Method and apparatus for bit resolution extension

A bit resolution extension device comprising:

• a distance acquiring unit which acquires a shortest distance from a central pixel to a positive contour and a shortest distance from the central pixel to a negative contour in a filtering region which scans the positive contour comprising large pixels of a fixed value and the negative contour comprising small pixels of a fixed value based on a value of the central pixel;
• a generator which generates an extension bit of the central pixel by interpolating the shortest distance from the central pixel to the positive contour and the shortest distance from the central pixel to the negative contour;
• and
• an adder which adds the extension bit as a lower bit of the central pixel.

A computer readable medium having recorded thereon a computer program for executing a bit resolution-extension method, the method comprising:

• acquiring a shortest distance from a central pixel to a positive contour and a shortest distance from the central pixel to a negative contour in a filtering region which scans the positive contour comprising large pixels of a fixed value and the negative contour comprising small pixels of a fixed value, based on a value of the central pixel;
• generating an extension bit of the central pixel by interpolating the shortest distance from the central pixel to the positive contour and the shortest distance from the central pixel to the negative contour;
• and
• adding the extension bit as a lower bit of the central pixel.

A bit resolution extension device comprising:

• means for acquiring a shortest distance from a central pixel to a positive contour and a shortest distance from the central pixel to a negative contour in a filtering region which scans the positive contour comprising large pixels of a fixed value and the negative contour comprising small pixels of a fixed value based on a value of the central pixel;
• means for generating an extension bit of the central pixel by interpolating the shortest distance from the central pixel to the positive contour and the shortest distance from the central pixel to the negative contour;
• and
• means for adding the extension bit as a lower bit of the central pixel.