KR101409852B1 - Scalable video encoding method according to the analysis of moving object in the video and apparatus thereof - Google Patents

Abstract

In the conventional image acquiring apparatus, the encoding quality is determined simply by the value manually set by the user. However, the above-described conventional method is disadvantageous in that it is not suitable for an application having a high degree of interest in an image only when there is a motion object in the image, such as a surveillance camera system. In order to overcome this disadvantage, according to the present invention, if a moving object exists in an image after detecting the motion object, the coding is performed with a high quality. On the contrary, if there is no moving object in the image, do. Accordingly, the absolute data amount of the image can be reduced, thereby increasing the efficiency of image storage and reducing the network bandwidth for image transmission.

Description

[0001] The present invention relates to a scalable video encoding method and apparatus, and more particularly,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scalable video coding method and apparatus, and more particularly, to a method of adaptively selecting a video coding method according to presence or absence of motion objects in an acquired video.

Image coding refers to an operation of converting an image signal represented by an analog method into a digital code divided into the presence or absence of a unit pulse. The most recently standardized H.264 / AVC standard has increased compression efficiency by various coding techniques. Distortion rate optimization technique for mode decision of macroblocks with block-based integer transform, multiple reference pictures for motion vector prediction, intrapredictive coding, pixel-based motion vector prediction, Optimization.

Information through intra-frame coding of H.264 / AVC can be roughly classified into three types: mode coding, prediction mode coding, and image coding. Especially, the prediction mode information in the encoded bitstream occupies a relatively larger portion as compared with the image information as the bit rate decreases.

Intra picture coding in the H.264 / AVC standard is performed in order to reduce the amount of bits required to encode the prediction mode information. In order to reduce the amount of bits required for encoding the prediction mode information, the most probable mode obtained by a smaller value among the prediction modes And uses a coding method that uses a match with information. This is because a small intra-picture prediction mode number is allocated in order of occurrence of nine intra-picture prediction modes.

Conventional image capturing apparatuses using such a coding method include a surveillance camera and a video camera. In the conventional technique, when the user manually sets the image encoding quality of the image acquisition apparatus, a method of encoding the image according to the set encoding quality is used.

However, the above-described conventional method is disadvantageous in that it is not suitable for an application having a high degree of interest in an image only when there is a motion object in the image, such as a surveillance camera system.

In order to solve the above-described problem, the present invention detects a motion object in a photographed image, and then performs encoding with high quality when a motion object exists in the image. On the other hand, when there is no motion object in the image, And a method of performing encoding with high quality.

The objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a scalable encoding apparatus for analyzing a motion object of an image according to an aspect of the present invention includes an image analyzer for analyzing an acquired image to determine whether there is a motion object, And a coding unit for performing coding on the acquired image based on the coding method determined by the coding method determining unit.

The coding method determination unit may determine at least one of Temporal Scalable Coding, Spatial Scalable Coding, and Signal-to-Noise Ratio (SNR) of the acquired image according to a determination result of the presence or absence of the motion object. Change one in a hierarchy.

In one embodiment, the image analyzing unit may determine whether or not a motion object is present in the acquired image. In this case, if it is determined that the motion object is present, the encoding method determining unit determines the number of encoded frames At least one of Scalable Coding, Spatial Scalable Coding, and Signal to Noise Ratio (SNR) is increased by a predetermined ratio from the basic setting value.

In another embodiment, the image analyzing unit determines whether a motion object is present in the acquired image and the number of motion objects, and the encoding method determining unit determines the number of the motion objects to be acquired At least one of Temporal Scalable Coding, Spatial Scalable Coding, and Signal to Noise Ratio (SNR) is increased from a basic setting value.

In another embodiment, the encoding method determining unit may determine the encoding method (at least one of the number of encoding frames, the encoding resolution, and the signal-to-noise ratio) determined in the previous frame according to the analysis result of the image analyzing unit, The encoding resolution, and the signal-to-noise ratio of the acquired image.

According to another aspect of the present invention, there is provided a scalable coding method according to motion object analysis of an image, comprising the steps of: determining an existence of a motion object by analyzing an acquired image; and encoding the acquired image adaptively according to the determination result. And encoding the acquired image based on the determined encoding method.

In one embodiment of the present invention, the determining step may include determining whether or not a motion object is present in the acquired image, and determining that the motion object is present, Temporal scalable coding, spatial scalable coding, and signal-to-noise ratio (SNR) by a predetermined ratio from a basic set value.

According to another embodiment of the present invention, the determining step may include determining whether a motion object is present in the acquired image and the number of the motion objects, And increasing at least one of a temporal scalable coding, a spatially scalable coding, and a signal-to-noise ratio (SNR) of an acquired image from a basic setting value.

Meanwhile, the image encoding method according to the present invention can be recorded in a computer-readable recording medium.

As described above, according to the present invention, it is possible to reduce the absolute data amount of an image by adaptively selecting an image encoding quality according to presence or absence of a motion object in an acquired image, thereby increasing the efficiency of image storage, Thereby reducing network bandwidth for the network.

1 is a block diagram illustrating a configuration of an image encoding apparatus according to an embodiment of the present invention.
2 is a flowchart illustrating an image encoding method according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, like reference numerals refer to like elements throughout. In the drawings, like reference numerals are used to denote like elements, and in the description of the present invention, In the following description, a detailed description of the present invention will be omitted.

1 is a block diagram illustrating a configuration of an image encoding apparatus according to an embodiment of the present invention.

1, an image encoding apparatus according to an embodiment of the present invention includes an image analysis unit 10 for analyzing an acquired image to determine whether there is a motion object, An encoding method determining unit 20 for determining an encoding method for the acquired image and an encoding unit 30 for encoding the acquired image based on the encoding method determined by the encoding method determining unit.

The image analyzing unit 10 analyzes the still image that has not been encoded yet to determine whether there is a motion object in the image.

In one embodiment, the image analysis unit 10 may determine whether a motion object exists only in the acquired image, and in another embodiment, the image analysis unit 10 may determine whether or not a motion object exists, The number of motion objects in the image can be determined.

The encoding method determination unit 20 adaptively determines an encoding method for the acquired image according to the determination result of the image analysis unit 10. [

Specifically, the coding method determining unit 20 determines a temporal scalable coding, a spatial scalable coding, a signal-to-noise ratio (SNR) Ratio, and SNR).

In one embodiment, the encoding method determination unit 20 can use any one of the three methods of changing the number of encoded frames, the encoding resolution, and the signal-to-noise ratio of the acquired image, or a combination of the three methods It is possible.

A method of changing the number of encoded frames of an image is to select a coding method that increases the number of frames per second when there is an object in the image based on the image analysis result. On the contrary, when there is no object in the image, It means choosing a method.

The method of changing the coding resolution of an image is to select a method of increasing the resolution when there is an object in the image based on the image analysis result and to select a method of lowering the resolution when there is no object in the image.

A method for changing the signal-to-noise ratio of an image is to select a method for increasing the coding quality of an image by increasing the signal-to-noise ratio of the image if there is an object based on the result of the image analysis. A method of reducing the coding quality of the image by lowering the signal-to-noise ratio is selected.

Hereinafter, an embodiment of a coding method selected by the coding method determining unit 20 according to the image analysis result of the image analyzing unit 10 will be described in detail.

In one embodiment, when the image analysis unit 10 determines only whether a motion object exists in the acquired image, the encoding method determination unit 20 determines whether the motion object exists in the acquired image, At least one of a number of encoded frames of an image, a coding resolution, and a signal-to-noise ratio is increased by a predetermined ratio from a basic setting value.

For example, the encoding method determining unit 20 selects a method of encoding the number of encoded frames at 60 fps when there is a motion object in the acquired image, and encodes the encoded image at a default setting value of 30 fps when there is no motion object Select.

In another embodiment, when the image analysis unit 10 determines not only whether a motion object is present, but also the number of motion objects, the encoding method determination unit 20 determines a number of motion objects by a predetermined ratio At least one of the number of encoded frames, the encoding resolution, and the signal-to-noise ratio of the acquired image is increased from a basic setting value.

For example, if the number of motion objects is 10 or more, 60 fps, 8 fps, 50 fps, 6 fps, 30 fps, 20 fps, and 10 fps, respectively, You can choose how to do it.

When the encoding method determination unit 20 changes the encoding method (at least one of the number of encoded frames, the encoding resolution, and the signal-to-noise ratio) determined in the previous frame according to the analysis result of the image analysis unit 10, A coding resolution, and a signal-to-noise ratio of the acquired image sequentially.

For example, if it is determined that the previous frame is coded at 60 fps and the current frame is coded at 30 fps, a method of adjusting the difference between the previous frame encoding method and the current frame encoding method, It is possible to use a method of sequentially controlling the quality of an image such as 60 fps-> 50 fps-> 40 fps-> 30 fps or vice versa: 30 fps-> 40 fps-> 50 fps-> 60 fps.

Meanwhile, the image encoding apparatus according to the embodiment of the present invention may further include a user operation unit 40 receiving a user's selection input. The user can apply the user input to the image encoding apparatus according to the present invention by using the user operation unit 40. Such user input is input to the image analysis unit 10 and the encoding method determination unit 20 .

For example, the user input applied through the user manipulation unit 40 may be to select a coding method of the acquired image.

If the user inputs an instruction to encode the acquired image at 40 fps through the user operation unit 40, the encoding unit 30 performs the encoding process for the acquired image through the user operation unit 40 in preference to the processing result of the encoding method determination unit 20. [ Processed user input.

In addition, the user can apply an instruction to end the image acquisition through the user operation unit 40, and the image encoding apparatus ends the image acquisition.

2 is a flowchart illustrating an image encoding method according to an embodiment of the present invention. Hereinafter, an image encoding method according to an embodiment of the present invention will be described with reference to FIG. 1 and FIG.

First, the image analysis unit 10 analyzes the acquired image to determine whether there is a motion object (S210).

In one embodiment, the image analysis unit 10 may determine whether a motion object exists only in the acquired image, and in another embodiment, the image analysis unit 10 may determine whether or not a motion object exists, The number of motion objects in the image can be determined.

Next, the encoding method determination unit 20 adaptively determines an encoding method for the acquired image according to the determination result (S220).

In one embodiment, the image analysis unit 10 determines only whether or not a motion object exists in the acquired image. If it is determined that a motion object exists, the encoding method determination unit 20 determines At least one of Temporal Scalable Coding, Spatial Scalable Coding, and Signal-to-Noise Ratio (SNR) is increased by a predetermined ratio from the basic setting value.

In another embodiment, if the image analysis unit 10 determines not only whether or not a motion object is present in the acquired image, but also the number of motion objects, the coding method determination unit 20 determines the number of motion objects based on the number of motion objects At least one of Temporal Scalable Coding, Spatial Scalable Coding, and Signal-to-Noise Ratio (SNR) of the acquired image is increased by a predetermined ratio.

The encoding unit 30 encodes the acquired image based on the encoding method determined by the encoding method determination unit 20 at step S230. If a specific user input for the encoding method is applied through the user operation unit 40 (S225), the encoding unit 30 performs encoding on the acquired image based on the specific user input (S230).

Thereafter, when a user input for ending the image acquisition through the user operation unit 40 is applied (S240), the image encoding apparatus ends the image acquisition.

  Meanwhile, the image encoding method according to the present invention can be implemented in the form of a program command which 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 instructions recorded on the medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of 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; Examples of program instructions, such as magneto-optical and ROM, RAM, flash memory and the like, can be executed by a computer using an interpreter or the like, as well as machine code, Includes a high-level language code. 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 present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It is to be understood that the invention may be embodied in other specific forms. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

Claims (9)

An image analyzer for analyzing an acquired image to determine whether there is a motion object and the number of motion objects;
A coding method determining unit that adaptively determines a coding method for the acquired image according to a determination result of the image analyzing unit; And
And an encoding unit that encodes the acquired image based on the encoding method determined by the encoding method determination unit,
Wherein the encoding method determination unit determines,
Wherein at least one of Temporal Scalable Coding, Spatial Scalable Coding, and Signal to Noise Ratio (SNR) of the acquired image is set to a predetermined value according to the number of the motion objects, To increase in
A Scalable Coding Device Based on Analysis of Moving Objects in. 2. The method of claim 1,
At least one of Temporal Scalable Coding, Spatial Scalable Coding, and Signal-to-Noise Ratio (SNR) of the acquired image according to a result of the presence or absence of the motion object Change
A Scalable Coding Device Based on Analysis of Moving Objects in. 2. The method of claim 1,
If it is determined that the motion object exists, at least one of Temporal Scalable Coding, Spatial Scalable Coding, and Signal-to-Noise Ratio (SNR) Increase by a set percentage
A Scalable Coding Device Based on Analysis of Moving Objects in.
delete 2. The method of claim 1,
When changing the encoding method (at least one of the number of encoding frames, the encoding resolution, and the signal-to-noise ratio) determined in the previous frame according to the analysis result of the image analyzing unit, the number of encoded frames of the acquired image, , And a signal-to-noise ratio
A Scalable Coding Device Based on Analysis of Moving Objects in. Analyzing the acquired image to determine whether the motion object exists and the number of the motion objects; Determining an encoding method for the acquired image adaptively according to the determination result; And performing encoding on the acquired image based on the determined encoding method,
Wherein the step of determining the encoding method comprises:
Wherein at least one of Temporal Scalable Coding, Spatial Scalable Coding, and Signal to Noise Ratio (SNR) of the acquired image is set to a predetermined value according to the number of the motion objects, Including increasing
A Scalable Coding Method Based on Analysis of Moving Objects in.
The method according to claim 6,
Wherein the step of determining the encoding method comprises:
If it is determined that the motion object exists, at least one of Temporal Scalable Coding, Spatial Scalable Coding, and Signal-to-Noise Ratio (SNR) By a predetermined ratio
A Scalable Coding Method Based on Analysis of Moving Objects in.
delete A computer-readable recording medium storing a program for executing the method according to any one of claims 6 to 7.

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