KR100410401B1 - Method for conversion of Red, Green, Blue signal and apparatus using the same - Google Patents

Abstract

The present invention relates to an apparatus for converting an image signal and a method thereof. An apparatus for converting red, green, and blue signals that can reduce chip area and reduce power consumption by converting a YUV signal into an RGB signal using an approximated equation. And to provide a method, the present invention is a red, green, blue signal conversion device, the numerical signal '2', '3', 'FA8', '4D8' or '1228' and the control signal and YUV A control unit for outputting a signal; A Y calculator for outputting the output signals 'Y << 4' and '3Y' by the control signal by inputting the Y signal and the numerical signal '3'; U which inputs the U signal and the numerical signal '2' and selectively outputs the output signals 'U' and 'U << 2' or the output signals '2U' and 'U << 5' by the control signal. A calculator; V which selectively outputs output signals 'V << 5' and '3V' or output signals 'V << 3' and 'V' by the control signal by inputting the numerical signal '3' and the V signal. A calculator; A first multiplexer configured to selectively output one of the signals 'FA8', '4D8' or '1228' by the control signal by inputting the numerical signals 'FA8', '4D8' and '1228'; The output signal of the Y calculating unit, the U calculating unit, the V calculating unit, and the first multiplexing unit is input, and the red (R), green (G) or An addition and subtraction unit for selectively outputting an operation result corresponding to each of the blue (B); And a light shifter unit for outputting the red (R), green (G), and blue (B) signals by shifting the output of the addition and subtraction unit to the lower bit by 4 bits.

Description

Method for converting red, green, and blue signals and apparatus therefor {Method for conversion of Red, Green, Blue signal and apparatus using the same}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high speed video format, and more particularly, to an apparatus and method for converting red, green, and blue (Red, Green, Blue) signals for a high speed video format using an approximation equation.

In general, in addition to the RGB format used for color television, there are YUV format, YIQ format, YCrCb format, and CMYK format used for color printers.

The RGB format expresses colors with data signals of R (Red), G (Green), and B (Blue), which implements colors. However, the YUV format displays the Y signal, which is a brightness component, and two U and V signals, which are color components. To transmit color data.

On the other hand, the YUV signal is a signal system mainly used in the PAL method, the PAL method is a standard method of the free signal used in the rest of Europe except France and some Eastern European countries, one of the two color difference signal, As a method of inverting and modulating a phase for each scan line, compatibility with a black and white television is inferior, but it is characterized by a low influence of a video signal on phase distortion generated in a recording or transmission path.

In order to express the above-described YUV signal, for example, on a television screen, it is necessary to convert it to an RGB signal. The standardization standard for this conversion is shown in ISO / IEC13818-2.

R = (70639 (Y-16) + 117504 (V-128) + 32768) / 216

G = (70639 (Y-16)-13954 (U-128)-34903 (V-128) + 32768) / 2 ¹⁶

B = (70639 (Y-16) + 138453 (U-128) + 32768) / 2 ¹⁶

That is, each signal of RGB is calculated through a calculation process such as multiplying or dividing each signal of YUV by a predetermined value.

However, when the conventional RGB conversion equation formed as described above is used in a hardware implementation as it is, there is a problem in that the logic is large because the multiplication factor is very large.

The present invention is to solve the above problems, by converting the red, green, blue signal by using an approximation equation, it is possible to reduce the number of gates according to the hardware implementation, it is possible to enable high-speed operation An object of the present invention is to provide a red, green, and blue signal converting apparatus and method thereof.

1 is a block diagram showing an apparatus for converting red, green, and blue signals according to the present invention;

2A to 2C are block diagrams showing the configuration of each calculation unit according to FIG. 1;

3a to 3c is a detailed configuration diagram showing each left shifter according to FIG.

4 is a detailed configuration diagram illustrating the light shifter unit according to FIG. 1.

* Description of the main parts of the drawing

10: control unit

20: Y calculation unit

30: U calculation unit

40: V calculation unit

50: first multiplexer

60: addition and subtraction

70: light shifter

In order to achieve the above object, the present invention, in the red, green, blue signal conversion device, the numerical signal '2', '3', 'FA8', '4D8' or '1228' and the control signal and YUV signal A control unit for outputting; A Y calculator for outputting the output signals 'Y << 4' and '3Y' by the control signal by inputting the Y signal and the numerical signal '3'; U which inputs the U signal and the numerical signal '2' and selectively outputs the output signals 'U' and 'U << 2' or the output signals '2U' and 'U << 5' by the control signal. A calculator; V which selectively outputs output signals 'V << 5' and '3V' or output signals 'V << 3' and 'V' by the control signal by inputting the numerical signal '3' and the V signal. A calculator; A first multiplexer configured to selectively output one of the signals 'FA8', '4D8' or '1228' by the control signal by inputting the numerical signals 'FA8', '4D8' and '1228'; The output signal of the Y calculating unit, the U calculating unit, the V calculating unit, and the first multiplexing unit is input, and the red (R), green (G) or An addition and subtraction unit for selectively outputting an operation result corresponding to each of the blue (B); And a light shifter unit for outputting the red (R), green (G), and blue (B) signals by shifting the output of the addition and subtraction unit to the lower bit by 4 bits.

In addition, the present invention is a video signal conversion method for converting the input YUV signal to a red (R), green (G), blue (B) signal, the numerical signal '2', '3', 'FA8' A first step of generating and outputting '4D8' and '1228'; A second step of outputting the output signals 'Y << 4' and '3Y' using the Y signal and the numerical signal '3' among the YUV signals; If the signal to be converted is the green (G) signal using the U signal and the numerical signal '2' among the YUV signals, the output signals 'U' and 'U << 2' are output, and the signal to be converted is the blue ( A third step of outputting an output signal '2U' and 'U << 5' if the signal B); If the signal to be converted is the red (R) signal using the V signal and the numerical signal '3' among the YUV signals, the output signals 'V << 5' and '3V' are output, and the signal to be converted is green (G). A fourth step of outputting the output signals 'V << 3' and 'V' if the signal; If the signal to be converted is a red (R) signal, the numerical signal 'FA8' is output; if the signal to be converted is a green (G) signal, '4D8' is output; and if the signal to be converted is a blue (B) signal, the numerical signal is outputted. A fifth step of outputting '1228'; A sixth step of calculating the following equation by combining the output signals output in the first to fifth steps when the signal to be converted is an red (R) signal; (Y << 4) + (V << 5) + 3Y-3V-FA8, when the signal to be converted is a green (G) signal, a seventh step of combining the output signal output in the first to the fifth step to calculate the following equation; (Y << 4)-(U << 2)-(V << 3) + 3Y + U-V + 4D8, when the converted signal is a blue (B) signal, output in the first to fifth steps An eighth step of combining the output signals to calculate the following equation; And (Y << 4) + (U << 5) + 3Y + 2U-1228) shifting the values calculated in the sixth to eighth steps by the lower four bits, respectively, to obtain red (R) and green ( G), and provides a red, green, blue signal conversion method comprising the step of outputting a blue (B) signal.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art may easily implement the technical idea of the present invention. .

RGB conversion according to the present invention is to simplify the coefficient to be multiplied by each YUV signal through an approximation equation.

1 is a block diagram showing an apparatus for converting an RBG signal according to an embodiment of the present invention.

Referring to FIG. 1, a control unit 10 for outputting numerical signals '2', '3', 'FA8', '4D8' or '1228' and control signals 'CS' and YUV signals, and the Y signal and the numerical value. Input the signal '3' to the Y calculator 20 for outputting the output signals 'Y << 4' and '3Y' by the control signal 'CS', and the U signal and the numerical signal '2' are input. And the U calculator 30 for selectively outputting the output signals 'U' and 'U << 2' or the output signals '2U' and 'U << 5' by the control signal 'CS', and the numerical value. Selectively outputting the output signals 'V << 5' and '3V' or the output signals 'V << 3' and 'V' by the control signal 'CS' with the input of the signal '3' and the V signal. Any one of 'FA8', '4D8' or '1228' by the control signal 'CS' with the V calculator 40 and the numerical signals 'FA8', '4D8' and '1228' as inputs. The first multiplexer 50 and the Y calculator 20, the U calculator 30 and the V calculator for selectively outputting (40) and the output signal of the first multiplexer 50 are input, and the red (R), green (G), or blue (B) is performed by calculating the input signal by the control signal 'CS'. The addition and subtraction unit 60 and the output of the addition and subtraction unit 60, which selectively output the operation results corresponding to each of the inputs, are shifted to the lower bits by 4 bits, and then red (R) and green (G). And a light shifter unit 70 for outputting a blue signal.

2A to 2C, the Y calculator 20 may include a first left shifter 210 and a Y signal for outputting 'Y << 4' by shifting the Y signal by 4 bits. And a first multiplier 2a for outputting '3Y' by inputting the numerical signal '3'.

The U calculator 30 includes a second multiplier 310 for outputting '2U', which is a result of multiplying the numerical signal '2' and the U signal, and 'U <shifting the U signal by two bits. A second left shifter unit 320 for outputting <2 ', a third left shifter unit 330 for outputting' U << 5 'by shifting the U signal by an upper bit by 5 bits, and the control signal' A second multiplexer 340 that outputs one of the signals' 2U 'and' U 'by CS' and 'U << 2' and 'U << 5' by the control signal 'CS'. And a third multiplexer 350 for outputting any one of the signals.

In addition, the V calculator 40 includes a third multiplier 410 for outputting '3V', which is a result of multiplying the numerical signal '3' and the V signal, and '' which shifts the V signal by two bits. A fourth left shifter unit 420 for outputting V << 2 ', a fifth left shifter unit 430 for outputting' V << 5 'in which the V signal is shifted by an upper bit by 5 bits, and the control The fourth multiplexer 440 outputs any one of the signals' 3V 'and' V 'by the signal' CS 'and' V << 2 'and' V << by the control signal 'CS'. And a fifth multiplexer 450 for outputting any one signal of 5 '.

The RGB conversion method of the present invention having the above-described configuration will be described in detail.

In the case of the above-described first equation used in ISO / IEC 13818-2, the coefficient is increased, so that it is difficult to implement the RGB conversion device as described above, so that the coefficient in each term of the first equation is reduced. Divide each term by 2 ¹² and discard the remainder.

R = (19 (Y-16) + 29 (V-128) + 8) / 2 ⁴

G = (19 (Y-16)-3 (U-128)-9 (V-128) + 8) / 2 ⁴

B = (19 (Y-16) + 34 (U-128) + 8) / 2 ⁴

Again, after solving for the second equation in parentheses, the order of each coefficient is put together and is as follows.

R = (16Y + 3Y + 32V-3V-4008) / 2 ⁴

G = (16Y + 3Y-4U + U-8V-V + 1240) / 2 ⁴

B = (16Y + 3Y + 32U + 2U-4648) / 2 ⁴

The third equation is rearranged as follows.

R = (2 ⁴ * Y + 3 * Y + 2 ⁵ V-3 * V-4008) / 2 ⁴

G = (2 ⁴ * Y + 3 * Y-2 ² * U + U-2 ³ * V-V + 1240) / 2 ⁴

B = (2 ⁴ * Y + 3 * Y + 2 ⁵ * U + 2 * U-4648) / 2 ⁴

Here, X of 2 ^x is an integer, and a number multiplied by 2 ^x is equivalent to shifting the upper bit by X, and dividing by 2 ^x shifts the number by X to the lower bit ( Right shift). Further, when the coefficients 4008, 1240, and 4648 having a large coefficient are displayed in hexadecimal, 'FA8', '4D8', and '1228', respectively.

Therefore, the fourth equation may be simplified as follows.

R = ((Y << 4) + (V << 5) + 3Y-3V-FA8) >> 4

G = ((Y << 4)-(U << 2)-(V << 3) + 3Y + U-V + 4D8) >> 4

B = ((Y << 4) + (U << 5) + 3Y + 2U-1228) >> 4

Here, "<<" represents a left shift, i.e., a shift to a higher bit as described above, and ">>" represents a light shift, i.e., a shift to a lower bit.

The shift operation of the first to fifth left shifter units 210, 320, 330, 420, and 430 may be performed by shifting the input data to the most significant bit as shown in FIGS. 3A to 3C. 3a is a first light shifter 210 for shifting 4-bit input data and outputting it, and FIG. 3b shows a second left shifter 320 and a fourth left shifter 320 for shifting 2-bit input data. 3C is a detailed configuration diagram of the third left shifter unit 330 and the fourth left shifter unit 430 outputting 5-bit shifted data. In FIGS. 3A to 3C, the bits to which the input terminal is not connected are floating bits, and all bits to which the upper bits are not connected are “0”.

In addition, as illustrated in FIG. 4, the light shifter unit 70 shifts the input data to the least significant bit and outputs the data by shifting the input data by 4 bits. Detailed configuration diagram of the. In FIG. 4, the bits to which the input terminal is not connected are floating bits, and all the bits to which the lower bits are not connected are “0”.

According to the present invention made as described above, when converting the image format of YUV420 or YUV422 to RGB, the conversion equation of 13818-2 is simplified by using an approximation formula, thereby reducing the gate by 30% and thus the area in hardware implementation. And it was found through the embodiment that the power consumption can be reduced.

Although the technical idea of the present invention has been described in detail according to the above preferred embodiment, it should be noted that the above-described embodiment is for the purpose of description and not of limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention.

The present invention made as described above has the effect of reducing the chip area and power consumption in the system for converting the YUV signal red, green, blue signal.

Claims (3)

In the video signal conversion apparatus, A control unit for outputting a numerical signal '2', '3', 'FA8', '4D8' or '1228', a control signal and a YUV signal; A Y calculator for outputting the output signals 'Y << 4' and '3Y' by the control signal by inputting the Y signal and the numerical signal '3'; U which inputs the U signal and the numerical signal '2' and selectively outputs the output signals 'U' and 'U << 2' or the output signals '2U' and 'U << 5' by the control signal. A calculator; V which selectively outputs output signals 'V << 5' and '3V' or output signals 'V << 3' and 'V' by the control signal by inputting the numerical signal '3' and the V signal. A calculator; A first multiplexer configured to selectively output one of the signals 'FA8', '4D8' or '1228' by the control signal by inputting the numerical signals 'FA8', '4D8' and '1228'; The output signal of the Y calculating unit, the U calculating unit, the V calculating unit, and the first multiplexing unit is input, and the red (R), green (G) or An addition and subtraction unit for selectively outputting an operation result corresponding to each of the blue (B); And A light shifter unit for outputting the red (R), green (G), and blue (B) signals by shifting the output bits of the addition and subtraction unit by 4 bits into the lower bits. Red, green, blue signal conversion device comprising a. The method of claim 1, The Y calculation unit, A first left shifter unit for outputting 'Y << 4' by shifting the Y signal to higher bits by 4 bits; And And a first multiplier for outputting '3Y' by inputting the Y signal and the numerical signal '3', The U calculation unit, A second multiplier for outputting '2U' which is a result of multiplying the numerical signal '2' and the U signal; A second left shifter unit for outputting 'U << 2' by shifting the U signal by two bits; A third left shift unit for outputting 'U << 5' by shifting the U signal by an upper bit by 5 bits; A second multiplexer which outputs one of the signals '2U' and 'U' according to the control signal; And A third multiplexer configured to output one of the signals 'U << 2' and 'U << 5' according to the control signal It is made, including The V calculation unit, A third multiplier (3) for outputting '3V' which is a result of multiplying the numerical signal '3' and the V signal; A fourth left shifter for outputting 'V << 2' by shifting the V signal by 2 bits to an upper bit; A fifth left shifter for outputting 'V << 5' by shifting the V signal by an upper bit by 5 bits; A fourth multiplexer configured to output one of the signals '3V' and 'V' according to the control signal; And A fifth multiplexer configured to output one of 'V << 2' and 'V << 5' according to the control signal Red, green, blue signal conversion device comprising a. In the video signal conversion method of combining the input YUV signal to red (R), green (G), blue (B) signal, A first step of generating and outputting the numerical signals '2', '3', 'FA8', '4D8', '1228'; A second step of outputting the output signals 'Y << 4' and '3Y' using the Y signal and the numerical signal '3' among the YUV signals; If the signal to be converted is the green (G) signal using the U signal and the numerical signal '2' among the YUV signals, the output signals 'U' and 'U << 2' are output, and the signal to be converted is the blue ( A third step of outputting an output signal '2U' and 'U << 5' if the signal B); If the signal to be converted is the red (R) signal using the V signal and the numerical signal '3' among the YUV signals, the output signals 'V << 5' and '3V' are output, and the signal to be converted is green (G). A fourth step of outputting the output signals 'V << 3' and 'V' if the signal; If the signal to be converted is a red (R) signal, the numerical signal 'FA8' is output; if the signal to be converted is a green (G) signal, '4D8' is output; and if the signal to be converted is a blue (B) signal, the numerical signal is outputted. A fifth step of outputting '1228'; A sixth step of calculating the following equation by combining the output signals output in the first to fifth steps when the signal to be converted is an red (R) signal; (Y << 4) + (V << 5) + 3Y-3V-FA8 A seventh step of combining the output signals output in the first to fifth steps when the signal to be converted is a green (G) signal to calculate the following equation; (Y << 4)-(U << 2)-(V << 3) + 3Y + U-V + 4D8 An eighth step of calculating the following equation by combining the output signals output in the first to fifth steps when the converted signal is a blue (B) signal; And (Y << 4) + (U << 5) + 3Y + 2U-1228) Shifting the values calculated in the sixth to eighth steps by the lower four bits and outputting the red (R), green (G), and blue (B) signals, respectively. Red, green, blue signal conversion method comprising a.