Abstract: A method and a device for applying a transformation to a data field are provided, wherein data points are transformed using at least one transformation rule, characterized in that the data field is divided into segments, that for each data point to be transformed of the data field a test is performed to identify the segment in which the data point is arranged, and that a transformation rule is subsequently selected depending on the segment found and the rule is applied to said data point.

Abstract: The invention relates to a method and a device for encoding the video level of a pixel of a picture into a subfield code word in a display device. It can be applied to every display device using a PWM (Pulse Width Modulation) technology and subfields for displaying video picture. The bits of the subfield code word are computed recursively one after the other from the bit having the most significant weight to the bit having the least significant weight. According to the invention, for determining the state of a bit of the subfield code word, a first threshold and a second threshold is associated with said bit, said second threshold being greater than said first threshold, and the video level to be encoded by this bit and its following bits in the subfield code word are compared to the first and second thresholds. If the video level is lower than the first threshold, a state “OFF” is allocated to the bit.