.[.A clock recovery circuit in a digital display unit for recovering a time reference signal associated with analog display data. The clock recovery circuit includes a phase-locked loop (PLL) implemented in digital domain and an analog filter to eliminate any undesirable frequencies from the output signal of the PLL. The PLL includes independent control loops to track long term frequency drifts of the time reference signal and the transient phase differences respectively. By providing such independent control loops, the generated clock can be better synchronized with the time reference signal..]. .Iadd.Scaling a source image formed of a number of source image elements to provide a destination image formed of a number of destination image elements using a line buffer and no frame buffer..Iaddend.