KR20110075129A - Camera having a wide dynamic range function - Google Patents

Abstract

PURPOSE: A camera with a wide dynamic range function is provided to normally perform a white balance operation which is a color signal processing process. CONSTITUTION: An image sensor unit(31) outputs an RGB signal of a long shutter speed and an RGB signal of a short shutter speed. A converting unit(32) changes signals into an YDrDb signal of the long shutter speed and an YDrDb signal of the shott shutter speed. A gain control unit(33) applies a high gain among the YDrDb signal of the long shutter speed to Y signal. A gain control unit(34) applies a low gain among the YDrDb signal of the short shutter speed to the Y signal.

Description

Camera with a wide dynamic range function

The present invention relates to a camera equipped with a wide dynamic range (WDR) function, which is performed when photographing a scene in which a high luminance subject and a low luminance subject exist simultaneously.

In general, a wide dynamic range (WDR) function, which is widely known, is used when, for example, a high luminance subject and a low luminance subject are simultaneously photographed by an image sensor of a camera, for example, filed. In a unit cycle, a long shutter speed operation for controlling the shutter speed long and a short shutter speed operation for short control are alternately performed.

A high gain is applied to the Y signal output by the long shutter speed to amplify the luminance level of the low luminance subject relatively high, and a low value is applied to the Y signal output by the short shutter speed. Gain is applied to amplify the luminance level of the high-luminance subject to a relatively low level, and then synthesize the respective output signals.

Accordingly, the luminance level of the high-luminance subject and the luminance level of the low-luminance subject are substantially the same, and then a white balance operation, which is a color signal processing process, is performed.

2 illustrates a configuration of an embodiment of a general CD camera. For example, an image sensor unit 11 and a first device may be included in a CCD camera having a wide dynamic range (WDR) function. The gain adjusting unit 12, the second gain adjusting unit 13, the combining unit 14, the white balance adjusting unit 15, the sensor driver 16, and the microcomputer 17 are configured to be included.

In addition, for example, as illustrated in FIG. 3, a mosaic pattern CDD image sensor in which Cy, Ye, G, and Mg are arranged is used as the image sensor unit 11. The CD image sensor outputs a YDrDb signal,

Y = {(G + Cy) + (Mg + Ye)} / 2 = {(G + B + G) + (R + B + R + G)} / 2 = {2B + 3G + 2R}

Dr = {(Mg + Ye)-(G + Cy)} = {2R-G}, -Db = {(G + Ye)-(Mg + Cy)} = {2B-G} do.

As a result, the image sensor unit 11 outputs the YDrDb signal by the calculation formula. In the sensor driver 16, as described above with reference to FIG. 1, the image sensor unit 11 is used. Is controlled by driving the long shutter speed and the short shutter speed, and the YDrDb signal of the long shutter speed and the YDrDb signal of the short shutter speed are input to the first gain adjusting part 12 and the second gain adjusting part 13, respectively. Be sure to

The first gain adjusting unit 12 applies a high gain to the Y signal among the YDrDb signals output by the long shutter speed to amplify the luminance level of the low luminance subject to a relatively high level, and the second gain to the second signal. The gain adjusting unit 13 applies a low gain to the Y signal among the YDrDb signals output by the short shutter speed, thereby amplifying the luminance level of the high luminance subject to be relatively low.

In addition, the synthesizing unit 14 synthesizes the YDrDb signals output through the first gain adjusting unit 12 and the second gain adjusting unit 13 as described above, and outputs the synthesized YDrDb signals to the white balance adjusting unit 15. Since the first gain adjusting unit 12 and the second gain adjusting unit 13 amplify only the Y signal among the YDrDb signals with different gain values, there is no effect on the DrDb signal, which is a color signal. Normal white balance operation can be performed.

4 illustrates a configuration of an embodiment of a general CMOS camera. For example, in a CMOS camera having a wide dynamic range (WDR) function, an image sensor 21 and a first sensor may be used. The gain adjusting unit 22, the second gain adjusting unit 23, the combining unit 24, the white balance adjusting unit 25, the sensor driver 26, and the microcomputer 27 are configured to be included.

In addition, as illustrated in FIG. 4, for example, a CMOS image sensor having a Bayer pattern in which B, G, R, and G are arranged is used. In the CMOS image sensor, an RGB signal is output, but G = (G + G) / 2, B = B, and R = R are applied.

Accordingly, the image sensor unit 21 outputs the RGB signal by the calculation formula. In the sensor driver 26, as described above with reference to FIG. 1, the image sensor unit 21 is used. Drive control by the long shutter speed and the short shutter speed, so that the RGB signal of the long shutter speed and the RGB signal of the short shutter speed are input to the first gain adjusting unit 22 and the second gain adjusting unit 23, respectively. do.

The first gain adjusting unit 22 applies a high gain to a G signal having a component close to a Y signal among the RGB signals output by the long shutter speed, thereby amplifying the level of the G signal relatively high. In the second gain adjusting unit 23, a low gain is applied to a G signal having a component close to a Y signal among the RGB signals output by the short shutter speed, thereby amplifying the level of the G signal relatively low. Let's go.

In addition, the combiner 24 synthesizes the RGB signals output through the first gain adjuster 22 and the second gain adjuster 23 as described above, and outputs the synthesized RGB signals to the white balance adjuster 25. Since the first gain adjusting unit 22 and the second gain adjusting unit 23 amplify the G signal, which is the color signal among the RGB signals, with different gain values, color distortion occurs, so that the white There is a problem that the balance operation cannot be performed normally.

For example, in a camera using a Bayer pattern CMOS image sensor, an RGB signal of a long shutter speed and an RGB signal of a short shutter speed, The present invention provides a camera having a wide dynamic range function that converts a long shutter speed YDrDb signal and a short shutter speed YDrDb signal, and applies different gain values only to the respective Y signals.

A camera having a wide dynamic range function according to the present invention includes an image sensor unit for outputting a long shutter speed RGB signal and a short shutter speed RGB signal; A conversion unit for converting the long shutter speed RGB signal and the short shutter speed RGB signal into a long shutter speed YDrDb signal and a short shutter speed YDrDb signal, respectively; A gain adjusting unit applying a high gain to a Y signal among the YDrDb signals of the long shutter speed and a low gain to a Y signal of the YDrDb signals of the short shutter speed; A synthesis unit for synthesizing the output signals amplified by the gain control unit, respectively; And a white balance adjusting unit for adjusting white balance of the synthesized output signal.

In addition, the image sensor unit, characterized in that the Bayer pattern CMOS image sensor is used,

The converting unit converts the RGB signal into a YDrDb signal, and applies a calculation formula of Y = 0.299 × R + 0.587 × G + 0.114 × B, Dr = (RY) / Y, and Db = (BY) / Y. Characterized in that.

A camera equipped with a wide dynamic range function according to the present invention is, for example, in a camera using a Bayer pattern CMOS image sensor, an RGB signal of a long shutter speed and a short shutter ( Short Shutter) converts the RGB signal of the long shutter speed into a YDrDb signal of the long shutter speed and a YDrDb signal of the short shutter speed, and then performs a wide dynamic range function to apply different gain values to the respective Y signals. By applying different gain values only to the Y signal irrespective of the color signals Dr and Db, the distortion of the color signals Dr and Db can be prevented in advance, thereby performing the white balance operation, which is a color signal processing process. You can do it normally.

Hereinafter, a preferred embodiment of a camera equipped with a wide dynamic range function according to the present invention will be described in detail with reference to the accompanying drawings.

In the camera equipped with the wide dynamic range function according to the present invention, for example, as illustrated in FIG. 6, the image sensor unit 31, the YDrDb converter 32, the first gain adjuster 33, and the first gain adjuster 33 are provided. The two gain adjusting unit 34, the combining unit 35, the white balance adjusting unit 36, the sensor driver 37, and the microcomputer 38 are configured to be included.

In addition, as illustrated in FIG. 7, for example, a CMOS image sensor having a Bayer pattern in which B, G, R, and G are arranged is used. In the CMOS image sensor, an RGB signal is output, but G = (G + G) / 2, B = B, and R = R are applied.

In the YDrDb converter 32, for example, as shown in Fig. 7, the RGB signal is converted into a YDrDb signal, but Y = 0.299 × R + 0.587 × G + 0.114 × B, Dr = ( RY) / Y and Db = (BY) / Y are applied.

Accordingly, the image sensor unit 31 outputs an RGB signal, and the YDrDb converter 32 converts and outputs the RGB signal into a YDrDb signal. As described above with reference to 1, the image sensor unit 31 is driven and controlled by the long shutter speed and the short shutter speed, so that the RGB signal of the long shutter speed and the RGB signal of the short shutter speed are converted into the YDrDb conversion unit ( 32).

The YDrDb converter 32 converts the RGB signal of the long shutter speed and the RGB signal of the short shutter speed into YDrDb signals of the long shutter speed and YDrDb signal of the short shutter speed, respectively. Input to the gain control unit 33 and the second gain control unit 34, respectively.

On the other hand, the first gain control unit 33, by applying a high gain to the Y signal of the YDrDb signal of the long shutter speed, to amplify the luminance level of the low-luminance subject relatively high, the second gain control unit In 34, a low gain is applied to the Y signal among the YDrDb signals of the short shutter speed, thereby amplifying the luminance level of the high luminance subject relatively low.

In addition, the synthesizing unit 35 synthesizes the YDrDb signals output through the first gain adjusting unit 33 and the second gain adjusting unit 34 as described above, and outputs the synthesized YDrDb signals to the white balance adjusting unit 36. Since the first gain adjusting unit 33 and the second gain adjusting unit 34 amplify only the Y signal among the YDrDb signals with different gain values, there is no effect on the DrDb signal, which is a color signal. The white balance operation, which is a color signal processing process, can be normally performed.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. , Alteration, substitution, addition, or the like.

1 is a diagram for explaining a general wide dynamic range (WDR) operation,

2 shows a configuration of an embodiment of a typical CD camera,

3 illustrates an embodiment of a YDrDb signal output by a CD image sensor of a general mosaic pattern.

4 shows a configuration of an embodiment of a general CMOS camera,

FIG. 5 illustrates an embodiment of an RGB signal output by a CMOS image sensor of a general Bayer pattern.

6 illustrates a configuration of a camera equipped with a wide dynamic range function according to the present invention.

FIG. 7 illustrates an embodiment in which an RGB signal output by a Bayer pattern CMOS image sensor is converted into a YDrDb signal according to the present invention.

[Description of Drawings]

31: image sensor unit 32: YDrDb conversion unit

33,34: gain control unit 35: synthesis unit

36: white balance adjustment unit 37: sensor drive unit

38: micom

Claims (3)

An image sensor unit for outputting a long shutter speed RGB signal and a short shutter speed RGB signal; A conversion unit for converting the long shutter speed RGB signal and the short shutter speed RGB signal into a long shutter speed YDrDb signal and a short shutter speed YDrDb signal, respectively; A gain adjusting unit applying a high gain to a Y signal among the YDrDb signals of the long shutter speed and a low gain to a Y signal of the YDrDb signals of the short shutter speed; A synthesis unit for synthesizing the output signals amplified by the gain control unit, respectively; And a white balance adjustment unit for adjusting the white balance of the synthesized output signal. The method of claim 1, The image sensor unit is a camera having a wide dynamic range function, characterized in that the Bayer pattern CMOS image sensor is used. The method of claim 1, The conversion unit converts the RGB signal into a YDrDb signal, A camera with a wide dynamic range function characterized by applying the formulas Y = 0.299 × R + 0.587 × G + 0.114 × B, Dr = (R-Y) / Y, and Db = (B-Y) / Y.

Images