An image processing device (51), comprising:
a decoding unit (62, 63, 64, 65) configured to decode an encoded stream to generate a decoded image; and
a filter unit (3 lb, 31) configured to apply a deblocking filtering to neighboring pixels neighboring a block boundary within the decoded image generated by the decoding unit, using a filter parameter set according to a range including a value greater than 17 in case that a quantization parameter is equal to 50 according to a relationship between a filter parameter used in case of clipping for the deblocking filter and the quantization parameter.
The image processing device (51) according to claim 1, wherein
the filter unit (31b, 31) is configured to apply the deblocking filter using the filter parameter with the value greater than 17 within the range.
The image processing device (51) according to claim 2, wherein
the filter parameter is a value set according to a quantization parameter.
The image processing device (51) according to claim 3, wherein
the quantization parameter is an average of quantization parameters between neighboring blocks neighboring the block boundary.
The image processing device (51) according to claim 4, wherein
the filter unit (31b, 31) is configured to apply the deblocking filter to the neighboring pixels within the decoded image using the filter parameter set according to the range including the value greater than 17 according to a relationship between the average of the quantization parameters and the filter parameter.
The image processing device (51) according to claim 5, wherein
the deblocking filter is configured to include a weak filter with a first strength and a strong filter with a second strength stronger than the first strength;

the filter parameter is a parameter used in case of selecting either one of the weak filter and the strong filter or clipping the filtered pixels after the strong filter.
The image processing device (51) according to claim 6, wherein
the block boundary is a boundary of a transformer unit for a transform process or a boundary of a prediction unit for a prediction process.
The image processing device (51) according to claim 7, wherein
the decoding unit (62, 63, 64, 65) comprises:
an arithmetic decoding unit (62) configured to perform an arithmetic decoding process on the encoded stream to generate quantized data;
an inverse quantization unit (63) configured to perform an inverse quantization process on the quantized data generated by the arithmetic decoding unit to generate transformation coefficient data; and
an inverse orthogonal transformation unit (64) configured to perform an inverse orthogonal transformation process on the transformation coefficient data generated by the inverse quantization unit.
The image processing device (51) according to claim 8, wherein
the decoding unit (62, 63, 64, 65) is configured to decode the encoded stream according to coding units derived from dividing a largest coding unit recursively.
. The image processing device (51) according to claim 9, wherein
the coding units are derived from dividing the largest coding unit in accordance with a quad-tree structure.
. The image processing device (51) according to claim 10, wherein
the largest coding unit is a coding unit in a root of the quadtree structure.
. The image processing device (51) according to claim 11,
wherein the largest coding unit is a block of fixed size under sequence level, and the coding unit is a block of variable size.

. An image processing method, comprising:
decoding an encoded stream to generate a decoded image; and applying a deblocking filtering to neighboring pixels neighboring a block boundary within the decoded image generated by the decoding unit, using a filter parameter set according to a range including a value greater than 17 in case that a quantization parameter is equal to 50 according to a relationship between a filter parameter used in case of clipping for the deblocking filter and the quantization parameter.
. The image processing method according to claim 13, comprising
applying the deblocking filter using the filter parameter with the value greater than 17 within the range.
. The image processing method according to claim 14, wherein
the filter parameter is a value set according to a quantization parameter.
. The image processing method according to claim 15, wherein
the quantization parameter is an average of quantization parameters between neighboring blocks neighboring the block boundary.
. The image processing method according to claim 16, comprising
applying the deblocking filter to the neighboring pixels within the decoded image using the filter parameter set according to the range including the value greater than 17 according to a relationship between the average of the quantization parameters and the filter parameter.
. The image processing method according to claim 17, wherein
the deblocking filter includes a weak filter with a first strength and a strong filter with a second strength stronger than the first strength, and
the filter parameter is a parameter used in case of selecting either one of the weak filter and the strong filter or clipping the filtered pixels after the strong filter.

'. The image processing method according to claim 18, wherein
the block boundary is a boundary of a transformer unit for a transform process or a boundary of a prediction unit for a prediction process.
i. The image processing method according to claim 19, wherein
the decoding comprises:
performing an arithmetic decoding process on the encoded stream to generate quantized data;
performing an inverse quantization process on the quantized data generated by the arithmetic decoding process to generate transformation coefficient data; and
performing an inverse orthogonal transformation process on the transformation coefficient data generated by the inverse quantization process.
. The image processing method according to claim 20,
comprising decoding the encoded stream according to coding units derived from dividing a largest coding unit recursively.
:. The image processing method according to claim 21,
wherein the coding units are derived from dividing the largest coding unit in accordance with a quad-tree structure.
. The image processing method according to claim 22,
wherein the largest coding unit is a coding unit in a root of the quadtree structure.
-. The image processing method according to claim 23,
wherein the largest coding unit is a block of fixed size under sequence level, and the coding unit is a block of variable size.