JPH02159186A - Moving image transmission equipment - Google Patents

Abstract

PURPOSE:To make encoding of a moving image highly efficient by extracting boundary information in an area divided according to the gradation level of a various density information and the representative value of the gradation level in the divided area, making the divided areas correspond to the representative values of the gradation level. CONSTITUTION:A boundary detector 4 divides digital variable density image information supplied from a buffer memory 3 into the areas according to a variable density level, and extracts their boundaries. A representative value extracting device 6 extracts the representative value while simultaneously referring to the said various density image information and the boundary information. A multiplexer 7 multiplexes the boundary information and the representative value, and outputs them to a transmission path 8. A receiving part discriminates and separates the said boundary information and the representative value from the information received by the transmission path 8, and transmits them to memories 11 and 12. A various density forming device 13 forms the various density image information equivalent to that applied from an information source based on the boundary information and the representative value information read from the memories 11 and 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a moving image transmission device devised to achieve highly efficient transmission using a wired or wireless medium. Furthermore, the present invention can also be applied to a moving image recording device by replacing the transmission path with a recording medium.

[Prior Art] Conventionally, moving images have been transmitted by using high-efficiency encoding as disclosed in Chapter 9 of the document ``Digital Signal Processing of Images'' (written by Fukinuki, published by Nikkan Kogyo Shimbunsha). This was done while reducing the amount of information to be transmitted. A specific example of this is disclosed in the document ``Color Videophone Using Analog Telephone Line'' (Ishikawa: Proceedings of the 103rd Research Meeting of the Institute of Image Electronics Engineers, No. 87-06-04).

[Problem to be Solved by the Invention J] According to the above-mentioned conventional technology, the grayscale information of an image is encoded with high efficiency within a frame or between frames. As a result, according to the document ``Color TV telephone using analog telephone line'', the image compression rate was 1/4 to 115th. Furthermore, even if a more complex method such as that described in Chapter 9 of the literature [Digital Signal Processing of Images] is used, the image compression rate is still lagging at most.
/200.

In order to further increase the image compression rate, the present invention provides a moving image transmission device that is equipped with means for transmitting boundary information of areas divided according to the degree of shading and representative values of the degree of shading of the divided areas. provide.

[Means for Solving the Problems 1] The present invention provides a moving image transmission device that includes a transmitting section and a receiving section and is configured to transmit and receive moving image information. A boundary extractor that divides an arbitrary frame of an image into regions and extracts boundaries of the divided regions to form boundary information; and a representative value extractor that extracts representative values of gradation levels of the divided regions. , means for associating the divided regions with the representative values of the gradation levels; and means for generating gradation information based on the received boundary information and the received representative values of the gradation levels. What is claimed is: 1. A moving image transmission device comprising: a receiving section equipped with a receiver;

The aim is to solve the above-mentioned problems by providing the following.

[Implementation example J Hereinafter, the present invention will be explained in detail based on the drawings.

FIG. 1 shows an embodiment of the present invention.

First, the transmitting section of the moving image transmitting apparatus of the present invention will be explained. In Figure 1, 1 is an information source that is composed of an imaging device such as a video camera, an image scanner, a VTR, a packaged video source such as a video disc, etc., and supplies 1 image information, and 2 is an information source supplied from information source 1. AD that converts analog gray scale image information into digital gray scale image information
The converter 3 is a buffer memory that temporarily stores the digital grayscale image information for timing adjustment and the like.

4 is a boundary extractor having a function of dividing the digital grayscale image information supplied from the buffer memory 3 into regions according to the grayscale level and extracting the boundaries of the regions;
5 is a memory that stores extracted boundary information. The boundary extractor 4 is composed of, for example, a two-dimensional digital filter. 6 is a representative value extractor that determines a representative value indicating the gray level for each of the divided areas. 8 The representative value extractor 6 is a buffer memory for making a one-to-one correspondence between areas and the gray level of that area. A multiplexer 7 extracts a representative value while simultaneously referring to the gray scale image information stored in the memory 5 and the boundary information stored in the memory 5. and the representative value supplied from the multiplexer and sent to the transmission line 8.

Next, the receiving section will be explained. Reference numeral 10 denotes a discriminator that discriminates and separates the boundary information and the representative value from the information received from the transmission line 8, and transmits the boundary information to the memory 11 and the representative value to the memory 12. The memory 11 stores boundary information for at least one frame, and the memory 12 stores representative values for at least one frame. 13 is a gradation image forming device that forms gradation image information equivalent to that given from the information source based on the boundary information read from the memory 11 and the representative value information read from the memory 12; 14 is a display device and a printing device; , an image output device such as a storage device.

The image information formed by the multiplexer 7 has a form as shown in FIG. 2, for example. In the same figure, 26.
27 are image information strings for l frames, each including a header information string 20.23, a boundary information string 21.24, and a representative (fi information string 22.25. Here, the boundary information string 21 (24 ) and the representative value expressed by the representative value information string 22 (25) are in one-to-one correspondence.

As described above, in order to establish a one-to-one correspondence between the area based on the boundary information string and the representative value based on the representative value information string, representative value extraction in the receiving device is performed, for example, as follows.

FIG. 3 shows a grayscale image for a certain l frames supplied from an information source l. In FIG. 3, 30 to 36 are boundaries expressed by the boundary information string, and boundary 3
All pixels within any region divided by 0 to 36 have equal gray level. Here, boundary 3
0 to 36 are obtained by processing the grayscale image using, for example, a two-dimensional digital filter.

Figure 4 shows the grayscale image and boundaries 30 to 36 shown in Figure 3.
FIG. 3 is a diagram illustrating a method for finding a representative value for each region when given. The representative value extractor 6 shown in FIG. 1 sequentially scans the screen based on the gradation information stored in the buffer memory 3 and the boundary information stored in the memory 5. Scanning is performed, for example, along the scanning line from the top left of the screen, and pixels 37, 45, 46, ..., 47, 48, ...
are picked up sequentially. In the process of scanning the screen as described above, operations are performed according to the following rules.

(1) If the boundary is not crossed when a new pixel is picked up, nothing is done.

(2) If the boundary has been crossed, it is checked whether or not the first pixel P picked up in the new area belongs to an area for which a representative value has already been determined.

(3) As a result of (2), if the pixel P belongs to an area for which a representative value has not yet been determined, the gray level of one pixel P is determined as the representative value of the area.

(4) If the pixel P belongs to an area where the representative value has already been determined, nothing is done.

At this time, if the image frame 50 is also considered as a boundary and follows the rule of 0 or more, when scanning the grayscale image in FIG. 4 (FIG. 3),
” Pixel 37.38.39.40.41.4
When 2.43.44 are picked up, the representative value of the area to which they belong will be determined. All pixels marked with an "x" are pixels whose representative value is not determined at the time of being picked up.

FIG. 5 is a flowchart showing the procedure for determining the above-mentioned representative value. In the figure, i is a number indicating which pixel a certain pixel is picked up when following a predetermined scanning order.

N is the total number of pixels existing within the screen. Operation 51.52
．． 53 indicates the above-mentioned operations (1) to (4).

Note that in the above description of the method and apparatus of the present invention, when interlaced images are targeted, the processing performed in frame units can also be performed in field units.

In addition, in all of the above descriptions of the present invention, the transmission path is assumed to be a recording medium, and "transmission" is replaced by "recording", "transmission path" is replaced by "recording medium", "transmission" is replaced by "writing", and "reception" is replaced by "recording". "
The present invention is also valid even if λ is expressed as ``readout''.

[Effects of the Invention] The present invention described above goes beyond the conventional high-efficiency encoding based on the statistical properties of images, by incorporating a method of extracting and transmitting boundary information of gray levels in gray images. This achieves even more efficient video encoding.

Boundary information is expressed by (1) binary values, that is, 1 bit, and (2) information in areas with the same gradation level is omitted and is expressed only by area edge information. An image compression rate of about 1/1000 or less can be expected just by representing the image using boundary information. As a result, by using the present invention, moving image transmission and recording can be realized with significantly higher efficiency than in the past.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of a moving image transmission device of the present invention. FIG. 2 is a diagram illustrating an example of an image information sequence transmitted by the transmission device of the present invention, and FIG. 3 is a diagram illustrating one frame with a grayscale image to be transmitted. FIG. 4 is a diagram for explaining a procedure for determining representative values of gray levels in the image illustrated in FIG. 3. FIG. 5 is a flowchart showing the procedure for determining the representative value. Figure 2 Figure 3

Claims (1)

[Claims] In a moving image transmission device comprising a transmitting section and a receiving section and configured to transmit and receive moving image information, an arbitrary frame of the moving image is divided into regions according to a gradation level of grayscale information, and the divided regions are divided into regions. a boundary extractor that extracts the boundaries of the divided regions to form boundary information; a representative value extractor that extracts representative values of the gradation levels of the divided regions; and a representative value extractor that extracts the representative values of the gradation levels of the divided regions; A transmitting section comprising means for associating representative values; and a receiving section comprising means for generating gray scale information based on the received boundary information and the received representative values of gradation levels. A moving image transmission device characterized by: