Abstract: Accurate measures of estimated spectral power and phase are derived from two spectral representations of each of one or more input signals generated by single-sideband filter banks including critically-sampled perfect-reconstruction filter banks implemented by generalized forms of Time Domain Aliasing Cancellation transforms. The derived measures of spectral magnitude and phase may be used in various applications including adaptive bit allocation in perceptual coding systems. An efficient implementation of one particular single-sideband critically-sampled filter bank comprises folding and shuffling blocks of real-valued input signal samples into blocks of complex-valued samples, rotating the complex-valued samples in the complex plane, transforming the rotated samples into transform coefficients, and rotating and shuffling the transform coefficients to form the spectral representation.

Abstract: An electronic image printing apparatus is provided on the front face thereof with an improved downloading film access door assembly. The door assembly pivots substantially under the force of gravity from an upright closed position to an extended fully open position wherein a film cassette may be inserted into and/or withdrawn from a film cassette receiving carriage which is disposed for controlled reciprocal sliding translation during the printing process. A dashpot is provided for dampening the pivotal movement of the film loading access door so that it progressively decelerates as it approaches its open extended position so as to gradually come to a stop without substantial vibration or shock. The dashpot also includes a spring which extends through the back wall thereof to counter the increase in the weight induced opening torque as the door pivots downwardly.