Electrical computers: arithmetic processing and calculating – Electrical digital calculating computer – Particular function performed
Reexamination Certificate
2001-01-03
2003-12-09
Mai, Tan V. (Department: 2121)
Electrical computers: arithmetic processing and calculating
Electrical digital calculating computer
Particular function performed
C708S303000
Reexamination Certificate
active
06662200
ABSTRACT:
BACKGROUND
This disclosure is related to pyramid filters.
In image processing it is often desirable to decompose an image, such as a scanned color image, into two or more separate image representations. In this context, these are referred to as background and foreground images. This descreening is also sometimes applied to remove halftone patterns that may exist in an original scanned image. For example, these halftone patterns may cause objectionable artifacts for human eyes if not properly removed. The traditional approach for this decomposition or descreening is to filter the color image in order to blur it. These blurred results are then used to assist in determining how much to blur and sharpen the image in order to produce the decomposition. Typically this blurring can be achieved using a “symmetric pyramid” filter. Symmetric pyramid finite impulse response (FIR) filters are well-known.
One disadvantage of this image processing technique, however, is that the complexity increases many fold when a number of pyramid filters of different sizes are applied in parallel in order to generate multiple blurred images, to apply the technique as just described. A brute force approach for this multiple pyramid filtering approach is to use multiple FIR filters in parallel, as illustrated in FIG.
1
. Such an approach demonstrates that the design and implementation of fast “symmetric pyramid filtering” architectures to generate different blurred images in parallel from a single source image may be desirable.
The numbers provided in parenthesis for each FIR block in
FIG. 1
represents the pyramid filter of corresponding length. For example, (1, 2, 1) are the filter coefficients for a symmetric pyramid finite impulse response (FIR) filter of order or length
3
. Likewise, (1, 2, 3, 2, 1) are the coefficients for an FIR pyramid filter of order
5
, and so forth.
Unfortunately, the approach demonstrated in
FIG. 1
has disadvantages. For example, inefficiency may result from redundant computations. Likewise, FIR implementations frequently employ multiplier circuits. While implementations exist to reduce or avoid the use of multipliers, such as with shifting and summing circuitry, that may then result in increased clocking and, hence, may reduce circuit through-put. A need, therefore, exists for improving pyramid filtering implementations or architectures.
REFERENCES:
patent: 4674125 (1987-06-01), Carlson et al.
patent: 4703514 (1987-10-01), Van Der Wal
patent: 4829378 (1989-05-01), LeGall
patent: 5359674 (1994-10-01), van der Wal
patent: 5561617 (1996-10-01), Van Der Wal
patent: 5886912 (1999-03-01), Miyake et al.
Peter J. Burt, et al., “The Laplacian Pyramid as a Compact Image Code”, IEEE Transactions on Communications, vol. Com-31, No. 4, Apr. 1983, XP000570701, 5 Pgs.
Sahinoglou, et al., “A High-Speed Pyramid Image Coding Algorithm for a VLSI Implementation”, IEEE Transactions of Circuits and Systems for Video Technology, vol. 1, No. 4, NY, Dec. 1991, XP000249319, pp. 369-374.
Dongning Li, “Minimum Number of Adders for Implementing a Multiplier and its Application to the Design of Multiplierless Digital Filters”, IEEE Transactions on Circuits ans Systems II: Analog and Digital Signal Processing, No. 7, NY, Jul. 1995, pp. 453-460.
Dempster, et al., “Comments on Minumum Number of Adders for Implementing a Multiplier and its Application to the Design of Multiplierless Digital Filters”, Analog and Digital Signal Processing, vol. 45, No. 2, IEEE Feb. 1998, XP 000771370, pp. 242-243.
Jaehne B, “Digitale Bildverarbeitung”, 1991, Springer-Verlag, Berlin Heidelberg, NY, XP 002208396, pp. 107-111.
K.R. Castleman, et al., “Simplified Design of Steerable Pyramid Filters”, Perceptive Scientific Instruments, Inc., League City, TX, 1998 IEEE, XP 10289971, pp. 329-332.
Mai Tan V.
Wong Sharon
LandOfFree
Multiplierless pyramid filter does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Multiplierless pyramid filter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Multiplierless pyramid filter will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3180398