JPH0487497A - Picture signal transmitter - Google Patents

Abstract

PURPOSE:To reduce a color picture data transmission time by using two B- channels for an ISDN transmission line so as to send a luminance signal component and a color difference signal component while applying compression coding to them respectively. CONSTITUTION:A picture data inputted to an input terminal 10 is fed to a YC separator circuit 20. The picture data inputted to the YC separator circuit 20 is separated into a luminance signal component data Y and two color difference signal component data Cr, Cb. The luminance signal component data Y is subject to compression coding at a coder 22 and the color difference signal component data Cr, Cb is subject to compression coding at a coder 24 respectively and they are outputted to an ISDN transmitter 26. Since the ratio of the luminance signal component data Y and the color difference signal component data Cr, Cb is set to be 4:2:2, the total data quantity of the luminance signal component data Y coded by the coder 22 and that of the color difference signal component data Cr, Cb coded by the coder 24 are almost equal to each other. Thus, the coding in the coders 22, 24 is implemented in parallel and finished in almost the same time.

Description

TECHNICAL FIELD The present invention relates to an image signal transmitting device, and more particularly to an image signal transmitting device for transmitting digital image signals to a communication line.

BACKGROUND ART As is well known, image signals have a large amount of information, and therefore, compression encoding is performed when transmitting or storing digital image signals. For example, in compression encoding of image signals, there is a method in which an image constituting one screen is divided into multiple blocks, the image data of each divided block is subjected to two-dimensional orthogonal transformation, and the orthogonally transformed data is encoded. Are known. However, in the case of color image data, luminance component data Y and color difference component data Cr and Cb are included.
Each of these component data must be encoded, and since the amount of data for each is large, it takes a long time to encode, and each of these encoded components must be transmitted individually, so it takes a long time to transmit. There was also the problem that it took time.

OBJECTS It is an object of the present invention to provide an image signal transmitting device that can eliminate the drawbacks of the prior art and shorten encoding and transmission times.

DISCLOSURE OF THE INVENTION According to the present invention, an image signal transmitting device that compresses and encodes color image data representing one screen image and transmits the compressed image data, which compresses and transmits the color image data representing one screen image, converts the color image data representing one screen image into luminance signal component data and color difference signal component data. A signal component separating means for separating data into data; a luminance signal component encoding means and a color difference signal component encoding means for respectively compressing and encoding the luminance signal component data and color difference signal component data separated by the signal component separating means; It has a component encoding means and a transmitting means for transmitting the luminance signal component data and color difference signal component data compression encoded by the color difference signal component encoding means, and the transmitting means transmits the compression encoded luminance signal component data and the color difference signal component data. Color difference signal component data is transmitted using two B channels of an ISDN transmission path.

According to the present invention, in an image signal transmission method in which color image data representing one screen of images is compressed and encoded and transmitted from the transmitting side to the receiving side, the transmitting side converts the color image data representing one screen of images into luminance Separate signal component data and chrominance signal component data, compress and encode the luminance signal component data and chrominance signal component data, respectively, and transmit the compression-encoded luminance signal component data and chrominance signal component data to the two Bs of the ISDN transmission line. The luminance signal component data and the color difference signal component data are transmitted to the receiving side via the channel, and the received luminance signal component data and color difference signal component data are respectively decoded to reproduce color image data.

DESCRIPTION OF EMBODIMENTS Next, embodiments of an image signal transmitting apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of an image signal transmitting device according to the present invention.

In this embodiment, an image signal obtained by a digital electronic still camera 12 or an image signal read from an image database such as an image file 14 is compressed, and the ISD
N (Integrated 5 services Dig
It is a device that transmits data on the B channel of the Internet Network.

In this image signal transmitting device, a digital electronic still camera 12 or an image data file 14 is connected to an input terminal IO. The digital electronic still camera 12 converts a single-screen analog image signal representing a field obtained by a solid-state imaging device into a corresponding digital signal, and outputs the digital signal to the input terminal 10 . Further connected to the input terminal 10 are an image data file 14, a keyboard 16, and a CRT 18.

The image data file 14 is a recording device that records various image data, and various image data are recorded in advance. Keyboards L and S are image data file 1
4, input instructions for reading specific image data. The CIF 718 displays image data read from the image data file 14.

A YC separation circuit 20 is connected to the input terminal 10. The YC separation circuit 20 separates the input image data into luminance signal component data Y and two color difference signal component data Cr and cb. Separated luminance signal component data Y and color difference signal component data Cr.

The ratio of cb data amount is usually 4:2:2.

Encoders 22 and 24 are connected to the YC separation circuit 20.

Encoders 22 and 24 compress and encode input image data. As compression encoding, for example, two-dimensional orthogonal transformation and Nofman encoding are performed.

That is, image data constituting one screen is divided into a plurality of blocks, data for each block is subjected to two-dimensional orthogonal transformation, and the orthogonally transformed data is normalized and then Huffman encoded.

The encoder 22 transmits the luminance signal component data Y to the encoder 24.
compresses and encodes the color difference signal component data Cr and cb, respectively, and outputs them to the ISDN transmitter 26.

As mentioned above, since the ratio of luminance signal component data Y and color difference signal component data Cr, Cb (7) is 4:2:2, the time required for encoding in encoders 22 and 24 is It will be almost the same.

This device is accommodated in the subscriber line of the I interface of the 15ON, and the ISDN transmitter 26 constitutes a part of the network termination equipment of the I interface. The ISDN transmitter 26 transmits the compressed and encoded image data sent from the encoders 22 and 24 to l5 by two B channels of l5OH.
This is a transmitter that transmits to the OH subscriber line.

As is well known, in the 15OH communication network, the basic interfaces are two B channels (user information transfer channels) with a transmission rate of 84 kbps and +8 kbps.
A D channel (circuit-switched signaling channel) with a transmission rate of ps is provided in a time-division multiplexed manner on the subscriber line. The ISDN transmitter 26 outputs data,
The compressed image data of the luminance signal component data Y sent from the encoder 22 is sent to the two B channels Bl and B2, and the color difference signal component data Cr and Cb sent from the encoder 24 are compressed by the channel B1. Image data to channel B2
, respectively, to the ISDN transmission path.

The operation of this transmission device will be explained.

When image data photographed by the digital electronic still camera 12 is transmitted, a single-screen analog image signal representing the field obtained by the solid-state imaging device is converted into a corresponding digital signal and sent to the input terminal IO. is input.

On the other hand, when transmitting specific image data from among the image data recorded in the image data file 14, the operator selects the image data to be transmitted from the keyboard 16.
instructions to do so are input. As a result, the designated image data is read from the image data file 14, and the CRT
It is displayed on 18 screens. The operator looks at the displayed image, confirms that it is the specified image, and further inputs instructions for compression encoding and transmission of this image from the keyboard 16, if necessary. As a result, the image data file 14
The image data read from is sent to the input terminal IO.

The image data input to the input terminal 10 is sent to the YC separation circuit 2
Sent to 0. The image data input to the YC separation circuit 20 is separated into luminance signal component data Y and two color difference signal component data Cr and cb. The data amount ratio is 4:2:2 in this embodiment. Y
The luminance signal component data Y separated by the C separation circuit 20 is input to the encoder 22, and the color difference signal component data Cr and cb are input to the encoder 24, respectively.

The luminance signal component data Y is compressed and encoded by the encoder 22, and the color difference signal component data Cr and cb are compressed and encoded by the encoder 24, and then output to the ISDN transmitter 26. As mentioned above, luminance signal component data Y, color difference signal component data C
Since the ratio of r and Cb is 4:2:2, the amount of luminance signal component data Y encoded in the encoder 22 and the color difference signal component data encoded in the encoder 24 are The total data amount of Cr and cb is approximately equal. Therefore, the encoding in encoders 22 and 24 occurs in parallel and ends at approximately the same time.

The data output to the ISDN transmitter 26 is transmitted via two B channels Bl and B2, and the compressed image data of the luminance signal component data Y sent from the encoder 22 is transmitted from the encoder 24 via channel B1. The compressed image data of the color difference signal component data Cr and Cb are respectively transmitted to the ISDN transmission line through the channel B2.

As described above, according to the present transmitting device, image data is separated into luminance signal component data Y and two color difference signal component data Cr and cb, and each of the data is compressed and encoded. Luminance signal component data Y and color difference signal component data Cr, Cb
The data amount ratio is usually 4:2:2, so 2
The time required for encoding the luminance signal component data and the color difference signal component data in the two encoders 22 and 24 is approximately the same. Therefore, the time required for encoding can be reasonably shortened. Further, the luminance signal component data Y and the color difference signal component data Cr, Cb are transmitted almost simultaneously to the two B channels B1. l5IIN by B 2
Since it can be transmitted to the transmission line, the transmission time is approximately 2
It can be shortened to one-fold.

FIG. 2 shows an embodiment of an image signal receiving device according to the present invention.

The receiving device includes an ISDN receiver 32. ISDN receiver 32 outputs the input compressed image data to decoders 34 and 36. That is, the compressed image data of the luminance signal component Y transmitted by channel B1 is transmitted to the decoder 34.
Then, the compressed image data of the color difference signal components Cr and cb transmitted through the channel B2 are outputted to the decoder 36, respectively. Decoders 34 and 36 decode the input compressed image data. That is, in this embodiment, after compressed image data is Huffman decoded, it is denormalized, two-dimensional orthogonal inverse transform is performed to obtain the original image data for each block, and these blows are combined to create the original image data. Obtain an image of one screen.

Decoders 34 and 36 are connected to YC memory 38. The YC memory 38 is a memory for temporarily storing the luminance signal component Y and color difference signal components Cr and Cb of the image data decoded by the decoders 34 and 36, and reading them out at the same timing. The YC memory 38 has a Y area 38Y that stores the luminance signal component Y and a C area 38G that stores the color difference signal components Cr and Cb. The output of the YC memory 38 is connected to a YC processing circuit 40.

The YC processing circuit 40 receives a luminance signal component Y and a color difference signal component Cr input from the YC memory 3B.

Combines the cb data and outputs color image data.

The output of the yc processing circuit 40 is transmitted to the CRT 42 and the keyboard 4.
6 and an image file 44. CRT 4
2 reproduces and displays the color image data input from the VC processing circuit 40. The keyboard 46 is an input means for the operator to input instructions such as recording the received image data in the image file 44. The image file 44 is a recording means for recording the received and decoded image data. be.

The operation of the receiving device will be explained.

Compressed image data transmitted from the ISDN transmission line through channels B1 and B2 is input to the ISDN receiver 32. The compressed image data input to the ISDN receiver 32 is
2: Output to II units 34 and 38. Channel B
The compressed image data of the luminance signal component Y transmitted by channel B2 is sent to the decoder 34, and the compressed image data of the color difference signal components Cr and cb transmitted by channel B2 is sent to the decoder 36.
Each is sent and decoded.

The luminance signal component Y and color difference signal components Cr and Cb of the image data decoded by the decoders 34 and 36 are YC
The signals are input to and stored in the Y area 38Y and C area 38C of the memory 38, respectively.

The data of the luminance signal component Y and the color difference signal components Cr and Cb, which are temporarily stored in the Y area 38Y and C area 38C of the YC memory 3B, are read out at the same timing and sent to the YC processing circuit 40. YC processing circuit 4
0, the luminance signal component Y and the color difference signal components Cr, C
The data in b is synthesized and the color image data is transferred to the CRT.
Sent to 42. The operator views the image displayed on the CRT 42, inputs necessary instructions from the keyboard 46, and records this image in the image file 44.

According to the above system, the two channels B1 and B2 of the ISDN transmission path are used to transmit the luminance signal component and the color difference signal component, respectively, so that the transmission time can be shortened. Moreover, since the luminance signal component and the chrominance signal component are each compressed and encoded before being transmitted, the amount of data to be transmitted is small and the transmission time is shortened, and furthermore, the luminance signal component and the chrominance signal component have almost the same amount of data. Therefore, the time required for transmission is not wasted.

Furthermore, in encoding in the transmitter, the two encoders 22 and 24 are used to encode the luminance signal component and the color difference signal component, respectively, so that the time required for encoding can be reduced to approximately half. Similarly, in decoding in the receiving device, since decoding is performed using two decoders 34 and 36, the time required for decoding is also shortened by approximately half. As described above, according to the present system, the time required for encoding, transmitting, and decoding color image data can be shortened, and image data can be transmitted and received at high speed.

Effects According to the present invention, the luminance signal component and the color difference signal component are compressed and encoded and transmitted using the two B channels of the ISDN transmission path, so that the transmission time of color image data can be shortened.

Furthermore, since the data bars of the luminance signal component and the color difference signal component are approximately equal, the times required for encoding, decoding, and transmission are approximately equal, and there is no wasted processing time.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of an image signal transmitting device according to the present invention, and FIG. 2 is a block diagram showing an embodiment of an image signal receiving device according to the present invention. Description of symbols of main parts Electronic still camera image file YC separation circuit encoder IS [3N transmitter ISDN receiver decoder YC memory YC processing circuit 12゜14. 20°22.24 26°32°34.3F3 38. 40°

Claims (2)

[Claims] 1. In an image signal transmitting device that compression encodes and transmits color image data representing one screen of images, the device separates the color image data representing one screen of images into luminance signal component data and color difference signal component data. luminance signal component encoding means and chrominance signal component encoding means for compressing and encoding the luminance signal component data and chrominance signal component data separated by the signal component separation means, respectively; a component encoding means and a transmitting means for transmitting the luminance signal component data and color difference signal component data compression encoded by the color difference signal component encoding means, the transmitting means transmitting the compression encoded luminance signal An image signal transmitting device characterized in that component data and color difference signal component data are transmitted using two B channels of an ISDN transmission path. 2. In an image signal transmission method in which color image data representing one screen image is compressed and encoded and transmitted from a transmitting side to a receiving side, the transmitting side converts the color image data representing one screen image into a luminance signal component. data and chrominance signal component data, compression encodes the luminance signal component data and chrominance signal component data, and transmits the compression encoded luminance signal component data and chrominance signal component data to two Bs of the ISDN transmission line. An image signal transmission method, characterized in that the image signal transmission method comprises: transmitting to the receiving side via a channel, decoding the luminance signal component data and the color difference signal component data received at the receiving side, and reproducing color image data.