JPS5840989A - Coding processing method and transmission controlling method of picture information - Google Patents

Abstract

PURPOSE:To transmit a picture information with high efficiency via a narrow band transmission line, by coding successively plural bit brains of the gradation component of the picture information converted into digital signals by the code corresponding to the changing point in the scanning line direction. CONSTITUTION:A picture 200 is stored in a bit brain 100' which is selected out of a memory array. The points x1-xj where the image data comprising (h) bits has changes are estimated by noticing an optional scanning line 20 when the picture 200 is scanned in the direction (x). This scanned data is shown in the form of a data train in which a changing point address xi is put in a set with a data Ci of (k) bits among addresses xi-xi+1. This coding is carried out for all scanned data of the picture 200.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for encoding #image information and a transmission control method suitable for transmission over a narrowband transmission line.

In order to transmit image information through a narrowband transmission line such as a telephone line, the scanning speed of the television scanning line has traditionally been slowed down.In this method, it is difficult to display the entire Im image. Another drawback is that it is difficult to grasp the image until all the image information has been transmitted, since the entire scanning of the 17 television screens must be completed.

In contrast, using recent digital signal processing technology,
A method of encoding image information has been proposed for the purpose of efficient transmission.For example, there is a method of sequentially transmitting image information converted to a digital signal starting from the highest bit plane of the 9th gradation level. Since images can be handled as binary information, there is an advantage that information can be compressed by run-length encoding in the same way as facsimile signals. Also.

Divide the image into several blocks, first transmit the average value of the gradation level of each boot block, then roughly divide the size of the blocks, reduce the size of the blocks, and calculate the average of only the bootsks that have a large error from the above average value. There is a method of repeatedly finding and transmitting values. This method has the advantage of being excellent in compressing the amount of information, but has the disadvantage that the equipment for encoding and decoding the information becomes complex.

The present invention uses a plurality of bit planes of gradation components of image information converted into a digital signal or bits 7'L/-7 of a plurality of color components of a color image converted into a digital signal at a change point in the scanning line direction or It is characterized by sequential encoding using run-length codes and codes corresponding to gradations or hoods corresponding to color components.

The purpose is to provide an encoding processing method and a transmission control method suitable for efficiently transmitting image information via a narrowband transmission path.

54?1 Figure 1 shows a configuration example of a known image memory composed of semiconductor elements, etc. for storing image information converted into digital signals. In Figure 0, 100 is a memory cell composed of a semiconductor IC memory etc. is a meso 7 ray that corresponds to the pixel array.

5 1-bit brains made up of MXNg votes, 101no!
105. 110 is an input terminal for image data converted into a digital signal; 111 is a control circuit for assigning quantized gradation levels to bit planes; 120 is a write circuit for writing data into the bit planes; 130 is a successive circuit for reading data from the bit plane; 112 is a successive selection control circuit for selectively controlling the data read from the memory 7 array 100; 11
3 is an output terminal. The image memory device configured as described above stores image information that is converted into a digital signal in which the 0 gradation level is quantized to zero bits. Also O1
Coordinate system g as shown on Mesosu 7 Ray 100 in the figure,
y is determined and the 0 image is scanned in one direction.

b bitplanes C2< of 100 memory arrays
If the readout selection control circuit 112 selects h **), the signal read out from the output terminal 113 becomes an h-bit digital signal. When the mesorial array is sequentially scanned in one direction, the resulting 1-bit digital signal can be encoded by the address of the point where this value changes and the b-bit code.

Figure 2 is an explanatory diagram showing the image information encoding processing method of the present invention. In Figure 2, lod represents the bit plane of the first bit selected from the meso array 100 shown in Figure 1. An image 200 is stored therein. Now, when focusing on an arbitrary scanning line 201 when scanning the zero image 200 in one direction, there is a point on this scanning line where the image data consisting of bits changes -t * 81 +
Suppose that ``'・s/ exists. That is, when the & bit data is set as C(((=1.2...,/).

CI from point #1 to point #1 Point #1'-I C torture Point sj~m1+ls C/ Suppose it was.

Such scan data is stored at a change point address m4. as shown in Figure 5t'3. and 9 points 14 to szi+s, the data C ((4m1.2...,7) is expressed as a set of data strings, and a termination code EOL tube is placed at the end of l scanning.

Such encoding is performed on all the scanned data of the image 200. For example, by encoding the S-bit quantized image bit plane by bit plane sequentially from the most significant bit plane using the above method, the entire image is encoded. Information can be encoded. In this encoding processing method, the smaller the number of changing points of the data on the scanning line, that is, the simpler the image is close to the 2m image, the more the amount of data converted into the original digital signal is Images can be encoded with less data.

The fourth example is an example of an encoding processing method using a run-length code used in facsimile, etc., instead of the change point address #1 in the example of FIG.

Here, the run-length code is one in which the distance between the change points l i=1-+1-II4 (4=1.2, . . . , /) is assigned to an appropriate code.

The fifth wave is 9. In Figure 1, which is an explanatory diagram showing the encoding processing method when the present invention is applied to color image information,
R, 100G, and 100B are red (9) and green (G1) when defeated.
．． The color image information of the color component of blue (Bl) is converted into a digital signal, and the color image information is stored in the image memo V of Fang 1, etc., and is converted into a digital signal in this way. For example, as shown in Figure 5, bit planes R&, G&, and Bk with a quantization level of %h bits are extracted one by one from the data of each color component of the information, and the extracted bit planes are superimposed. Focusing on an arbitrary scanning line 201 when the m image 200 is scanned in one direction, the scanning data obtained at this time is the change point address m4, the change point # (and Data C1 between 14+1
It can be expressed as , and encoded as shown in Figure 3 or Figure 4. In this case, data C (is Rh.

It consists of a total of 3 bits, 1 bit each for Gh and Bh. By performing such encoding on all scanned data of the 0 image 200, and sequentially extracting and repeating each bit plane from the R, G, and B image information each quantized with arithmetic bits, a color image is created. encode information.

The above explanation deals with the case where one bit plane is extracted from the image information of each color component and encoded, but it is also possible to extract multiple arbitrary bit planes, superimpose them, and encode them. . For example, R, G, H
If each 2-bit plane is extracted from the image and encoded, C- will be represented by 6-bit data.

A method of transmitting encoded image data using the encoding processing method described above will be explained with reference to FIG. The data obtained by extracting a plurality of bit planes from the image data converted into a digital signal and encoding them using the above method is called encoded plane data. Suppose that bit planes are extracted and encoded. Among the data encoded in this way, the encoded plane data corresponding to the most significant bit are sequentially numbered 1, 2, . −.

K (=!I'6) is attached, and the encoded plane data is transmitted in numerical order along with an encoding parameter indicating the bit position in the original image data.

In this way, since the image data corresponding to the upper bits of the original image are transmitted sequentially, if the data pipes transmitted to the terminal device having 9 image frames ν and a display section are decoded, m images can be decoded. Since the high-luminance portion of the image is displayed on the display unit in sequence, the outline of the image can be grasped quickly before all information is transmitted.

The above transmission control method can also be applied to the color image information explained in the 5tPS diagram.

The above effect tube can be obtained by sequentially transmitting encoded data for the bit plane of the most significant bit of each color component.

As described above, according to the present invention, it is possible to efficiently compress and encode multi-tone seven-tone image information or color image information.

By sequentially transmitting data starting from data corresponding to high brightness levels, a summary of one image's information can be obtained even when using a narrowband transmission line! (The advantage is that you can know.

What is an apparatus that implements such an encoding processing method?

It can be easily configured by an image memory having a control circuit that can read out each bit plane, a circuit for comparing the read data, and an address counter circuit. Also, in order to decode the transmitted encoded data, +
There is an advantage that data writing to the iI image memory can be easily performed by controlling it.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an image memory device for storing image information converted into digital signals, Fig. 2 is an explanatory diagram of the encoding processing method of the present invention, and Fig. 3 shows encoded l-scan data. A configuration diagram showing an example of expression. Figure 4 @ is a configuration diagram showing another example of representation of encoded l-scan data, Figure 5 is an explanatory diagram showing a method of encoding color image information, and Figure 6 is a diagram showing how encoded data is transmitted. FIG. 3 is an explanatory diagram showing a transmission control method in this case. In the figure, 100 is an image memory consisting of a plurality of bit planes, 200 is an image stored in the image memory, and 201
is one scanning line on the image, 100R. 100G and 100B are ffM of red, green, and blue components, respectively.
An image memory in which image information is stored is shown. Patent Applicant: Nippon Telegraph and Telephone Public Corporation Patent Attorney Mori 1) Hirozai 3rd Eye

Claims (1)

[Claims] (1) Extract only -h (2<&<II) bit information from image information quantized with % (2<IB) bits. For each scan of the screen, perform the operation to obtain a set f of pairs of data change point coordinates or run length codes and data values for the entire screen, and then perform the above operation for the image information of the remaining bits of the image information. A method for encoding an image 111@, characterized by sequential repetition. (Illusion) In the image information encoding method recited in claim 1, color image information that is separated into six color components and each quantized with a plurality of bits is converted into a single image from the image information of each color component. Alternatively, only multiple bits of image information are extracted and superimposed.The operation of encoding the combined image information by the method is sequentially repeated for the remaining bits of image information of the color image information. (3) Extract only h (2≦1<s) bit information from the image information quantized with duck (2≦悌) bits for each scan of 0 screen. By performing an operation to obtain data change point coordinates or a set of pairs of run length code and data value for the entire screen, and roughly repeating the above operation sequentially for the remaining bits of image information of the image information. Regarding encoded data: Data that encodes the information extracted sequentially from the image information including the most significant bit is placed at the beginning, and then the encoded data of the image information of the lower bits is sequentially arranged and transmitted. A method for controlling encoded data transmission of image information, characterized by: