KR20150057039A - method of adjusting white balance in image outputting device - Google Patents

Abstract

According to the present invention, a white balance adjusting method used in an image output device includes the steps of: setting a quadratic curve passing through three predetermined reference color coordinates in a color gamut; moving a color coordinate along the quadratic curve by a predetermined movement unit according to a color temperature adjusting signal; and acquiring the gain for each RGB signal corresponding to the moved color coordinate to apply the gains to the RGB signals.

Description

[0001] The present invention relates to a method of adjusting a white balance in a video output apparatus,

The present invention relates to a video output apparatus, and more particularly, to a white balance adjustment method in a video output apparatus.

A variety of video output devices including a TV, a notebook, a smart phone, a digital video device, and a projector are commercially available. In such video output devices, color temperature adjustment is a basic process for image adjustment, and white color balance determination of white color coordinates as a reference of all colors through color temperature adjustment is referred to as white balance.

However, the reference color coordinates of white can be set differently for each video mode of the video output device, which is important enough to compensate for each variation of each product in mass production. In addition, optimum white balance is required depending on the type of external light or illumination and the contents that affect the viewing environment of the user.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide various white balancing methods capable of calculating a gain of a video signal in a desired color temperature range in an accurate and efficient manner.

It is another object of the present invention to provide a white balance adjustment method capable of smooth and continuous color coordinate movement in a color region.

It is another object of the present invention to provide a white balance adjustment method capable of performing white balance and color region mapping based on measurement results of a specific pattern including RGBW color regions.

Another aspect of the present invention is to provide a white balance adjustment method capable of performing a substantial white balance in two reference modes and calculating an RGB gain based on a calculation for another reference mode.

It is another object of the present invention to provide a white balance adjustment method capable of moving color coordinates to color coordinates included in a two-dimensional region within a certain range on a color region.

Another object of the present invention is to provide a white balance adjustment method capable of automatically adjusting a white balance based on status information or inducing adjustment to an optimal color coordinate.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not intended to limit the invention to the precise forms disclosed. Other objects, which will be apparent to those skilled in the art, It will be possible.

According to another aspect of the present invention, there is provided a method of adjusting a white balance in a video output apparatus, the method comprising: setting a quadratic equation curve passing through three predetermined reference color coordinates in a color gamut; Moving color coordinates along the quadratic equation curve in a predetermined moving unit based on a color temperature adjustment signal; And obtaining a gain for each of the RGB signals corresponding to the moved color coordinates, and applying the gain to the RGB signals.

Wherein the step of shifting the color coordinates based on the color temperature adjustment signal includes shifting the color coordinates along the quadratic equation curve by a predetermined distance in the horizontal direction of the color region based on the color temperature adjustment signal .

Wherein the step of moving the color coordinates based on the color temperature adjustment signal includes the step of moving the color coordinates along the quadratic equation curve in units of a predetermined distance in the vertical axis direction of the color region based on the color temperature adjustment signal .

The step of shifting the color coordinates based on the color temperature adjustment signal may include shifting the color coordinates based on the color temperature adjustment signal by a predetermined distance unit along the quadratic equation curve.

The step of obtaining gain for each of the RGB signals corresponding to the shifted color coordinate may include applying the color coordinate values of the respective colors and the shifted color coordinate values to the additive mixture formula so that the relative ratio of the gains ; And normalizing the gain of the RGB signal based on the maximum gain among the gains of the RGB signal to obtain gain for each of the RGB signals.

According to another aspect of the present invention, there is provided a method of adjusting a white balance in a video output apparatus, the method comprising: outputting a specific pattern including an RGBW color region corresponding to a specific color coordinate; Sensing luminance and color coordinates of each of the RGBW color regions; And correcting a predetermined reference color coordinate corresponding to the white balance reference mode in consideration of the difference between the color coordinates of the sensed W color area and the specific color coordinates.

The white balance adjustment method in the video output apparatus may further include a step of calculating a gain of each of the RGB colors corresponding to the specific color coordinates based on the sensing result. The white balance adjustment method in the video output apparatus may further include a step of calculating gamut mapping coefficients based on the sensing result and performing gamut mapping by applying the calculated gamut mapping coefficients can do.

The specific pattern may further include a background area for APL (Average Picture Level) measurement.

According to another aspect of the present invention, there is provided a method of adjusting a white balance in a video output apparatus, the method comprising: performing white balance adjustment corresponding to first and second modes; Calculating a RGB luminance ratio corresponding to the third mode by applying a predetermined reference RGB gain corresponding to the third mode to an RGB additive mixing formula; Calculating a gain for each of the RGB signals corresponding to the third mode based on the calculated RGB luminance ratio; And interpolating a white balance adjustment unit between the first and second modes and the third mode.

The coordinate value in the horizontal axis direction of the color gamut of the third mode may be a specific coordinate value between the coordinate values in the horizontal axis direction of the first and second modes. The coordinate value in the vertical axis direction of the color gamut of the third mode may be a specific coordinate value between the coordinate values in the vertical axis direction of the first and second modes.

Wherein the step of interpolating the white balance adjustment unit between the first mode and the second mode and the third mode comprises the step of interpolating between the color coordinates corresponding to the first and second modes and the color coordinates corresponding to the third mode As shown in FIG.

Wherein the step of interpolating the white balance adjustment unit between the first and second modes and the third mode comprises the steps of: obtaining a gain of RGB color corresponding to each of the first and second modes and RGB Or the ratio of the gain of the color.

According to another aspect of the present invention, there is provided a method of adjusting a white balance in a video output device, the method comprising the steps of: generating a color temperature trajectory by connecting a plurality of reference color coordinates on a color gamut, A first sub-white balance adjustment step of shifting the color coordinates; And a second sub-white balance adjustment step of using color coordinates along a second line that is crossed with the first line.

The second line may be a line of a vertical deviation direction of a color temperature trajectory in consideration of a correlated color temperature. The white balance adjustment method in the video output apparatus may further include obtaining status information from the operation status of the video output apparatus and the surrounding environment and calculating an optimal color coordinate corresponding to the obtained status information have.

The method of adjusting white balance in the image output apparatus may further include automatically performing white balance to the calculated optimum color coordinates. The white balance adjustment method in the image output apparatus may further include performing a user interfacing operation for deriving the white balance adjustment to the calculated recommended color coordinates.

Meanwhile, the status information may be acquired based on at least one of the content output from the video output device, the brightness of the surroundings, and the RGB sensitivity of the surroundings.

The white balance adjustment method in the video output apparatus according to the embodiment of the present invention can be implemented by executing a computer program for implementing the video output apparatus driving method stored in the computer readable recording medium.

According to the white balance adjustment method in the video output apparatus according to the present invention, the gain of the video signal in a desired color temperature range can be calculated accurately and efficiently.

According to the white balance adjustment method in the video output device according to the present invention, it is possible to adjust the white balance through smooth and continuous color coordinate movement in the color gamut.

According to the white balance adjustment method in the video output apparatus according to the present invention, white balance and gamut mapping can be performed together based on the measurement result of the specific pattern including the RGBW color region.

According to the white balance adjustment method in the video output apparatus according to the present invention, the actual white balance can be performed in the two reference modes, and the RGB gain based on the calculation can be calculated for the other reference modes.

According to the white balance adjustment method in the video output apparatus according to the present invention, it is possible to move the color coordinates to the color coordinates included in the two-dimensional region within a certain range on the color region.

According to the white balance adjustment method in the video output apparatus according to the present invention, the white balance can be automatically adjusted based on the situation information, or the adjustment to the optimum color coordinates can be induced.

1 is a block diagram of a video output apparatus according to the present invention.
2 is a view for explaining a concept of a color region used in a white balance adjustment method in a video output apparatus according to the present invention.
3 is a flowchart illustrating an example of a white balance adjustment method in a video output apparatus according to the present invention.
FIG. 4 is a diagram for explaining how a two-dimensional equation curve is set according to the white balance adjustment method shown in FIG.
FIG. 5 shows an example in which the color coordinates are shifted according to the white balance adjustment method shown in FIG.
Fig. 6 shows an example in which the color coordinates are shifted according to the white balance adjustment method shown in Fig.
FIG. 7 shows an example in which the color coordinates are shifted according to the white balance adjustment method shown in FIG.
8 is a flowchart showing another example of the white balance adjustment method in the video output apparatus according to the present invention.
Fig. 9 shows an example of a specific pattern displayed on the video output apparatus 100 according to the white balance adjustment method shown in Fig.
Fig. 10 shows an example in which correction for the color coordinates corresponding to the specific pattern provided is performed according to the white balance adjustment method shown in Fig.
11 shows an example in which gamut mapping corresponding to the video output apparatus is performed according to the white balance adjustment method shown in Fig.
12 is a flowchart showing still another example of a white balance adjustment method in a video output apparatus according to the present invention.
FIG. 13 shows an example of an interpolation curve in the xy coordinate system derived according to the white balance adjusting method shown in FIG. 12, and FIG. 14 shows an example of the interpolation curve in the u'v 'coordinate system derived according to the white balance adjusting method shown in FIG. An example of an interpolation curve is shown.
Fig. 15 shows examples of color coordinates corresponding to the first to third modes to which the white balance adjustment method shown in Fig. 12 is applied.
16 is a flowchart showing still another example of a white balance adjustment method in the video output apparatus according to the present invention. Hereinafter, the driving method will be described with reference to necessary drawings.
17 shows a color area in which a white balance adjustment method in the video output device according to the present invention is performed.
FIG. 18 is a diagram for explaining a concept in which the white balance adjustment region is expanded according to the white balance adjustment method shown in FIG.
19 is a flowchart showing still another example of a white balance adjustment method in the video output apparatus according to the present invention.
FIG. 20 shows an example of a GUI for white balance adjustment guidance provided according to the white balance adjustment method shown in FIG.

The foregoing objects, features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Like reference numerals designate like elements throughout the specification. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

Hereinafter, a video output apparatus according to the present invention will be described in detail with reference to the drawings. The suffix "module" and " part "for the components used in the following description are given or mixed in consideration of ease of specification, and do not have their own meaning or role.

1 is a block diagram of a video output apparatus 100 according to the present invention. The video output apparatus described in this specification may include a TV, a monitor, a notebook, a smart phone, a projector, and the like. However, the scope of the present invention is not limited thereto.

1, the video output apparatus 100 includes a communication unit 110, an A / V input unit 120, a user input unit 130, a sensing unit 140, a display unit 150, an audio output unit 160 A memory 170, a power supply unit 180, and a control unit 190. The components shown in FIG. 1 are not essential, so that the video output device 100 may have more or fewer components. Hereinafter, the components will be described in order.

The communication unit 110 may include one or more modules that enable wire / wireless communication between the video output apparatus 100 and the communication network. For example, the communication unit 110 may include a broadcast receiving module, a mobile communication module, a wireless Internet module, a short distance communication module, and the like. The communication unit 110 can receive a broadcast signal through the communication network.

The A / V (Audio / Video) input unit 120 is for inputting an audio signal or a video signal. Although not shown in FIG. 1, the AV input unit 120 may include a camera, a microphone, and the like. The camera processes an image frame such as a still image or a moving image obtained by the image sensor in the video communication mode or the photographing mode. The microphone receives the external acoustic signal and processes it as electrical voice data.

The user input unit 130 generates input data for controlling the operation of the video output apparatus 100 by the user. The user input unit 130 may include a key pad dome switch, a touch pad (static / static), a jog wheel, a jog switch, and the like.

The sensing unit 140 may sense the current state of the image output apparatus 100 or may detect the state of the user and may sense the environmental condition of the image output apparatus 100. [ The data sensed by the sensing unit 140 may serve as a basis for controlling the operation of the image output apparatus 100.

The display unit 150 displays and outputs information processed by the video output apparatus 100. The display unit 150 may be implemented as a liquid crystal display, a thin film transistor-liquid crystal display, an organic light-emitting diode, or a flexible display . The display unit 151 may include a display unit for outputting an image, and a polarizing film for filtering and outputting the image at a predetermined polarization angle.

In addition, the display unit 150 may output an image according to a polarizing glasses system or a shutter glass system in order to allow a user to recognize a three-dimensional stereoscopic image. However, the method for implementing the three-dimensional stereoscopic image is not limited to the above-described examples.

The sound output unit 160 outputs a sound signal related to a function performed by the image output apparatus 100. The sound output unit 160 may include a receiver, a speaker, a buzzer, and the like. Also, the sound output unit 160 may output sound through the earphone jack.

The memory 170 may store a program for the operation of the controller 190, and may temporarily or permanently store the input / output data. The memory 170 may temporarily or permanently store image data output through the display unit 150 and corresponding sound data. In addition, the memory 170 may store an algorithm for converting normal citation image data to color image data for color blindness according to the type of color weakness.

The memory 170 may be a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (e.g., SD or XD memory), a RAM (Random Access Memory), SRAM (Static Random Access Memory), ROM (Read Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), PROM , An optical disc, and the like. The video output apparatus 100 may operate in association with a web storage that performs a storage function of the memory 170 on the Internet.

The control unit 190 typically controls the overall operation of the video output apparatus 100.

The power supply unit 190 may receive external power and internal power under the control of the controller 190 and supply power required for operation of the respective components. The power supply unit 190 may receive external power and internal power under the control of the controller 190 and supply power necessary for operation of the respective components.

The various embodiments described herein may be embodied in a recording medium readable by a computer or similar device using, for example, software, hardware, or a combination thereof.

According to a hardware implementation, the embodiments described herein may be implemented as application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays May be implemented using at least one of processors, controllers, micro-controllers, microprocessors, and electrical units for performing functions. In some cases, And may be implemented by the control unit 190.

According to a software implementation, embodiments such as procedures or functions may be implemented with separate software modules that perform at least one function or operation. The software code may be implemented by a software application written in a suitable programming language. Also, the software codes may be stored in the memory 170 and executed by the control unit 190. [

2 is a view for explaining a concept of a color region used in a white balance adjustment method in a video output apparatus according to the present invention.

The color gamut 200 shown in FIG. 3 is a color gamut representing a whole color that can be realized in a natural color. The triangle-shaped color region 300 in the entire color region represents the entire range of colors that can be implemented in the image output apparatus 100. The white balance to be discussed in this specification is made in the small triangular shaped color region 300.

3 is a flowchart illustrating an example of a white balance adjustment method in a video output apparatus according to the present invention. Hereinafter, the driving method will be described with reference to necessary drawings.

First, a quadratic equation curve passing through the three reference color area coordinates is set in the color area (S100). Each of the reference modes may be stored in the memory 170 of the image output apparatus 100 with corresponding color coordinates set in advance. The quadratic equation can be determined based on the coordinate values of each of the modes.

Here, the three reference color gamut coordinates may be a cool mode, a mediun mode, or a warm mode. The cool mode is a mode in which the blue color is the largest among the above modes and gives the coldest feeling among the above modes. The warm mode is a mode in which the influence of the red color is greatest among the reference modes, and the warm mode is the strongest mode among the reference modes. And, the medium mode is a mode that gives a feeling of being somewhere between the cool mode and the warm mode. The names of these reference modes are arbitrarily named, and the scope of the present invention is not limited thereto.

FIG. 4 is a diagram for explaining how a two-dimensional equation curve is set according to the white balance adjustment method shown in FIG.

Referring to FIG. 4, it can be seen that a quadratic equation curve connecting the cool mode, the medium mode, and the warm mode, which is a standard for the white balance of the image output apparatus, is set in the color region. The coefficients of the two-dimensional equation can be calculated based on the color coordinates corresponding to the three reference modes. The color coordinates corresponding to the three reference modes are stored in the memory 170 in advance.

And a quadratic equation curve is set based on the color coordinate values corresponding to the reference modes. It is assumed that the color coordinates corresponding to the warm mode are (0.3127, 0.3290), the color coordinates corresponding to the medium mode are (0.2850, 0.2934), and the color coordinates corresponding to the cool mode are (0.2715, 0.2698). Then, in the above quadratic equation, the coefficient a for the square of x can be set to -11.247, the coefficient b for x to be 8.007, and the constant c to -1.075. The color coordinates of the warm mode are color coordinates corresponding to 6500K corresponding to sunlight.

The color temperature trajectory set along the quadratic equation curve according to the present invention is smoother and continuous than the conventional color temperature trajectory set in a dotted line connecting the coordinates of the reference modes.

See FIG. 3 again. When the color temperature adjustment signal is received (S110), the controller 190 of the image output device 100 may shift the color coordinates in a predetermined moving unit along the quadratic equation curve (S110). Here, the movement of the color coordinate means moving the color coordinate of the white color which is the reference origin of all the colors.

Here, the color temperature adjustment signal may be a color coordinate movement signal received from the white balance adjustment device, or may be a signal received based on a user's remote controller operation in a state of entering the white balance adjustment mode. For example, when entering the white balance adjustment mode, the channel up button and the channel down button of the remote controller may be set as input means for color coordinate movement. However, the scope of the present invention is not limited thereto.

The reference of the color coordinate movement may be a reference color coordinate corresponding to the medium mode. The predetermined moving unit may be determined based on the quadratic equation curve. This will be described in more detail with reference to FIG. 5 to FIG.

When the color coordinates are shifted, the controller 190 obtains the gain of each of the RGB colors corresponding to the moved color coordinates, and applies the obtained gain to each of the RGB signals (S120). The gain corresponding to each of the RGB signals can be obtained based on the additive mixture formula for the RBG hues of the following equations (1) and (2).

x4 and x4 represent the color coordinates to be obtained based on the RGB color. a1, a2, and a3 denote the gains of the respective RGB colors. x1, x2, and x3 represent the color coordinates of each color of RGB applied. Y1, Y2, and Y3 represent the luminance (%) of each color of RGB.

In Equations (1) and (2), the color coordinates and the brightness of each color of R, G, and B may be measured or may be stored in the memory 170 in advance. Therefore, when the equations (1) and (2) are solved together, the relative ratio of the gain of each color of RGB can be calculated. More specifically, assuming that the gain of a specific color is 1, a specific ratio of the specific color to the specific gain of the remaining color can be calculated. By normalizing the gain for each of the RGB colors thus calculated to the highest gain value, the gain of each of the RGB colors can be calculated.

FIG. 5 shows an example in which the color coordinates are shifted according to the white balance adjustment method shown in FIG.

Referring to FIG. 5, it can be seen that the color coordinates are shifted along the quadratic equation curve set in step S110 based on the color temperature adjustment signal, but shifted by a certain distance unit in the horizontal axis direction of the color area. In the white balance adjustment mode, it is assumed that the color coordinates are located in the color coordinates corresponding to the medium mode, and the channel up button and the channel down button of the remote controller are assigned to the color coordinate movement. This is also true in Figs. 6 and 7

When the user operates the channel up button once in the white balance adjustment mode, the controller 190 moves the color coordinates to color coordinates having coordinate values of x1 on x1 and y1 on the two-dimensional equation curve corresponding to x1 . When the user operates the channel up button a plurality of times, the controller 190 sets the color coordinates to x-coordinate shifted at the x-coordinate multiple times, a value on the quadratic equation curve corresponding to the shifted x- As shown in FIG. The color coordinate movement by the channel down button operation can be easily derived from the color coordinate movement based on the channel up button operation, and a detailed description thereof will be omitted.

Fig. 6 shows an example in which the color coordinates are shifted according to the white balance adjustment method shown in Fig.

Referring to FIG. 6, it can be seen that the color coordinates are shifted along the quadratic equation curve set in step S110 based on the color temperature adjustment signal, but are shifted by a certain distance unit in the vertical axis direction of the color area.

When the user operates the channel up button once in the white balance adjustment mode, the controller 190 moves the color coordinates to color coordinates having coordinate values of x1 on the two-dimensional equation curve corresponding to y1 and y1 which are equal intervals in y0 . When the user operates the channel up button a plurality of times, the controller 190 sets the color coordinates to the y-coordinate shifted by the plural times at y0, the value on the quadratic curve corresponding to the shifted y-coordinate, As shown in FIG. The color coordinate movement by the channel down button operation can be easily derived from the color coordinate movement based on the channel up button operation, and a detailed description thereof will be omitted.

FIG. 7 shows an example in which the color coordinates are shifted according to the white balance adjustment method shown in FIG.

Referring to FIG. 7, it can be seen that the color coordinates move along the quadratic equation curve set in step S110 based on the color temperature adjustment signal, but are shifted by a certain distance unit on the two-dimensional equation curve.

When the user operates the channel up button once, the control unit 190 moves the color coordinates to (x1, y1) located at equal distance from the medium mode color coordinates. When the user operates the channel up button one more time, the controller 190 moves the color coordinates to (x2, y2) located at the same distance from (x1, y1).

On the other hand, the controller 190, in which the channel down button is operated, can move the color coordinates in the medium mode color coordinates to (x3, y3), (x4, y4) at regular intervals along the quadratic equation curve.

Meanwhile, the gain of each of the RGB colors corresponding to the reference mode as a reference for white balance adjustment in the video output apparatus according to the present invention may be predetermined and stored in the memory 170.

Table 1 below shows an example of a gain for each of the RGB colors corresponding to each of the reference modes stored in the memory 170.

Referring to Table 1, it can be seen that the R color has the highest gain in the warm mode and the medium mode, and the B color has the highest gain in the cool mode with the cold feeling. Also, the warm mode is matched to the movie image, the medium mode is matched to the standard image or the arbitrary mode use, and the cool mode is matched to the active image. On the other hand, the gain of each RGB color in each reference mode and the image mode corresponding to each reference mode can be set or changed by the user or the manufacturer of the product.

8 is a flowchart showing another example of the white balance adjustment method in the video output apparatus according to the present invention.

First, the control unit 190 of the image output apparatus 100 outputs a specific pattern including regions of RGBW hues corresponding to specific color coordinates (S200). Here, the specific color coordinate may be a color coordinate corresponding to a specific reference mode as a reference in white balance adjustment. The specific color coordinate may be a color coordinate for a color temperature of 6500K corresponding to sunlight.

FIG. 9 shows an example of a specific pattern 400 displayed on the video output apparatus 100 according to the white balance adjustment method shown in FIG.

9, the specific pattern 400 includes an R color region 410, a G color region 420, a B color region 430, and a W color region 440, It can be seen that it is set for APL adjustment. The APL adjustment background can be set by adjusting the background level to measure the most typical APL in a PDP module, such as OLED, where the brightness varies according to APL. That is, the specific pattern can be used for APL measurement as well as white balance adjustment.

More specifically, the specific pattern may be a pattern corresponding to a color temperature 65OOK corresponding to sunlight. At this time, the color coordinates corresponding to the specific pattern are predetermined as (0.3127, 0.3290). Therefore, ideally, the color coordinates of the W color area 440 should be sensed as (0.3127, 0.3290), but actually color coordinates having a difference therefrom are sensed. More accurate white balance adjustment can be performed by correcting this difference. This will be described in more detail with reference to FIG.

Referring back to FIG. In a state where the specific pattern is output (S200), the luminance and color coordinates of each of the RGBW color regions are sensed (S210). The luminance and color coordinates of each of the RGBW color regions may be sequentially sensed by a single meter or may be simultaneously sensed by four meters.

On the other hand, the luminance and color coordinates of each of the RGBW color regions sensed in this way can be used to calculate the gain of the RGB color in the specific pattern. For example, as described above, the sensing result may be applied to Equation 1 and Equation 2 to calculate the RGB color gain corresponding to the specific pattern.

Referring back to FIG. When the luminance and color coordinates of each of the RGBW color regions are sensed (S210), color gamut mapping is performed on a color region that can be implemented in the image output apparatus 100 based on the sensing result (S220) . The color gamut mapping may be performed by calculating a color gamut mapping coefficient based on the sensing result, and applying the calculated gamut mapping coefficient to the RGB signal.

After the color gamut mapping is performed (S220), a step of correcting the reference color coordinates previously set on the basis of white balance by considering the difference between the color coordinates of the sensed W color gamut and the specific color coordinates is performed S230).

Fig. 10 shows an example in which correction for the color coordinates corresponding to the specific pattern provided is performed according to the white balance adjustment method shown in Fig. Hereinafter, the process of performing the correction will be described in more detail with reference to necessary drawings.

9, when the specific pattern corresponds to 6500K, the sensing color coordinates for the W color area 440 should be (0.3127, 0.3290), but in fact, the W color area 440 The sensed color coordinates are (0.3100, 0.3290). The color coordinate correction is performed by adding 0.0090 larger than the sensed color coordinates to the horizontal direction (i.e., the x-axis direction) of the color region and adding 0.0027 to the longitudinal direction (i.e., the y-axis direction) of the color region . If 6500K is a color temperature corresponding to a specific reference mode as a reference of white balance, such a nucleation coordinate correction process corresponds to a reference color coordinate correction for the reference color coordinate mode.

If the 6500K does not correspond to the reference mode as a reference for white balance, the white balance reference mode is selected in consideration of the difference between the sensing color coordinate value for the W color gamut 400 and the predetermined color coordinate value The reference color coordinates that have been set in advance can be corrected. Thus, more accurate white balance can be performed based on the corrected reference color coordinates.

As a method of correcting the reference color coordinates corresponding to the reference mode in consideration of the difference between the sensing color coordinate value for the W color area 400 and the predetermined color coordinate value, A color coordinate value is added or subtracted from the reference color coordinate. However, the method of correcting the reference color coordinate corresponding to the reference mode by considering the difference between the sensing color coordinate value for the W color area 400 and the predetermined color coordinate value is not limited to the above-described method.

FIG. 11 shows an example in which gamut mapping corresponding to the video output apparatus 100 is performed according to the white balance adjustment method shown in FIG.

Referring to FIG. 11, it can be understood that the color gamut mapping can be performed by rotating the color gamut corresponding to the image output device 100 by a predetermined angle in the clockwise direction according to the white balance adjustment method. The rotation reference may be a color coordinate of each of the RGB colors sensed. Meanwhile, the color gamut mapping according to the white balance adjustment method may be performed such that the reference color coordinates are changed in an area corresponding to at least one color among RGB colors in the color gamut by referring to the color coordinates of the sensed RGB color ≪ / RTI >

Equation (3) mathematically shows that color gamut mapping and white balance adjustment for RGB input signals are performed according to the white balance adjustment method shown in FIG.

Referring to Equation (3), in accordance with the white balance adjustment method, the RGB color signals Ri, Gi, and Bi are multiplied by a matrix for color region mapping in the RGB region to perform color region mapping, (Rgain, Ggain, Bgain) are multiplied to indicate that the RGB color output signal is determined. Here, the matrix for color gamut mapping may be for rotating the color gamut by a predetermined angle in a specific direction.

12 is a flowchart showing still another example of a white balance adjustment method in a video output apparatus according to the present invention. Hereinafter, the driving method will be described with reference to necessary drawings.

First, white balance adjustment corresponding to the first mode and the second mode is performed (S300). Here, the first mode may be a cool mode, which is one of the reference modes of white balance adjustment, and the second mode may be a warm mode, which is another reference mode of white balance adjustment.

If the white balance adjustment for the first mode and the second mode is performed (S300), the reference RGB gain predetermined in correspondence with the third mode is applied to the RGB additive mixture formula, and the RGB luminance ratio Is calculated (S310). The RGB mixing method may be expressed by Equations (1) and (2).

In the additive mixing formula, it can be seen that the gain and luminance of the RBG color are always multiplied to affect the calculation of the color coordinates. That is, the gain of the RGB color directly affects the luminance of the RGB color, and the adjustment of the gain of the RGB color is equivalent to the adjustment of the luminance of the RGB color. Therefore, even if the luminance of the RGB color is fixed to an arbitrary value, it is possible to obtain the desired luminance by adjusting the gain corresponding to it.

If the gain of the RGB color is arbitrarily set, the luminance ratio may be estimated. On the contrary, when the luminance ratio of the RGB color is set, the gain of the RGB color corresponding thereto can be estimated.

(4) and (5), assuming that the luminance ratio (Y3) corresponding to one color is 1, the luminance ratio (Y1 , Y2).

Referring again to FIG. 12, when the RGB luminance ratio corresponding to the third mode is calculated (S310), the step of calculating the gain for each of the RGB signals corresponding to the third mode based on the calculated RGB luminance ratio (S320). Then, a step of interpolating the white balance adjustment unit between the first and second modes and the third mode is performed (S330).

Wherein the step of interpolating the white balance adjustment unit between the first mode and the second mode and the third mode comprises the step of interpolating between the color coordinates corresponding to the first and second modes and the color coordinates corresponding to the third mode As shown in FIG.

For example, the unit for adjusting the white balance between the first mode and the third mode may be a unit for adjusting the distance between the color coordinates corresponding to the first mode and the color coordinates corresponding to the third mode, Lt; / RTI > The white balance adjustment unit between the second mode and the third mode may be performed in the same manner as the white balance adjustment unit setting method between the first mode and the third mode.

Wherein the step of interpolating the white balance adjustment unit between the first and second modes and the third mode comprises the steps of: obtaining a gain of RGB color corresponding to each of the first and second modes and RGB Or the ratio of the gain of the color.

For example, the white balance adjustment unit between the first mode and the third mode can be determined based on an interval obtained by evenly dividing the ratio of the RGB gains in both modes. This can be applied to the white balance adjustment unit between the second mode and the third mode.

As described above, the white balance adjustment method is different from the conventional white balance adjustment in which the white image is set on the screen and the gain of the RGB color is set for each color temperature corresponding to the reference mode, Perform the adjustment, but for other modes, perform a virtual white balance adjustment that applies the calculated RGB color gain. Therefore, the time spent in white balance adjustment can be reduced and the resulting product mass production time reduced.

13 shows an example of an interpolation curve in the xy coordinate system derived according to the white balance adjustment method shown in Fig. 12, and Fig. 14 shows an example of the interpolation curve in the u'v 'coordinate system derived according to the white balance adjustment method shown in Fig. An example of an interpolation curve is shown.

13 and 14, the second interpolation formula using the quadratic equation curve is applied together as shown in FIG. 13 and 14, it can be seen that the interpolation curve according to the present invention has a smooth and continuous shape as compared with a conventional interpolation line implemented with a straight line connecting reference color coordinates corresponding to the reference mode. That is, according to the white balance adjustment method of the present invention, it is possible to perform smooth and continuous white balance adjustment over the white balance adjustment according to the conventional method.

Fig. 15 shows examples of color coordinates corresponding to the first to third modes to which the white balance adjustment method shown in Fig. 12 is applied. For reference, in FIG. 15, white balance for the first mode, that is, the cool mode and the warm mode, is practically performed according to the white balance adjustment method shown in FIG. 12, and then, for the third mode, It is assumed that white balance is performed. Here, the hot mode means a mode in which the warm feeling is stronger than the warm mode.

15A and 15B, the horizontal axis coordinate value of the color gamut of the third mode is a specific coordinate value between the horizontal axis coordinate values of the first and second modes . However, in the example of FIG. 15 (b), it can be seen that the coordinate value in the vertical axis direction of the third mode can be larger than the vertical axis value of the first and second modes.

15 (b) and 15 (c), the coordinate values in the vertical axis direction of the color gamut of the third mode are the specific coordinate values between the coordinate values in the vertical axis direction of the first and second modes . However, in the example of FIG. 15 (c), it can be seen that the coordinate value in the horizontal axis direction of the third mode can be larger than the horizontal axis value in the first and second modes.

16 is a flowchart showing still another example of a white balance adjustment method in the video output apparatus according to the present invention. Hereinafter, the driving method will be described with reference to necessary drawings.

First, a first sub-white balance adjustment step for shifting the color coordinates along a first line indicating a color temperature trajectory connecting a plurality of reference color coordinates on a color area is performed (S400). Such first sub-white balance adjustment may be performed according to various white balance adjustment methods as described above.

Then, a second sub-white balance adjustment step of using color coordinates along the second line to be crossed with the first line is performed (S410). The second line may be a line in the vertical deviation direction of the color temperature trajectory in consideration of the correlated color temperature. That is, at the time of white balance adjustment, color coordinate movement in the orthogonal direction of the adjustment section along the color temperature line connecting the existing reference color coordinates is additionally possible.

Therefore, according to the white balance adjustment method, the white balance adjustable range can be expanded to a two-dimensional plane as compared with the conventional method in which white balance is performed along the color temperature trajectory in the form of a one-dimensional line.

Meanwhile, an example of a method of moving a color coordinate in a white balance adjustment mode performed by a user will be described. For example, the left and right keys of the remote controller are assigned to the color coordinate movement along the first line, and the up and down keys of the remote controller can be assigned to the color coordinate movement along the second line.

17 shows a color region in which the white balance adjustment method in the video output apparatus 100 according to the present invention is performed.

Referring to FIG. 17, it can be seen that only a part of the color gamut 200 of the entire natural color can be implemented in the image output apparatus 100, and in particular, the white balance adjustment can be performed in some areas (500) .

FIG. 18 is a diagram for explaining a concept in which the white balance adjustment region is expanded according to the white balance adjustment method shown in FIG. 18 is an enlarged view of the white balance adjustment area shown in Fig.

Referring to FIG. 18, it can be seen that, according to the white balance adjustment method, it is possible to perform color coordinate movement along a line connecting color coordinates corresponding to a warm mode, a medium mode, and a cool mode. According to the white balance adjustment method, the color coordinates can be shifted also in the vertical deviation direction of the color temperature trajectory, and it can be seen that the substantially white balance adjustable region in the color region is extended to the two-dimensional region.

19 is a flowchart showing still another example of a white balance adjustment method in the video output apparatus according to the present invention. Hereinafter, the driving method will be described with reference to necessary drawings.

Status information is obtained from the operation status of the video output apparatus and the surrounding environment (S500). The status information may be acquired based on at least one of the content output from the video output apparatus 100, the brightness of the surroundings, and the RGB sensitivity of the surroundings. However, the scope of the present invention is not limited thereto.

If the context information is obtained (S500), the step of calculating the optimal color coordinate corresponding to the obtained context information is performed (S510). That is, in consideration of the operation state of the current image output apparatus 100 and the surrounding environment, the most suitable color coordinate is calculated.

When optimal color coordinates based on the context information are calculated (S510), a user interfacing operation is performed to induce the white balance adjustment to the calculated recommended color coordinates (S520). The user interfacing operation is for guiding the user to change the optimum color coordinates by adjusting the currently set color coordinates, and may include an interfacing operation through images, a user interfacing operation through voice, a interfacing operation through vibration, etc. have. However, the scope of the present invention is not limited thereto.

Here, instead of the user interfacing operation for guiding the adjustment to the optimum color coordinates in the white balance adjustment method in the video output apparatus, a step of automatically performing white balance to the calculated optimum color coordinates may be performed.

In some cases, the present invention may be implemented in a combination of the white balance adjustment method shown in FIG. 16 and the white balance adjustment method shown in FIG. 19.

FIG. 20 shows an example of a GUI for white balance adjustment guidance provided according to the white balance adjustment method shown in FIG.

Referring to FIG. 20, according to the white balance adjustment method, the user can move the color coordinates along the first line, which is the color temperature trajectory connecting the warm mode, the medium mode, and the cool mode, And the second line connecting the red direction (R50) and the red direction (R50).

In FIG. 20, numeral 50 indicates that the color coordinate movement in the specific direction from the color coordinates of the medium mode is possible in 50 steps. That is, according to the present invention, a total of 100 color coordinate shifts are possible for each of the first and second lines.

The state of FIG. 20 is as follows. The position of the current color coordinate is the color coordinate corresponding to the medium mode. The position of the optimal color coordinate calculated in consideration of the current illuminance and illumination color is recommended. Then, the user can perform the white balance adjustment by moving the color coordinates corresponding to the medium mode to the recommended color coordinates by operating the up, down, left, and right direction keys.

Each of the white balance adjustment methods in the video output device according to the present invention may be implemented in a program form that can be executed through various computer means and recorded in a computer readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program recorded on the medium may be those specially designed and constructed for the present invention or may be those known to those skilled in the computer software.

Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of programs include high-level language code that can be executed by a computer using an interpreter or the like, as well as machine code as produced by a compiler. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the equivalents of the claims, as well as the claims.

100: video output device 110:
120: A / V input unit 130: user input unit
140: sensing unit 150: display unit
160: Acoustic output unit 170: Memory
180: power supply unit 190: control unit

Claims (20)

Setting a quadratic equation curve passing through three predetermined reference color coordinates in a color gamut;
Moving color coordinates along the quadratic equation curve in a predetermined moving unit based on a color temperature adjustment signal; And
And obtaining a gain for each of the RGB signals corresponding to the moved color coordinates and applying the gain to the RGB signals. The method according to claim 1, wherein the step of shifting the color coordinates based on the color temperature adjustment signal comprises:
Wherein the color coordinate is moved along the quadratic equation curve in units of a certain distance in the horizontal axis direction of the color region based on the color temperature adjustment signal. The method according to claim 1, wherein the step of shifting the color coordinates based on the color temperature adjustment signal comprises:
And moving the color coordinates along the quadratic equation curve in units of a predetermined distance in the vertical axis direction of the color region based on the color temperature adjustment signal. The method according to claim 1, wherein the step of shifting the color coordinates based on the color temperature adjustment signal comprises:
And moving the color coordinates based on the color temperature adjustment signal in units of a predetermined distance along the quadratic equation curve. The method of claim 1, wherein the step of obtaining a gain for each of the RGB signals corresponding to the moved color coordinates comprises:
Calculating a relative ratio of gain to each of the RGB signals by applying a color coordinate value of each color and a shifted color coordinate value to an additive mixing formula; And
And normalizing the gains based on a maximum gain among the gains for the RGB signals to obtain gain for each of the RGB signals. Outputting a specific pattern including an area of each of RGBW colors corresponding in advance to a specific color coordinate;
Sensing luminance and color coordinates of each of the RGBW color regions; And
And a step of correcting a predetermined reference color coordinate corresponding to the reference mode of white balance in consideration of the difference between the color coordinate of the sensed W color area and the specific color coordinate, . 7. The white balance adjustment method according to claim 6,
And calculating a gain of each of the RGB colors corresponding to the specific color coordinate based on the sensing result. 7. The white balance adjustment method according to claim 6,
Further comprising the steps of: calculating a color gamut mapping coefficient based on the sensing result and performing gamut mapping using the calculated gamut mapping coefficient; Adjustment method. 7. The method according to claim 6,
And a background area for APL (Average Picture Level) measurement. Performing white balance adjustment corresponding to the first mode and the second mode;
Calculating a RGB luminance ratio corresponding to the third mode by applying a predetermined reference RGB gain corresponding to the third mode to an RGB additive mixing formula;
Calculating a gain for each of the RGB signals corresponding to the third mode based on the calculated RGB luminance ratio; And
And interpolating a white balance adjustment unit between the first mode and the second mode and the third mode. 11. The method according to claim 10, wherein the coordinate values in the horizontal axis direction of the color gamut of the third mode,
Axis coordinate values of the first mode and the second mode is a specific coordinate value between the coordinate values in the horizontal axis direction of the first mode and the second mode. 11. The method according to claim 10, wherein the coordinate value in the vertical axis direction of the color gamut of the third mode,
Wherein the predetermined coordinate value is a specific coordinate value between coordinate values in the vertical axis direction of the first and second modes. 11. The method of claim 10, wherein interpolating the white balance adjustment unit between the first and second modes and the third mode comprises:
And a white balance adjustment unit for setting the white balance adjustment unit between the first and second modes and the third mode based on the distance between the color coordinates corresponding to the first and second modes and the color coordinates corresponding to the third mode, Wherein the interpolating step comprises interpolating the white balance of the video output device. 11. The method of claim 10, wherein interpolating the white balance adjustment unit between the first and second modes and the third mode comprises:
And the gain of the RGB color corresponding to the third mode and the gain of the RGB color corresponding to the first mode and the second mode, And a step of interpolating the balance adjustment unit. A first sub-white balance adjustment step of moving the color coordinates along a first line indicating a color temperature trajectory connecting a plurality of reference color coordinates on a color area; And
And a second sub-white balance adjustment step of using color coordinates along a second line that is crossed with the first line. 16. The method of claim 15,
Wherein a line of the vertical deviation direction of the color temperature trajectory takes into account the correlated color temperature. 16. The white balance adjustment method according to claim 15,
Further comprising the step of obtaining status information from the operating state of the video output apparatus and the surrounding environment and calculating an optimal color coordinate corresponding to the obtained status information . 18. The white balance adjustment method according to claim 17,
Further comprising the step of automatically performing white balance to the calculated optimal color coordinates. ≪ RTI ID = 0.0 > 18. < / RTI > 18. The white balance adjustment method according to claim 17,
Further comprising: performing a user interfacing operation to induce white balance adjustment to the calculated recommended color coordinates. 18. The method according to claim 17,
Wherein the brightness information is obtained based on at least one of a content output from the video output device, a brightness of the surroundings, and RGB sensitivity of the surroundings.

Images