US Patent 10405000 One-dimensional transform modes and coefficient scan order

Methods and apparatus are provided for performing one-dimensional (1D) transform and coefficient scanning. An encoder may apply 1D transform in either a horizontal or a vertical direction. The encoder may then determine a coefficient scan order based on the 1D transform direction. The scan order may be determined to be in a direction orthogonal to the 1D transform direction. The encoder may further flip the coefficients prior to scanning. The flipping may also be in a direction orthogonal to the 1D transform direction. A decoder may receive indications from the encoder with respect to the 1D transform, coefficient scanning, and/or coefficient flipping. The decoder may perform functions inverse to those performed by the encoder based on the indications.