JP2839055B2 - Image editing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compression / expansion means for compressing and outputting input image data at a set compression ratio and for expanding and outputting the input compressed data. The present invention relates to an image editing apparatus which is separately provided corresponding to compression / expansion of a field.

[0002]

2. Description of the Related Art The conventional image editing apparatus described above compresses a large amount of video data and stores it in storage means when editing any video data into new video data. It is for reproducing as a visible image, and as shown in FIG.
It was configured to perform time-division processing. For example, a switching means c is provided to switch both the compression operation and the expansion operation at the same time so that an image of one frame composed of an odd field and an even field is compressed or expanded in a time-division manner corresponding to each field. . More specifically, the route of the data line d and the compression / decompression mode are switched by switching the input signal to the switching means c with digital signals of “H” and “L”.

[0003]

When an image is edited using a plurality of image data as materials, the image data is stored in a large-capacity storage means for easy handling, and the necessary data is stored in the storage means. It is convenient to read the image data. Then, in order to efficiently store the image data in the storage unit having a limited capacity, it is necessary to compress and store the image data by the image editing apparatus. By the way, the reduction rate of the capacity of the compressed data with respect to the original image data differs depending on the compression rate and the image, and the reduction rate tends to increase when the compression rate is increased and decreases when the compression rate is decreased. Depending on the compression method (for example, the international standard JPEG method), it is impossible to faithfully reproduce the original image at the time of decompression due to the use of the lossy encoding method. Has a difference in superiority in the expanded image. Therefore, the compression ratio must be set with the quality of the decompressed image in mind, but in order to determine whether the set compression ratio is appropriate, the compressed data must be decompressed again. It is essential to actually reproduce the information on the display means and visually check it. This is the same when transmitting compressed data via a line. However, in the conventional image editing apparatus, since the compression means and the expansion means cannot be operated at the same time, after the compression means completes the compression and stores the data in the storage means, the compressed data is stored in the storage means. A procedure of reading, expanding by the expansion means, and reproducing the data on the display means must be provided, and there is a disadvantage that this procedure is extremely complicated and time-consuming. For this reason, the conventional image editing apparatus may adopt an overlapping configuration in which two units are prepared and data compressed by one compression unit is expanded by another expansion unit, but economic efficiency is inferior. There is a disadvantage that. An object of the present invention is to eliminate the above-mentioned conventional disadvantages.

[0004]

In order to achieve this object, the image editing apparatus according to the present invention comprises a first mode in which both of the compression / expansion means perform either the compression or expansion operation. A mode switching means for switching to a second mode in which one compression / expansion means performs the compression operation and the other compression / expansion means performs the expansion operation on data compressed by the one compression / expansion means. It is in.

[0005]

When the image data is compressed at the already determined compression ratio and stored in the storage medium, and when the compressed data is extracted and expanded from the storage medium, the first mode is set by the mode switching means. In other words, in the case of compressing, the image data constituting the odd field and the even field of the input image data of one frame is stored at the compression ratio set in correspondence with both the compression / expansion means. In the case of compressing and outputting by dividing and expanding, in the case of input compressed data, both compressing / expanding means correspond to the compressed data constituting the odd field and the even field, respectively, in a time-division manner. Decompress and output. Also, when compressing image data and storing it on a storage medium, if the appropriate compression rate is unknown, or if the image quality at the time of reproducing the compressed data at the set compression rate is to be checked, etc. The second mode is set by the mode switching means. In this case, one of the compression / expansion means compresses the image data of either the even field or the odd field at a temporary compression ratio,
Decompress the compressed data by the other compression / decompression means,
The output data is output to a CRT or the like. An image displayed on a CRT or the like is a so-called frame-dropping screen (30 fields / second), and the quality of the image quality can be easily and promptly determined by visual observation. As a result, when it is determined that the compression ratio needs to be changed, the compression ratio is reset and the above operation is repeated. By reproducing the image data on the display device using the image data thus expanded, the quality of the reproduced image is visually checked every time the compression operation is performed. If dissatisfied, the compression ratio setting is changed on the spot and appropriate compression is performed. Under the rate, it can be quickly stored in the storage means.

[0006]

Thus, according to the present invention, while input image data is compressed at a set compression ratio and output,
Mode switching is a very simple circuit even in a conventional image editing apparatus configured to provide a pair of compression / expansion means for expanding and outputting input compressed data in accordance with time-division compression / expansion. An economical image editing apparatus capable of easily setting an appropriate compression ratio and evaluating a reproduced image image can be provided simply by adding means.

[0007]

Embodiments will be described below. As shown in FIG. 6, an image editing apparatus that handles color images handles an image signal input from a video signal output terminal of a laser disk player LD, a video deck VD, or the like as a still image for each frame, and generates a predetermined compressed data. To storage device M
And the storage device 7 such as a hard disk HD and the host computer HC.
This is a device that takes in compressed data transferred from the same, edits and synthesizes it, transfers it to the storage device 7, expands it into image data, and outputs it to a video signal input terminal such as a laser disk player LD or a video deck VD. substrate)
As implemented in the host computer HC.

More specifically, as shown in FIG. 1, an NTSC image signal input from a video signal output terminal is converted into an RGB analog signal by an encoder 1, and the encoded RGB analog signal is converted to an A / D signal. The data is converted into digital image data (pixel data) by the converter 2. A first compression / expansion means 3 for compressing the odd field of the image data and a second compression / expansion means 4 for compressing the even field are provided. And output to the recording means 7 and the like via the interface circuit 6. On the other hand, the compressed data stored in the recording means 7 and the like is input to the first compression / expansion means 3 and the second compression / expansion means 4 for each of the odd field and the even field via the interface circuit 6 and decompressed by time division. 8 are alternately output as image signals of odd and even fields. Further, the D / A converter 9
It is converted to a GB analog signal, and the
The image signal is converted into a C-system image signal and output to a video signal input terminal.

The above-described image editing apparatus includes a gate circuit G
Gate circuits G1, G2, G3, G4, and G5 are provided, and the compression / expansion operation is switched by the gate circuits G1, G2, and G3, and both of the compression / expansion means 3 and 4 are operated by the gate circuits G4 and G5. A first mode in which either the compression or expansion operation is performed, one compression / expansion means 3 performs the compression operation, and the other compression / expansion means 4
Switches to the second mode in which the data compressed by one of the compression / decompression means 3 is expanded. That is, the gate circuits G4 and G5 serve as mode switching means. More specifically, as shown in FIG. 2, the compression / expansion control signal for controlling the gate circuits G1, G2, G3 is set to "L", and the mode switching signal for controlling the gate circuits G4, G5 is set to "L".
When "H" and "L" are set, the gate circuit G2 is turned on, the gate circuit G3 is turned off, the gate circuit G4 is turned on, and the gate circuit G5 is turned off, and the compression operation is performed. As shown in FIG. When the control signal is set to "H" and the mode switching signal is set to "H", "H", the gate circuit G2
Is turned off, the gate circuit G3 is turned on, the gate circuit G4 is turned off, and the gate circuit G5 is turned off, and the extension operation is performed.
When the compression / expansion control signal is set to "L" and the mode switching signal is set to "L" and "H", as shown in FIG. 4, the gate circuit G2 is turned on, the gate circuit G3 is turned off, and the gate circuit G3 is turned off. The circuit G4 is turned off, the gate circuit G5 is turned on, and the image data of the odd field compressed by the first compression / expansion means 3 is expanded by the second compression / expansion means 4 and output to the video signal input terminal.

The compression / expansion means 3 and 4 are respectively provided with IS
US CC meeting O / CCITT JPEG standard
It is configured using CL550B which is an IC manufactured by Ube Microelectronics (Sea Cube Microelectronics). Specifically, FIG.
And a pixel bus interface 31 for storing one frame of raster data as input image data, dividing and outputting each block of 8 × 8 pixels, and outputting the reproduced image data in reverse. Is subjected to DCT (Discrete Cosine Transform) based on a DCT (Discrete Cosine Transform) coefficient table 34, and the transformed output is quantized based on a quantization table 35 for determining a compression ratio, and then the two-dimensional coefficients are arranged in one dimension. A processor 32 that performs zigzag scanning and further converts the one-dimensional quantized data into a Huffman code based on the Huffman table 36 and a decompression process that is the reverse operation, and inputs and outputs the compressed data to a host computer HC and the like. A host bus interface 33 for processing, the host computer HC, etc. Between, are constituted from the control data bus interface 37 for inputting and outputting control data of the data such as various for input and output timing control of the data.

The image editing apparatus is constructed on a single board and is configured to be mounted in an expansion slot of the host computer HC.
(Discrete cosine transform) Table data such as a coefficient table 34, a quantization table 35, and a Huffman table 36 are transferred. That is, the compression ratio can be arbitrarily set variably by the quantization table data transferred from the host computer HC.

The operation of the image processing system will be described below with reference to the flowchart shown in FIG. A video signal, which is an image signal output from the laser disc player LD, is output to a CRT connected to the host computer HC. The operator looks at the image on the display screen or the like, and transfers appropriate quantization table data to the image processing apparatus to set a compression ratio according to the image. Mode switching means G4
G5 is set to the second mode by controlling the first mode, the first compression / expansion means 3 compresses the image signal of the odd field, and the second compression / expansion means 4 simultaneously decompresses the compressed data. The image signal reproduced by the expansion means 11 is represented by C
Display output to RT. The operator visually checks the screen displayed on the CRT to determine whether or not the compression ratio is appropriate. If it is determined that a preferable reproduced image cannot be obtained, the operator stops the compression operation, and then adds new preferable quantization table data. Is transferred to the image processing apparatus, and the compression processing is restarted from the beginning. If it is determined that the compression ratio is appropriate, the mode switching means G4
G5 is controlled to set the first mode, the compression operation is started, and the compressed data is transferred to the recording device 7.

Hereinafter, another embodiment of the present invention will be described. In the above embodiment, the compression / expansion means is a U.S. C-Cube Mic.
Although the configuration using the CL550B, which is an IC manufactured by R. Electronics (Sea Cube Microelectronics), has been described, the configuration is not limited to this, and the configuration can be made using any IC.
Also, the present invention is not limited to those that handle NTSC video signals, and can be applied to any video signal. In this case, the function of the encoder 1 may be changed to a function corresponding to the function. In the above embodiment, the description has been given of the case where the image to be compressed in the second mode is limited to odd fields. However, the present invention is not limited to this, and may be configured using even fields.

In the above embodiment, an example in which the time-division processing is performed on a field-by-field basis has been described.

In the above embodiment, the case where the compression / expansion algorithm of the JPEG system is used has been described. However, the compression system is not limited to this and can be applied to any system. Further, the image processing apparatus according to the present invention includes a device having a compression / decompression function for improving data transmission and storage efficiency for image data such as a video conference / video phone call, a color still image, and a color moving image, and an AVCC (audiovisual / video). It can be used for devices that contribute to computer / communication) integration.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a block diagram of an image editing apparatus.

FIG. 2 is a block diagram of an image editing apparatus.

FIG. 3 is a block diagram of an image editing apparatus.

FIG. 4 is a block diagram of an image editing apparatus.

FIG. 5 is a block diagram of a main part.

FIG. 6 is a schematic configuration diagram of an image processing system.

FIG. 7 is a flowchart.

FIG. 8 is a block diagram of a conventional image editing apparatus.

[Explanation of symbols]

 3 First compression / expansion means 4 Second compression / expansion means G4, G5 Mode switching means

Claims (1)

(57) [Claims] A compression / expansion means (3), (4) for expanding input compressed data and outputting the compressed image data while compressing and outputting the input image data at a set compression ratio is provided. An image editing apparatus comprising a pair corresponding to compression and decompression, wherein said compression and decompression means (3) and (4) both perform one of said compression and decompression operations. One compression / expansion means (3) performs the compression operation, and the other compression / expansion means (4) switches to the second mode in which the data compressed by the one compression / expansion means (3) is expanded. An image editing apparatus provided with mode switching means (G4) and (G5).