A method of generating an attribute map for processing an image. An image encoded into a plurality of segments is received. Each segment is characterized by a position within a base region associated with the image and is encoded according to a corresponding encoding format. A segment from the plurality of segments is decoded into a sub-image. The sub-image is associated with a combination operation and an attribute value derived based on at least one of a segment decoding format and a segment encoding format. The combination operation determines a process of combining the sub-image with the underlying base region. An information-carrying pixel value in the sub-image is determined based on the sub-image pixel content and the attribute value associated with the sub-image. The attribute map for processing the image is generated using the attribute value associated with the sub-image for at least one pixel of the attribute map.