Encoder for encoding a picture into a quality-scalable data stream, comprising: base encoding means for encoding the picture into a base encoding data stream representing a representation of the picture with a first picture sample bit depth; prediction means for providing a prediction of the picture based on the representation of the picture with the first picture sample bit depth, the prediction of the picture having a second picture sample bit depth being higher than the first picture sample bit depth, the prediction means comprising mapping means for performing, on the representation of the picture with the first picture sample bit depth, a mapping of samples from a first dynamic range corresponding to the first picture sample bit depth to a second dynamic range greater than the first dynamic range and corresponding to the second picture sample bit depth to obtain the prediction of the picture, with using different mapping mechanisms for luma and chroma components of the samples and/or different mapping mechanisms for different regions of the picture; and residual encoding means for encoding a prediction residual of the prediction into a bit-depth enhancement layer data stream, wherein the residual encoding means comprises a transform module for transform the prediction residual to a spectral domain to obtain spectral components, a quantization module for quantizing the spectral components to obtain quantized transform values and an entropy coding module for entropy coding the quantized transform values using Huffman coding or arithmetic coding; and combining means for forming the quality-scalable data stream based on the base encoding data stream, the bit-depth enhancement layer data stream and mapping information specifying the mapping mechanism used by the mapping means. base encoding means for encoding the picture into a base encoding data stream representing a representation of the picture with a first picture sample bit depth; prediction means for providing a prediction of the picture based on the representation of the picture with the first picture sample bit depth, the prediction of the picture having a second picture sample bit depth being higher than the first picture sample bit depth, the prediction means comprising mapping means for performing, on the representation of the picture with the first picture sample bit depth, a mapping of samples from a first dynamic range corresponding to the first picture sample bit depth to a second dynamic range greater than the first dynamic range and corresponding to the second picture sample bit depth to obtain the prediction of the picture, with using different mapping mechanisms for luma and chroma components of the samples and/or different mapping mechanisms for different regions of the picture; and residual encoding means for encoding a prediction residual of the prediction into a bit-depth enhancement layer data stream, wherein the residual encoding means comprises a transform module for transform the prediction residual to a spectral domain to obtain spectral components, a quantization module for quantizing the spectral components to obtain quantized transform values and an entropy coding module for entropy coding the quantized transform values using Huffman coding or arithmetic coding; and combining means for forming the quality-scalable data stream based on the base encoding data stream, the bit-depth enhancement layer data stream and mapping information specifying the mapping mechanism used by the mapping means.