1. (Amended) An image processing apparatus for encoding image data while a coding unit, which is a unit having a hierarchical structure, is adopted as a processing unit, the image processing apparatus comprising:
a predicted quantization parameter setting unit for setting a predicted quantization parameter for a current coding unit by using multiple quantization parameters which are set for multiple surrounding coding units located around the current coding unit;
a difference quantization parameter setting unit for setting a difference quantization parameter indicating a difference value between the quantization parameter which is set for the current coding unit and the predicted quantization parameter which is set by the predicted quantization parameter setting unit;
a coding unit for generating a bit stream by encoding the image data with the coding unit being adopted as the processing unit; and
a transmission unit for transmitting the bit stream generated by the coding unit and the difference quantization parameter which is set by the difference quantization parameter setting unit.
2. The image processing apparatus according to claim 1, wherein the predicted quantization parameter setting unit sets the predicted quantization parameter by applying prediction calculation to multiple quantization-parameters which are set for the multiple surrounding

coding units.
3. The image processing apparatus according to claim 2,
wherein the predicted quantization parameter setting unit
sets the predicted quantization parameter as a median
value of multiple quantization parameters which are set
for the multiple surrounding coding units, by applying
median calculation to the multiple quantization
parameters which are set for the multiple surrounding
coding units.
4. The image processing apparatus according to claim 3, wherein when all the multiple surrounding coding units are in available state, the predicted quantization parameter setting unit applies the median calculation to the multiple quantization parameters which are set for the multiple surrounding coding units.
5. The image processing apparatus according to claim 2, wherein the predicted quantization parameter setting unit sets the predicted quantization parameter as an average value of multiple quantization parameters which are set for the multiple surrounding coding units, by applying average calculation to the multiple quantization parameters which are set for the multiple surrounding coding units.
6. The image processing apparatus according to claim 5, wherein when the determination unit determines that one of the surrounding coding units is in available state, the predicted quantization parameter setting unit applies

average calculation to the multiple quantization parameters which are set for the multiple surrounding coding units.
7. The image processing apparatus according to claim 5,
wherein the predicted quantization parameter setting unit
sets the predicted quantization parameter as weighted
average value of multiple quantization parameters which
are set for the multiple surrounding coding units, by
applying weighted average calculation to multiple
quantization parameters which are set for multiple
surrounding coding units which are selected by the
selection unit.
8. The image processing apparatus according to claim 7, wherein the predicted quantization parameter setting unit sets the weighted average calculation such that a larger weight is given to a surrounding coding unit having the same size as a size of the current coding unit.
9. The image processing apparatus according to claim 7, wherein the predicted quantization parameter setting unit sets the weighted average calculation in such a manner that a larger weight is given to a surrounding coding unit having a larger size.
10. The image processing apparatus according to claim 2, wherein, with respect to a coding unit that has been coded, the multiple surrounding coding units include a coding unit adjacent to a left side of the current coding unit, a coding unit adjacent to an upper side of the

current coding unit, and a coding unit adjacent to an upper left side of the current coding unit.
11. The image processing apparatus according to claim
10, wherein the multiple surrounding coding unit further
includes a coding unit adjacent to an upper right side of
the current coding unit and a coding unit adjacent to a
lower left side of the current coding unit.
12. The image processing apparatus according to claim 2,
further comprising a determination unit for determining
whether the surrounding coding unit is in available state
or not,
wherein the predicted quantization parameter setting unit changes the method of the prediction calculation in accordance with a number of coding units which are determined to be available by the determination unit.
13. The image processing apparatus according to claim 1,
further comprising a determination unit for determining
whether a surrounding coding unit located within a
current maximum coding unit is in available state or not
when the predicted quantization parameter is set,
wherein the predicted quantization parameter setting unit sets the predicted quantization parameter by using only a quantization parameter of a coding unit that is determined to be in available state by the determination unit.
14. The image processing apparatus according to claim

13, wherein when the current coding unit is located at the front of the current maximum coding unit, the predicted quantization parameter setting unit sets, as the predicted quantization parameter, a quantization parameter of a coding unit located at the last of the maximum coding unit immediately before.
15. The image processing apparatus according to claim 2,
further comprising a setting unit for setting type data
indicating a type of the prediction calculation,
wherein the transmission unit transmits the type data which are set by the setting unit.
16. The image processing apparatus according to claim
15, wherein the setting unit sets the type data for each
maximum coding unit which is a coding unit in an
uppermost layer or slice.
17. The image processing apparatus according to claim
16, wherein the transmission' unit transmits type data,
which are set by the setting unit, as a parameter set of
a bit stream generated by the coding unit.
18. (Amended) An image processing method for an image
processing apparatus for encoding image data while a
coding unit, which is a unit having a hierarchical
structure, is adopted as a processing unit, the image
processing method comprising:
causing a predicted quantization parameter setting unit to set a predicted quantization parameter for a current coding unit by using multiple quantization

parameters which are set for multiple surrounding coding units located around the current coding unit;
causing a difference quantization parameter settinc unit to set a difference quantization parameter indicating a difference value between the quantization parameter which is set for the current coding unit and the predicted quantization parameter which is set by the predicted quantization parameter setting unit;
causing a coding unit to generate a bit stream by encoding the image data with the coding unit being adopted as the processing unit; and
causing a transmission unit to transmit the generated bit stream and the difference quantization parameter which is set.
19. (Amended) An image processing apparatus for decoding a bit stream encoded while a coding unit, which is a unit having a hierarchical structure, is adopted as a processing unit, the image processing apparatus comprising:
a receiving unit for receiving a difference quantization parameter indicating a difference value between a quantization parameter which is set for a current coding unit and a predicted quantization parameter obtained by predicting from multiple quantization parameters which are- set for multiple surrounding coding units located around the current coding unit, and a bit stream obtained by encoding image data with the coding unit being adopted as the processing unit;
a quantization parameter setting unit for setting

the quantization parameter of the current coding unit using the difference quantization parameter received from the receiving unit; and
a decoding unit for decoding the bit stream received from the receiving unit by using the quantization parameter which is set by the quantization parameter setting unit.
20. (Amended) An image processing method for an image processing apparatus for decoding a bit stream encoded while a coding unit, which is a unit having a hierarchical structure, is adopted as a processing unit, the image processing method comprising:
causing a receiving unit to receive a difference quantization parameter indicating a difference value between a quantization parameter which is set for a current coding unit and a predicted quantization parameter obtained by predicting from multiple quantization parameters which are set for multiple surrounding coding units located around the current coding unit, and a bit stream obtained by encoding image data with the coding unit being adopted as the processing unit;
causing a quantization parameter setting unit to set the quantization parameter of the current coding unit using the difference quantization parameter received; and
causing a decoding unit to decode the bit stream received by using the quantization parameter which is set.
21. (Amended) An image processing apparatus for
encoding image data while a coding unit,- which is a unit

having a hierarchical structure, is adopted as a processing unit, the image processing apparatus comprising:
a determination unit for determining whether multiple surrounding coding units located around a current coding unit is in available state or not when a predicted quantization parameter is set;
a predicted quantization parameter setting unit for setting a predicted quantization parameter for the current coding unit by using only a quantization parameter of a coding unit that is determined to be in available state by the determination unit;
a difference quantization parameter setting unit for setting a difference quantization parameter indicating a difference value between the quantization parameter which is set for the current coding unit and the predicted quantization parameter which is set by the predicted quantization parameter setting unit;
a coding unit for generating a bit stream by encoding the image data with the coding unit being adopted' as the processing unit; and
a transmission unit for transmitting the bit stream generated by the coding unit and the difference quantization parameter which is set by the difference quantization parameter setting unit.
22. The image processing apparatus according to claim 21, wherein when the current coding unit is located at the front of the current maximum coding unit, the
predicted quantization parameter setting unit sets, as the predicted quantization parameter, a quantization

parameter of a coding unit located at the last of the maximum coding unit immediately before.
23. (Amended) An image processing method for an image processing apparatus for encoding image data while a coding unit, which is a unit having a hierarchical structure, is adopted as a processing unit, the image processing method comprising:
causing a determination■unit to determine whether multiple surrounding coding units located around a current coding unit is in available state or not when a predicted quantization parameter is set;
causing a predicted quantization parameter setting unit to set a predicted quantization parameter for the current coding unit by using only a quantization parameter of a coding unit that is determined to be in available state;
causing a difference quantization parameter setting unit to set a difference quantization parameter indicating a difference value between the quantization parameter which is set for the current coding unit and the predicted quantization parameter which is set;
causing a coding unit to generate a bit stream by encoding the image data with the coding unit being adopted as the processing unit; and
causing a transmission unit to transmit the generated bit stream and the difference quantization parameter which is set.
24, (Amended) An image processing apparatus for decoding a bit stream encoded while a coding unit, 'which

is a unit having a hierarchical structure, is adopted as a processing unit, the image processing apparatus comprising:
a receiving unit for receiving a difference quantization parameter indicating a difference value-between a quantization parameter which is set for a current coding unit which is target of decoding processing and a predicted quantization parameter which is a prediction value of the quantization parameter,■and a bit stream obtained by encoding image data with the coding unit being adopted as the processing unit;
a determination unit for determining whether multiple surrounding coding units located around the current coding unit is in available state or not when the predicted quantization parameter is set;
a predicted quantization parameter setting unit for setting a predicted quantization parameter for the current coding unit by using only a quantization parameter of a coding unit that is determined to be in available state by the determination unit;
a quantization parameter generation unit for generating a quantization parameter of the current coding unit by adding the quantization parameter which is set for the current coding unit and the difference quantization parameter received by the receiving unit; and
a decoding unit for decoding the bit stream received by the receiving unit by using the quantization parameter generated by the quantization parameter generation unit.

25. (Amended) An image processing method for an image processing, apparatus for decoding a bit stream encoded while a coding unit, which is a unit having a hierarchical structure, is adopted as a processing unit, the image processing method comprising:
causing a receiving unit to receive a difference quantization parameter indicating a difference value between a quantization parameter which is set for a current coding unit and a predicted quantization parameter which is a prediction value of the quantization parameter, and a bit stream obtained by encoding image data with the coding unit being adopted as the processing unit ;
causing a determination unit to determine whether multiple surrounding coding units located around the current coding unit is in available state or not when the predicted quantization parameter is set;
causing a predicted quantization parameter setting unit to set a predicted quantization parameter for the current coding unit by using only a quantization parameter of. a coding unit that is determined to be in available state;
causing the quantization parameter generation unit to generate a quantization parameter of the current coding unit by adding the quantization parameter which is set for the current coding unit and the difference quantization parameter received; and
causing a decoding unit to decode the received bit stream by using the quantization parameter generated.