Method of obtaining filtered values in a horizontal and vertical direction
In one embodiment, the method includes obtaining at least three horizontally successive reference pixel values including a pixel to be filtered, and applying first weight factors to at least each of the three horizontally successive reference pixel values. The first weight factors are different according to pixel position. A first filtered value is obtained by summing at least the three weighted horizontally successive pixel values. The method further includes obtaining at least three vertically successive reference pixel values including a pixel to be filtered, and applying second weight factors to at least each of the three vertically successive reference pixel values. The second weight factors are different according to pixel position. A second filtered value is obtained by summing at least the three weighted vertically successive pixel values.
1. A method of removing a blocking phenomenon using properties of two blocks in a loop filtering system, comprising:
determining whether at least one of a first block and a second block has non-zero transform coefficient information, and the second block being adjacent to the first block,
determining a filter strength value in consideration of a presence of the non-zero transform coefficient information,
determining coefficients, for pixels on a block boundary between the first and second blocks, based on the filter strength value, and
calculating values of the pixels on the block boundary based on the determined coefficients, the calculating including performing a bit shift operation, the calculating step further including,
calculating values of at least two successive pixels in the first block based on pixel values of the at least two successive pixels in the first block, and
calculating values of at least two successive pixels in the second block based on pixel values of the at least two successive pixels in the second block, wherein the bit shift operation uses an integer wherein the integer is greater than one.
2. The method of claim 1 , wherein
the coefficients are determined to be varied depending on the filter strength value.