Optimum partition of two-dimensional frequency band with human visual sensitivity for subband image coding

2003 ◽  
Vol 34 (3) ◽  
pp. 96-110
Author(s):  
Masashi Kameda ◽  
Kohhei Ohtake ◽  
Makoto Miyahara
Keyword(s):  
Frequency Band ◽  
Image Coding ◽  
Visual Sensitivity ◽  
Two Dimensional ◽  
Optimum Partition

Mycielski Based 2d-Predictive Image Coding Algorithm

2016 ◽  
Vol 850 ◽  
pp. 144-151 ◽  
Author(s):  
Mehmet Fidan ◽  
Ömer Nezih Gerek
Keyword(s):  
Image Coding ◽  
Predictive Coding ◽  
Prediction Method ◽  
Physical Distance ◽  
Prediction Algorithm ◽  
Two Dimensional ◽  
Two Dimensional Image ◽  
Past Data ◽  
And Performance ◽  
Definition Of

The Mycielski method is a prospering prediction algorithm which is based on searching and finding largest repeated binary patterns. It uses infinite-past data to devise a rule based prediction method on a time series. In this work, a novel two-dimensional (image processing) version of the Mycielski algorithm is proposed. Since the dimensionality definition of “past” data increases in two-dimensional signals, the proposed algorithm also needs to handle how the boundaries of the pixel cliques are iteratively extended in the neighborhood of a current pixel. The clique extension invokes novel similarity search strategies that depend on the chosen physical distance metric. The proposed prediction algorithm is used for predictive image compression and performance comparisons with other predictive coding methods are presented.

Optimized Driver Placement for Array-Driven Flat-Panel Loudspeakers

2017 ◽  
Vol 42 (1) ◽  
pp. 93-104 ◽  
Author(s):  
David A. Anderson ◽  
Michael C. Heilemann ◽  
Mark F. Bocko
Keyword(s):  
Frequency Band ◽  
Mode Coupling ◽  
Dynamic Force ◽  
Two Dimensional ◽  
Flat Panel ◽  
Piezoelectric Patch ◽  
Optimal Force ◽  
Network Method ◽  
Point Forces ◽  
Bending Modes

Abstract The recently demonstrated ‘modal crossover network’ method for flat panel loudspeaker tuning employs an array of force drivers to selectively excite one or more panel bending modes from a spectrum of panel bending modes. A regularly spaced grid of drivers is a logical configuration for a two-dimensional driver array, and although this can be effective for exciting multiple panel modes it will not necessarily exhibit strong coupling to all of the modes within a given band of frequencies. In this paper a method is described to find optimal force driver array layouts to enable control of all the panel bending modes within a given frequency band. The optimization is carried out both for dynamic force actuators, treated as point forces, and for piezoelectric patch actuators. The optimized array layouts achieve similar maximum mode coupling efficiencies in comparison with regularly spaced driver arrays; however, in the optimized arrays all of the modes within a specified frequency band may be independently addressed, which is important for achieving a desired loudspeaker frequency response. Experiments on flat panel loudspeakers with optimized force actuator array layouts show that each of the panel modes within a selected frequency band may be addressed independently and that the inter-modal crosstalk is typically −30 dB or less with non-ideal drivers.

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