Picture codec and teleconference terminal equipment

A communication terminal which transmits and receives an image signal through a digital communication line by use of an image input means which inputs an image signal, and an image output means which outputs the image signal, said communication terminal comprising:

• first coding means which executes a first coding process with respect to the input image signal from said image input means to output first coded image data;
• second coding means which executes a second coding process with respect to said input image signal to output second coded image data;
• communication control means which transmits and receives said first and/or second coded image data via said digital communication line;
• first decoding means which decodes the first coded image data received by said communication control means via said digital communication line to generate first decoded image data;
• second decoding means which decodes the second coded image data received by said communication control means via said digital communication line to generate second decoded image data;
• screen display processing means which selects two image signals among said first decoded image data, said second decoded image data, and said input image signal, and controls a display in a manner such that a first image signal of said two image signals thus selected is displayed in a first region of said image output means, and a second image signal of said two image signals is displayed in a second region of said image output means;
• and
• an operation unit for operating said communication terminal,
• wherein said display processing means, in accordance with information input through said operation unit, a executes display process to display said first image signal which had been displayed in said first region in said second region, and to display said second image signal which had been displayed in said second region in said first region.