Method and device for providing compensation offsets for a set of reconstructed samples of an image

A device for decoding an image composed of a plurality of samples, each sample having a sample value, the device comprising:

• a sample value receiving unit which receives encoded sample values;
• a position receiving unit which receives encoded position data representing a position;
• an offset receiving unit which receives encoded data representing offsets;
• a selecting unit which decodes the position data and which selects, based on the decoded position data, classes from among a plurality of predetermined classes, each said class defining a range of sample values within a full range of the sample values, into which class a sample is put if its sample value is within the range of the class concerned, and the selected classes being a fixed number of successive classes, spanning in combination a fixed range of sample values smaller than one half of said full range, the position data for the selected successive classes being equal to a first sample value in said fixed range divided by a class size;
• a sample decoding unit which decodes the encoded samples to provide reconstructed sample values;
• an offset decoding unit which decodes the encoded data representing offsets to provide offsets;
• an associating unit which associates the offsets respectively with the classes of the selected successive classes;
• and
• a loop filter which performs loop filtering on the reconstructed sample values, the loop filtering comprising applying the offset associated with each class of the selected successive classes to reconstructed sample values within the range of the class concerned.