Method of filtering an image including application of a weighted average operation

A coding and decoding method comprising:

• a discrete cosine transform (DCT) unit performing a DCT operation with respect to divided blocks of an image to generate DCT coefficients;
• a quantization unit quantizing the DCT coefficients and transmitting the DCT coefficients in a form of a bit stream through a transmission channel;
• a dequantization unit dequantizing the DCT coefficients received through the transmission channel;
• an inverse DCT unit performing an inverse DCT operation with respect to the dequantized DCT coefficients to form a reconstructed image, and
• a filtering process unit filtering each pixel of each block of the reconstructed image by selecting one of a plurality of filtering masks based upon a position of said pixel in said block;
• and averaging said pixel and candidate pixels within the selected filtering mask.

A method of filtering an image, comprising:

• selecting a filtering mask based on a position of a pixel to be filtered, the filtering mask including the pixel to be filtered and at least one candidate pixel;
• and
• filtering, with a filtering unit, the pixel to be filtered by applying a weighted averaging operation to the pixel to be filtered and the at least one candidate pixel, the weighted averaging operation including,
• applying weight to at least one of the pixel to be filtered and the at least one candidate pixel in producing a weighted sum value, and
• performing a shift operation on the weighted sum value to divide by a desired value.

A method of filtering an image, comprising:

• selecting a filtering mask based on a position of a pixel to be filtered, the filtering mask including the pixel to be filtered and at least one candidate pixel;
• and
• filtering, with a filtering unit, the pixel to be filtered by applying a weighted averaging operation to the pixel to be filtered and the at least one candidate pixel, the weighted averaging operation including,
• applying weight to at least one of the pixel to be filtered and the at least one candidate pixel in producing a weighted sum value, and
• dividing the weighted sum value by a desired value, the applied weight being associated with the desired value.