Methods and systems for inter-layer image parameter prediction

A method for predicting an offset factor for a target block of a multi-layer image, wherein said multi-layer image comprises a lower-dynamic-range layer and a higher-dynamic-range layer and said offset factor is used to predict said higher-dynamic-range layer from said lower-dynamic-range layer, said method comprising:

• a) determining a target scaling parameter for said target block;
• b) determining a first scaling parameter and a first offset parameter for a first adjacent block, said first adjacent block being adjacent to said target block;
• c) if said target scaling parameter and said first scaling parameter are substantially equal, setting a target offset parameter equal to said first offset parameter;
• d) determining a second scaling parameter and a second offset parameter for a second adjacent block, said second adjacent block being adjacent to said target block;
• e) if said target scaling parameter, said first scaling parameter and said second scaling parameter are substantially equal, setting said target offset parameter equal to the average of said first offset parameter and said second offset parameter;
• f) fitting a mathematical model to said first scaling parameter, said second scaling parameter, said first offset parameter and said second offset parameter;
• and
• g) if none of said target scaling parameter, said first scaling parameter and said second scaling parameter are substantially equal, determining a target offset parameter for said target block using said target scaling parameter and said mathematical model.

A system for predicting an offset factor for a target block of a multi-layer image, wherein said multi-layer image comprises a lower-dynamic-range layer and a higher-dynamic-range layer and said offset factor is used to predict said higher-dynamic-range layer from said lower-dynamic-range layer, said system comprising:

• a) a target scaling parameter processor for determining a target scaling parameter for said target block;
• b) a first parameter processor for determining a first scaling parameter and a first offset parameter for a first adjacent block, said first adjacent block being adjacent to said target block;
• c) a first parameter designator for setting a target offset parameter equal to said first offset parameter, if said target scaling parameter and said first scaling parameter are substantially equal;
• d) a second parameter designator for determining a second scaling parameter and a second offset parameter for a second adjacent block, said second adjacent block being adjacent to said target block;
• e) a second parameter designator for setting said target offset parameter equal to the average of said first offset parameter and said second offset parameter, if said target scaling parameter, said first scaling parameter and said second scaling parameter are substantially equal;
• f) a modeler for fitting a mathematical model to said first scaling parameter, said second scaling parameter, said first offset parameter and said second offset parameter;
• and
• g) a third parameter designator for determining a target offset parameter for said target block using said target scaling parameter and said mathematical model, if none of said target scaling parameter, said first scaling parameter and said second scaling parameter are substantially equal.