A signal processing apparatus includes a first signal processing circuit and the second signal processing circuit. The first signal processing circuit receives a first signal. The first signal processing circuit has a power end connecting to a first voltage and a reference ground end. The second signal processing circuit receives a second signal. The second signal processing circuit has a power end which is electrically coupled to the reference ground end of the first signal processing circuit or equals the reference ground end of the first signal processing circuit. The second signal processing circuit has a reference ground end connecting to a second voltage.

Apparatus and method for an output stage of an amplifier are disclosed. A current source circuit provides current to a transistor connected to the amplifier output node to produce output voltage, and the current source circuit has two current mirror paths, one of which replicates the output voltage at the output node. As the output voltage approaches rail, more current is steered to the current mirror path not replicating the output voltage and provides additional current or voltage necessary to keep the current source circuit operational.

Example-based edge-aware directional texture painting techniques are described. Inputs are received that define a target direction field and a plurality of edges as part of a target shape mask. A texture is synthesized from a source image by the computing device to be applied to the set of pixels of the target mask using a source shape mask and a source direction field. The source shape mask defines a plurality of edges of the source mask such that the synthesized texture applied to the plurality of edges of the target shape mask correspond to respective ones of the plurality of edges of the source shape mask. The source direction field is taken from the source image such that the synthesized texture applied to the target direction field corresponds to the source direction field. The pixels in the user interface are painted by the computing device using the synthesized texture.