Method and recording format for image compression

A method for processing data of a sub-picture of a picture, comprising:

• providing an object of the sub-picture;
• forming a binary bit map of the object;
• determining the most significant two bits of a section of consecutive bits in the binary bit map;
• compressing the section in a first format if the most significant bit having a first binary value is followed by the second most significant bit having a second binary value;
• recording the number (n1) of consecutive bits having the second binary value that follow the most significant bit in N1 bits, wherein N1 is the smallest integer that satisfies n1≦2N1−1;
• compressing the section in a second format if the most significant bit having the first binary value is followed by the second most significant bit having the first binary value;
• and
• recording the number (n2) of consecutive bits having the first binary value that follow the most significant bit in N2 bits, wherein N2 is the smallest integer that satisfies n2≦2N2−1.

A method capable of data compression and decompression for a sub-picture of a picture, comprising:

• determining an object of the sub-picture;
• forming a binary bit map of the object;
• determining a compression rule capable of compressing a section of consecutive bits in the binary bit map by determining the most significant two bits of the section;
• compressing the section of consecutive bits in accordance with the compression rule to form a compressed section;
• and
• recording a parameter corresponding to the compression rule in a data format,
• wherein the parameter determines a length of the compressed section.

A data format capable of recording compression information for an object of a sub-picture, comprising:

• a first field capable of recording a parameter corresponding to a compression rule for compressing a section of consecutive bits in a binary bit map of the object;
• and
• a second field capable of recording a compressed section formed by compressing the section of consecutive bits in accordance with the compression rule,
• wherein the parameter determines a length of the compressed section.