JPH10276430A - Adaptive simplified motion jpeg compressing device and adaptive simplified motion jpeg compressing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adaptive simplified motion JPEG compressing device and method which suppress data quantity and obtain satisfactory moving image compressed data. SOLUTION: Preprocess control 6 compares the images of one preceding field and one subsequent field in a moving image compressing procedure, decides compressibility in accordance with its result and performs frame drop. JPEG data is acquired by performing a DCT 7 of data which is undergone the preprocessing, quantizing 8 it in accordance with the compressibility and finally performing Huffman coding 9 of it. Also, the data transfer speed of a reproducing device that becomes a target is considered and compressed. A prescribed transfer rate is a transfer rate to a recording medium that records compressed image data, e.g. a hard disk 11. Further, a compression operation is automatically controlled to an optimum level in the transfer rate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention
The present invention relates to an adaptive simple motion JPEG compression apparatus and an adaptive simple motion JPEG compression method for creating a compressed image conforming to the EG (Joint Picture Expert Group / International Standardization Working Group for Color Still Image Coding).

[0002]

2. Description of the Related Art Conventionally, Huffman coding and the like have been used for compression / reproduction of image data. FIG. 5 is a block diagram showing a configuration example of a conventional general image data compression apparatus. In the moving image reproduction of the image data compression device of the first conventional example, reproduction is possible by preparing a reproduction decoder device conforming to the MPEG standard. However, the device becomes expensive.

[0003] Therefore, by continuously reproducing images conforming to the JPEG standard, apparently moving images can be reproduced. Adaptive simple motion JPEG compression apparatus and adaptive simple motion JPE using this JPEG standard
In general, in the G compression method, an inexpensive moving image reproducing apparatus and method can be configured.

For example, Japanese Patent Application Laid-Open No. 5-28445 of the prior art 2
The "information recording / reproducing apparatus" disclosed in Japanese Patent Publication No. 4 (1999) includes a compression / expansion device for compressing and recording a digital video signal according to the JPEG standard, and expanding and reproducing the reproduction compressed data according to the JPEG standard. This compression / expansion device is constituted by a moving image radar that performs a switching operation every frame scanning period.

[0005] In the "compression image coding apparatus" of Japanese Patent Application Laid-Open No. H5-115055 of prior art 3, a component image signal is switched to an LPF for limiting a frequency band by a switch, and then input to an AD converter to receive digital information. , A DCT transformer, a quantizer, and a Huffman encoder reduce the data amount. Further, the compressed image data is accumulated by the FIFO and output at a constant data rate. The signal of the OF detector for detecting the amount of data stored in the FIFO is given to the control terminal of the switch,
By limiting the frequency band of the image signal before compression so that O does not overflow, it works to make the compressed image data rate constant and constitutes an image compressor with a fixed data rate.

[0006]

However, the technique of the above-mentioned prior art 2 is an apparatus having only a function of continuously reproducing still images. Further, in the third conventional example, even if the compression ratio setting function is provided, once the compression ratio is set to a certain value, the encoding is performed at the compression ratio until the end. In addition, since there is a limit on the transfer rate of data from the recording medium of the compressed data reproducing apparatus, it takes a very long time to complete encoding work for the deterioration of image quality and the amount of data.

When the problems of the above conventional example are examined in more detail, the following problems arise in obtaining efficient moving image data. A first problem is that if a compression rate is set once when compressing a moving image, encoding is performed at the same compression rate until the end. For this reason, since the compression ratio is constant even when the scene (scene) changes, a redundant image or too much compression depending on the scene, that is, an image in which the image quality is deteriorated occurs.

The second problem is that it is necessary to perform compression while minimizing image quality degradation while taking the transfer rate into consideration, so that it is necessary to confirm the encoding operation many times.

The present invention provides an adaptive simple motion JPEG in which the amount of data is suppressed and good moving image compressed data is obtained.
An object of the present invention is to provide a compression apparatus and an adaptive simple motion JPEG compression method.

[0010]

To achieve this object, an adaptive simple motion JPEG compression apparatus according to the first aspect of the present invention determines a scene based on a current signal of a moving image, a signal before one field, and a signal after one field. A scene determination unit for performing the determination, a selection unit for selecting a thinning level based on a result of the scene determination, a quantization control unit for controlling a compression ratio, and a GC control unit for controlling the number of frames. It is characterized in that image data can be compressed in accordance with the transfer rate.

[0011] The predetermined transfer rate may be a transfer rate to a recording medium for recording the compressed image data.

Further, the adaptive simple motion JPEG compression apparatus has overall operation control means for controlling the operation of the entire apparatus, and the overall operation control means automatically controls the compression operation to an optimum level within the transfer rate. Good to do.

An adaptive simple motion J according to the invention of claim 4
The PEG compression method includes a scene determination step of performing scene determination based on a current signal of a moving image, a signal before one field, and a signal after one field, a selection step of selecting a thinning level based on a result of the scene determination, and control of a compression ratio. And a GC control step of controlling the number of frames.
It is characterized in that it is possible to compress image data adapted to a predetermined transfer rate.

The predetermined transfer rate may be a transfer rate to a recording medium for recording the compressed image data.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an adaptive simplified motion JPEG compression apparatus and an adaptive simplified motion JPEG compression method according to an embodiment of the present invention. 1 to 4 show an embodiment of an adaptive simplified motion JPEG compression apparatus and an adaptive simplified motion JPEG compression method according to the present invention.

FIG. 1 shows an example of a system configuration to which an adaptive simplified motion JPEG compression apparatus and an adaptive simplified motion JPEG compression method are applied. In FIG. 1, an adaptive simplified motion JPEG compression apparatus according to the present embodiment is configured as a system in which the output of a VTR (video tape recorder) 1 is connected to two systems to an encoder body, and a hard disk 11 is connected to an output unit. Have been.

The encoder body includes a VTR 1, a GC (gain control) 2, an A / D (AD converter) 3,
PLL (Phase Locked Loop) 4, SG (Signal Generator) 5, PRI PROCESS C
ONTROL6, DCT (Discrete Cosine Transform Block)
7, a quantization (quantization block) 8, a Huffman coding (Huffman coding block) 9, and a decoder 10.

An adaptive simple motion JPEG having the above configuration
In the compression device, the material of the moving image compressed to the VTR 1 is
The hard disk 11 stores the compressed data. The encoder main body is a device for compressing a moving image material.

First, a video tape of a moving picture material is placed in a VTR1.
And the data is supplied to the encoder main body. The supplied video signal is split into two, the first signal is
The level is adjusted in the GC2 section, and the analog signal is converted to a digital signal in the A / D3 block, and PRE PRO
Input to CESS CONTROL6. Also, the second signal is synchronized by the PLL4 block,
The timing signal is generated in 5 parts and PRE PROCESS
Input to CONTROL6.

PRE PROCESS CONTROL
6, scene determination of the moving image data, GC2 control, thinning control, and quantization control are performed.
Is input to DCT is performed by DCT 7, quantization is performed by quantization 8, and Huffman coding 9 is performed.
It becomes JPEG compressed data. The data is recorded on the hard disk 11 and is subjected to inverse conversion of the JPEG compressed data by the decoder 10 and output to the monitor for confirming the compressed data in real time.

FIG. 2 shows PRE PROCESS C.
3 shows a more detailed first configuration example inside the ONCONTROL 6.
The digital signal of A / D3 is stored in a field memory (ME
M) 12, a field memory (MEM) 13, and a difference detector (DET) 14 performs a scene determination based on a current signal, a signal before one field, and a signal after one field, and a selector controller (sel) based on the result.
(cont) 16 controls the thinning of the selector (select) 15. In addition, quantization / controller (co
At nt) 17, the compression ratio of the quantized block is controlled.
Further, the compressed data from the Huffman coded block is rate detected by a transfer rate detector (DET) 19, and as a result, a gain control controller (GC con
t) At 18, control the level of GC2.

Next, an operation example of this embodiment will be described in detail with reference to FIGS. As an operation procedure of this device, PLAY is transferred from the transfer rate DET19 to the VTR1.
Give instructions. Playback is performed once, and if the rate falls within the transfer rate (S1 / Yes), the process ends. If not (S1 / No), transfer rate D
The ET 19 issues a REW instruction to the VTR 1, and when the REW is completed, the reproduction is performed again. Next, if the difference DET14 can be thinned out, sel cont16 is
The thinning is performed by controlling ct15 (S2). If the result is within the transfer rate (S3 / Yes), the process ends. Otherwise (S3 / No), transfer rate DET again
19 causes the VTR 1 to perform REW and PLAY.

Next, GC2 is controlled by GC cont18 (S4). As a result, if the transfer rate is within the transfer rate (S5 / Yes), the process is terminated.
o), REW from the transfer rate DET19 to the VTR1 again
And PLAY.

Next, as a result of the seal determination based on the difference DET14,
For scenes that can be compressed, quantization cont17
To control the quantization 8 (S6). If the result is within the transfer rate (S7 / Yes), the process ends. Otherwise (S7 / No), control of the quantization 8 part (S6)
Are repeatedly executed (S6, S7).

FIG. 3 shows the PRE PROCESS CONT.
4 shows a more detailed second configuration example inside the ROL 6. That is, FIG. 3 shows another different embodiment adapted to the pre-processing unit of FIG.

In FIG. 3, the transfer rate DET 19, sel cont 16, quantization cont 17, GC c
A system in which each block of ont18 is replaced by a one-chip microcomputer and controlled by a program is adopted.

In the above moving picture compression method, it is checked whether or not the current scene has changed from the previous scene by comparing the image one field before and one field after. In this check, if there is a change, control is applied to the quantization block to increase the compression ratio. If there is no change, control is performed on the quantization block to reduce the compression ratio, and the frame is further dropped. This frame drop is performed basically in the same procedure as the processing procedure of FIG.

As described above, by controlling the compression ratio and the frame dropping control suitable for the scene, the data amount is suppressed, and good moving image compressed data can be obtained.

Therefore, in order to perform optimization with the conventional apparatus, the compression ratio is manually set for each scene (scene), and a great deal of manual work has occurred. , And the optimal compression ratio can be automatically set. In order to enable this processing, the adaptive simplified motion JPEG compression apparatus or method according to the present embodiment compares the image one field before and one field after in the moving image compression procedure. Decision or drop frames. The pre-processed data is subjected to DCT, quantized according to the compression ratio, and finally subjected to Huffman coding to obtain JPEG data. Also, compression is performed in consideration of the data transfer speed of the target reproducing apparatus.

The above embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited thereto, and various modifications can be made without departing from the gist of the present invention.

[0031]

As is clear from the above description, the adaptive simple motion JPEG compression apparatus and the adaptive simple motion JPEG compression method of the present invention can be applied to the present embodiment of the present invention.
Scene determination is performed based on the pre-field signal and the post-field signal. Based on the result of the scene determination, a thinning level is selected, the compression ratio is controlled, and the number of frames is controlled. Therefore, it is possible to compress the image data adapted to the predetermined transfer rate. According to this procedure, the compression ratio according to the scene can be automatically controlled by performing processing on the moving image data before performing compression and performing scene determination. In addition, by monitoring the compressed data at the transfer rate DET and taking into account the transfer rate of reproduction, it is possible to obtain compressed data giving priority to image quality.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a system configuration example applied to an embodiment of an adaptive simple motion JPEG compression apparatus and an adaptive simple motion JPEG compression method according to the present invention.

FIG. 2 is a block diagram illustrating a more detailed first configuration example of a preprocessing unit.

FIG. 3 is a block diagram showing a more detailed second configuration example of a preprocessing unit.

FIG. 4 is a flowchart showing an operation example.

FIG. 5 is a block diagram illustrating a configuration example of a conventional general image data compression apparatus.

[Explanation of symbols]

 1 VTR (Video Tape Recorder) 2 GC (Gain Control) 3 A / D (AD Converter) 4 PLL (Phase Locked Loop) 5 SG (Signal Generator) 6 PRE PROCESS CONTROL 7 DCT (Discrete Cosine Transform) 8) Quantization (quantization block) 9 Huffman coding (Huffman coding block) 10 Decoder 11 Hard disk 12 Field memory 13 Field memory 14 Difference detector 15 Selector 16 Selector controller 17 Quantization controller 18 Gain control・ Controller 19 Transfer rate detector 20 Microcomputer

Claims (5)

[Claims] 1. A current signal of a moving image, a signal before one field,
A scene determination unit that performs a scene determination based on a signal after one field, a selection unit that selects a thinning level based on a result of the scene determination, and a quantization control unit that controls a compression ratio;
An adaptive simple motion JPEG compression apparatus, comprising: GC control means for controlling the number of frames, and capable of compressing image data adapted to a predetermined transfer rate. 2. The adaptive simple motion J according to claim 1, wherein the predetermined transfer rate is a transfer rate to a recording medium for recording the compressed image data.
PEG compression device. 3. The adaptive simple motion JPEG compression apparatus further comprises an overall operation control means for controlling the operation of the entire apparatus, wherein the overall operation control means controls the compression operation to an optimum value within the transfer rate. 3. The adaptive simple motion JPEG compression apparatus according to claim 1, wherein the control is automatically performed to a level. 4. A current signal of a moving image, a signal before one field,
A scene determination step of performing a scene determination based on a signal after one field, a selection step of selecting a thinning level based on a result of the scene determination, and a quantization control step of controlling a compression ratio;
An adaptive simple motion JPEG compression method, comprising: a GC control step of controlling the number of frames; and enabling compression of image data adapted to a predetermined transfer rate. 5. The adaptive simple motion J according to claim 4, wherein the predetermined transfer rate is a transfer rate to a recording medium for recording the compressed image data.
PEG compression method.