Screen transfer apparatus and method thereof and program storage medium

A screen transfer method that communicates with a screen display apparatus that displays image data on a screen, comprising:

• generating image data to be displayed on the screen, with a portion of said image data to be compressed and transferred;
• storing in a dictionary memory or memories dictionary data for each of a corresponding one of a plurality of divided areas, each forming a different part of a whole area of the screen;
• identifying overlapped divided areas that include the portion of said image data to be compressed and transferred;
• dividing the image data in each overlapped divided area in a vertical direction or a horizontal direction of the screen to generate pieces of divided image data for each overlapped divided area, wherein a vertical width or a horizontal width of each piece is less than that of the corresponding divided areas;
• compressing each piece of the divided image data belonging to each of the divided areas by using to compress a piece of divided image data the dictionary data corresponding to the divided area in which that piece resides to generate a corresponding piece of compressed image data for each piece of divided image data;
• storing each compressed piece of the divided image data belonging to each of the divided areas in a corresponding portion of the dictionary memory or memories to update the dictionary data therein;
• and
• transmitting the compressed image data belonging to each of the divided areas in an order defined by a rule given in advance.

A non-transitory computer-readable medium storing a computer program that causes, when executed by a computer, the computer to perform the steps of:

• generating image data to be displayed on the screen, with a portion of said image data to be compressed and transferred;
• storing in a dictionary memory or memories dictionary data for each of a corresponding one of a plurality of divided areas, each forming a different part of a whole area of the screen;
• identifying overlapped divided areas that include the portion of said image data to be compressed and transferred;
• dividing the image data in each overlapped divided area in a vertical direction or a horizontal direction of the screen to generate pieces of divided image data for each overlapped divided area, wherein a vertical width or a horizontal width of each piece is less than that of the corresponding divided areas;
• compressing each piece of the divided image data belonging to each of the divided areas by using to compress a piece of divided image data the dictionary data corresponding to the divided area in which that piece resides to generate a corresponding piece of compressed image data for each piece of divided image data;
• storing each compressed piece of the divided image data belonging to each of the divided areas in a corresponding portion of the dictionary memory or memories to update the dictionary data therein;
• and
• transmitting the compressed image data belonging to each of the divided areas in an order defined by a rule given in advance.