KR20190027405A - Method and apparatus for omnidirectional security video coding in using padding technique - Google Patents

Abstract

The present invention relates to an image encoding and decoding technology in high-quality video compressing method and apparatus for an omnidirectional security camera. More specifically, the present invention relates to a method and an apparatus for effectively predicting a motion through padding reflecting a geometric principle of an omnidirectional camera.

Description

TECHNICAL FIELD [0001] The present invention relates to an image padding method and apparatus for an omnidirectional camera,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image encoding and decoding technique in a high-definition video compression method and apparatus for an omnidirectional security camera, and more particularly, to a method and an apparatus for effectively improving coding efficiency through effective padding in image encoding.

In recent years, there has been a growing demand for a variety of devices and systems for security, due to increasing social anxiety due to crime such as indiscriminate crimes against unspecified persons, retaliatory crimes against certain targets, and crimes against socially vulnerable people. In particular, since security cameras can be used as evidence for crime scenes or impression descriptions of criminals, demand for personal safety as well as national demand is increasing. However, due to the limited conditions in transmission or storage of acquired data, image quality deteriorates or there is a real problem that can only be saved as a low-quality image. In order to utilize a variety of security camera images, a high-quality compression method capable of storing a high-quality image with a low data amount is required.

In most image compression, since the sub-decode efficiency is shown through the compression between images, various inventions that effectively compress the images are performed. An effective padding method is an important technique for improving prediction efficiency and improving coding efficiency.

Some embodiments of the present invention aim at effectively compressing image data acquired via a forward directional security camera.

It is to be understood, however, that the technical scope of the present invention is not limited to the above-described technical problems, and other technical problems may exist.

According to an aspect of the present invention, an apparatus and method for decoding an image according to an embodiment of the present invention perform padding using values of neighboring pixels that reflect a feature using a geometric feature of a projected image.

To this end, in an embodiment of the present invention, an information acquisition unit for calculating and predicting information of an image using image information and camera information parsing unit and parsing information, and a reconstruction pixel value of a geometric position based on the acquired information And a motion compensation performing unit for performing motion prediction and compensation decoding using the padding performed by the padding unit and the padded image.

In order to improve inter picture prediction coding efficiency, the present invention generates padding data by reflecting characteristics of an image and performs motion prediction and compensation in the sub-decoder using the generated padding data. Can be improved.

FIG. 1 is a block diagram showing a configuration of a video decoding apparatus according to an embodiment of the present invention.
FIG. 2 illustrates location information of decoded pixels used in padding according to an exemplary embodiment of the present invention. Referring to FIG.
3 is various embodiments in which an image of an omnidirectional camera is projected.
FIG. 4 illustrates a method of constructing a frame from a projected image in an embodiment of the present invention.
Fig. 5 shows another embodiment of the shape of the projection and the method of constructing the frame.
FIG. 6 is an embodiment of padding for the case where the projected image is spread out in a plane as shown in FIG. 3 (A), and each patch is separately added / decoded.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings attached hereto, so that those skilled in the art can easily carry out 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 order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout this specification, when a part is referred to as being 'connected' to another part, it includes not only a case where it is directly connected but also a case where the part is electrically connected with another part in between. In addition, when an element is referred to as being "comprising" an element throughout the specification, it is understood that the element may include other elements, but not other elements, unless specifically stated otherwise.

The term (or step) or step of (~) used in the present specification does not imply a step for.

Also, the terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

In addition, the components shown in the embodiments of the present invention are shown independently to represent different characteristic functions, which does not mean that each component is composed of separate hardware or software constituent units. That is, each constituent unit is described by arranging each constituent unit for convenience of explanation, and at least two constituent units of each constituent unit may be combined to form one constituent unit or one constituent unit may be divided into a plurality of constituent units to perform a function. The integrated embodiments and the separate embodiments of each of these components are also included in the scope of the present invention without departing from the essence of the present invention.

First, the terms used in the present application will be briefly described as follows.

The video decoding apparatus may be a personal security camera, a private security system, a military security camera, a military security system, a personal computer (PC), a notebook computer, a portable multimedia player (PMP) , A wireless communication terminal, a smart phone, a TV application server, and a service server, and may be a user terminal such as various devices, a communication for performing communication with a wired / wireless communication network, A communication device such as a modem, a memory for storing various programs and data for inter-screen or intra-picture prediction for decoding or decoding an image, and a microprocessor for executing and calculating and controlling a program. can do.

In addition, an image encoded with a bitstream by an encoder can be transmitted in real time or in non-real time via a wired or wireless communication network such as the Internet, a local area wireless communication network, a wireless LAN network, a WiBro network, a mobile communication network, Universal Serial Bus), and the like, and can be decoded and restored into an image and reproduced.

In general, a moving picture may be composed of a series of pictures, and each picture may be divided into a coding unit such as a block. It is to be understood that the term " picture " described below can be used as a substitute for another term having an equivalent meaning such as an image, a frame, etc., and can be understood by those skilled in the art to which the present embodiment belongs will be. It will be understood by those skilled in the art that the term coding unit may be replaced with other terms having equivalent meanings such as unit blocks, blocks, and the like.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the present invention, the same elements will not be described in detail.

FIG. 1 illustrates a decoding apparatus for performing image decoding on a block-by-block basis using block division information according to an embodiment of the present invention. The decoding apparatus includes an entropy decoding unit 110, an inverse quantization unit 120, an inverse transform unit 130, an inter picture prediction unit 140, an intra prediction unit 150, a loop filter unit 160, (170).

The entropy decoding unit 110 decodes the input bitstream 100 and outputs decoded information such as syntax elements and quantized coefficients. The output information includes various information for performing decoding and decoding, and this information may include information on the image and image acquisition cameras. The image and image acquisition information can be transmitted in various forms and units and can be calculated or predicted using information extracted from a bitstream or extracted from a bitstream.

The inverse quantization unit 120 and the inverse transformation unit 130 receive the quantization coefficient, perform inverse quantization and inverse transformation in order, and output a residual signal.

The inter-picture prediction unit 140 calculates a motion vector using a difference motion vector and a predictive motion vector extracted from the bit stream, performs motion compensation using the reconstructed image stored in the reconstructed image storage unit 170, Signal. At this time, padding is performed with respect to a reference image for performing motion prediction. At the time of padding, padding is performed using the information of the opposite side decoded like the bright shade of FIGS. 2A and 2B. When it is difficult to directly refer to the opposite side decoding information as in the case of the dark shade of FIG. 2 (C), padding is performed through interpolation using data of bright shade. According to an embodiment of the present invention, padding is performed with pixel values of opposite sides, and artifacts can be removed through filtering and used as reference images. The filtering may be performed selectively according to the embodiment, the encoder may transmit the selection information to the decoder, perform the filtering based on the information received from the decoder, or may perform the filtering based on the padding method between the sub- It is possible to use the embodiments selectively and without any additional information. In addition, the horizontal and vertical lengths of the pixels that perform padding are performed at a fixed size by the promise between the subdecoders.

3 is various embodiments in which an image of an omnidirectional camera is projected. Fig. 9 (A) is an illustration of a projection onto a cube. In the embodiment, the number of sensors may be six so as to match the number of the respective projected planes, but fewer or more cases are possible. When a projection is made to a regular hexahedron, images of six planes are generated. In order to compress and transmit the images, one plane may be composed of one frame as shown in FIG. 4 (A) Six images may be composed of one frame and transmitted. At this time, the position of the six surfaces in FIG. 4 (B) may vary depending on the embodiment. FIG. 4 (C) corresponds to an embodiment in which a projection of an image is made up of one frame in the case of a figure having 12 faces. Embodiments relate to a method of projecting images or images obtained by a camera having a plurality of sensors at the same time and constructing one frame for convenience of compression and transmission. The method includes various types of sensors And may vary depending on the embodiment

Fig. 5 shows another embodiment of the shape of the projection and the method of constructing the frame. In Fig. 5, the white part is the part where the acquired image is projected and the actual image data exists, and the parting part is the part where there is no image data. Depending on the method of projection or the method of constructing the frame, the data may not exist in a form filled with a general rectangular frame. In this case, the encoder must transmit the corresponding information to the decoder. According to an embodiment, a white portion may be padded to form a rectangular frame, and a portion may be added / decoded, or the corresponding portion may be added / decoded without padding. In both methods, the subscriber / decoder needs to know and use the information, and can transmit the corresponding information from the encoder to the decoder, or it can be done through the promise of the subscription / decryption period.

FIG. 6 is an embodiment of padding for the case where the projected image is spread out in a plane as shown in FIG. 3 (A), and each patch is separately added / decoded. 3 (A) is expanded as shown in FIG. 3 (B), and it can be transformed into a rectangular shape as shown in (A). At this time, it is determined by the system end where the respective faces are located, and the information may be performed without a separate information transmission procedure by the promise between the sub-decoders, or may be decoded by the encoder through the upper level context information such as HLS And can refer to the information after decoding by the decoder. At this time, the decoded data to be referred to when padding will be information on the surface where the edge is encountered when (B) is folded, and this will be explained as a basic geometrical knowledge. Although the embodiment has been shown for an image projected on a cube, in the case of other projection examples of FIG. 3 or various projections not described in the present invention, data used in padding can be defined using the geometric principle. The padding data can be calculated through interpolation filtering for a space in which data is insufficient as in the embodiment of FIG.

Not applicable

Claims (2)

A video decoding method comprising:
An acquisition camera and a video information parsing step;
Acquiring image information from the parsing information;
Performing padding on a decoded image using a restored pixel value of a geometric position based on the acquired information;
And performing motion prediction and compensation decoding using the padded image. The method according to claim 1,
Designating information of a padded image as a geometric neighboring area, firstly padding the data, performing filtering on pixels adjacent to the padded data, and performing motion prediction and compensation decoding using the data Way

Images