Encoding and decoding methods and corresponding devices

A coding device comprising one or more processors and at least one memory configured to:

• determine and encode a first syntax element specifying whether a block is split vertically or horizontally into two sub-blocks;
• determine based on a value if a condition allowing an asymmetric split is fulfilled for the block, and determining and encoding a second syntax element specifying whether the block is split symmetrically or asymmetrically responsive to the value;
• and
• determine and encoding a split mode syntax element specifying a position of the split in the block.

An apparatus comprising:

• a decoding device adapted to decode a bitstream comprising at least one image, wherein the decoding device comprises one or more processors and at least one memory configured to:
• decode, from the bitstream, a first syntax element specifying whether a block is split vertically or horizontally into two sub-blocks;
• determine from a value depending on at least a third syntax element of the bitstream if an asymmetric split is allowed for the block, and decode a second syntax element of the signal specifying whether the block is split symmetrically or asymmetrically responsive to the value;
• and
• decode, from the bitstream, a split mode syntax element specifying a position of the split in the block;
• and,
• a display device for displaying the at least one image.

A method comprising:

• receiving a signal comprising data representative of an image;
• decoding, from the signal, a first syntax element specifying whether a block of the image is split vertically or horizontally into two sub-blocks;
• determining from a value depending on at least a third syntax element of the signal if an asymmetric split is allowed for the block, and decoding a second syntax element from the signal specifying whether the block is split symmetrically or asymmetrically responsive to the value;
• and
• decoding, from the signal, a split mode syntax element specifying a position of the split in the block.

A method comprising:

• determining and encoding in a signal representative of an image a first syntax element specifying whether the block is split vertically or horizontally into two sub-blocks;
• determining based on a value if a condition allowing an asymmetric split is fulfilled for the block, and determining and encoding in the signal a second syntax element specifying whether the block is split symmetrically or asymmetrically responsive to the value;
• determining and encoding in the signal a split mode syntax element specifying a position of the split in the block;
• and
• transmitting the signal.

A method comprising:

• transmitting a signal comprising data representative of an image, wherein the data comprises:
• a first syntax element specifying whether a block of the image is split vertically or horizontally into two sub-blocks;
• a third syntax element on which depends a value allowing an asymmetric split for the block and a second syntax element specifying whether the block is split symmetrically or asymmetrically;
• and
• a split mode syntax element specifying a position of the split in the block.

A method comprising:

• receiving a signal comprising data representative of an image, wherein the data comprises:
• a first syntax element specifying whether a block of the image is split vertically or horizontally into two sub-blocks;
• a third syntax element on which depends a value allowing an asymmetric split for the block and a second syntax element specifying whether the block is split symmetrically or asymmetrically;
• and
• a split mode syntax element specifying a position of the split in the block.

An apparatus comprising:

• an antenna configured to receive a signal;
• and
• a decoding device comprising one or more processors and at least one memory, configured to:
• decode, from the signal, a first syntax element specifying whether a block is split vertically or horizontally into two sub-blocks;
• determine from a value depending on at least a third syntax element of the signal if an asymmetric split is allowed for the block, and decode a second syntax element of the signal specifying whether the block is split symmetrically or asymmetrically responsive to the value;
• and
• decode, from the signal, a split mode syntax element specifying a position of the split in the block.

An apparatus comprising:

• a coding device comprising one or more processors and at least one memory configured to:
• determine and encode, in a signal, a first syntax element specifying whether the block is split vertically or horizontally into two sub-blocks;
• determine based on a value if a condition allowing an asymmetric split is fulfilled for the block, and determining and encoding a second syntax element in the signal specifying whether the block is split symmetrically or asymmetrically responsive to the value;
• and
• determine and encode, in the signal, a split mode syntax element specifying a position of the split in the block;
• and
• an antenna configured to transmit the signal.