KR100671152B1 - Video recorder having a function of self-controlling the recording condition - Google Patents

Abstract

The present invention relates to an image storage device, and more particularly, to an image storage device capable of efficiently reducing a storage space of image data by self-controlling a storage condition of image data. The present invention includes a setting unit for receiving and storing a storage condition determined according to the luminance value; A luminance value calculator for calculating a current luminance value of the image data from the obtained image data; A storage condition determining unit determining a storage condition corresponding to the current luminance value calculated by the luminance value calculating unit as a current storage condition according to the corresponding relationship set in the setting unit; And a storage unit for storing the image data under the current storage condition determined by the storage condition determining unit.

Description

VIDEO RECORDER HAVING A FUNCTION OF SELF-CONTROLLING THE RECORDING CONDITION}

1 is a view showing a change in the size of the image data stored in the day and night time zone of the conventional DVR.

2 is a view showing a setting menu of another conventional DVR.

3A is a diagram illustrating a threshold setting menu provided by a setting unit of a DVR according to an embodiment of the present invention.

FIG. 3B is a diagram illustrating a threshold setting process performed through the threshold setting menu of FIG. 3A.

3C is a view for explaining a process of setting a storage condition according to a luminance value made in a setting unit of a DVR according to an embodiment of the present invention.

FIG. 4A is a diagram for describing a process of obtaining an average value of luminance values of image data in YUV format by the luminance value calculator of the DVR according to an embodiment of the present invention.

4B is a diagram for describing a process of obtaining an average value of luminance values of image data in an RGB format by the luminance value calculator of a DVR according to an embodiment of the present invention.

FIG. 5 is a diagram schematically illustrating an overall flow of self-controlling a storage condition of image data in a DVR according to an embodiment of the present invention.

The present invention relates to an image storage device, and more particularly, to an image storage device capable of efficiently reducing a storage space of image data by self-controlling a storage condition of image data.

In the current CCTV configuration, video recording is mostly occupied by DVR (Digital Video Recorder), and one of the most important points of DVR performance is how much video can be recorded with a certain hard disk capacity. It is.

The CCTV cameras that make up the system together with the DVR use a device called CCD, which improves the sensitivity of low-light cities by amplifying the gain within the camera up to about 38db (about 79x) as the ambient illumination decreases. However, the increase in the gain inside the camera consequently increases the noise.

The DVR uses a compression tool such as MJPEG or MPEG to compress the video, and such a codec has a greatly increased video noise component at night as the compressed video size depends on the amount of motion in the acquired video. This results in a relatively large image size recorded on the DVR in low light conditions.

1 is a view showing a change in the size of the image data stored in the day and night time zone of the conventional DVR.

As shown in the case of AGC (Automatic Gain Control) On, based on a CCTV camera using a 1/4 "CCD, the amount of recording in the night time zone is increased by about 4 times compared to the daytime time. Field is the normal camera setting that amplifies the gain when the illuminance is lowered.

That is, at night time, the capacity of the hard disk is unnecessarily consumed despite the loss of the subject discrimination ability by DVR recording due to deterioration of the illumination condition.

Compared to the state in which the gain of the camera is turned off from the normal camera operating method, it can be seen that the recording amount in the night time zone is slightly reduced compared to the day time in AGC Off. This is because the night time zone is relatively less moving than the day time zone.

2 is a view showing a setting menu of another conventional DVR.

In order to solve the above problems, a DVR has been proposed to distinguish images of day time zones and night time zones and to store images by different storage conditions of day time zones and night time zones.

The DVR converts analog video into digital video and delivers the video captured through the PCI bus inside the computer. The DVR displays the digital video signal acquired through the video capture board on the monitor and stores it on the hard disk. It can be divided into two parts of dedicated software that plays a role.

The video capture board is controlled through a dedicated capture board driver. The controllable items are represented by a video format of an image source, an output format of a digital image, and an output resolution of a digital image.

In addition, the items that can be controlled through the DVR-dedicated software include the storage speed per second and the degree (quality) of the video compression.

Therefore, the user can directly designate the daytime time zone with insufficient illumination and the nighttime zone with insufficient illumination through the setting menu as shown in FIG. 2, and the storage conditions for each day and night time zone, for example, the number of images to be stored per second (FrameRate). ), The quality of the compressed video, the resolution of the compressed video, etc., respectively, and then save the video data at the recording resolution, the number of frames, and the recording quality for the current time zone immediately before saving to the hard disk. To do the job.

However, the DVR of FIG. 2 does not sufficiently reflect the change in illumination according to the change of seasons and weather, and also has no limitation in efficiency because it cannot reflect the ambient illumination conditions of the DVR installation place at all.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to change the storage condition of image data by itself in response to a luminance value, thereby making it possible to reduce the storage capacity of a hard disk very efficiently. The purpose is to provide

In order to achieve the above object, the present invention, a setting unit for receiving and storing a storage condition determined according to the luminance value; A luminance value calculator for calculating a current luminance value of the image data from the obtained image data; A storage condition determining unit determining a storage condition corresponding to the current luminance value calculated by the luminance value calculating unit as a current storage condition according to the corresponding relationship set in the setting unit; And a storage unit for storing the image data under the current storage condition determined by the storage condition determining unit.

Preferably, the luminance value calculator calculates an average value of luminance values of each pixel of the image data and calculates the value as a current luminance value.

Here, when the starting address of the memory containing the image data is called g_pixel,

If the image data is in YUV format, the luminance value of the i-th pixel is the value of (g_pixel + (i * 2 + 1)), and the average value of the luminance value is the sum of the luminance values of all the pixels divided by the total number of pixels. Value.

In addition, when the image data is in RGB format, Bi is a value of (g_pixel + (i * 3)) address, Gi is a value of (g_pixel + (i * 3) + 1) address, and Ri is (g_pixel + ( i * 3) + 2) is the value of address, and the luminance value of the i-th pixel is (Bi + Gi + Ri) / 3, and the average value of the luminance value is the total number of pixels after adding the luminance values of all the pixels. Divided by

Preferably, the setting unit receives and stores a threshold value and a storage condition determined according to the magnitude between the luminance value and the threshold value, and the storage condition determination unit is configured to store the current luminance value calculated by the luminance value calculator. And the magnitude between the threshold value are compared, and the storage condition corresponding to the comparison result is determined as the current storage condition according to the corresponding relationship set in the setting section.

According to another exemplary embodiment of the present invention, the video storage device receives video data of a plurality of channels, and the brightness value calculator calculates an average value of the brightness values of the video data of all the channels and converts the current data into the current brightness values. And the storage condition determining unit determines a storage condition corresponding to the current luminance value calculated by the luminance value calculating unit as the current storage condition of the image data of all channels according to the corresponding relationship set in the setting unit. do.

In addition, the present invention, a setting unit for receiving and storing a storage condition set by setting the luminance value and the time zone as an AND, OR, NAND or NOR condition; A luminance value calculator for calculating a current luminance value of the image data from the obtained image data; A time zone calculator for calculating a current time zone; A storage condition determining unit determining a current storage condition corresponding to a current luminance value and a current time zone calculated by the luminance value calculator and the time zone calculator according to the corresponding relationship set in the setting unit; And a storage unit for storing the image data under the current storage condition determined by the storage condition determining unit.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The image storage device of the present invention includes a setting unit, a luminance value calculator, a storage condition determiner, and a storage unit.

The setting unit is a component that receives and stores a storage condition according to the luminance value from the user.

The luminance value calculator is a component that calculates the current luminance value of the image data from the obtained image data.

The storage condition determining unit is a component that determines the storage condition corresponding to the current luminance value calculated by the luminance value calculating unit as the current storage condition according to the correspondence set in the setting unit.

The storage unit is a component that stores the image data under the current storage condition determined by the storage condition determining unit.

3A is a diagram illustrating a threshold setting menu provided by a setting unit of a DVR according to an embodiment of the present invention.

As shown, in order to distinguish between day and night, the user moves the slide bar to set the threshold value m_nYctl. The threshold is a variable that is arbitrarily set by the user.

FIG. 3B is a diagram illustrating a threshold setting process performed through the threshold setting menu of FIG. 3A.

The luminance value of the image data may have a value of 0 to 255 (00h to FFh). Therefore, map the threshold set by the user to 0 ~ 255 using the slide bar. 'm_nSld' represents a percentage value of the slide bar.

3C is a view for explaining a process of setting a storage condition according to a luminance value made in a setting unit of a DVR according to an embodiment of the present invention.

The storage condition determined by the magnitude between the average value (m_nYavg) of the luminance values of all the pixels of the image data and the threshold value is set by the user and stored. That is, when the average value of the luminance value is greater than or equal to the threshold value, the illumination intensity is regarded as a daytime period with sufficient illumination, and the number of images to be stored per second (m_nFps), the quality of the compressed image (m_nQly), and the resolution of the compressed image (m_nRes) are set to a large value. When the average value of the luminance value is less than the threshold value, it is regarded as a night time when illumination is insufficient and sets the number of images to be stored per second (m_nFps), the quality of the compressed image (m_nQly), and the resolution of the compressed image (m_nRes) to a small value.

The number of images to be stored per second (m_nFps), the quality of the compressed image (m_nQly), and the resolution of the compressed image (m_nRes) are variables set by the user and are values that can be arbitrarily set by the user for day and night.

FIG. 4A is a diagram for describing a process of obtaining an average value of luminance values of image data in YUV format by the luminance value calculator of the DVR according to an embodiment of the present invention.

The digital video signal obtained from the video capture board of the DVR is transferred to the software via the PCI bus in YUV or RGB format. When the digital video data obtained from the video capture card is in YUV format, the average value of the luminance value is as shown in FIG. 4A. You can get it.

If the transmitted digital video signal is 320 x 240 size, it consists of 76,800 pixels. When the start address of the memory containing the digital video signal acquired by the video capture board is designated as g_Pixel, the luminance value Yi of the i-th pixel may be calculated as follows.

Yi = * (g_Pixel + (i * 2 + 1))

The luminance value calculator calculates the current luminance value by adding up the luminance values of each pixel obtained using the above basic principle and dividing by the total number of pixels.

'WIDTH' and 'HEIGHT' indicate the width and height of the acquired image data.

4B is a diagram for describing a process of obtaining an average value of luminance values of image data in an RGB format by the luminance value calculator of the DVR according to an embodiment of the present invention.

When the digital image data obtained from the video capture card is in RGB format, the average value of the luminance values may be obtained as shown in FIG. 4B.

In the RGB format, the luminance value Yi of the i-th pixel is calculated as follows.

Bi = * (g_Pixel + (i * 3)

Gi = * (g_Pixel + (i * 3) + 1

Ri = * (g_Pixel + (i * 3) + 2

Yi = (Bi + Gi + Ri) / 3

The luminance value of each pixel obtained using the above basic principle is added together, and the current luminance value is calculated by dividing by the total number of pixels.

FIG. 5 is a diagram schematically illustrating an overall flow of self-controlling a storage condition of video data in a DVR according to an embodiment of the present invention.

First, a threshold value is set through the setting unit as shown in FIG. 3B. Further, as shown in Fig. 3C, the storage condition is set according to the magnitude between the luminance value and the threshold value.

Then, as in FIG. 4A or 4B, the luminance value calculator calculates a current luminance value from the obtained image data. In the embodiment of Fig. 5, an embodiment of calculating an average value of luminance values of each pixel as a current luminance value is shown.

Then, the storage condition determining unit compares the current luminance value with the threshold value, and determines the storage condition corresponding to the comparison result as the current storage condition according to the correspondence set in the setting unit. That is, if the current illuminance is low, the storage condition determines the storage condition so that the storage unit can store the image data at the recording speed / resolution / image quality set by the user for the daytime time. If the current illuminance is night, the user sets the nighttime time. The storage condition determines the storage conditions so that the storage can store the image data at a recording speed / resolution / quality.

The present invention may have various embodiments in addition to the embodiments shown in FIGS. 3A to 5.

For example, in the embodiments of FIGS. 3A to 5, the current luminance value and the storage condition are set to be divided into two sections, day and night, but may be configured to be divided into a plurality of sections. In this case, it may be preferable that the corresponding relationship between the luminance value and the storage condition is set in the form of a relational expression.

In addition, when the image storage apparatus receives the image data of the plurality of channels, the storage condition corresponding to the average value of the luminance values of the image data of all the channels may be collectively applied to the storage of the image data of all the channels.

For example, most DVRs use 16 channels as the number of camera input channels. In this case, the storage condition of the image data may be configured to be controlled independently for each channel, but may be configured to be controlled to be common to all channels. The collective control method is preferable when all the cameras are installed under the same environment.

According to the batch control method, the luminance value calculator calculates an average value of luminance values of video data of all channels and calculates the value as a current luminance value. The storage condition determiner determines the storage condition corresponding to the current luminance value calculated by the luminance value calculator as the current storage condition of the image data of all channels.

As another embodiment of the present invention, the video storage device of the present invention may be configured in conjunction with a time zone setting method by the user as shown in FIG.

In this case, the setting unit receives and stores a storage condition determined by setting a luminance value and a time zone as an AND, OR, NAND or NOR condition. For example, when the luminance value is equal to or greater than the threshold set by the user and when the time zone corresponds to 08 to 18:00 as the AND condition, the storage condition is set by distinguishing the above two conditions from the other cases. It is.

In this case, the image storage device needs a time zone calculator that calculates a current time zone in addition to the luminance value calculator.

The storage condition determiner determines the current luminance condition calculated by the luminance value calculator and the time zone calculator and the storage conditions corresponding to the current time zone as the current storage conditions according to the correspondence set in the setting unit.

DVR of the above embodiment can further minimize the malfunction of the DVR recording condition change process according to the change in illuminance.

According to the above configuration, the present invention can calculate the brightness level of the acquired image data to control the recording speed, resolution, and degree of compression on their own, and compared to the conventional DVR to record the amount of video recording that can be stored on the hard disk of the same capacity. Can be increased.

Claims (7)

delete A setting unit configured to receive and store a storage condition determined according to a luminance value; A luminance value calculator for calculating a current luminance value of the image data from the obtained image data; A storage condition determining unit determining a storage condition corresponding to the current luminance value calculated by the luminance value calculating unit as a current storage condition according to the corresponding relationship set in the setting unit; And And a storage unit configured to store image data under the current storage condition determined by the storage condition determiner. And the luminance value calculator calculates an average value of luminance values of each pixel of the image data and calculates the average value as a current luminance value. The method of claim 2, When the starting address of the memory containing the image data is called g_pixel, If the image data is in YUV format, The luminance value of the i-th pixel is the value of (g_pixel + (i * 2 + 1)). And an average value of luminance values is a value obtained by adding luminance values of all pixels and dividing by the total number of pixels. The method of claim 2, When the starting address of the memory containing the image data is called g_pixel, If the image data is in RGB format, Bi is the value of (g_pixel + (i * 3)) Gi is the value of (g_pixel + (i * 3) + 1) Ri is the value of (g_pixel + (i * 3) + 2) The luminance value of the i-th pixel is a value of (Bi + Gi + Ri) / 3 And an average value of luminance values is a value obtained by adding luminance values of all pixels and dividing by the total number of pixels. The method of claim 2, The setting unit stores and receives a threshold value, a storage condition determined according to a magnitude between a luminance value and the threshold value, The storage condition determining unit compares the magnitude between the current luminance value calculated by the luminance value calculating unit and the threshold value, and stores the storage condition corresponding to the comparison result according to the corresponding relationship set in the setting unit. And a self-control function of a storage condition of the image data. The method according to any one of claims 2 to 5, The image storage device receives image data of a plurality of channels, The luminance value calculator calculates an average value of luminance values of image data of all channels, and calculates the value as a current luminance value. The storage condition determining unit may determine a storage condition corresponding to the current luminance value calculated by the luminance value calculating unit as a current storage condition of image data of all channels according to a corresponding relationship set in the setting unit. An image storage device having a self control function of a storage condition of the image data. delete

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