KR20000001340A - Apparatus and method to encode moving image utilizing same shape information - Google Patents

Abstract

PURPOSE: An apparatus and method are provided to encode a moving image utilizing a same shape information, so that display quality is improved. CONSTITUTION: The apparatus comprises an information extractor(111), a transmission bandwidth searcher(116), a shape-similarity discriminator(112), a sensed quality encoder(114), a shape encoder(113) and an encoded data combiner(115). The information extractor(111) extracts a shape information and a sensed quality information from the individual image data. The transmission bandwidth searcher(116) searches a transmission bandwidth from the transmission traffic state. The shape-similarity discriminator(112) sets a similarity reference according to the transmission bandwidth information, and discriminates the shape-similarity of the individual image. The sensed quality encoder(114) encodes a sensed quality information. The shape encoder(113) encodes a shape information from the information extractor(111) according to the discrimination data from shape-similarity discriminator(112). The encoded data combiner(115) combines the sensed quality encoded data from sensed quality encoder(114) and the shape encoded data from the shape encoder(113).

Description

Video encoding apparatus and method using same shape information

The present invention relates to shape coding which reduces the number of coded bits by only indicating that shapes are similar without encoding the corresponding shapes when it is determined that the shapes of the image objects are similar in whole or in part. The present invention relates to a shape encoding apparatus and a method of determining a criterion for the similarity of shapes according to the size of a bandwidth.

Here, the image object is a set of pixels (picture elements) having similar properties, and is represented as a screen area having a certain shape on the screen.

The prior art expresses the shape in the alpha plane and the texture in the picture element value as shown in the Moving Picture Expert Group-4 (MPEG-4) international standardization work. In the case where the shape of the image object does not change between screens in encoding all the blocks composed of the blocks, the information of the same shape for each block is encoded every time.

In addition, the conventional technique is to reduce the number of bits by encoding only the information that the shape is the same, instead of encoding the shape information in the case of encoding the contour of the shape when the overall shape of the image object does not change significantly between screens It was.

However, these methods can reduce the number of coded bits by encoding only information of the same shape instead of shape information, but are useful in a transmission environment having a fixed transmission bandwidth because the shape similarity is determined without considering the change in the transmission bandwidth. On the other hand, there is a problem in that it is not appropriate to cope with the case where the number of output coded bits needs to be changed in a transmission environment in which the transmission bandwidth changes frequently, such as the Internet.

Accordingly, the present invention devised to solve the above-described problems is to inform the fact that the shapes are similar without encoding the corresponding shapes if it is determined that the shapes of the image objects are similar in whole or in part. Accordingly, an object of the present invention is to provide an encoding apparatus and method for determining shape similarity according to the size of a transmission bandwidth in shape coding which reduces the number of encoded bits.

1 is a block diagram of a video encoding apparatus using the same shape information according to an embodiment of the present invention.

2 is a flowchart of a video encoding method using the same shape information according to an embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

111: shape and texture information extraction unit 112: shape similarity determination unit

113: shape encoder 114: texture encoder

115: coded data combination unit 116: transmission bandwidth investigation unit

The apparatus of the present invention for achieving the above object, the shape and texture information extraction means for extracting the shape information and texture information from the image object data input from the outside; Transmission bandwidth investigation means for investigating transmission traffic conditions to find available transmission bandwidths; Shape similarity determining means for determining whether or not the shapes of the image objects are similar between screens by receiving the available transmission bandwidth information from the transmission bandwidth investigation means and setting similarity determination criteria; Texture encoding means for receiving and encoding texture information; Shape encoding means for encoding shape information input from said shape and texture information extracting means in accordance with the discrimination data input from said shape similarity determining means; And coded data combining means for combining the texture coded data input from the texture coding means and the shape coded data input from the shape coding means.

In addition, the method of the present invention, the first step of separating the shape information and texture information for the received image object; A second step of performing shape coding if the shapes are not similar according to the shape similarity discrimination criterion, and not performing shape coding if the shapes are similar; And a third step of combining and outputting the encoded data.

Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to FIGS.

According to the present invention, if the available transmission bandwidth decreases during transmission of a video in a transmission environment in which the transmission bandwidth changes frequently, such as the Internet, the criteria for determining the similarity of shapes are alleviated, so that some similar shapes are regarded as the same shape. According to the transmission of the shape information, the picture quality is reduced to some extent, but the number of coded bits can be output in accordance with the smaller transmission bandwidth. On the contrary, as the available transmission bandwidth increases, the criterion for the similarity of shapes is strengthened, thereby ensuring the image quality as much as the relatively larger transmission bandwidth.

1 is a block diagram of a video encoding apparatus using the same shape information according to an embodiment of the present invention.

As shown in the figure, the video code and the device using the same shape information according to an embodiment of the present invention, the shape information and texture information is extracted from the image object data, the shape information is the shape similarity determination unit 112 and the shape Available input from the shape and texture information extractor 111 and the transmission bandwidth checker 116 output to the shape encoding part 113 and the texture information output to the texture encoding part 114. The shape similarity determiner 112 and the shape similarity determiner 112 output the information indicating the similarity of the shape to the shape encoder 113 and determine whether the shape of the image object is similar to the whole screen according to the transmission bandwidth information. If not, the shape information is encoded and the shape coded data is output to the coded data combination unit 115. If the shapes are similar, the shape coding is not performed. Combines the data output from the shape encoder 113, the texture encoder 114, the shape encoder 113, and the texture encoder 114, which encodes the texture information and outputs the texture encoded data to the encoded data combiner. Encoded data combination unit 115 for outputting the combined encoded data, a transmission bandwidth investigation unit for determining the available transmission bandwidth by examining the state of the transmission traffic (transmission) information and transmitting the available transmission bandwidth information to the shape similarity determination unit 112 ( 116 is provided.

Now, the operation of the video encoding apparatus using the same shape information according to an embodiment of the present invention will be described in detail.

The shape and texture information extractor 111 extracts the shape information and texture information from the image object data. The shape and texture information extracting unit 111 extracts the shape information and texture information from the image object data. The alpha plane information representing the shape is extracted and used, and the pixel values corresponding to the image object are extracted and used as texture information.

The shape similarity determining unit 112 compares the alpha plane displaying the shape of the image object between the screens by moving the screen horizontally and horizontally, if the number of pixels included in the region that does not coincide with each other does not exceed the threshold value (T). The shapes are determined to be similar.

At this time, the reference value (T) is changed according to the available transmission bandwidth, and the relationship between the reference value (T), the available transmission bandwidth (B), the initial reference value (Ts), and the initial transmission bandwidth (Bs) is as follows. Is displayed as:

T = Ts x (Bs / B);

As the available transmission bandwidth decreases, the reference value is increased to determine that the shape is similar, which reduces the number of bits used for shape encoding. On the contrary, when the available transmission bandwidth increases, the reference value is decreased to determine that the shape is similar. This decreases the number of bits used for shape coding. Here, the average available transmission bandwidth is set as the initial transmission bandwidth, and in this case, a reference value experimentally obtained is set as an initial reference value to obtain a desired image quality. The initial reference value is set differently according to the application field in consideration of the transmission environment or the characteristics of the video.

If the shape encoder 113 determines that the shapes are not similar to each other according to the discrimination data of the shape similarity discrimination unit 112, such as a known method published through the MPEG-4 standardization operation, the shape encoder 113 encodes the shape information, and the shapes are similar. If it is determined that the information is determined, the information similar to the shape is output without encoding the shape information.

The texture encoder 114 uses a motion compensated Discrete Cosine Transform (DCT) encoding method for a texture information represented by a pixel (picture element) value, as in a known method published through MPEG-4 standardization. Encode

The encoded data combiner 115 combines the data output from the shape encoder 113 and the texture encoder 114 and outputs one encoded bit stream.

The transmission band investigator 116 finds an available transmission bandwidth by examining transmission traffic conditions by using a known Internet protocol and transmits the available transmission bandwidth information to the shape similarity determination unit 112.

2 is a flowchart of a video encoding method using the same shape information according to an embodiment of the present invention.

As shown in the figure, the video encoding method using the same shape information according to an embodiment of the present invention, first receives the image object data (210), and receives the image object is divided into the shape and texture (211) ).

Subsequently, the available transmission bandwidth is examined (212), and shape similarity determination criteria according to the available available transmission bandwidth is determined (213).

Subsequently, it is determined whether the divided shapes are similar according to the determined discrimination criteria (214), and if similar, texture coding is performed (215), the encoded data are combined (217), and if not similar, shape and texture coding are performed. 216, the coded data is combined (217).

Subsequently, it is determined whether data to be encoded remains (218), and if it remains, the process is repeated from the step 210 of receiving the video object data, and if not, the process ends.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the spirit of the present invention for those skilled in the art to which the present invention pertains, and the above-described embodiments and accompanying It is not limited to the drawing.

In the present invention as described above, when the available transmission bandwidth decreases during transmission of a video in a transmission environment in which the transmission bandwidth is frequently changed, such as the Internet, the criteria for similarity of shapes are alleviated accordingly, so that some similar shapes are regarded as the same shape. By processing, the picture quality decreases to some extent due to transmission of inaccurate shape information, but the number of encoded bits can be output in accordance with the smaller transmission bandwidth. On the contrary, when the available transmission bandwidth increases, a criterion for the similarity of shapes is determined. There is an enhanced effect to ensure the image quality as much as the relatively large transmission bandwidth.

Claims (7)

Shape and texture information extraction means for extracting shape information and texture information from image object data input from the outside; Transmission bandwidth investigation means for investigating transmission traffic conditions to find available transmission bandwidths; Shape similarity determining means for determining whether or not the shapes of the image objects are similar between screens by receiving the available transmission bandwidth information from the transmission bandwidth investigation means and setting similarity determination criteria; Texture encoding means for receiving and encoding texture information; Shape encoding means for encoding shape information input from said shape and texture information extracting means in accordance with the discrimination data input from said shape similarity determining means; And Coded data combining means for combining texture coded data input from the texture coding means and shape coded data input from the shape coding means; Video encoding device comprising a. The method of claim 1, The shape coding means, When the discrimination data inputted from the shape similarity determining means indicates that the shapes are similar, only the information that the shapes are similar without encoding the shape information input from the shape and texture information extracting means is output, and from the shape similarity determining means And the shape information inputted from the shape and texture information extracting means to output shape coding data when the discriminating data input indicates that the shapes are not similar. The method according to claim 1 or 2, The shape similarity determining means, And when the available transmission bandwidth is smaller, more cases are determined to be similar, and when the available transmission bandwidth is larger, fewer cases are determined to be similar. The method according to claim 1 or 2, The shape similarity determining means, When the alpha plane displaying the shape of the image object is compared between the screens by moving the screen horizontally and horizontally, it is determined that the shape is similar when the number of pixels included in the region that does not coincide with each other does not exceed a predetermined threshold value (T). Video encoding apparatus, characterized in that. The method of claim 4, wherein The predetermined reference value is In the relationship between the discrimination reference value (T) and the available transmission bandwidth (B), the initial reference value (Ts) and the initial transmission bandwidth (Bs) T = Ts x (Bs / B); Video encoding apparatus characterized in that determined by. In the video encoding method applied to a video encoding apparatus, A first step of dividing the received image object into shape information and texture information; A second step of encoding shape information and texture information according to shape similarity determination criteria according to available transmission bandwidths; And Third step of combining and outputting encoded data Video encoding method comprising a. The method of claim 6, The second step, A fourth step of examining the available transmission bandwidth by examining the transmission traffic status; Setting a shape similarity determination criterion using an available transmission bandwidth, an initial reference value, and an initial transmission bandwidth; A sixth step of determining whether the shapes are similar depending on whether the number of pixels included in the areas that do not coincide with each other exceeds a predetermined reference value by comparing the alpha planes representing the shapes of the image objects by moving the screen horizontally and horizontally step; And As a result of the determination of the eighth step, a seventh step of performing texture coding if the shapes are similar, and performing shape and texture coding if the shapes are not similar. Video encoding method comprising a.