Digital Video Plot Interpolation Using Static-Coefficient Delay Filtering
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Solution Overview
Problem
Existing methods for generating a continuous plot from discrete time-sampled data require complex processes, such as converting between digital and analog signals and varying filter coefficients, which are computationally intensive and inefficient.
Innovation Solution
A digital filter with predetermined static coefficients is used in conjunction with a variable delay to produce interpolated values, allowing for a more continuous plot without the need to change coefficients or shift operands, using a Farrow configuration with stages having incremental or function-differing coefficients and a variable delay element to alter the interaction of coefficients and sample values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If digital-to-analog conversion and low-pass filtering are used to generate continuous plots, then plot continuity is improved, but device complexity and computational load increase
Solution Approach 1:
The patent replaces the mechanical/analog signal conversion process (digital-to-analog converter and analog low-pass filter) with a purely digital computational approach. A digital filter applies correlation factors to time-sampled data points to directly compute interpolated values, eliminating the need for physical analog conversion hardware while achieving the same plot continuity effect.
Solution Approach 2:
The patent changes the parameter being varied from analog voltage levels to digital correlation factors. Instead of converting to analog and filtering, the system varies correlation factors (weights) applied to different time-sampled points to generate interpolated values, achieving continuous plots through digital parameter adjustment rather than analog signal processing.
2Measurement precision
If filter coefficients are varied to produce interpolated values, then interpolation accuracy is improved, but computational efficiency deteriorates
Solution Approach 1:
The patent pre-calculates and stores correlation factors in a lookup table before processing the actual data. These pre-computed factors are then simply retrieved and applied to the time-sampled points, avoiding the need to compute complex filter coefficients in real-time and significantly improving computational efficiency while maintaining interpolation accuracy.
Solution Approach 2:
The patent uses pre-computed correlation factor patterns that can be reused across different interpolation operations. Instead of calculating unique filter coefficients for each interpolation task, the system copies and applies appropriate pre-stored correlation factor sets, reducing computational load while preserving the accuracy benefits of varied coefficients.
Data Source
AI summary
A video display for digitized video data interpolates values between time samples, such as luminance over a horizontal line or over an average of all the horizontal lines in a video signal, so as to produce a digitally plotted test display resembling the continuous line display of an oscilloscope. A digital impulse response filter has stored coefficients that contribute as factors to the values of interpolated data points to fill the line display between sample values. Instead of changing the coefficients to produce variations interpolating the output between sample values, the coefficients are held constant and a delay factor is varied to alter the extent to which the respective coefficients and sample values interact and contribute to the interpolated values.