Apparatus for coding or decoding an image by executing variable-length coding/decoding and fixed-length coding/decoding

An apparatus for decoding an image, comprising:

• an extraction unit configured to extract a plurality of bits from a code string acquired;
• a decoding unit configured to execute variable-length decoding to the plurality of bits including a most significant bit, and to execute fixed-length decoding to the plurality of bits including a least significant bit;
• a connection unit configured to acquire a transformation coefficient by connecting the plurality of bits each decoded;
• and
• an inverse transformation unit configured to generate the image by executing frequency-inverse transformation to the transformation coefficient,
• wherein the decoding unit executes variable-length decoding to the plurality of bits when the plurality of bits is positioned higher than a predetermined bit position, and executes fixed-length decoding to the plurality of bits when the plurality of bits is positioned lower than the predetermined bit position.

A method for coding an image, comprising:

• acquiring a transformation coefficient by executing frequency transformation to the image;
• extracting a plurality of bits from the transformation coefficient;
• executing variable-length coding to the plurality of bits including a most significant bit;
• and
• executing fixed-length coding to the plurality of bits including a least significant bit,
• wherein said variable-length coding to the plurality of bits is executed when the plurality of bits is positioned higher than a predetermined bit position, and said fixed-length coding to the plurality of bits is executed when the plurality of bits is positioned lower than the predetermined bit position.

A method for decoding an image, comprising:

• extracting a plurality of bits from a code string;
• executing variable-length decoding to the plurality of bits including a most significant bit;
• executing fixed-length decoding to the plurality of bits including a least significant bit;
• acquiring a transformation coefficient by connecting the plurality of bits each decoded;
• and
• generating the image by executing frequency-inverse transformation to the transformation coefficient,
• wherein said variable-length decoding to the plurality of bits is executed when the plurality of bits is positioned higher than a predetermined bit position, and said fixed-length decoding to the plurality of bits is executed when the plurality of bits is positioned lower than the predetermined bit position.

A non-transitory computer readable medium for causing a computer to perform a method for coding an image, the method comprising:

• acquiring a transformation coefficient by executing frequency transformation to the image;
• extracting a plurality of bits from the transformation coefficient;
• executing variable-length coding to the plurality of bits including a most significant bit;
• and
• executing fixed-length coding to the plurality of bits including a least significant bit,
• wherein said variable-length coding to the plurality of bits is executed when the plurality of bits is positioned higher than a predetermined bit position, and said fixed-length coding to the plurality of bits is executed when the plurality of bits is positioned lower than the predetermined bit position.

A non-transitory computer readable medium for causing a computer to perform a method for decoding an image, the method comprising:

• extracting a plurality of bits from a code string;
• executing variable-length decoding to the plurality of bits including a most significant bit;
• executing fixed-length decoding to the plurality of bits including a least significant bit;
• acquiring a transformation coefficient by connecting the plurality of bits each decoded;
• and
• generating the image by executing frequency-inverse transformation to the transformation coefficient,
• wherein said variable-length decoding to the plurality of bits is executed when the plurality of bits is positioned higher than a predetermined bit position, and said fixed-length decoding to the plurality of bits is executed when the plurality of bits is positioned lower than the predetermined bit position.