A receiving apparatus comprising: a receiver configured to receive a video bitstream from an encoder of a transmitting apparatus, the bitstream comprising a moving video image divided in time into a plurality of frames with each frame being divided in space into a plurality of encoded blocks, each encoded block having a common format representing a plurality of components of a channel in a colour space, the plurality of components comprising a plurality of frequency domain components in a spatial frequency domain or a plurality of pixels in a spatial domain, wherein each of the plurality of the encoded blocks comprises a different set of quantized values of the components, including at least a value of a first of said components being quantized from amongst a first scheme of quantized levels such that the quantized value corresponds to a quantized level of the first scheme; wherein the bitstream received from the encoder is characterised in that it further comprises a look-up table mapping the quantized levels of the first scheme to de-quantized respective levels, wherein the look-up table defines a non-uniform distribution of the de-quantized levels in proportion with one another; wherein the receiving apparatus further comprises a de-quantizer (80, 83, 90) operatively coupled to the receiver, configured to send an indication concerning a screen in a signal to the transmitting apparatus, and configured to use the look-up table received in the bitstream from the encoder and determined based on said indication to de-quantize the different quantized values of the first component in a plurality of the blocks, by converting the quantized values of the first component to de-quantized values corresponding to ones of the de-quantized levels of the first scheme; and wherein the receiving apparatus is configured to output a video image to the screen based on the conversion by said de-quantizer. a receiver configured to receive a video bitstream from an encoder of a transmitting apparatus, the bitstream comprising a moving video image divided in time into a plurality of frames with each frame being divided in space into a plurality of encoded blocks, each encoded block having a common format representing a plurality of components of a channel in a colour space, the plurality of components comprising a plurality of frequency domain components in a spatial frequency domain or a plurality of pixels in a spatial domain, wherein each of the plurality of the encoded blocks comprises a different set of quantized values of the components, including at least a value of a first of said components being quantized from amongst a first scheme of quantized levels such that the quantized value corresponds to a quantized level of the first scheme; wherein the bitstream received from the encoder is characterised in that it further comprises a look-up table mapping the quantized levels of the first scheme to de-quantized respective levels, wherein the look-up table defines a non-uniform distribution of the de-quantized levels in proportion with one another; wherein the receiving apparatus further comprises a de-quantizer (80, 83, 90) operatively coupled to the receiver, configured to send an indication concerning a screen in a signal to the transmitting apparatus, and configured to use the look-up table received in the bitstream from the encoder and determined based on said indication to de-quantize the different quantized values of the first component in a plurality of the blocks, by converting the quantized values of the first component to de-quantized values corresponding to ones of the de-quantized levels of the first scheme; and wherein the receiving apparatus is configured to output a video image to the screen based on the conversion by said de-quantizer.