JPH04107084A - Picture compressing device - Google Patents

Abstract

PURPOSE:To improve the reproducibility and the editing efficiency of a data file after edition, and to easily obtain a snychronization with sounds by arranging a time code adder which corresponds to each frame of picture data by one to one at a stage which is previous to a prediction encoder. CONSTITUTION:When analog composite signals are inputted, they are A/D converted by an A/D converter 13, separated into luminance signals and color differential signals by a Y/C separator 15, and outputted to a time code adder 17 as the picture data. The time code adder 17 compresses data for one frame, adds a pseudo time code to each frame after compression, and outputs it to a TDM converter 19. The data are processed for time-division multiplexing adaptively by the converter 19, and applied to a low-pass filter 23 after the quantity of data is adjusted by a frame thinner 21. After that, the data are outputted by a prediction encoder 25 as the data file.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image compression device, and in particular to an image compression device that is used in an image editing device and compresses data on the premise that the compressed data will be edited. Related to improvements.

[Prior Art] Conventionally, as this type of image compression device, one having a configuration as shown in FIG. 8, for example, is known.

That is, an analog composite signal as a source image input in frame units is converted into a digital signal by the A/D converter 1, and a luminance signal (Y signal) is converted by the Y/C separator 3.
It outputs image data separated into color difference signals (C signal: RY signal and B-Y signal), and performs time division multiplexing (Time Di
vision multiplex (hereinafter abbreviated as TDM) A converter 5 processes the image data by time division multiplexing, a low-pass filter 7 removes noise, and a predictive encoder 9 compresses the image data using a predictive coding method. It is configured to create a data file, and this data file is recorded on a recording device 11 such as a node disk, and is used after being edited as appropriate.

Note that there is also a configuration in which the source image is a composite signal that has been digitized in advance and is directly input to the Y/C separator 3.

These recorded data files are compressed moving image files or files consisting of a plurality of frames, and can be edited frame by frame.

[Problems to be Solved by the Invention] However, in the image compression device as described above, as shown in FIG. Generally, frames are recorded in correspondence with each other, and each frame is managed in association with a relative number.

Therefore, when performing editing such as cutting out some frames in a data file and replacing or inserting them with frames in other data files, it is difficult to create a good edited data file, and it is difficult to create a good edited data file. Poor reproducibility and poor editing efficiency.

Also, since it is not possible to tell which part of the source image was created by compressing the compressed data file, it is difficult to synchronize the source image and source audio when they are compressed and edited separately. Editing is complicated because synchronization must be achieved through trial and error.

The present invention has been made in order to solve these conventional drawbacks, and is an image compression method that allows the creation of data files that have good reproducibility and editing efficiency after editing, and are also easy to synchronize with audio. It provides equipment.

[Means for Solving the Problems] In order to solve such problems, the present invention provides a Y/C separator that Y/C separates a digital image signal input in frame units into a luminance signal and a color difference signal; A time division multiplex converter that time division multiplexes Y/C separated image data; a low pass filter that removes noise from the time division multiplexed image data; and a low pass filter that removes noise from the time division multiplexed image data; Alternatively, it has a predictive encoder that performs compression by interframe predictive coding, and a time code adder that is placed before the predictive encoder and adds a time code that corresponds one-to-one to each frame of the image data. It is configured.

Further, the present invention can also be configured such that a frame thinner that thins out image data frame by frame is disposed downstream of the time code adder.

Moreover, in the present invention, as the time code adder,
It can be configured to generate a pseudo time code, to add a time code input from the outside and temporarily held, and to switch between these time codes and add them to the image data.

[Function] In the present invention having such a means, the time code adder adds time information to the image data separated by the Y/C separator from the digital image signal input in frame units as time information. Since the time codes are added in a one-to-one correspondence to each frame, the time information of each frame of compressed image data is preserved even if the predictive encoder performs intra-frame or inter-frame compression processing.

Furthermore, in a configuration in which the time code adder is placed before the frame thinner, even if frame thinning is performed to adjust the amount of compressed image data, the time information of the relevant frame is preserved.

In a configuration in which the time code adder generates a pseudo time code, it is possible to add a time code to a source image that does not have a time code, and the time code adder can also input a time code from an external source. When configured to temporarily hold and add a time code, if a source image with a time code is input from the outside, a time code corresponding to the frame being processed is added.

Furthermore, if the time code adder is configured to switch between these time codes and add them to the image data, it is possible to add time codes to various source images regardless of the presence or absence of time codes.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of an image compression device according to the present invention.

In the figure, the A/D converter 13 converts an analog composite signal as a source image input in units of toolem into A/D converter 13.
/D conversion, and is connected to a Y/C separator 15. The Y/C separator 15 separates the digitally converted signal into a luminance signal and a color difference signal, and outputs the image data to the time code adder 17. It is something to do.

Note that a pre-digitized composite signal can be directly input to the Y/C separator 15.

The time code adder 17 has a function of compressing data for one frame, and adds a time code (details will be described later) consisting of hours, minutes, seconds, and a frame number to the compressed image data for the frame being processed. It is attached to each frame and outputted, and is connected to the TDM converter 19.

The configuration of the time code adder 17 is, for example, as shown in FIG.
a memory 17a that stores and outputs the input time code for a predetermined period of time in synchronization with the frame of the digital composite signal; a time code generator 17b that internally generates a pseudo time code; Alternatively, it is formed with a switch 17d that switches the time code from the time code generator 17b and outputs it to the bus 17c.

Note that the memory 17a stores and outputs the external time code only during the period during which the time code adder 17 compresses data for one frame.

Both external timecode and pseudo timecode are
As shown in the figure, it functions as an absolute address consisting of hours, minutes, seconds, and a frame number, and a frame has 30
The seconds are sexagesimal, the minutes are sexagesimal, and the hours are appropriately selected: 30 frames advance 1 second, 60 seconds advance 1 minute,
The clock advances one hour in 60 minutes. Note that FIG. 3 shows the image data in an uncompressed state.

The TDM converter 19 is a known device that adaptively processes time division multiplexing of image data consisting of a luminance signal and a color difference signal in order to time division multiplex exchange the image data, and is connected to the frame thinner 21. There is.

The frame thinner 21 thins out every appropriate frame to adjust the amount of compressed data.

For example, if the amount of information contained in the source image is large, such as an image reproduced from a CD-ROM, 150
Frame thinning is performed in order to keep the transmission rate within KB (see 5th section below). However, this frame thinner 21 is not essential.

A low-pass filter 23 for removing noise in image data is connected to the frame thinner 21, and a predictive encoder 25 is connected to the low-pass filter 23.

This predictive encoder 25 compresses image data within/between frames using a predictive encoding method, and outputs the compressed image data with a time code attached to each frame, as a data file. For example, it is connected to a recording device (not shown) that records on a storage medium such as a hard disk.

Note that the time code outputted from the above-mentioned time code adder 17 along with the image data passes through the same route as the image data, but is not subjected to compression processing.

Next, the operation of the image compression apparatus described above will be briefly explained.

When an analog composite signal is input, it is A/D converted by an A/D converter 13, separated into a luminance signal and a color difference signal by a Y/C separator 15, and outputted to a time code adder 17 as image data.

When a digital composite signal is directly input to the Y/C separator 15, the digital composite signal is
/C is separated and added to the time code adder 17.

The time code adder 17 appropriately compresses the data for one frame, and in synchronization, the switch 17d selects the time code generator 17b and outputs the time code generator 1.
A pseudo time code from 7b is attached to each compressed frame, and the time coded image data as shown in Figure 3 is transferred to TD.
Output to M converter 19.

FIG. 4 shows conventional compressed image data, and since information about how many frames after an adjacent frame is stored in each frame itself is not stored, the relationship between each frame cannot be specified.

On the other hand, in the image data from the time code adder 17, time information between adjacent frames is preserved.

The time code adder 17 switches the switch 17 when the digital composite signal is input to the Y/C separator 15.
c selects memory 17a and attaches the external time code from memory 17a. and output.

The subsequent processing is the same for both image data to which an internally generated pseudo time code or an external time code is attached.

The image data with the time code is sent to the TDM converter 19
The frame thinner 21 thins out appropriate frames to adjust the data amount as shown in FIG. Added to 23.

In a configuration that does not use the frame thinner 21, the time-division multiplexed image data is directly applied to the low-pass filter 23 to remove noise.

After that, the image data is compressed within/between frames in the predictive encoder 25, and the compressed image data is output along with the time code that passed through the same route without being compressed, as a data file. It is output to a recording device (not shown).

For example, a data file consisting of image data with a time code, as shown in FIG. 6, output from such an image compression device is cut out (8th to 16th frames) and converted into a data file as shown in FIG. When this is connected to the first frame of a data file consisting of image data with a time code, one edited data file as shown in FIG. 7 is edited and created.

In this case, since the time code corresponding to each frame is absolute address data, by referring to the time code and image data, a new data file as shown in Figure 7 can be edited accurately, so the edited data file can be reproduced. It has good performance, and is easy and efficient to edit.

What's more, by looking at the time code of the edited data file, you can accurately identify the frames in the original data file.

Also, when compressing the audio data in Figure 3 that corresponds to the source image and synchronizing the data file and editing it as shown in Figure 7, you can easily edit the audio file by referring to the time code. can be synchronized with the beginning of

Note that in the above configuration, an absolute address is assigned to each frame of image data, but the present invention may also be configured to assign a relative number to each frame from the first frame in the image data, and in this case, each frame is assigned an absolute address. Easily editable by referring to relative numbers.

[Effects of the Invention] As explained above, the image compression device of the present invention includes a time code adder that adds a time code to each frame of image data, which is placed before the predictive encoder, and adds a time code to the image data frame by frame. Since the configuration is such that a data file is created by adding time information in real time and performing compression processing, etc., editing work such as cutting out moving images etc. can be done by using the time code for the created data file. can be done accurately and easily, and the reproducibility of frame data is not lost.

Moreover, by using the time code, it is possible to edit and create a data file that is well synchronized with the audio.

Further, in a configuration in which the frame thinning device is placed after the time code adding device, even if frame thinning is performed, it is possible to accurately grasp frames, and time information between frames is preserved.

If the time code adder is configured to generate pseudo time codes, it becomes possible to add pseudo time codes generated within the device even to source images that do not have time codes, and the data file structure can be improved. It is easy to unify the system.

Furthermore, if the time code adder is configured to add time codes input from an external source and temporarily held, it is possible to perform compression processing on source images with time codes, or to compress and thin out image data. You can create data files with accurate timecode attached to each frame.

Furthermore, if the time code adder is configured to switch between external time code and internally generated pseudo time code and add it to the image data, the data file structure can be changed to support various source images. Further unification can be achieved.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of an image compression device according to the present invention, FIG. 2 is a block diagram showing an example of the time code adder in FIG. 1, and FIG. 3 is a block diagram showing uncompressed image data. Figure 4 is a conceptual diagram showing a data file consisting of conventional compressed image data, Figures 5 and 6 are conceptual diagrams of conventional compressed image data.
The figure is a conceptual diagram of a data file consisting of image data created by the image compression device of the present invention, and FIG. 7 is a conceptual diagram showing the state of a data file edited using the image data created by the image compression device of the present invention. FIG. 8 is a block diagram showing a conventional image compression device, and FIG. 9 is a conceptual diagram of a data file consisting of image data created by the image compression device shown in FIG. 1.13...A/D converter, 3.15.
・・・・・・Y/C separator, 5.19・・・・・・
. . . TDM converter, 7.23 . . . Low-pass filter, 9.25 . . . Predictive encoder,
11・・・・・・・・・・・・・・・ Recording device,
17... Time code adder, 17a... Memory, 17b... ...... Time code generator, 17d... Switch, 21... Frame thinner.

Claims (5)

[Claims] (1) A Y/C separator that Y/C separates the digital image signal input in frame units into a luminance signal and a color difference signal, and a time division multiplex converter that time division multiplexes the Y/C separated image data. a low-pass filter that removes noise from the time-division multiplexed image data; and a predictive encoder that compresses the image data from the low-pass filter by intraframe or interframe predictive coding. An image compression apparatus characterized in that a time code adder for adding a time code that corresponds one-to-one to each frame of the image data is disposed at a stage before the predictive encoder. (2) The image compression apparatus according to claim 1, further comprising a frame thinner that thins out the image data frame by frame, and the time code adder is arranged before the frame thinner. (3) The image compression apparatus according to claim 1 or 2, wherein the time code adder generates a pseudo time code. (4) The image compression apparatus according to claim 1 or 2, wherein the time code adder adds a time code input from the outside and temporarily held. (5) The time code adder generates a pseudo time code, inputs the time code from the outside and forms it so that it can be temporarily held, and also switches between the pseudo time code and the external time code to add it to the image data. The image compression device according to claim 1 or 2, wherein the image compression device is an additional device.