Method and apparatus for encoding binary image using adaptive template and method and apparatus for decoding the same

A binary image decoding method using an adaptive template, the method comprising:

• applying a window having a predetermined size and shape to a predetermined number of previous pixels and peripheral pixels of the previous pixels, and acquiring correlations between the previous pixels and the peripheral pixels within the window;
• determining relative locations having high correlation with the previous pixels within the window based on the acquired correlations;
• generating a template based on the determined relative locations;
• and
• performing binary arithmetic decoding on a current pixel by using the generated template.

A binary image encoding apparatus using an adaptive template, the apparatus comprising:

• a correlation acquirer which applies a window having a predetermined size and shape to a predetermined number of previous pixels and peripheral pixels of the previous pixels, and acquires correlations between the previous pixels and the peripheral pixels within the window;
• a correlation accumulator which determines relative locations having high correlation with the previous pixels within the window based on the acquired correlations;
• a template renewer which generates a template based on the determined relative locations;
• and
• an arithmetic encoder which performs binary arithmetic encoding on a current pixel by using the generated template.

A binary image decoding apparatus using an adaptive template, the apparatus comprising:

• a correlation acquirer which applies a window having a predetermined size and shape to a predetermined number of previous pixels and peripheral pixels of the previous pixels, and acquires correlations between the previous pixels and the peripheral pixels within the window;
• a correlation accumulator which determines relative locations having high correlation with the previous pixels within the window based on the acquired correlations;
• a template renewer which generates a template based on the determined relative locations;
• and
• an arithmetic decoder which performs binary arithmetic decoding on a current pixel by using the generated template.

A binary image encoding or decoding method using an adaptive template, the method comprising:

• adaptively generating a template based on correlations between previous pixels and peripheral pixels;
• and
• performing binary encoding or decoding on a current pixel by using the generated template,
• wherein the adaptively generating the template comprises:
• determining a size and a shape of the template according to accumulated correlations between the previous pixels and the peripheral pixels.