Image decoding method, image coding method, image decoding apparatus, image coding apparatus, and image coding and decoding apparatus

An image decoding method of decoding a coded picture, the image decoding method comprising:

• obtaining a boundary control flag for controlling a sample adaptive offset operation for a slice boundary of a current slice to be decoded included in the coded picture;
• decoding the current slice;
• and
• performing the sample adaptive offset operation in accordance with the boundary control flag jointly on at least one pixel in the current slice that has been decoded and on at least one pixel in a different slice that has been decoded, the pixels being in a vicinity of at least one of a top slice boundary or a left slice boundary of the current slice.

An image coding method of coding a picture, the image coding method comprising:

• coding a boundary control flag for jointly controlling a deblocking filter operation and a sample adaptive offset operation for a slice boundary of a current slice to be coded included in the picture;
• coding the current slice;
• reconstructing the current slice from data generated by the coding of the current slice;
• performing the deblocking filter operation based on the boundary control flag only on at least one of a top slice boundary or a left slice boundary among all slice boundaries of the current slice that has been reconstructed;
• and
• performing the sample adaptive offset operation dependent on the boundary control flag only on the at least one of the top slice boundary or the left slice boundary among all the slice boundaries of the current slice that has been reconstructed.

An image coding method of coding a picture, the image coding method comprising:

• coding a boundary control flag for controlling a sample adaptive offset operation for a slice boundary of a current slice to be coded included in the picture;
• coding the current slice;
• reconstructing the current slice from data generated by the coding of the current slice;
• and
• performing the sample adaptive offset operation in accordance with the boundary control flag jointly on at least one pixel in the current slice that has been reconstructed and on at least one pixel in a different slice that has been reconstructed, the pixels being in a vicinity of at least one of a top slice boundary or a left slice boundary of the current slice.