JPH08322025A - Different kind video system interchangeable encoder - Google Patents

Abstract

PURPOSE: To perform normal image coding transmission without requiring a video system converter separately when image coding transmission between a transmission side and a reception side with different video systems in performed. CONSTITUTION: This encoder is equipped with a first format converter 15 which converts the signals of image parts on 525 horizontal scanning lines that is one frame of an NTSC system to a prescribed format in which the horizontal direction is formed with M pixels, and the vertical direction with L pixels and with N frames per second, a first encoder/decoder circuit 6 and a second encoder/decoder circuit 9 which performs coding/decoding processing on a digital signal system provided with the prescribed format, and a second format converter 21 which converts a reproduced signal of prescribed format reproduced by the second encoder/decoder circuit 9 to the image parts on 625 horizontal scanning lines that is one frame of a PAL or SECAM system, and the first format converter 15 and the first encoder/decoder circuit 6 are arranged on the transmission side, and the second format converter 21 and the second encoder/decoder circuit 9 on the reception side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image coding / decoding device.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram showing a configuration of a transmitting side and a receiving side in a conventional image coding and transmitting apparatus for the same video system. In the figure, 2 is an A / D converter that converts the input video signal 1 into a digital image signal 3, and 4 is a Y / C separator that separates a luminance signal Y component and a color difference signal C component. Send signal 5. Reference numeral 6 denotes a transmitting side encoding / decoding circuit which performs encoding transmission processing on the image signal, and outputs encoding information 7. 8 is a digital transmission line,
Reference numeral 9 is a receiving side encoding / decoding circuit for reproducing an image signal from the encoded information 7, and outputs an image reproduction signal 10. 11
Is a Y / C combiner for combining the luminance signal Y component and the color difference signal C component, and sends out the Y / C combined signal 12. A D / A converter 13 converts the Y / C combined signal 12 into an analog output signal 14.

Next, the operation of the conventional image coding and transmitting apparatus shown in FIG. 4 will be described. Now, in the input side video signal 1 on the transmission side, in the case of the NTSC system, 30 frames per second and 525 horizontal scanning lines per frame, and in the case of the PAL or SECAM system, 25 frames per second and 625 horizontal scanning lines per frame. Is. The same applies to the analog output signal 14 on the receiving side. First, on the transmitting side, the input video signal 1 is converted by the A / D converter 2 into the digital image signal 3 excluding the horizontal synchronization and vertical synchronization portions, and then,
The Y / C separator 4 separates the luminance signal Y component and the color difference signal C component. Next, in the transmitting side encoding / decoding circuit 6,
Image coding is performed on M (M is a positive integer) pixels in the horizontal direction and L (L is a positive integer) pixels in the vertical direction as a coding target range of the Y / C separated signal 5 by the Y / C separator 4. Then, the frame information is dropped and the coded information 7 is sent to the digital transmission line 8. At this time, for L pixels in the vertical direction, only one field in one frame is to be encoded, and the number of pixels to be encoded is limited by sampling lines at equal intervals. The same applies to M pixels in the horizontal direction. On the other hand, on the receiving side, the receiving side encoding / decoding circuit 9 uses the encoded information 7 received from the digital transmission line 8 by the number of M pixels in the horizontal direction and L in the vertical direction.
The image reproduction signal 10 having the number of pixels is generated, and the Y / C synthesizer 11 is generated.
Then, the luminance signal Y component and the color difference signal C component are combined while performing linear interpolation in the horizontal and vertical directions, and the Y / C combined signal 12 is converted by the D / A converter 13 to output the analog output signal 14. . It should be noted that, for a frame that has been dropped due to dropped frames, the immediately preceding image reproduction signal is repeatedly output.

[0004]

Since the above-described conventional image coding and transmitting apparatus is configured as described above, when the transmitting side and the receiving side have different video systems, the image on the transmitting side and the image on the receiving side are different from each other. Since the ratio of the image portion to the entire screen in the vertical direction is different between them and the reproduced image is distorted, there is a problem that a new video format conversion device is required on the transmission side or the reception side.

The present invention has been made to solve the above problems, and provides a heterogeneous video system compatible encoding device capable of performing video communication between different video systems without externally adding the above video system conversion device. The purpose is to

[0006]

A heterogeneous video system compatible encoding apparatus according to the present invention provides a signal of an image portion in 525 horizontal scanning lines which is one frame of the NTSC system with M pixels in the horizontal direction and L pixels in the vertical direction. Pixels, a first format converter for converting into a predetermined format of N frames per second, a first encoding / decoding circuit for performing an encoding / decoding process on a digital signal sequence having the above-mentioned predetermined format, and The second encoding / decoding circuit and the reproduction signal having the predetermined format reproduced by the second encoding / decoding circuit are converted into an image portion in 625 horizontal scanning lines which is one frame of the PAL or SECAM system. A second format converter, the first format converter and the first encoding / decoding circuit are arranged on the transmitting side, and the first format converter and the first encoding / decoding circuit are arranged on the receiving side. By high-speed steel and a second format converter and a second encoding and decoding circuit, and performs image encoding transmission to the receiving side from the transmitting side by using different video systems from each other. In addition, signals of an image portion in 625 horizontal scanning lines, which is one frame of the PAL or SECAM system, include M pixels in the horizontal direction and L pixels in the vertical direction.
A first format converter for converting into a predetermined format of N frames per second, a first encoding / decoding circuit for performing an encoding / decoding process on a digital signal sequence having the above-mentioned predetermined format, and a second A second format for converting an encoding / decoding circuit and a reproduction signal having the above predetermined format reproduced by the second encoding / decoding circuit into an image portion in 525 horizontal scanning lines which is one frame of the NTSC system. A first conversion device and a first encoding / decoding circuit on the transmitting side, and a second conversion device and a second encoding / decoding circuit on the receiving side. Are arranged to perform image coding transmission from the transmission side to the reception side using different video systems.

[0007]

FIG. 1 is a block diagram showing a configuration of a transmitting side and a receiving side in a heterogeneous video system compatible encoding apparatus according to an embodiment of the present invention. It is the same as the conventional example shown in FIG. In the figure,
Reference numeral 15 is a format converter on the transmission side, which outputs a format-converted signal 16. Reference numeral 17 denotes a transmission side frame memory, which sends out a frame signal 18 to be encoded. 1
Reference numeral 9 is a receiving side frame memory for storing the image reproduction signal 10, and sends out the image reproduction signal 20. Reference numeral 21 is a receiving side format converter, which is a format converted signal 22.
Is sent. FIG. 2 is an explanatory diagram showing an example of the transmission side format conversion in the case where the transmission side video system is the PAL or SECAM system in the heterogeneous video system compatible encoding device of FIG.
FIG. 3 is an explanatory diagram showing an example of receiving-side format conversion in the case where the receiving-side video system is the PAL or SECAM system in the heterogeneous video system compatible encoding apparatus of FIG.

In this heterogeneous video system compatible encoding apparatus, the format converter uses the PAL or SECAM video system as a format converter to coarsely sample vertical lines as compared with the NTSC system. In the PAL or SECAM method on the receiving side, the number of line interpolations in the vertical direction is increased as compared with the case of the NTSC method, so that the image ratios of the entire screen in the vertical direction on the transmitting side and the receiving side are matched. To

Next, the operation of the heterogeneous video system compatible encoding apparatus according to the embodiment of the present invention shown in FIG. 1 will be described. With respect to the Y / C separated signal 5 on the transmitting side, in the transmitting side format converter 15, the input video signal 1 is NT.
In the case of the SC method, starting from a predetermined line, L lines are simply sampled from n × L (n and L are positive integers and n × L is smaller than 525) lines of the image portion. On the other hand, in the case of the PAL or SECAM method, the number of horizontal scanning lines in one frame is 625, which is larger than that in the NTSC method. Therefore, one of six input lines is thinned out using the weighted average between lines. Generate a line of books.
FIG. 2 shows an embodiment of the transmission side format conversion in the case where the input video signal 1 is of the PAL or SECAM system. The format-converted signal 16 is temporarily stored in the transmission side frame memory 17, and then read out as the encoding target frame signal 18 in accordance with the encoding processing timing of the transmission side encoding / decoding circuit 6. The encoded information 7 sent from the transmitting side encoding / decoding circuit 6 is transmitted to the digital transmission line 8.

On the other hand, the image reproduction signal 10 reproduced by the reception side encoding / decoding circuit 9 is stored in the reception side frame memory 19 and then read out as the image reproduction signal 20 at every frame cycle of the reception side video system. At this time, frames that have been dropped due to the encoding process on the transmission side or PA
In the case of the L or SECAM system and the frame missing when the receiving side is the NTSC system, the immediately preceding image reproduction signal 20 is repeatedly read. Next, in the receiving side format converter 21, when the receiving side video system is the NTSC system, linear interpolation is performed on the L lines of the image reproduction signal 20 to generate the n × L lines, PA
In the case of the L or SECAM method, in addition to the above linear interpolation, interpolation is performed at a ratio of 1 in 5 to n × L × 1.2.
(N × L × 1.2 is a positive integer) lines are generated.
FIG. 3 shows an embodiment of the format conversion on the receiving side when the receiving side video system is the PAL or SECAM system. The format-converted signal 22 that is format-converted by the reception-side format converter 21 is output to the Y / C combiner 11, and the D / A converter 11 performs D / A conversion after combining the luminance signal Y component and the color difference signal C component. Then, the analog output signal 14 is output in the receiving side video system. In the above embodiment, the number of pixels to be encoded in the encoding / decoding circuit is fixed, but the number and range of pixels to be encoded can be switched in the format converter.

[0011]

As described above, according to the present invention, in the heterogeneous video system compatible encoding apparatus, the transmitting side and the receiving side are provided with the encoding / decoding circuits for performing the encoding / decoding processing, respectively, and the transmitting side is encoded. Since the format converter is provided at the front stage of the decoding circuit and at the rear stage of the receiving side encoding / decoding circuit, the device can be constructed at low cost and the video communication between different video systems is extremely versatile. This has the excellent effect of providing a highly compatible heterogeneous video system compatible encoding device.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a transmission side and a reception side in a heterogeneous video system compatible encoding apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an example of transmission side format conversion in the case where the transmission side video system in the heterogeneous video system compatible encoding apparatus of FIG. 1 is the PAL or SECAM system.

FIG. 3 is an explanatory diagram showing an example of receiving side format conversion in the case where the receiving side video system in the heterogeneous video system compatible encoding device of FIG. 1 is the PAL or SECAM system.

FIG. 4 is a block diagram showing a configuration of a transmission side and a reception side in a conventional image encoding and transmitting apparatus for the same video system.

[Description of Codes] 1 Input video signal 2 A / D converter 3 Digital image signal 4 Y / C separator 5 Y / C separated signal 6 Transmitting side encoding / decoding circuit 7 Encoding information 8 Digital transmission line 9 Reception Side encoding / decoding circuit 10, 20 Image reproduction signal 11 Y / C combiner 12 Y / C combined signal 13 D / A converter 14 Analog output signal 15 Transmission side format converter 16, 22 Format converted signal 17 Transmission Side frame memory 18 Frame signal to be encoded 19 Reception side frame memory 21 Reception side format converter.

Claims (2)

[Claims] 1. A signal of an image portion in 525 horizontal scanning lines, which is one frame of the NTSC system, is converted into M in the horizontal direction.
A first format converter for converting a pixel into a predetermined format having L pixels in the vertical direction and N frames per second;
Reproduced by the first encoding / decoding circuit and the second encoding / decoding circuit for performing the encoding / decoding process on the digital signal sequence having the predetermined format, and the second encoding / decoding circuit. A second format converter for converting the reproduced signal having the predetermined format into an image portion in 625 horizontal scanning lines which is one frame of the PAL or SECAM system, and the first format converter on the transmission side. By disposing the first encoding / decoding circuit, and disposing the second format converter and the second encoding / decoding circuit on the receiving side, from the transmitting side using different video systems. A heterogeneous video system compatible encoding device, which performs image encoding transmission to a receiving side. 2. A signal of an image portion in 625 horizontal scanning lines, which is one frame of an input signal of the PAL or SECAM system, is converted into a predetermined format having M pixels in the horizontal direction, L pixels in the vertical direction, and N frames per second. A first format converter for converting, a first coding / decoding circuit and a second coding / decoding circuit for coding / decoding the digital signal sequence having the predetermined format, and second And a second format converter for converting the reproduced signal having the above-mentioned predetermined format reproduced by the encoding / decoding circuit of the above into an image portion in 525 horizontal scanning lines which is one frame of the NTSC system, and is provided on the transmission side. The first format converter and the first encoding / decoding circuit are arranged, and the second format converter and the second format converter are provided on the receiving side.
And a coding / decoding circuit of the above are arranged to perform image coding transmission from a transmitting side to a receiving side using different video systems from each other.