CN1106118C

CN1106118C - Color space signal conversion device and method

Info

Publication number: CN1106118C
Application number: CN 98120890
Authority: CN
Inventors: 徐荣富
Original assignee: Winbond Electronics Corp
Current assignee: Winbond Electronics Corp
Priority date: 1998-09-29
Filing date: 1998-09-29
Publication date: 2003-04-16
Anticipated expiration: 2018-09-29
Also published as: CN1249630A

Abstract

A color space signal conversion device and method, including expanding a standard conversion formula of four starting chromaticity color items to obtain conversion values including preset items and compensation items, which are linearly combined to obtain conversion values of the starting chromaticity color items, and combining the conversion values of these starting chromaticity color items with a brightness (Y) color space signal according to a standard conversion formula to obtain a red, green, and blue (RGB) color space signal, thereby achieving the effect of reducing costs and simplifying the structure.

Description

Color space signal conversion equipment and method

The present invention relates to the method and the device thereof in a kind of conversioning colour space, relate in particular to a kind ofly, be converted to the color space signal conversion equipment and the method for digital RGB (RGB) color space signal by digital brightness chrominance color spaces signal.

On multimedia computer system, often need and close vision signal (Video Signal) and figure signal (GraPhic signal), vision signal wherein, be to be brightness-colourity (Luminance-Chrominance) color space signal, have and to transmit by low frequency range, and the advantage of less data storing, can take from an image processing system with extracting ability (Capture or frame grabbing capability), or from CD, as the digital CD (DVD:Digital Video Disc) or the video image playback system at networking.And computer screen shows, be to use RGB (Red-Green-Blue: color space signal R-G-B), for this vision signal can be shown at computer, therefore, (Y is brightness with YCbCr brightness-chrominance color spaces signal, Cb, Cr are colourity), it is necessary being converted to the rgb color space signal.

In optical digital disk is used, the color of pixel, normal 4: 2: 2 the spatial resolution form of YCbCr that uses, because human vision, for the sensitivity of colourity, be lower than sensitivity to brightness, use the pixel colourity Cb and the Cr of YCbCr expression in 4: 2: 2 one image, compared to brightness in the horizontal direction, as long as half resolution is just enough, even, at video image compression (MPEG for example, when JPEG etc.) combining with the optical digital disk application, the resolution of image vertical direction more can be cut down half with chrominance C b and Cr, become the form of YCbCr 4: 2: 0 or 4: 1: 1, therefore chrominance C b and Cr often follow brightness Y to transmit alternately, when color space is changed, can common source, and can reduce the treatment element of whole color space conversion apparatus.

The committee (the Comite Consultatif International desRadiocommunications:CCIR) is conferred in the communication of international wireless electricity, CCIR 601 specifications of suggestion, set up following formula, the color space with the YCbCr YC is converted to rgb color space:

R＝Y+1.402(Cr-128)…………(a.1)

G＝Y-0.714(Cr-128)-0.344(Cb-128)……(a.2)

B＝Y+1.772(Cb-128)……(a.3)

If use U and V, representative displacement colourity (Cb-128) reaches (Cr-128) respectively, and then above-mentioned formula can be rewritten as:

R＝Y+1.402V……(b.1)

G＝Y-0.714V-0.344U……(b.2)

B＝Y+1.772U……(b.3)

Wherein, Y, Cb, color space element spares such as Cr are in the expression of eight bits, and the scope of Y is (0,255), and the scope of U and V is (128,127).

The color space conversion, normally utilize multiplier, or inspect table, reach the multiplication of matrices computing, if make multiplier with hardware, design and fabrication can be quite complicated, so cost is higher, if inspect table and use, construct simplyr, cost is also lower, and because of matrix multiplication operation, it often is the key of decision color space conversion hardware complexity, so, inspect the usage quantity of table, also just determined the price of color space conversion apparatus, in order to carry out formula (a.1)～(a.3) of YCbCr to the rgb color space conversion, color space converter in the past, for 1.402 (Cr-128), 0.714 (Cr-128), 0.344 (Cb-128) and 1.772 four multiplyings such as (Cb-128), often to use four and inspect table.Though this color space converter than 3 * 3 multiplication matrix of another kind use in the past was cheap,, but still have and can't reduce the use of inspecting table quantity, and simplified structure, the shortcoming that reduces cost.

The object of the present invention is to provide a kind of by digital YCbCr YC color space signal, be converted to the digital rgb color space signal, and can reach the color space signal conversion equipment and the method for the effect that reduces color space conversion apparatus cost and simplified structure.

In order to realize purpose of the present invention, a kind of color space signal conversion method that is provided, be to be converted to digital RGB R according to one group of standard handovers formula by digital brightness chrominance color spaces signal, G, the B color space signal, described chrominance color spaces signal is to be U and V color space signal, this standard handovers formula comprises R=Y+1.402V, G=Y-0.714V-0.344U, B=Y+1.772U and have four initial colourity color item 1.402V, 0.714V, 0.344U, 1.772U be characterized in: this color space signal conversion method comprises following step: this initial colourity color item 1.402V respectively, 0.714V, 0.344U, 1.772U launch to become the linear combination that only comprises a default Xiang Yuyi compensation term respectively; An if code presupposition generator, to produce a default hand over word for this conversion value of default, make this default hand over word in one first sequential, the one first chrominance color spaces signal U of U, V in the corresponding described brightness and color spacing wave, and in one second sequential, one second chrominance color spaces signal V among corresponding described brightness and color spacing wave U, the V; An if compensation codes generator, to produce one is the compensation hand over word of the conversion value of this compensation term, make this compensation hand over word, in this first sequential, the first chrominance color spaces signal U among corresponding described brightness and color spacing wave U, the V, in this second sequential, the second chrominance color spaces signal V among corresponding described brightness and color spacing wave U, the V; To default hand over word, with the compensation hand over word from this compensation codes generator, the linear combination of the aforementioned expansion of substitution, to obtain the conversion value of described initial colourity color item 1.402V, 0.714V, 0.344U, 1.772U from this code presupposition generator; And, make up a described conversion value and the brightness and color spacing wave Y of described initial colourity color item 1.402V, 0.714V, 0.344U, 1.772U, to obtain red bluish-green color space signal according to this standard handovers formula.

In order to realize purpose of the present invention, a kind of color space signal conversion equipment that is provided, in order to digital brightness chrominance color spaces signal is converted to the red bluish-green color space signal R of numeral according to one group of standard handovers formula, G, B, described chrominance color spaces signal is to be U and V color space signal, this standard handovers formula comprises R=Y+1.402V, G=Y-0.714V-0.344U, B=Y+1.772U and have four initial colourity color item 1.402V, 0.714V, 0.344U, 1.772U, and with described initial colourity color item 1.402V, 0.714V, 0.344U, 1.772U launch to become the linear side's formula that includes only a default Xiang Yuyi compensation term, be characterized in, this device includes: a code presupposition generator, to produce a default hand over word for this conversion value of default, make this default hand over word, at the corresponding one first chrominance color spaces signal U of one first sequential, at the corresponding one second chrominance color spaces signal V of one second sequential; One compensation codes generator to produce a compensation hand over word for the conversion value of this compensation term, makes this compensation hand over word, in this first sequential to should the first chrominance color spaces signal, in this second sequential to should the second chrominance color spaces signal; One linear combination member, be connected to this code presupposition generator and this compensation codes generator, with to from this code presupposition generator should default hand over word, with this compensation hand over word from this compensation codes generator, according to the in addition linear combination of linear side's formula of aforementioned expansion, to obtain the conversion value of described initial colourity color item 1.402V, 0.714V, 0.344U, 1.772U; And an output combining unit, be connected to this linear combination member, with according to this group conversion formula, make up the described conversion value of described initial colourity color item, and a brightness and color spacing wave Y, obtain red bluish-green color space signal.

Owing to adopted above-mentioned technical solution, be color space signal conversion equipment of the present invention and method, adopt default hand over word and compensation hand over word, time sharing shared in two chrominance color spaces signals, and finish one by digital brightness chrominance color spaces signal, be converted to the color space signal conversion equipment of digital rgb color space signal, therefore at code presupposition generator or compensation codes generator, table is inspected in use, or multiplier, the effect that just can reach effective simplification circuit, reduces cost.

Below in conjunction with drawings and Examples color space signal conversion equipment of the present invention and method are elaborated, in the accompanying drawing:

Fig. 1 is the function block schematic diagram of the color space conversion apparatus of the present invention's first preferred embodiment.

Fig. 2 is the function block schematic diagram of the color space conversion apparatus of the present invention's second preferred embodiment.

Fig. 3 is the function block schematic diagram of the color space conversion apparatus of the present invention's the 3rd preferred embodiment.

Fig. 4 is the function block schematic diagram of the color space conversion apparatus of the present invention's the 4th preferred embodiment.

Fig. 5 is the function block schematic diagram of the color space conversion apparatus of the present invention's the 5th preferred embodiment.

Fig. 6 is the code presupposition of preferred embodiment of the present invention and the block schematic diagram of compensation codes generator.

In the following preferred embodiment that discloses, among code presupposition generator and compensation codes generator, one of them uses and inspects table unit (Look-up table unit) at least.If code presupposition generator and compensation codes generator can use the single table unit of inspecting simultaneously, can be better.

As shown in Figure 1, it is first preferred embodiment of color space conversion apparatus of the present invention, comprise a multiplexer 1, one code presupposition generator 2, one compensation codes generator 3, one comprises shift unit 41,43, adder 42,45,46 and the linear combination member of subtracter 44, one first latch 5, one second latch 6, one the 3rd latch 7, one quad latch 8, one first output combining unit 9, one second output combining unit 10 and one the 3rd output combining unit 11, this first output combining unit 9, the second output combining unit 10 and the 3rd output combining unit 11 can be referred to as the output combining unit.And this shift unit 41,43, adder 42,45,46, the detailed implementation detail of subtracter 44 and

latch

5,6,7,8 is the circuit engineerings that belong to general, so no longer be described in detail at this.

This multiplexer 1 receives numeral input chrominance color spaces signal Cb and Cr, and responds clock signal (timing select signals) tu and tv, and output Cb or one of them chrominance color spaces signal of Cr.From the chrominance color spaces signal that this multiplexer 1 sends, pass to this code presupposition generator 2 and this compensation codes generator 3, to produce default hand over word and compensation hand over word.

In the present invention's first preferred embodiment, this compensation hand over word is with 0.013 (C-128) expression, be the conversion value of compensation term, and default hand over word is with 1.402 (C-128) expression, is default conversion value.Wherein C when the tu sequential, represents Cb chrominance color spaces signal, when the tv sequential, represents Cr chrominance color spaces signal.If use U and V to replace Cb and Cr, with expression input chrominance color spaces signal, then default hand over word and compensation hand over word become 1.402C and 0.013C respectively.Wherein C when the tu sequential, represents U chrominance color spaces signal, when the tv sequential, represents V chrominance color spaces signal.

As previously mentioned, the conversion formula of standard comprises four groups of initial colourity color items (Chrominance-in-colorterms), just 1.402 (Cr-128), 0.714 (Cr-128), 0.344 (Cb-128) and 1.772 (Cb-128).In the present invention, the conversion formula of standard (a.1) is to (a.3), can be by launching initial colourity color item, be rewritten into to include only default the linear combination with compensation term.

In the present invention's first preferred embodiment, a since initial colourity color item 1.402 (Cr-128) wherein, equaled default, be not need to launch again with this initial colourity color item 1.402 (Cr-128), and other initial colourity color item 0.714 (Cr-128), 0.344 (Cb-128) and 1.772 (Cb-128), and be not equal to default or compensation term, then can launch becomes:

0.714(Cr-128)-1/2(1.402)(Cr-128)+0.013(Cr-128)…(c.1)

0.344(Cb-128)＝1/2[1/2(1.402)(Cb-128)+0.013(Cb-128)]-0.013(Cb-128)…(c.2)

1.772(Cb-128)＝1.402(Cb-128)+1/2[1/2(1.402)(Cb-128)+0.013(Cb-128)]+0.013(Cb-128)…(c.3)

This linear combination member is to (c.3) according to above-mentioned expansion (c.1), will be from this code presupposition generator 2 and this compensation codes generator 3 and the default hand over word that comes is made up with the compensation hand over word, to obtain the conversion value of these initial colourity color items, allow the conversion of color space, as long as default hand over word of linear combination and compensation hand over word just can reach.Further content please be joined following explanation.

From the default hand over word of this code presupposition generator 2, just 1.402 (C-128) via this shift unit 41, carry out the right dislocation of arithmetic, will preset hand over word divided by two, obtain 1/2 (1.402 (C-128))=0.701 (C-128) value.Compensation hand over word from this compensation codes generator 3, also just become 0.013 (C-128),, add the output valve 0.701 (C-128) of this shift unit 41 through this adder 42, with when the tv sequential, C=Cr obtains the conversion value of initial colourity color item 0.714 (Cr-128).

The arithmetic right dislocation is carried out in the output 0.714 (C-128) of 43 pairs of these adders 42 of this shift unit, just divided by two, obtains exporting 0.357 (C-128).From the output valve 0.357 (C-128) of this shift unit 43, carry out subtractions through this subtracter 44, deduct 0.013 (C-128), with when the tu sequential, C=Cb obtains the conversion value of initial colourity color item 0.344 (Cb-128).

Default hand over word 1.402 (C-128) from this code presupposition generator 2.Pass through this adder 45 again, add 0.357 (C-128) output valve of this shift unit 43, obtain the output of 1.759 (C-128).From the compensation hand over word 0.013 (C-128) of this compensation codes generator 3, through this adder 46, add the output valve 1.759 (C-128) of this adder 45, when the tu sequential, C=Cb obtains the conversion value of initial colourity color item 1.772 (Cb-128).

This first latch 5 when the tv sequential, pins the default hand over word from this code presupposition generator 2, to obtain required Cr-in-R conversion value, and 1.402 (Cr-128) just.

This second latch 6 when the tv sequential, pins the output valve of this adder 42, to obtain required Cr-in-G conversion value, and 0.714 (Cr-128) just.

The 3rd latch 7, when the tu sequential, the output valve of pinning this subtracter 44, to obtain required Cb-in-G conversion value, 0.344 (Cb-128) just.

This quad latch 8 when the tu sequential, pins the output valve of this adder 46, to obtain required Cb-in-B conversion value, and 1.772 (Cb-128) just.

This first output combining unit 9 comprises an adder, adds the output valve and the digital Y luminance signal of this first latch 5, to obtain the R color space signal.

This second output combining unit 10 comprises an adder 101 and a subtracter 102, and this adder 101 is in order to add the output valve of this second latch 6 and the 3rd latch 7.This subtracter 102 is in order to deduct the output valve of this adder 101 from digital Y luminance signal, to obtain the G color space signal.

The 3rd output combining unit 11 comprises an adder, with output valve and the digital Y luminance signal that adds this quad latch 8, to obtain the B color space signal.

Just,, know by (a.1) with the R chrominance signal: R=Y+1.402 (Cr-128) that is with default hand over word 1.402 (C-128), when the tv sequential, add Y brightness, just can obtain.

For the G chrominance signal, by (a.2) G=Y-0.714 (Cr-128)-0.344 (Cb-128) as can be known, with initial colourity color item, behind the formula (c.1) and formula (c.2) of substitution with default item and compensation term expansion, obtain (Cr-128)-0.013 (Cr-128)-1/2[1/2 (1.402) (Cb-128)+0.013 (Cb-128) of G=Y-1/2 (1.402)]+0.013 (Cb-128), be exactly the output 1/2[1/2 (1.402) (Cb-128)+0.013 (Cb-128) of output [1/2 (1.402) (Cr-128)+0.013 (Cr-128)] the-the 3rd latch 7 of G=Y one second latch 6]-0.013 (Cb-128).And the like can obtain the B chrominance signal.So, as long as uses code presupposition and compensation codes to be base components, in addition linear combination, preface obtains the conversion value of initial colourity color item in due course, and the establishing criteria conversion formula adds the Y luminance signal again, just can finish the color space of YCbCr to RGB and change.

As shown in Figure 2, second preferred embodiment of color space signal conversion equipment of the present invention, this color space signal conversion equipment comprises that a multiplexer 1, code presupposition generator 21, a compensation codes generator 31, comprise

shift unit

52,53,

adder

55,56, the linear combination member of

subtracter

51,54, one first latch 5, one second latch 6, one the 3rd latch 7, a quad latch 8, one first output combining unit 9, one second output combining unit 10 and one the 3rd output combining unit 11.

The present invention's second preferred embodiment is similar with above-mentioned first preferred embodiment haply, but, in the present invention's second preferred embodiment, default hand over word is to represent with 0.714 (C-128), conversion value for default, the compensation hand over word then still with 0.013 (C-128) expression, is the conversion value of compensation term.Wherein C when the tu sequential, represents Cb chrominance color spaces signal, when the tv sequential, represents Cr chrominance color spaces signal.If use U and V to replace Cb and Cr, with expression input chrominance color spaces signal, then default hand over word and compensation hand over word become 0.714C and 0.013C respectively.Wherein C when the tu sequential, represents U chrominance color spaces signal, when the tv sequential, represents V chrominance color spaces signal.

For the present invention's second preferred embodiment,, do not need to launch since initial colourity color item 0.714 (Cr-128) has equaled default.And because initial colourity color item 1.402 (Cr-128), 0.344 (Cb-128) and 1.772 (Cb-128), and be not equal to default or compensation term, then can launch becomes:

1.402(Cr-128)＝2[0.714(Cr-128)-0.013(Cr-128)]

0.344(Cb-128)＝1/2[0.714(Cb-128)]-0.013(Cb-128)

1.772(Cb-128)＝2[0.714(Cb-128)-0.013(Cb-128)]+1/2[0.714(Cb-128)]+0.013(Cb-128)

This linear combination member is according to above-mentioned expansion, and the default hand over word and the combination of compensation hand over word that will come from this code presupposition generator 21 and this compensation codes generator 31 are to obtain the conversion value of these three initial colourity color items.

From the default hand over word of this code presupposition generator 21,, deduct compensation hand over word from this compensation codes generator 3 via this subtracter 51.This shift unit 52 is carried out the displacement of arithmetic left-hands, is one and multiply by two computing, with when the tv sequential, obtains the conversion value of initial colourity color item 1.402 (Cr-128).That is to say that the output valve of this first latch 5 is: 2*[0.714 (Cr-128)-0.013 (Cr-128)].And know R=Y+1.402 (Cr-128)=Y+2[0.714 (Cr-128)-0.013 (Cr-128) by (a.1)], just the output valve of first latch 5 adds the Y value, is the R value.

From the default hand over word of this code presupposition generator 21, carry out arithmetic right dislocation (just divided by two) via this shift unit 53.Default hand over word is passed through this subtracter 54 again by divided by after two, deducts the compensation hand over word from this compensation codes generator 31, and when the tu sequential, obtains the conversion value of initial colourity color item 0.344 (Cb-128).

This adder 55 adds the output valve from this shift unit 52 and 53.This adder 56 adds the output valve of this adder 55, and from the compensation hand over word of this compensation codes generator 31, when the tu sequential, obtains the conversion value of initial colourity color item 1.772 (Cb-128).

This first latch 5 in the tv sequential, pins the output valve of this shift unit 52, obtains the conversion value of required Cr-in-R, just 1.402 (Cr-128).

This second latch 6 in the tv sequential, pins the default hand over word from this code presupposition generator 21, to obtain the conversion value of Cr-in-G, and 0.714 (Cr-128) just.

The 3rd latch 7 in the tu sequential, pins the output valve of this subtracter 54, obtaining the conversion value of Cb-in-G, that is 0.344 (Cb-128).

This quad latch 8 in the tu sequential, pins the output valve of this adder 56, to obtain required Cb-in-B conversion value, and 1.772 (Cb-128) just

And this first to the 3rd

output combining unit

9,10,11 etc., the effect as having as described above shown in the first embodiment of the invention, same as the prior art, so no longer be described in detail at this.As shown in Figure 3, be the 3rd preferred embodiment of color space signal conversion equipment of the present invention.In the present invention's the 3rd preferred embodiment, this color space signal conversion equipment comprises that a multiplexer 1, code presupposition generator 22, a compensation codes generator 32, comprise

shift unit

62,63,65, the linear combination member of adder 66 and subtracter 61,64, one first latch 5, one second latch 6, one the 3rd latch 7, a quad latch 8, one first output combining unit 9, one second output combining unit 10 and one the 3rd output combining unit 11.

The present invention's the 3rd preferred embodiment and aforementioned these embodiment are roughly the same, but in the present invention's the 3rd preferred embodiment, default hand over word be made as 0.357 (C-128) and the compensation hand over word be made as 0.013 (C-128), C wherein, when the tu sequential, represent Cb chrominance color spaces signal, when the tv sequential, represent Cr chrominance color spaces signal.If use U and V to replace Cb and Cr, with expression input chrominance color spaces signal, then default hand over word and compensation hand over word become 0.357C and outer 0.013C respectively.Wherein C when the tu sequential, represents U chrominance color spaces signal, when the tv sequential, represents V chrominance color spaces signal.

Therefore, for the present invention's the 3rd preferred embodiment, initial colourity color item 1.402 (Cr-128), 0.714 (Cr-128), 0.344 (Cb-128) and I.772 (Cb-128), can launch becomes:

0.714(Cr-128)＝2(0.357)(Cr-128)

1.402(Cr-128)＝2[2(0.357)(Cr-128)-0.013(Cr-128)]

0.344(Cb-128)＝0.357(Cb-128)-0.013(Cb-128)

1.772(Cb-128)＝2[2(0.357)(Cb-128)]+0.357(Cb-128)-0.013(Cb-128)

This linear combination member is according to above-mentioned expansion, and the default hand over word and the combination of compensation hand over word that will come from this code presupposition generator 22 and this compensation codes generator 32 are to obtain the conversion value of initial colourity color item.

From the default hand over word of this code presupposition generator 22, through this shift unit 63, carry out the displacement of arithmetic left-hand, multiply by two will preset hand over word, in the tv sequential, obtain the conversion value of initial colourity color item 0.714 (Cr-128).

The output 0.714 (C-128) of this shift unit 63 through this subtracter 61, deducts the compensation hand over word from this compensation codes generator 32.This shift unit 62 is carried out the displacement of arithmetic left-hand, multiply by two with the output valve to this subtracter 61, in the tv sequential, obtains the conversion value of initial colourity color item 1.402 (Cr-128).

From the default hand over word of this code presupposition generator 22, deduct compensation hand over word through this subtracter 64 from this compensation codes generator 32, in the tu sequential, obtain the conversion value of initial colourity color item 0.344 (Cb-128).

This shift unit 65 to the output valve 0.714 (C-128) of this shift unit 63, is carried out arithmetic left-hand displacement (multiply by two).And this adder 66 adds and the output valve of this subtracter 64 and this shift unit 65 with in the tu sequential, obtains the conversion value of initial colourity color item 1.772 (Cb-128).

This first latch 5 in the tv sequential, pins the output valve of this shift unit 62, obtains the conversion value of required Cr-in-R, just 1.402 (Cr-128).

This second latch 6 in the tv sequential, pins the output valve of this shift unit 63, to obtain the conversion value of Cr-in-G, and 0.714 (Cr-128) just.

The 3rd latch 7 in the tu sequential, pins the output valve of this subtracter 64, to obtain the conversion value of Cb-in-G, and 0.344 (Cb-128) just.

This quad latch 8 in the tu sequential, pins the output valve of this adder 66, to obtain required Cb-in-B conversion value, and 1.772 (Cb-128) just.

And this first to the 3rd

output combining unit

9,10,11 etc. acts on as having as described above shown in these embodiment, and is same as the prior art, so no longer be described in detail at this.

As shown in Figure 4, be the 4th preferred embodiment of color space signal conversion equipment.

In the present invention's the 4th preferred embodiment, the color space signal conversion equipment comprises that a multiplexer 1, code presupposition generator 23, a compensation codes generator 33, comprise

shift unit

72,73,74, the linear combination member of adder 76,

subtracter

71,75, one first latch 5, one second latch 6, one the 3rd latch 7, a quad latch 8, one first output combining unit 9, one second output combining unit 10 and one the 3rd output combining unit 11.

The present invention's the 4th preferred embodiment is roughly similar to the various embodiments described above.But in the present invention's the 4th preferred embodiment, default hand over word is made as 1.428 (C-128) and the compensation hand over word is made as 0.013 (C-128), C wherein, when the tu sequential, represent Cb chrominance color spaces signal, when the tv sequential, represent Cr chrominance color spaces signal.If use U and V to replace Cb and Cr, with expression input chrominance color spaces signal, then default hand over word and compensation hand over word become 1.428C and outer 0.013C respectively.Wherein C when the tu sequential, represents U chrominance color spaces signal, when the tv sequential, represents V chrominance color spaces signal.

Therefore, for the present invention's the 4th preferred embodiment, initial colourity color item 1.402 (Cr-128), 0.714 (Cr-128), 0.344 (Cb-128) and 1.772 (Cb-128), the equation that can be unfolded as follows:

1.402(Cr-128)＝2[1/2(1.428)(Cr-128)-0.013(Cr-128)]

0.714(Cr-128)＝1/2(1.428)(Cr-128)

0.344(Cb-128)＝1/2[1/2(1.428)(Cb-128)]-0.013(Cb-128)

1.772(Cb-128)＝1.428(Cb-128)+1/2[1/2(1.428)(Cb-128)]-0.013(Cb-128)

This linear combination member is according to above-mentioned expansion, and the default hand over word and the combination of compensation hand over word that will come from this code presupposition generator 23 and this compensation codes generator 33 are to obtain the conversion value of initial colourity color item.

From the default hand over word of this code presupposition generator 23, through this shift unit 73, carry out arithmetic right dislocation (divided by two), in the tv sequential, obtain the conversion value of initial colourity color item 0.714 (Cr-128).

The output 0.714 (C-128) of this shift unit 73 through this subtracter 71, deducts the compensation hand over word from this compensation codes generator 33.This shift unit 72 is carried out the displacement of arithmetic left-hand, multiply by two with the output valve to this subtracter 71, in the tv sequential, obtains the conversion value of initial colourity color item 1.402 (Cr-128).

This shift unit 74 is the output valves 0.714 (C-128) to this shift unit 73, carries out arithmetic right dislocation (divided by two).And this subtracter 75 deducts the compensation hand over word from this compensation codes generator 33 with the output valve of this shift unit 74, in the tu sequential, obtains the conversion value of initial colourity color item 0.344 (Cb-128).

This adder 76 adds the default hand over word from this code presupposition generator 23, and the output valve 0.344 (Cb-128) of this subtracter 75, in the tu sequential, obtains the conversion value of initial colourity color item 1.772 (Cb-128).

This first latch 5 in the tv sequential, pins the output valve of this shift unit 72, obtains the conversion value of required Cr-in-R, just 1.402 (Cr-128).

This first latch 6 in the tv sequential, pins the output valve of this shift unit 73, to obtain the conversion value of Cr-in-G, and 0.714 (Cr-128) just.

The 3rd latch 7 in the tu sequential, pins the output valve of this subtracter 75, to obtain the conversion value of Cb-in-G, and 0.344 (Cb-128) just.

This quad latch 8 in the tu sequential, pins the output valve of this adder 76, to obtain required Cb-in-B conversion value, and 1.772 (Cb-128) just.

And this first to the 3rd

output combining unit

9,10,11 etc. acts on as having as described above shown in these embodiment, to same as the prior art, so no longer be described in detail at this.

As shown in Figure 5, be the 5th preferred embodiment of color space signal conversion equipment of the present invention.In the present invention's the 5th preferred embodiment, this color space signal conversion equipment comprises a multiplexer 1, code presupposition generator 24, a compensation codes generator 34, one comprises shift unit 82,83, adder 81,84 linear combination members, one first latch 5, one second latch 6, one the 3rd latch 7, a quad latch 8, one first output combining unit 9, one second output combining unit 10 and one the 3rd output combining unit 11.

The present invention's the 5th preferred embodiment is roughly similar to above-mentioned these embodiment, but in the present invention's the 5th preferred embodiment, default hand over word be made as 0.714 (C-128) and the compensation hand over word be made as 0.344 (C-128), C wherein, when the tu sequential, represent Cb chrominance color spaces signal, when the tv sequential, represent Cr chrominance color spaces signal.If use U and V to replace Cb and Cr, with expression input chrominance color spaces signal, then default hand over word and compensation hand over word become 0.714C and 0.334C respectively.Wherein C when the tu sequential, represents U chrominance color spaces signal, when the tv sequential, represents V chrominance color spaces signal.

Therefore, for the present invention's the 5th preferred embodiment,, equal the conversion value of initial colourity color item 0.714 (Cr-28) and 0.344 (Cb-128) respectively since preset hand over word and compensation hand over word.Thereby only need equation that other two initial colourity color items 1.402 (Cr-128) and 1.772 (Cb-128) are unfolded as follows:

1.402(Cr-128)＝0.714(Cr-28)+2[0.344(Cr-128)]

1.772(Cb-128)＝2[0.714(Cb-128)]+0.344(Cb-128)

This linear combination member is according to above-mentioned expansion, and the default hand over word and the combination of compensation hand over word that will come from this code presupposition generator 24 and this compensation codes generator 34 are to obtain the conversion value of two initial colourity color items.

From the compensation hand over word of this compensation codes generator 34,, carry out left-hand displacement (multiply by two) through this shift unit 83.This adder 81 adds the default hand over word from this code presupposition generator 24, and the output valve of this shift unit 83, in the tv sequential, obtains the conversion value of initial colourity color item 1.402 (Cr-128).

From the default hand over word of this code presupposition generator 24,, carry out arithmetic left-hand displacement (multiply by two) through this shift unit 82.This adder 84 adds the output valve of this shift unit 82, and from the compensation hand over word of this compensation codes generator 34, in the tu sequential, obtains the conversion value of initial colourity color item 1.772 (Cb-128).

This first latch 5 in the tv sequential, pins the output valve of this adder 81, obtains the conversion value of required Cr-in-R, just 1.402 (Cr-128).

This second latch 6 in the tv sequential, pins the default hand over word from this code presupposition generator 24, to obtain the conversion value of Cr-in-G, and 0.714 (Cr-128) just.

The 3rd latch 7 in the tu sequential, pins the compensation hand over word from this compensation codes generator 34, to obtain the conversion value of Cb-in-G, and 0.344 (Cb-128) just.

This quad latch 8 in the tu sequential, pins the output valve of this adder 84, to obtain required Cb-in-B conversion value, and 1.772 (Cb-128) just.

And this first to the 3rd

output combining unit

In aforementioned listed each embodiment, code presupposition generator and compensation codes generator can use and inspect table.If with code presupposition generator and compensation codes generator, inspect table unit (unit) with one and implement, as shown in Figure 6, then code presupposition generator and compensation codes generator will include only a simple circuit, therefore memory storage for example can reduce the cost of color space conversion apparatus of the present invention.

As shown in Figure 6, this is inspected table unit 12 and comprises that a code presupposition that comprises default hand over word partly 121 and one comprises the compensation codes part 122 that compensate hand over word.As selected chrominance color spaces signal Cb or Cr, consult this and inspect table unit 12, can be via first output (P) and second output (C), export the character code (codeword) of a correspondence, and this character code comprises a default hand over word from this code presupposition part 121, and a compensation hand over word from this compensation codes part 122.Should default hand over word be to provide, and this compensation hand over word be provided by second output (C) by first output (P).

Though in the embodiment of above-mentioned announcement, be to select for use the conversion value of initial colourity color item as default hand over word, in addition, also can use the conversion value of initial colourity color item, hand over word is same as the prior art by way of compensation, so no longer be described in detail at this.

Specifically, though each preferred embodiment of the present invention is to represent with the calcspar of hardware circuit,, the present invention can use microprocessor (MicroProcessor) and relevant systematic memory body easily and efficiently, to reach the computing of conversion.

Claims

1. A color space signal conversion method is converted to digital red, green and blue R, G, B color space signals by digital brightness chromaticity color space signals according to a set of standard conversion formulas, and the chromaticity color space signals are U And V color space signal, the standard conversion formula includes R=Y+1.402V, G=Y-0.714V-0.344U, B=Y+1.772U and has four initial chroma color items 1.402V, 0.714V, 0.344U, 1.772U, characterized by:

The color space signal conversion method comprises the following steps:

expand each initial chroma color item 1.402V, 0.714V, 0.344U, 1.772U into a linear combination including only one default item and one compensation item;

A preset code generator is set to generate a preset conversion code that is the conversion value of the default item, so that the preset conversion code corresponds to a U, V in the brightness color space signal at a first timing The first chromaticity color space signal U is corresponding to a second chromaticity color space signal V in the luminance color space signals U and V at a second time sequence; a compensation code generator is set to generate one for the luminance color space signal V; The compensation conversion code of the conversion value of the compensation item, so that the compensation conversion code, at the first timing, corresponds to the first chrominance color space signal U among the brightness color space signals U, V, and at the second timing, corresponds to A second chrominance color space signal V among the luma color space signals U and V;

The preset conversion code from the preset code generator and the compensation conversion code from the compensation code generator are substituted into the linear combination of the aforementioned expansion to obtain the initial chromaticity color items 1.402V, 0.714V, 0.344 U, the converted value of 1.772U; and

According to the standard conversion formula, the conversion values of the initial chroma color items 1.402V, 0.714V, 0.344U, 1.772U are combined with a luminance color space signal Y to obtain red, blue and green color space signals.

2. color space signal conversion method as claimed in claim 1, is characterized in that:

The color space signal conversion method further includes: at the first timing, providing the first chroma color space signal U to the preset code generator and the compensation code generator, and at the second timing, providing the second Steps of sending the chroma color space signal V to the preset code generator and the compensation code generator.

3. The color space signal conversion method according to claim 1, characterized in that: before combining the luminance color space signal Y, further comprising a process of locking the initial chromaticity color items 1.402V, 0.714V, 0.344U , the step of converting the value of 1.772U.

4. The color space signal conversion method according to claim 1, characterized in that: the first chroma color space signal U=(Cb-128) and the second chroma color space signal V in the chroma color space signal = (Cr-128).

5. The color space signal conversion method according to claim 1, wherein the preset item is one of the initial chroma color items.

6. The color space signal conversion method according to claim 1, wherein the compensation item is one of the initial chroma color items.

7. The color space signal conversion method according to claim 1, wherein the preset item and the compensation item are two of the initial chroma color items.

8. The color space signal conversion method according to claim 1, wherein one of the preset code generator and the compensation code generator uses a lookup table unit.

9. The color space signal conversion method according to claim 1, wherein the preset code generator and the compensation code generator share a single lookup table unit.

10. A color space signal conversion device, used to convert digital luminance and chromaticity color space signals into digital red, green and blue R, G, and B color space signals according to a set of standard conversion formulas, and the chromaticity color space signals are for U and V color space signals, the standard conversion formula includes R=Y+1.402V, G=Y-0.714V-0.344U, B=Y+1.772U and has four initial chromaticity color items 1.402V, 0.714V , 0.344U, 1.772U, and expand the initial chromaticity color items 1.402V, 0.714V, 0.344U, 1.772U into a linear equation that only includes a default item and a compensation item, characterized in that: the device Including:

A preset code generator, to generate a preset conversion code for the conversion value of the default item, so that the default conversion code corresponds to a first chroma color space signal U at a first time sequence, and at a first time sequence The second time sequence corresponds to a second chromaticity color space signal V; a compensation code generator to generate a compensation conversion code for the conversion value of the compensation item, so that the compensation conversion code corresponds to the first color at the first time sequence a chroma color space signal corresponding to the second chroma color space signal at the second timing;

a linear combination component, connected to the default code generator and the compensation code generator, for the default conversion code from the default code generator and the compensation conversion code from the compensation code generator, according to The aforementioned expanded linear square formulas are linearly combined to obtain the conversion values of the initial chroma color items 1.402V, 0.714V, 0.344U, and 1.772U; and

An output combination unit connected to the linear combination component to combine the conversion value of the initial chroma color item and a brightness color space signal Y according to the set of conversion formulas to obtain a red, blue and green color space signal.

11. The color space signal conversion device according to claim 10, characterized in that: the color space signal conversion device further comprises a multiplexer connected to the preset code generator and the compensation code generator, the multiplexer The channel converter provides the first chroma color space signal at the first timing, and provides the second chroma color space signal at the second timing to the preset code generator and the compensation code generator.

12. The color space signal conversion device according to claim 10, characterized in that: the color space signal conversion device further comprises a latch connected between the linear combination component and the output combination unit, to lock the converted value of the starting chroma color item before combining the luma color space signal.

13. The color space signal conversion device according to claim 10, characterized in that: the first chroma color space signal U=(Cb-128) and the second chroma color space signal in the chroma color space signal V=(Cr-128).

14. The color space signal conversion device as claimed in claim 10, wherein the preset item is one of the initial chroma color items.

15. The color space signal conversion device according to claim 10, wherein the compensation item is one of the initial chroma color items.

16. The color space signal conversion device according to claim 10, wherein the default item and the compensation item are two of the initial chroma color items.

17. The color space signal conversion device according to claim 10, wherein one of the preset code generator and the compensation code generator uses a lookup table unit.

18. The color space signal conversion device according to claim 10, wherein the preset code generator and the compensation code generator share a single lookup table unit.