JPH11243541A - Still image data storage communication method and still image data storage communication device - Google Patents

Abstract

(57) [Summary] [Problems] The present invention provides a method for transmitting compressed still image data stored in a self-terminal to a partner terminal having a smaller capacity than the data, and decompressing the self-terminal again. An object of the present invention is to provide a still image data storage communication method and a still image data storage communication device which enable high-compression to communicate still image data with a terminal having a small memory capacity. SOLUTION: When still image data exceeding the capacity of a memory 18 of a partner terminal is compressed and stored in a memory 11 of the own terminal, and the data is transmitted to a partner terminal control unit 17 through a communication line 13, The still image codec 9 temporarily expands the still image data and recompresses it to the memory capacity of the partner terminal, so that the still image data exceeding the capacity of the memory 18 of the partner terminal can be transmitted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a still picture data storage communication method and apparatus for communicating compressed still picture data.

[0002]

2. Description of the Related Art Hitherto, still image data stored at a certain compression rate has been transmitted to a partner terminal at the same compression rate.
Hereinafter, the configuration will be described with reference to the drawings.

FIG. 5 is a block diagram of a conventional still image data storage communication device. In the figure, 10 is its own terminal control unit, 11 is a memory, 12 is a line interface, 13 is a communication line,
16 is a line interface, 17 is a partner terminal control unit,
18 is a memory. As shown in FIG. 5, the still image data stored at a certain compression rate in the memory 11 of the terminal itself is
Transmitted to the partner terminal control unit 17 through the communication line 13;
Data having the same compression rate is stored in the memory 18 of the partner terminal.

[0004]

In such a conventional still image data storage communication device, transmission cannot be performed if the memory capacity of the partner terminal is smaller than the transmission data.

[0005] The present invention solves the above-mentioned problems, and a still image data storage and communication method and a still image data generating method capable of generating still image data according to the memory capacity of a partner terminal and transmitting the still image data to a terminal having a small memory capacity. It is intended to provide a data storage communication device.

[0006]

According to the still image data storing and communicating method of the present invention, image data which has been JPEG-compressed using a certain quantization table is temporarily expanded by a decoder using the same quantization table. The quantization table control unit selects a quantization table for increasing the compression rate, and generates highly compressed JPEG image data by an encoder using the quantization table. With this configuration, still image data corresponding to the memory capacity of the partner terminal can be generated and transmitted to a terminal having a small memory capacity.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 is a method of temporarily expanding image data that has been JPEG-compressed using a certain quantization table by a decoder using the same quantization table, and then controlling the quantization table. The section selects a quantization table for further increasing the compression ratio, and generates highly compressed JPEG image data by the encoder using the quantization table. With this configuration, it is possible to generate still image data according to the memory capacity of the partner terminal and transmit the still image data to a terminal having a small memory capacity.

[0008] The invention according to claim 2 is a method in which J
A memory for storing PEG-compressed still image data, a still image codec unit for generating compressed image data of the still image data stored in the memory, communication, compression, decompression,
A control unit for controlling storage and the like, wherein the still image codec unit once decompresses JPEG-compressed image data using a certain quantization table by a decoder using the same quantization table, The quantization table control unit selects a quantization table that increases the compression ratio, and uses the quantization table to perform the J-level compression with the encoder.
This is for generating PEG image data. With this configuration, when data is transmitted, compressed data having a small capacity can be generated.

According to a third aspect of the present invention, the control unit controls the quantization table in accordance with the free space information of the memory transmitted from the partner terminal, and outputs the J output from the encoder.
Optimum JPEG compression is performed while comparing the amount of PEG compressed image data with the amount of free memory. With this configuration, highly compressed image data can be generated.

According to a fourth aspect of the present invention, a notice of the free space of the memory of the partner terminal is received from the partner terminal, and recompression is performed so as to fit in the memory of the partner terminal. With this configuration, it is possible to optimally compress the still image data according to the memory capacity of the partner terminal.

(Embodiment 1) FIG. 1 is a block diagram of a still image data storage / communication apparatus according to Embodiment 1 of the present invention, and FIG. 1 (a) shows the expansion of JPEG-compressed image data. FIG. 1B shows a method of performing JPEG compression of image data.

In FIG. 1A, reference numeral 1 denotes compressed image data compressed by JPEG, 2 denotes a decoder for decoding coded data, 3 denotes restored image data decoded by the decoder 2, and 4 denotes quantum data. 5 shows a conversion table designation unit. In FIG. 1B, reference numeral 5 denotes an encoder for encoding image data, and reference numeral 6 denotes JP again.
EG-compressed recompressed image data, 7 indicates a quantization table designating section, and 8 indicates a quantization table group and a control section.

By specifying the same quantization table as used in the compression in the quantization table designating section 4, the compressed image data 1 JPEG-compressed using a certain quantization table is temporarily expanded by the decoder 2. For the expanded restored image data 3, a quantization table group and a control unit 8 select a quantization table that further increases the compression rate.
By setting the quantization table in the quantization table designating section 7, the encoder 5 performs JPEG compression again, and recompressed image data 6 is generated.

FIG. 2 is a block diagram of a terminal unit of the still image data storage communication device according to the first embodiment of the present invention. In FIG. 2, reference numeral 9 denotes a still image codec for performing JPEG compression / expansion, 10 denotes a terminal control unit, 11 denotes a memory for storing image data, 12 denotes a line interface,
Reference numeral 3 denotes a communication line.

JPEG compression at a certain compression ratio
When transmitting the still image data stored in 1 to the partner terminal, the still image codec 9 temporarily decompresses the data by the method shown in FIG. Small compressed data can be generated.

(Embodiment 2) FIG. 3 is a block diagram of a still image data storage / communication apparatus according to Embodiment 2 of the present invention. FIG. 3 (a) expands JPEG-compressed image data. The method is shown in FIG.
4 shows a method for performing PEG compression. In FIG. 3 (a), 1 is JPEG-compressed image data, 2 is a decoder for decoding encoded data, 3 is restored image data decoded by the decoder 2, and 4 is a quantization table designation. Indicates a part. In FIG. 3B, reference numeral 5 denotes an encoder for encoding image data, reference numeral 6 denotes recompressed image data which has been JPEG-compressed again, reference numeral 7 denotes a quantization table designating section, and reference numeral 14 denotes various quantization table patterns. Quantization table group, 15
Denotes a compression ratio control unit for selecting an optimal quantization table while comparing the free space of the partner memory with the recompressed image data 6.

The quantization table designating section 4 designates the same quantization table as that at the time of compression, so that the JPEG-compressed compressed image data 1 is temporarily expanded by the decoder 2 using a certain quantization table. The decompressed restored image data 3 is selected from the quantization table group 14 by a quantization table for further increasing the compression ratio, and is again JPEG-compressed by the encoder 5. In the encoder 5, J
In order to know the amount of PEG-compressed data, the number of bits of encoded data is counted. Further, the compression ratio control unit 15 compares the free space of the memory transmitted from the partner terminal with the recompressed image data 6, and when the recompressed image data 6 is larger than the free space of the memory, the compression ratio is increased. Is selected from the quantization table group 14, and re-compression is performed by the encoder 5 again. This operation is repeated until the compressed data becomes smaller than the memory capacity of the partner terminal to generate optimal JPEG compressed data.

FIG. 4 is a block diagram of the entire system of a still image data storage communication device according to the second embodiment of the present invention. In FIG. 4, reference numeral 9 denotes a still image codec for performing JPEG compression / expansion, reference numeral 10 denotes a local terminal control unit, reference numeral 11 denotes a memory of the local terminal for storing image data, reference numeral 12 denotes a line interface, reference numeral 13 denotes a communication line, and reference numeral 15 denotes a compression ratio control unit. , 16 is a line interface, 17 is a partner terminal control unit, and 18 is a memory of the partner terminal.

When transmitting JPEG still image data to the partner terminal control unit 17, a notification of the free space of the memory 18 is received from the partner terminal control unit 17 through the communication line 13 in advance, and the still image is transmitted by the method shown in FIG. By performing compression / expansion by the codec 9 and the compression ratio control unit 15, it is possible to generate compressed data according to the free space of the memory 18 of the partner terminal.

[0020]

According to the present invention, since still image data is compressed in accordance with the capacity of the memory of the partner terminal, still image data is transmitted even when the memory of the partner terminal is smaller than the transmission data. can do.

[Brief description of the drawings]

FIG. 1 is a block diagram of a still image data storage communication device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a terminal unit of the still image data storage communication device according to the first embodiment of the present invention.

FIG. 3 is a block diagram of a still image data storage communication device according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of an entire system of a still image data storage communication device according to a second embodiment of the present invention.

FIG. 5 is a configuration diagram of a conventional still image data storage communication device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressed image data 2 Decoder 3 Reconstructed image data 4 Quantization table designating unit 5 Encoder 6 Recompressed image data 7 Quantization table designating unit 8 Quantization table group and control unit 9 Still image codec 10 Own terminal control unit 11 Memory DESCRIPTION OF SYMBOLS 12 Line interface 13 Communication line 14 Quantization table group 15 Compression rate control part 16 Line interface 17 Remote terminal control part 18 Memory

Claims (4)

[Claims] An image data compressed by JPEG using a certain quantization table is once decompressed by a decoder using the same quantization table, and then a quantization table control unit increases the compression rate. Is selected by the encoder using the quantization table,
A still image data storage communication method characterized by generating PEG image data. 2. A memory for storing still image data JPEG-compressed at a certain compression ratio, a still image codec for generating compressed image data of the still image data stored in the memory, communication, compression, and decompression. A still image codec unit, which once decompresses JPEG-compressed image data using a certain quantization table by a decoder using the same quantization table, Still image data storage communication characterized in that a quantization table control unit selects a quantization table for increasing the compression ratio and generates highly compressed JPEG image data by an encoder using the quantization table. apparatus. 3. The control unit controls a quantization table in accordance with information on a free space of a memory transmitted from a partner terminal, and stores a JPEG compressed image data amount output from an encoder and a memory free space of the partner terminal. 2. The method for storing and communicating still image data according to claim 1, wherein the optimum JPEG compression is performed while comparing. 4. The still image data storage communication method according to claim 1, wherein the compression rate is determined by receiving a notification of the free space of the memory of the partner terminal from the partner terminal.