An encoder for encoding input data to generate corresponding encoded data, wherein the encoder is operable to process the input data and to encode original values of at least a portion thereof, using at least one delta encoding algorithm, into delta values that are expressed using a value range that is not increased as compared to a value range of the original values, wherein the at least one delta encoding algorithm comprises at least one of: ODelta, DDelta, IDelta, PDelta and is implemented by using a data processing arrangement for applying to the input data at least one of: differential encoding and sum encoding to generate one or more corresponding encoded sequences of data, and wherein the at least one delta encoding algorithm is implemented by selecting at least one of: (a) ODelta, wherein the data processing arrangement is used to subject the one or more corresponding encoded sequences to a wrap around a maximum value and/or a wrap around a minimum value, by addition or subtraction of a wrapValue, for generating the encoded output data (DA2 or DA3), wherein the wrapValue is highValue - lowValue + 1, where the highValue is a highest occurring number value of the one or more corresponding encoded sequences, and a lowValue is a lowest occurring number value of the one or more corresponding encoded sequences; (b) DDelta, wherein the delta values are expressed without sign, when the delta values include only negative values and in IDelta when the data values include only positive values; (c) PDelta, wherein an offset value is used to express the delta values within the value range of the original values, wherein the selection of at least one delta encoding algorithm is performed on the basis that the selected at least one delta encoding algorithm results in entropy reduction; and to generate one or more predictors for use in encoding one or more subsequent portions of the input data, wherein the encoder is also operable to encode data generated by the at least one delta encoding algorithm and the one or more predictors by employing at least one entropy encoding algorithm to generate the encoded data, wherein the one or more predictors include at least one of: (i) one or more temporal predictors; (ii) one or more local spatial predictors which are subject to quantization; (iii) one or more local spatial predictors utilizing pre-computed values. (a) ODelta, wherein the data processing arrangement is used to subject the one or more corresponding encoded sequences to a wrap around a maximum value and/or a wrap around a minimum value, by addition or subtraction of a wrapValue, for generating the encoded output data (DA2 or DA3), wherein the wrapValue is highValue - lowValue + 1, where the highValue is a highest occurring number value of the one or more corresponding encoded sequences, and a lowValue is a lowest occurring number value of the one or more corresponding encoded sequences; (b) DDelta, wherein the delta values are expressed without sign, when the delta values include only negative values and in IDelta when the data values include only positive values; (c) PDelta, wherein an offset value is used to express the delta values within the value range of the original values, (i) one or more temporal predictors; (ii) one or more local spatial predictors which are subject to quantization; (iii) one or more local spatial predictors utilizing pre-computed values.