KR20120072476A - Apparatus and method for providing image - Google Patents

Abstract

PURPOSE: An image providing device and a method thereof are provided to effectively increase picture quality based on histogram equalization. CONSTITUTION: A histogram generating unit(110) generates a histogram about an input image. A histogram correcting unit(120) increases and decreases a histogram value of the input image. A pixel conversion function producing unit(140) produces a pixel conversion function by equalizing the histogram corrected by the histogram correcting unit. An output image generating unit(145) generates an output image from an input image based on the pixel conversion function. The pixel conversion function producing unit minimizes a power consumption amount of a display device which outputs the output image based on the pixel conversion function.

Description

Image providing device and method thereof {APPARATUS AND METHOD FOR PROVIDING IMAGE}

The present invention relates to an image providing apparatus and a method thereof.

Recently, mobile devices such as mobile phones have become possible to shoot high resolution video. However, since image quality is low due to poor lighting and photographing apparatus, a method of increasing contrast is used to improve low quality image. In particular, histogram equalization is one of the representative histogram correction techniques, and has been used as a representative image quality improvement technique due to its simple implementation and strong contrast ratio improvement.

Histogram equalization improves image quality by transforming a histogram biased into a specific portion to have a uniform distribution. In addition, the data is not added to improve the original image, but the shape of the histogram is analyzed to expand the histogram so that the distribution exists over a wider area where the brightness distribution is biased into a specific portion.

However, the histogram equalization technique causes severe deformation in pixels with a large number of histograms, resulting in loss of atmosphere and contour effects, and noise increase in dark screens.

On the other hand, in view of the power consumed by the display, a low power image providing method is very important and various studies have been made. In other words, considering that the amount of power consumed by the display is very large compared to other components, it is very important to reduce the power consumption of the display.

Recently, self-luminous displays such as OLEDs (Organic Light Emitting Diodes) and Plasma Display Panels (PDPs) have been spotlighted as next-generation displays to replace LCDs due to their excellent color reproducibility, wide viewing angle, and fast response speed. Unlike LCDs, self-luminous displays have advantages in terms of signal processing by self-emitting in units of individual pixels (ie, pixels) without backlight.

However, the existing image providing methods are mostly related to the TFT-LCD, and the image quality improvement method for the self-luminous display is insignificant. That is, the conventional display low power scheme is mainly specialized for LCD, and the hardware approach such as optimized circuit configuration is mainly used.

Accordingly, there is a need to effectively improve image quality based on histogram equalization and to minimize power consumption by using characteristics of a self-luminous display.

One object of the present invention is to provide an image providing apparatus and method for effectively improving image quality based on histogram equalization and minimizing power consumption using characteristics of a self-luminous display.

As a technical means for achieving the above technical problem, the image providing apparatus according to an embodiment of the present invention, the histogram generator for generating a histogram for the input image, the histogram correction unit for increasing or decreasing the histogram value of the input image, the number of histograms A pixel conversion function calculation unit for calculating a pixel conversion function through equalization of the histogram modified by the government, and an output image generation unit for generating an output image from the input image based on the pixel conversion function, wherein the pixel conversion function calculating unit The power consumption of the display device to which the output image is output is minimized based on the function.

In addition, the image providing method according to an embodiment of the present invention comprises the steps of (a) generating a histogram of the input image, (b) modifying the histogram value of the input image, (c) pixel conversion through equalization of the modified histogram Calculating a function; and (d) generating an output image from the input image based on the pixel conversion function, wherein step (c) includes power consumption of the display device outputting the output image based on the pixel conversion function. Try to be minimal.

According to any one of the above-described means for solving the problems of the present invention, it is possible to effectively improve the image quality based on histogram equalization, and to minimize the power consumption by using the characteristics of the self-luminous display.

In addition, according to any one of the above problem solving means of the present invention, by reducing the histogram value of the pixel region protruding beyond the reference value among the histogram values of the input image, when the image quality improvement based on histogram equalization To solve the conventional problem that the brightness of the excessively changed, the noise increase and the atmosphere disappears of the original image.

In addition, according to any one of the problem solving means of the present invention described above, it is possible to easily adjust the magnitude of the power consumption and contrast ratio through the parameter value.

)가 5일 때 저전력 알고리즘을 적용한 결과를 도시한다.1 is a block diagram of a video quality conversion device that is commonly used.
2 is a block diagram of an image providing apparatus according to an exemplary embodiment.
3 is a flowchart illustrating an image providing method according to an embodiment of the present invention.
4 illustrates a modified histogram and an equalized pixel conversion function according to an embodiment of the present invention.
5 is a diagram illustrating control parameters for histogram correction according to an embodiment of the present invention.

Shows the result of applying the low power algorithm when 5).

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between . In addition, when a part is said to "include" a certain component, which means that it may further include other components, except to exclude other components unless otherwise stated.

1 is a block diagram of a video quality conversion device that is commonly used.

As illustrated in FIG. 1, the apparatus 101 for converting image quality includes a histogram generator 110, a cumulative distribution function calculator 112, and a transform function calculator 114.

)은 확률밀도함수(

)로 나타낼 수 있으며, 확률밀도함수(

)는 입력영상의 히스토그램(

)을 전체 픽셀수로 나누어 얻어질 수 있다. 확률밀도함수(

)는 하기 수학식 1과 같이 정의될 수 있다.The histogram generator 110 generates a histogram of the input image (data). Here, the histogram of the input image (

) Is the probability density function (

) And the probability density function (

) Shows the histogram (

) Can be obtained by dividing) by the total number of pixels. Probability density function (

) May be defined as in Equation 1 below.

[Equation 1]

)은 명암도 즉, 밝기의 세기(

)를 가진 픽셀의 수를 나타낸다. 또한, 1은 행(column) 벡터를 나타내고, 해당 모든 요소들은 1값을 나타낸다.

(Transpose)는 전치 행렬을 만드는 연산자이다.here, First histogram (

) Is the intensity or brightness intensity (

Indicates the number of pixels with In addition, 1 represents a column vector and all corresponding elements represent 1 value.

(Transpose) is an operator that creates a transpose matrix.

)를 차례로 더하여 생성된 명암도(

)의 누적분포함수(

)는 하기 수학식 2와 같이 정의될 수 있다.The cumulative distribution function calculating unit 112 calculates a cumulative distribution function for the histogram of the input image. Here, the cumulative distribution function calculating unit 112 may calculate a normalized cumulative distribution from the brightness distribution of the input image. That is, the probability density function of Equation 1

), Followed by a contrast

Cumulative distribution function of)

) May be defined as in Equation 2 below.

[Equation 2]

The conversion function calculator 114 generates a pixel conversion function that readjusts the dynamic range of each intensity of the input image (or the original image). That is, the pixel conversion function is generated by multiplying the cumulative distribution function by the maximum intensity, and an output image having a high contrast ratio can be obtained by converting each input pixel of the input image into an output pixel.

In this way, the dynamic range of the contrast values of the input image is readjusted through the pixel conversion function, and the pixel conversion function may be defined as in Equation 3 below.

&Quot; (3) "

는 최대 명암도를 나타내고, 예컨대 8비트 영상에서는 255값을 나타낸다. 그리고, 화소 변환 함수(

)를 차분 행렬(

)을 이용하여 벡터로 나타내면, 하기 수학식 4와 같이 정의할 수 있다.here,

Denotes the maximum contrast, for example, 255 in an 8-bit image. And the pixel conversion function (

) Is the difference matrix (

When expressed as a vector using), it can be defined as Equation 4 below.

&Quot; (4) "

)은

로 정의될 수 있다.Where the difference matrix (

)silver

It can be defined as.

)의 열 벡터(

)는 하기 수학식 5와 같이 정의될 수 있다.Then, the histogram (

Column vector of

) May be defined as in Equation 5 below.

[Equation 5]

In the histogram equalization method described above, the pixel conversion function causes a steep gradient change when the histogram bin has a large value. Due to this phenomenon, the brightness of the image may be excessively changed, and problems such as an increase in noise and an atmosphere loss of the original image may occur.

Therefore, the image providing apparatus 100 to be described later may improve image quality more effectively and reduce power consumption. In this case, the image providing apparatus 100 may include components of the image quality converting apparatus 101 in another embodiment. Hereinafter, it will be described in more detail with reference to FIG.

2 is a block diagram of an image providing apparatus according to an exemplary embodiment.

As shown in FIG. 2, the image providing apparatus 100 according to an exemplary embodiment of the present invention may include a histogram generator 110, a histogram corrector 120, a power consumption calculator 130, and a pixel conversion function calculator 140. The output image generator 145 and the storage 150 are included. The image providing apparatus 100 may effectively improve image quality by using histogram equalization and minimize power consumption by using characteristics of a self-luminous display such as OLED and PDP. The image providing device 100 may be implemented as a self-luminous display.

The histogram generator 110 generates a histogram of the input image as described with reference to FIG. 1.

The histogram correction unit 120 increases or decreases the histogram value of the input image. For example, the histogram correction unit 120 may reduce a large value of the histogram bin of the pixel region protruding beyond the reference value among the histogram values of the input image based on the log-based function, or may reduce the small value of the histogram bin below the reference value. You can increase the value. Here, in another embodiment, the histogram correction unit 120 may be configured in the above-described elements of FIG. 1 and used to increase or decrease the histogram value of the input image.

This can solve the conventional problems of excessive brightness, image noise, and loss of atmosphere of the original image when performing image enhancement based on histogram equalization.

)을 수정된 히스토그램 값(

)으로 변환한다.Specifically, the histogram correction unit 120 uses the log function of Equation 6 below to determine the histogram value of the input image (

) Is a modified histogram value (

To).

&Quot; (6) "

는 입력영상의 히스토그램(

) 내에 존재하는 최대 요소(maximum element)를 나타내고, 1값은 로그함수가 음의 값을 가지는 것을 방지하는 값이고,

는 히스토그램 수정 레벨을 조절하는 제어 파라미터이다. 여기서,

값이 커질수록 명암비는 증가하고

값이 작을수록 명암비는 감소한다. 즉,

값을 크게 하면,

가

에 선형적으로 비례하고, 히스토그램은 덜 강하게 수정된다. 반대로

값을 작게 하면,

가

에 관계없이 수정된 히스토그램을 일정하게 하는 상수가 된다.here,

Is the histogram of the input image (

) Represents the maximum element existing in (), and a value of 1 is a value that prevents the logarithm function from having a negative value.

Is a control parameter that adjusts the histogram correction level. here,

As the value increases, the contrast ratio increases.

The smaller the value, the lower the contrast ratio. In other words,

If you increase the value,

end

Linearly proportional to, the histogram is modified less strongly. Contrary

If you decrease the value,

end

Irrespective of this, it is a constant that makes the modified histogram constant.

이 상술한 수정된 히스토그램을 나타낸다고 정의하면, 원본 영상의 히스토리그램(

)대신 수정된 히스토그램(

)에 의해 히스토그램 처리 절차가 수행될 수 있다. 보다 상세히 설명하면, 상술한 수학식 4 및 수학식 5는 하기 수학식 7과 같이 정의되는 수정된 히스토그램에 의해 수행될 수 있다. And,

If it is defined that this modified histogram represents the histogram of the original image (

Modified histogram (

Can be performed by the histogram processing procedure. In more detail, the above-described Equations 4 and 5 may be performed by a modified histogram defined as Equation 7 below.

[Equation 7]

은 수정된 히스토그램의 합이 최대 밝기 값인 255가 되도록 하는 정규화된 벡터로서 하기 수학식 8과 같이 정의될 수 있다. here,

Is a normalized vector such that the sum of the modified histograms is 255, the maximum brightness value, and may be defined as in Equation 8 below.

[Equation 8]

)를 이용하여 수학식 7을 계산하고 이를 기초로 후술될 화소 변환 함수 산출부(140)를 통해 히스토그램 균등화가 수행될 수 있다. 이때,

을 최소화시켜 명암비를 증가시킴으로써 히스토그램 균등화를 수행할 수 있다. Then, the difference matrix (

The histogram equalization may be performed using the pixel conversion function calculation unit 140, which will be described later, using Equation (7). At this time,

Histogram equalization can be performed by minimizing the ratio to increase the contrast ratio.

Meanwhile, the embodiment of the present invention may not only improve image quality by using histogram equalization, but also reduce power consumption.

The power consumption calculator 130 calculates a power consumption calculation function (TDP) for calculating the power consumption of the display (device) for outputting the output image generated by the output image generator 145, which will be described later. In this case, the power consumed by one pixel in the power consumption of the self-emission display (eg, OLED) is proportional to the power of γ used for gamma correction, and may be defined as in Equation 9 below.

[Equation 9]

는 입력 화소에 독립적으로 디스플레이를 구동하기 위해 소모되는 전력이며,

,

,

는 RGB 각각의 채널을 표현할 때의 전력 소모 비율이다. 각각의 RGB 채널은 실험적으로 지수 γ에 비례한다. here,

Is the power consumed to drive the display independently of the input pixels,

,

,

Is the power consumption ratio when expressing each channel of RGB. Each RGB channel is experimentally proportional to the index γ.

는 입력영상의 화소와 무관한 요소이고, 정전력(static power) 소모에 있어서 무시할 수 있는 값이다. 또한, 보통의 디스플레이에서 감마는 2값으로 근사될 수 있다. 그리고, 칼러 영상을 표현하기 위한 전체 전력 소모(TDP,Total Dissipated Power)는 하기 수학식 10과 같이 정의될 수 있다.In this case, γ has a characteristic almost identical to the value used in gamma correction,

Is an element that is independent of the pixel of the input image, and is a negligible value in the static power consumption. In addition, gamma can be approximated to two values in a normal display. The total power dissipation power (TDP) for expressing the color image may be defined as in Equation 10 below.

&Quot; (10) "

은 영상에서 픽셀의 수를 나타내고,

는

번째 RGB 칼러 벡터를 나타낸다.here,

Represents the number of pixels in the image,

Is

The first RGB color vector.

In addition, considering that the general image processing processes only the YUV color space, in particular, the Y element that is sensitive to human vision, instead of the RGB color space, the total power consumption expressed in the self-emission display may be modeled as in Equation 11 below. have.

&Quot; (11) "

은

번째 픽셀의 휘도를 나타낸다.here,

silver

It represents the luminance of the first pixel.

)과 화소 변환 함수(

)를 이용하여 자체 발광형 디스플레이의 전체 소모량을 나타내면 수학식 11은 하기 수학식 12와 같이 정의될 수 있다.Then, the histogram (

) And pixel conversion functions (

When the total consumption of the self-emissive display is represented using Equation 11, Equation 11 may be defined as Equation 12 below.

[Equation 12]

가 된다. 여기서 전력 소모를 줄이기 위해서는

를 감소시키면 된다.That is, since the power consumption of the image displayed on the self-emissive display is the sum of the power consumed by each pixel, it is represented by the histogram diagonal matrix and the output pixel vector.

Becomes In order to reduce power consumption here

Reduce the

)를 산출한다. The pixel conversion function calculator 140 may convert the pixel conversion function (eg, the equalization of the histogram modified by the histogram correction unit 120).

) Is calculated.

In addition, the pixel conversion function calculator 140 minimizes the power consumption of the display on which the output image is output based on the pixel conversion function. Here, the pixel conversion function calculator 140 may maximize the contrast ratio of the input image and reduce power consumption by using the self-emissive display characteristics.

을 최소화시켜 명암비를 최대화시키고, 상기 수학식 12에서

를 최소화시켜 전력 소모를 감소시킬 수 있다. 이를 위해, 화소 변환 함수 산출부(140)는 라그랑지안(Lagrangian) 승수법을 이용하여 하기 수학식 13의

이 최소값이 되도록 한다. More specifically, in Equation 7

To maximize the contrast ratio, and

By minimizing the power consumption can be reduced. To this end, the pixel conversion function calculation unit 140 uses the Lagrangian multiplier to perform the following equation (13).

Let this be the minimum value.

[Equation 13]

)는

로 정의될 수 있다. 그리고, 화소 변환 함수(

)의 마지막 요소

는 전력 소모량 감소 인자(

)로 인해 255보다 적을 수 있다. 이때 출력영상의 동적 범위의 감소를 줄이기 위해

=255의 조건을 기초로

와

을 수정함으로써

함수에 추가한다. 보다 구체적으로 설명하면, 차분 행렬

에 [0, 0, …, 0, 1] 열을 추가한 증강행렬

와

에 255 요소를 더 추가한

를 적용하면,

는 이하 수학식 14와 같이 정의된다.Where the contrast ratio maximization factor (

)

It can be defined as. And the pixel conversion function (

) Last element

Is the power consumption reduction factor (

) May be less than 255. At this time, to reduce the reduction of the dynamic range of the output image

Based on a condition of = 255

Wow

By modifying

To the function. More specifically, the difference matrix

On [0, 0,... , 0, 1] Augmented Matrix with added columns

Wow

Add more 255 elements to the

If you apply

Is defined as in Equation 14 below.

[Equation 14]

를 0로 셋팅하여 수학식 14를 계산하면, 하기 수학식 15의 벡터식으로 정의된다.

To calculate the equation (14) by setting to 0, it is defined as a vector equation of the following equation (15).

[Equation 15]

는 전력 감소 및 명암비 조절을 수행하는 제어 파라미터로서, 제한된 조건 안에서 두 가지 효과의 나타내도록 한다. 즉,

가 0 값이면 전력 소모량이 고려되지 않은 명암비 증가만 반영된 화소 변환 함수(

)를 얻게 된다. 그리고,

를 증가시키면 전력 소모량이 고려된 화소 변환 함수를 얻게 되고, 적은 수의 픽셀들이 출력영상에서 큰 명암도 값에 할당된다.

은 수정된 히스토그램의 합이 최대 밝기 값인 255가 되도록 하는 정규화된 벡터를 의미한다. here,

Is a control parameter for performing power reduction and contrast ratio adjustment, and exhibits two effects within limited conditions. In other words,

Is a value of 0, the pixel conversion function reflects only the increase in contrast ratio without considering power consumption.

) And,

Increasing the results in the pixel conversion function considering the power consumption, and a small number of pixels are assigned to a large intensity value in the output image.

Means a normalized vector such that the sum of the modified histograms is the maximum brightness value of 255.

)의 최대값도 역시 최대 밝기 값 255가 되도록 만들어 주기 위해서, 차분 행렬

에 [0, 0, …, 0, 1] 열을 추가한 증강행렬

와

에 255 요소를 더 추가한 벡터

를 적용하여 계산하면, 원하는 0<

<255인 화소변환벡터를 얻을 수 있다.In addition, as described above, the pixel conversion function (

), So that the maximum value is also the maximum brightness value of 255, the difference matrix

On [0, 0,... , 0, 1] Augmented Matrix with added columns

Wow

A vector with 255 more elements added to it

Calculate by applying the desired 0 <

A pixel conversion vector of <255 can be obtained.

)는 매우 작은 값으로서 조절하기 어려우므로 입력 화소의 합을 곱한 값인

로 대체할 수 있다. 이때,

는 하기 수학식 16으로 정의될 수 있다. Then, the parameter (

) Is a very small value that is difficult to control, so the product of the sum of the input pixels

Can be replaced with At this time,

May be defined by Equation 16 below.

[Equation 16]

는 입력영상에서

번째 픽셀의 휘도를 나타낸다. 따라서,

대신

를 제어 파라미터로 이용할 수 있다. here,

In the input image

It represents the luminance of the first pixel. therefore,

instead

Can be used as a control parameter.

)에 기초하여 입력영상으로부터 출력영상을 생성한다.The output image generator 145 performs the pixel conversion function (

Generate an output image from the input image.

The storage unit 150 stores algorithms for providing a low power high contrast image. For example, an algorithm for increasing or decreasing the histogram value of the input image and converting the histogram value into a modified histogram value and an algorithm for calculating the amount of power consumed to drive the display outputting the input image may be stored. In addition, the storage unit 150 may store various setting values, programs, necessary functions and variable definitions, etc. in order to carry out the present invention.

)를 조종하여 저전력의 정도를 자유자재로 변화시킬 수 있다. 특히, 밝은 영상은 더 많은 전력을 소모하므로 화질 혹은 명암비를 유지한 상태로 많은 전력 소모를 줄일 수 있다. 또 경우에 따라서는 원본 영상보다 전력 소모는 적으면서 화질을 높일 수도 있다.By converting the image using the above-described process, the display device can reduce power consumption while maintaining the maximum contrast ratio of the image. In addition, control parameters (

), You can freely change the degree of low power. In particular, bright images consume more power, which can reduce power consumption while maintaining image quality or contrast ratio. In some cases, the image quality may be improved while using less power than the original image.

3 is a flowchart illustrating an image providing method according to an embodiment of the present invention.

First, a histogram of an input image is generated (S301).

Next, the histogram value of the input image is corrected (S311). That is, the histogram value of the pixel area protruding beyond the reference value among the histogram values of the input image may be corrected based on the log-based function. See Equation 6 above.

Next, a pixel conversion function for minimizing the power consumption of the display is calculated through equalization of the modified histogram (S321). For this, refer to Equations 13 to 16 described above.

In operation S331, an output image is generated from the input image based on the pixel conversion function.

4 illustrates a modified histogram and an equalized pixel conversion function according to an embodiment of the present invention.

)의 값이 7, 5, 2 순으로 작아짐에 따라 변동이 줄어드는 것을 알 수 있는 데 이는 명암비가 감소함을 나타낸다. 그리고 제어 파라미터(

)의 값이 작아질수록 입력영상의 히스토그램은 더 크게 수정됨을 알 수 있다.4A illustrates a histogram of an input image and a histogram modified using the above-described equation (6). Where control parameters (

As the value of) decreases in the order of 7, 5, and 2, the variation decreases, indicating that the contrast ratio decreases. And control parameters (

As the value of) decreases, the histogram of the input image is modified to be larger.

)의 값이 작아지면서 입력영상과 동일한 출력영상을 만드는 화소 변환 함수로 바뀌는 것을 알 수 있다.4B illustrates a pixel conversion function obtained by equalizing the correction histogram. Control parameters (

As the value of) decreases, it turns into a pixel conversion function that produces the same output image as the input image.

)가 5일 때 저전력 알고리즘을 적용한 결과를 도시한다.5 is a diagram illustrating control parameters for histogram correction according to an embodiment of the present invention.

Shows the result of applying the low power algorithm when 5).

)가 0이면, 상기 도 4의 (b)에서 제어 파라미터(

)가 5일 경우와 동일하게 된다. 여기서, 제어 파라미터(

) 값이 커질수록 그래프가 아래로 내려가며 출력 화소가 입력 화소보다 낮은 값을 가져 영상이 어두워진다. 결과적으로 얻어지는 영상은 낮은 전력 소모를 보이게 된다.As shown in Figure 5, the power consumption related control parameters (

) Is 0, the control parameter (

Is the same as when 5. Where control parameters (

As the value increases, the graph goes down and the output pixel gets lower than the input pixel, resulting in darker image. The resulting image shows low power consumption.

Each component illustrated in FIGS. 1 and 2 may be configured as a kind of 'module'. The term 'module' refers to a hardware component such as software or a Field Programmable Gate Array (FPGA) or an Application Specific Integrated Circuit (ASIC), and the module performs certain roles. However, a module is not limited to software or hardware. A module may be configured to reside on an addressable storage medium and may be configured to execute one or more processors. The functionality provided by the components and modules may be combined into a smaller number of components and modules or further separated into additional components and modules.

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is shown by the following claims rather than the above description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

110: histogram generator
120: histogram correction
130: power consumption calculator
140: pixel conversion function calculation unit
145: output image generation unit
150: storage unit

Claims (13)

In the image providing device,
A histogram generator for generating a histogram for the input image;
A histogram correction unit for increasing or decreasing a histogram value of the input image,
A pixel conversion function calculator for calculating a pixel conversion function through equalization of the histogram modified by the histogram correction unit;
An output image generation unit for generating an output image from the input image based on the pixel conversion function,
The pixel conversion function calculation unit is configured to minimize the power consumption of the display device outputting the output image based on the pixel conversion function.
Image providing device.
The method of claim 1,
The histogram correction unit
The image providing apparatus of claim 1, wherein the histogram value of the pixel area protruding above the reference value from the histogram value of the input image is decreased or the histogram value below the reference value is increased.

The method of claim 1,
The histogram correction unit
And a histogram value of the input image is increased or decreased based on a log-based function, and the histogram value of the input image is increased or decreased based on Equation 1 below.
<Equation 1>

In Equation 1,

Is the histogram of the input image (

) Represents the maximum element existing in (), and a value of 1 is a value that prevents the logarithm function from having a negative value.

Indicates the parameter that adjusts the histogram correction level.

As the value increases, the contrast increases.

The smaller the value, the lower the contrast ratio.
The method of claim 1,
And a power consumption calculator configured to calculate power consumption of the display device based on the sum of power consumed by each pixel of the output image output to the display device.
The method of claim 1,
The pixel conversion function calculation unit
Function result value of the following equation (2)

) To minimize the power consumption.
&Quot; (2) &quot;

In Equation 2, the contrast ratio maximization factor (

)of

Represents the difference matrix,

Is a normalized vector such that the sum of histogram values of the modified input image is the maximum brightness value, and a power consumption reduction factor (

Parameter to ()

) Is a parameter to adjust the power consumption and contrast ratio.

Is the histogram (

) And pixel conversion functions (

The power consumption is represented by the histogram diagonal matrix and the output pixel vector.
The method of claim 5, wherein
The pixel conversion function calculation unit
The parameter calculated on the sum of input pixels representing the luminance of each pixel in the input image;

Control parameter defined by

The image providing device to adjust the power consumption by using a).
A self-luminous display having an image providing device according to any one of claims 1 to 6.
In the image providing method using an image providing device,
(a) generating a histogram of the input image;
(b) modifying a histogram value of the input image;
(c) calculating a pixel conversion function through equalization of the modified histogram, and
(d) generating an output image from the input image based on the pixel conversion function;
In step (c),
The power consumption of the display device outputting the output image is minimized based on the pixel conversion function.
How to provide video.
The method of claim 8,
Step (b) is
And reducing the histogram value of the pixel area protruding beyond the reference value among the histogram values of the input image or increasing the histogram value below the reference value.
The method of claim 8,
Step (b) is
The histogram value of the input image is modified based on a log-based function, and the histogram value of the input image is modified based on Equation 1 below.
<Equation 1>

In Equation 1,

Is the histogram of the input image (

) Represents the maximum element existing in (), and a value of 1 is a value that prevents the logarithm function from having a negative value.

Indicates the parameter that adjusts the histogram correction level.

As the value increases, the contrast ratio increases.

The smaller the value, the lower the contrast ratio.
The method of claim 8,
In step (c),
And calculating power consumption of the display device based on a sum of power consumed by each pixel of the output image output to the display device.
The method of claim 8,
The step (c)
Function result value of the following equation (2)

) To be the minimum value, thereby minimizing the power consumption.
&Quot; (2) &quot;

In Equation 2, the contrast ratio maximization factor (

)of

Represents the difference matrix,

Is a normalized vector such that the sum of histogram values of the modified input image is the maximum brightness value, and a power consumption reduction factor (

Parameter to ()

) Is a parameter to adjust the power consumption and contrast ratio.

Is the histogram (

) And pixel conversion functions (

The power consumption is represented by the histogram diagonal matrix and the output pixel vector.
The method of claim 8,
The step (c)
The parameter calculated on the sum of input pixels representing the luminance of each pixel in the input image;

Control parameter defined by

) To adjust the power consumption.

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