Method and device for encoding or decoding an image comprising encoding of decoding information representing prediction modes

A method, by a computing device, for encoding an image, the method comprising:

• receiving the image within an original sequence of digital images received as an input by the computing device;
• encoding the image into encoded data, the encoding comprising the encoding of mode information representing a prediction mode for encoding a current block of pixels according to an Intra coding mode;
• encapsulating the encoded data within a bitstream output from the computing device;
• wherein encoding the current block of pixels comprises for the determination of set of most probable prediction modes:
• defining at least one candidate for a most probable prediction mode to be the mode information of a neighbor-block if it exists;
• and wherein
• a candidate for a most probable prediction mode is horizontal or vertical mode information if this neighbor-block exists and has been encoded using a predetermined coding mode,
• wherein the predetermined coding mode is neither inter coding mode nor intra coding mode.