuit (11) is connected with coding circuit (3) with decoding circuit (1).

4, colour switching and gamut extension device in the laser display according to claim 2 is characterized in that control circuit (4) adopts single-chip microcomputer, and its model is PLC2046; It is the chip of AD9884 that decoding circuit (1) adopts model; It is the chip of FPGA100F that programmable logic device (2) adopts model; It is the chip of TDA8501 that coding circuit (3) adopts model.

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