KR950004112B1 - Digital image data filtering apparatus - Google Patents

Abstract

a synchronization signal divider for receiving the composite image signal to thereby divide the horizontal/vertical synchronization signal; a window signal generator for generating a window signal for selecting the analog/digital converted part in the horizontal scanning line of the composite image signal with reference to the divided horizontal synchronization signal; storing the analog/digital converted data; and a filtering part for filtering the data memorized in the memory during the inactive time which excludes the active time of the window signals, and memorizing the filtered data in the memory.

Description

Digital video data filtering device using inactivity time

1 is a block diagram of an apparatus for filtering digital image data using inactivity time according to the present invention.

2 is a diagram illustrating a general composite video signal and a window signal.

* Explanation of symbols for main parts of the drawings

10: synchronization signal separation unit 12: window signal generation unit

14: memory control unit 16: filtering unit

18: memory 20: analog / digital converter.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to video signal processing, and more particularly, to filtering of digitally converted video data that is performed during inactivity time.

Before coding data in a device related to a video signal such as a video telephone, the general process is to first create a composite video signal as a video camera for the scene to be transmitted, and convert the video signal among the composite video signals through an analog / digital converter. The digital signal is converted into a digital signal, and the changed digital signal is stored in a predetermined processing unit (for example, one screen) in a memory and then filtered. One of the reasons for filtering is to suppress noise generated by analog hardware prior to analog / digital conversion. Data that has undergone digital filtering is coded. Coding of data is a signal processing technique that compresses this data to transmit a large amount of information of a digitally converted video signal with limited bandwidth.

As described above, analog / modified signals are generally stored in memory on a screen basis and this stored data is coded by screen filtering. Since this real-time filtering time occupies a predetermined time before the coding time, the coding system High speed signal processing has always been required.

The present invention is to filter the screen unit before coding by scanning line unit at the inactive time including the retrace of the scanning line as one method of increasing the signal processing period of the coding system requiring such high speed signal processing.

One scan line can be divided into an active time and an inactive time. The active time is a time occupied by an image signal necessary for the actual filtering to be analog / digital converted in one of the complex video signals, and the inactive time is a horizontal synchronization signal and a burst signal. It is the time occupied by the section cut by the video format of the synchronization signal and the video signal. In this case, the active time may be generally generated by generating a window signal based on the horizontal synchronization signal. The device for filtering by using the inactivity time from such separate active and inactivity time has not been developed until now.

Accordingly, an object of the present invention is to provide an apparatus for performing filtering at inactive time in order to increase the signal processing period of a coding system.

According to the present invention, an apparatus for filtering digital image data in an inactive time includes a synchronization signal separation unit for receiving a composite image signal and separating horizontal and vertical synchronization signals, and a horizontal synchronization signal separated from the synchronization signal separation unit. A window signal generation unit for generating a window signal for selecting an analog / digital change portion in the horizontal scan line of the composite video signal as a reference, and the analog / digital conversion for displaying a portion of the window signal to be analog / digital converted; A memory for storing the stored data, a filtering unit for filtering the data stored in the memory during the inactive time which is a time other than the active time of the window signal, and storing the filtered data in the memory, and the analog / digital converted data. Stored in the memory 18 during the active time, and the inactivity And a memory controller to control the memory during the sexual period.

Hereinafter, the present invention will be described in detail with reference to the drawings.

1 is a device for filtering digital image data during inactivity time according to the present invention, and includes a synchronization signal processor 10, a window signal generator 12, a memory controller 14, a filter 16, and a memory 18. FIG. ), Analog / digital converter 20 is configured.

The synchronization signal separator 10 is a general circuit unit that receives a composite video signal and separates vertical and horizontal synchronization signals. The window signal generator 12 is connected to the synchronization signal separator 10 and based on the horizontal synchronization signal. It is a general circuit part that generates a window signal that distinguishes active time from inactive time.

The analog / digital converter 20 is connected to the window signal generator 12 to receive the window signal, and separates the active time from the composite video signal inputted to another input terminal based on the signal, thereby converting the image data of the separated active time. It is a general circuit part to perform digital conversion.

The memory controller 14 is connected to the window signal generator and receives a signal of a window separating active and inactive times, and based on this signal, is connected to the analog / digital converter 20 during the active time, and analog / It is a general memory for storing digitally converted data and filtered data.

FIG. 2 (a) shows a typical composite video signal of one scan line, and FIG. 2 (b) shows a signal of a window for distinguishing necessary image data for analog / digital conversion among general composite video signals. A typical composite video signal is a horizontal synchronization signal for determining the start point of horizontal scanning, a burst signal which is inserted immediately after horizontal synchronization (this part is called a back porch) and serves as a reference for matching the type of color on the transmission / reception side, and image contrast. And a luminance signal representing saturation and color.

Among the composite video signals described above, only the gray signal and the color signal (the section A of FIG. 2 (a) is necessary for the actual analog / digital conversion, and the extraction of this signal is the window signal shown in FIG. 2 (b). In this window signal, the portion "H" is the active time that is to be analog / digital converted, and the portion "L" is the inactivity time, i.e., the present invention is analog / digital in the section A of FIG. The filtered data is filtered during the interval (B).

Hereinafter, the present invention will be described in detail with reference to FIGS. 1 and 2.

When the composite video signal (FIG. 2a) is input to the synchronization signal separator 10, the horizontal synchronization signal is separated and output to the signal generator 12 of the window. The window signal generator 12 generates a window signal (FIG. 2 (b)) based on the horizontal synchronization signal and outputs the window signal to the memory controller 14 and the analog / digital converter 20. The analog digital converter 20 separates the active and inactive times of the composite video signal by using the window signal, and outputs the analog / digital conversion of the video signal during the active time to the memory 18. The memory controller 14 stores the analog / digital-converted data in the memory 18 when the time is active based on the input window signal, and filters the data stored in the memory when the time is inactive. Memory back to memory. The data stored after filtering in the scanning line unit is output to the coding system in a predetermined unit (for example, a screen unit).

Therefore, since coding can be performed by filtering analog / digital-converted data during inactivity time using inactivity time, which is not available in the conventional method of filtering one screen before coding, coding requiring high-speed signal processing The system can avoid complexity, and if the coding system of the same speed can improve the performance of the coding system.

Claims (1)

In filtering analog / digital converted digital image data, a synchronization signal separation unit 10 for receiving a composite video signal and separating horizontal and vertical synchronization signals, and a horizontal synchronization signal separated by the synchronization signal separation unit 10 A window signal generation unit 12 for generating a window signal for selecting an analog / digital change portion in the horizontal scan line of the composite video signal on the basis of the reference, and an active portion for displaying the portion to be analog / digital converted among the window signals; An analog / digital converter 20 for analog / digital converting a composite video signal corresponding to an active time for a time, a memory 18 for storing the analog / digital converted data, and a time excluding the active time of the window signal Filter the data stored in the memory 18 during the inactive time and store the filtered data in the memory 18. The key stores the filtering unit 16 and the analog / digital-converted data in the memory 18 during the active time, and causes the filtering unit 16 to control the memory 18 during the inactive time. Apparatus comprising an adjuster (18).