Picture encoding device, picture decoding device, and picture communication system

A picture encoding device operable to encode a plurality of time-series pictures, the picture encoding device comprising:

• a first encoder;
• a second encoder which performs in parallel with the first encoder;
• an intermediate buffer;
• an encoding target picture controller;
• and
• a field divider which divides a picture into a first field which includes an I picture and comprises an even-numbered column picture which comprises even-numbered pixels of each pixel lines, and a second field which includes a P picture and comprises an odd-numbered column picture which comprises odd-numbered pixels of each pixel lines,
• wherein the encoding target picture controller supplies one of the first column picture and the second column picture to the first encoder and the other to the second encoder,
• wherein the first encoder refers to picture information in the first field to encode the first field creates a reference picture from an encoding result, and writes the reference picture in the intermediate buffer,
• wherein the second encoder refers to picture information in the second field and the reference picture stored in the intermediate buffer to encode the second field, and
• wherein the second encoder is coupled to the field divider in parallel with the first encoder.

A picture decoding device operable to decode a plurality of time-series pictures from a first and a second encoded stream supplied from a first encoder and a second encoder, respectively, the picture decoding device comprising:

• a first decoder;
• a second decoder which performs in parallel with the first decoder;
• an intermediate buffer;
• and
• a decoding target image controller,
• wherein the first decoder refers only to the first encoded stream to decode picture information of a corresponding picture, creates a reference picture from a decoding result, and writes the reference picture to the intermediate buffer,
• wherein the second decoder refers to the second encoded stream and the reference picture stored in the intermediate buffer to decode picture information of a picture corresponding to the second encoded stream,
• wherein the decoding target image controller makes the second decoder start decoding a picture with reference to the reference picture concerned, before a following reference picture is written in the intermediate buffer from the first decoder,
• wherein the first encoded stream comprises even-numbered pixel lines of a picture including an I picture,
• wherein the second encoded stream comprises odd-numbered pixel lines of a picture including a P picture, and
• wherein the second encoder is coupled to a field divider in parallel with the first encoder, the field divider dividing a picture into the picture including the I picture and the picture including the P picture.

A picture communication system, comprising:

• a transmitter including a picture encoding device and an output control device;
• a transmission line;
• and
• a receiver including a picture decoding device,
• wherein the picture encoding device is operable to encode a plurality of time-series pictures, and comprises:
• a first encoder;
• a second encoder which performs in parallel with the first encoder;
• an intermediate buffer;
• an encoding target picture controller;
• and
• a field divider which divides a picture into a first field which includes an I picture and comprises even-numbered pixel lines, and a second field which includes a P picture and comprises odd-numbered pixel line,
• wherein the first encoder refers to picture information in a picture of an encoding target to encode the picture information of the first field of the picture concerned, outputs a first encoded bit string, creates a reference picture from the encoding result, and writes the reference picture in the intermediate buffer,
• wherein the second encoder refers to picture information in a picture of an encoding target and the reference picture stored in the intermediate buffer, to encode the picture information of the second field of the picture concerned and outputs a second encoded bit string,
• wherein the encoding target picture controller makes the second encoder start encoding a picture with reference to the reference picture concerned, before a following reference picture is written in the intermediate buffer by the first encoder,
• wherein the output control device applies time-division multiplexing to the first encoded bit string and the second encoded bit string, and sends them out to the transmission line as an encoded stream,
• wherein the receiver supplies the encoded stream inputted from the transmission line to the picture decoding device, and makes the picture decoding device decode the encoded stream, and
• wherein the second encoder is coupled to the field divider in parallel with the first encoder.