U.S. patent application number 11/412183 was filed with the patent office on 2007-11-01 for apparatus for monitor, storage and back editing, retrieving of digitally stored surveillance images.
This patent application is currently assigned to International Business Machines Corporation. Invention is credited to Oliver K. Ban.
Application Number | 20070252895 11/412183 |
Document ID | / |
Family ID | 38647920 |
Filed Date | 2007-11-01 |
United States Patent
Application |
20070252895 |
Kind Code |
A1 |
Ban; Oliver K. |
November 1, 2007 |
Apparatus for monitor, storage and back editing, retrieving of
digitally stored surveillance images
Abstract
A system and method of recording digitally stored surveillance
images comprises dividing a series of continuous digital picture
image frames according to timing intervals; storing a reference
image in a frame buffer of a motion analyzer; detecting a motion
difference between a captured image and the reference image;
attributing a motion code and time stamp on the captured image; and
recording the captured image when the motion code and time stamp
match a predetermined threshold.
Inventors: |
Ban; Oliver K.; (Austin,
TX) |
Correspondence
Address: |
FREDERICK W. GIBB, III;Gibb & Rahman, LLC
2568-A RIVA ROAD
SUITE 304
ANNAPOLIS
MD
21401
US
|
Assignee: |
International Business Machines
Corporation
Armonk
NY
|
Family ID: |
38647920 |
Appl. No.: |
11/412183 |
Filed: |
April 26, 2006 |
Current U.S.
Class: |
348/143 |
Current CPC
Class: |
G11B 27/105 20130101;
G11B 27/28 20130101; G11B 27/034 20130101 |
Class at
Publication: |
348/143 |
International
Class: |
H04N 7/18 20060101
H04N007/18 |
Claims
1. A method of recording digitally stored surveillance images, said
method comprising: dividing a series of continuous digital picture
image frames according to timing intervals; storing a reference
image in a frame buffer of a motion analyzer; detecting a motion
difference between a captured image and said reference image;
attributing a motion code and time stamp on said captured image;
and recording said captured image when said motion code and time
stamp match a predetermined threshold.
2. The method of claim 1, further comprising: coding a position of
pixels located in a foreground of a digital picture image frame;
sending the coded positions of said pixels located in said
foreground of said digital picture image frame to said frame buffer
of said motion analyzer; separating a background pixel group from a
foreground pixel group in said digital picture image frames based
on the coded positions; and compressing said pixels in said
foreground pixel group.
3. The method of claim 2, further comprising configuring said
motion analyzer with dimension register arrays adapted to code the
position of said pixels located in said foreground of said digital
picture image frame.
4. The method of claim 2, further comprising configuring said
motion analyzer with a comparator array comprising exclusive OR
computer-graphic logic adapted to separate said background pixel
group from said foreground pixel group.
5. The method of claim 1, further comprising configuring said
motion analyzer as a mini Cathode Ray Tube Controller (CRTC).
6. The method of claim 1, wherein a configuration of said motion
analyzer is variable.
7. The method of claim 1, wherein said captured image is recorded
only when a motion or a difference between said captured image and
said reference image is detected.
8. A program storage device readable by computer, tangibly
embodying a program of instructions executable by said computer to
perform a method of recording digitally stored surveillance images,
said method comprising: dividing a series of continuous digital
picture image frames according to timing intervals; storing a
reference image in a frame buffer of a motion analyzer; detecting a
motion difference between a captured image and said reference
image; attributing a motion code and time stamp on said captured
image; and recording said captured image when said motion code and
time stamp match a predetermined threshold.
9. The program storage device of claim 8, wherein said method
further comprises: coding a position of pixels located in a
foreground of a digital picture image frame; sending the coded
positions of said pixels located in said foreground of said digital
picture image frame to said frame buffer of said motion analyzer;
separating a background pixel group from a foreground pixel group
in said digital picture image frames based on the coded positions;
and compressing said pixels in said foreground pixel group.
10. The program storage device of claim 9, wherein said method
further comprises configuring said motion analyzer with dimension
register arrays adapted to code the position of said pixels located
in said foreground of said digital picture image frame.
11. The program storage device of claim 9, wherein said method
further comprises configuring said motion analyzer with a
comparator array comprising exclusive OR computer-graphic logic
adapted to separate said background pixel group from said
foreground pixel group.
12. The program storage device of claim 8, wherein said method
further comprises configuring said motion analyzer as a mini
Cathode Ray Tube Controller (CRTC).
13. The program storage device of claim 8, wherein a configuration
of said motion analyzer is variable.
14. The program storage device of claim 8, wherein said captured
image is recorded only when a motion or a difference between said
captured image and said reference image is detected.
15. A system for recording digitally stored surveillance images,
said system comprising: a series of continuous digital picture
image frames dividable according to timing intervals; a motion
analyzer adapted to store a reference image; a motion detector
operatively connected to said motion analyzer, wherein said motion
detector is adapted to detect a motion difference between a
captured image and said reference image; an image differentiator
operatively connected to said motion analyzer, wherein said image
differentiator is adapted to attribute a motion code and time stamp
on said captured image; and a recorder operatively connected to
said motion analyzer, wherein said recorder is adapted to record
said captured image when said motion code and time stamp match a
predetermined threshold.
16. The system of claim 15, wherein said motion analyzer further
comprises: a dimension register array adapted to code a position of
pixels located in a foreground of a digital picture image frame; a
frame buffer adapted to store the coded positions of said pixels
located in said foreground of said digital picture image frame; a
comparator adapted to separate a background pixel group from a
foreground pixel group in said digital picture image frames based
on the coded positions; and an image compressor adapted to compress
said pixels in said foreground pixel group.
17. The system of claim 16, wherein said motion analyzer comprises
a comparator array comprising exclusive OR computer-graphic logic
adapted to separate said background pixel group from said
foreground pixel group.
18. The system of claim 15, wherein said motion analyzer comprises
a mini Cathode Ray Tube Controller (CRTC).
19. The system of claim 15, wherein a configuration of said motion
analyzer is variable.
20. The system of claim 15, wherein said captured image is recorded
only when a motion or a difference between said captured image and
said reference image is detected.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application generally relates to co-pending U.S. patent
applications entitled (1) "Method and Apparatus for Fast and
Flexible Digital Image Compression Using Programmable Sprite
Buffer" (Docket No. YOR920050501US1) and (2) "Method and Apparatus
for a Fast Graphic Rendering Realization Methodology Using
Programmable Sprite Control" (Docket No. YOR920050502US1), filed
concurrently herewith, the contents of which in their entireties
are herein incorporated by reference;
BACKGROUND
[0002] 1. Technical Field
[0003] The embodiments herein generally relate to digital video
imaging systems, and, more particularly, to motion analysis control
for digital video surveillance imaging systems.
[0004] 2. Description of the Related Art
[0005] Conventional video surveillance systems 100 are generally
passive recording-based systems, typically either analog or digital
based, as shown in FIG. 1. Generally, the recordings are
time-based, and some are time-based mixed with place and other text
information. These time-based systems 100 typically use a time
stamp as a reference point with scanning and panning function
control and associated text information recorded on a recordable
tape mechanism either with an analog format or a digital format.
Generally, the conventional video surveillance system 100 is an
open-ended architecture, thus the contents of the recording
typically have to be viewed or analyzed by a human in a very time
consuming manner, which tends to create a limitation on the image
analysis and retrieving process. Accordingly, there remains a need
for a new technique for analyzing digitally-stored surveillance
images.
SUMMARY
[0006] In view of the foregoing, the embodiments herein provide a
method of recording digitally stored surveillance images, and a
program storage device readable by computer, tangibly embodying a
program of instructions executable by the computer to perform the
method, wherein the method comprises dividing a series of
continuous digital picture image frames according to timing
intervals; storing a reference image in a frame buffer of a motion
analyzer; detecting a motion difference between a captured image
and the reference image; attributing a motion code and time stamp
on the captured image; and recording the captured image when the
motion code and time stamp match a predetermined threshold.
[0007] The method may further comprise coding a position of pixels
located in a foreground of a digital picture image frame; sending
the coded positions of the pixels located in the foreground of the
digital picture image frame to the frame buffer of the motion
analyzer; separating a background pixel group from a foreground
pixel group in the digital picture image frames based on the coded
positions; and compressing the pixels in the foreground pixel
group. Moreover, the method may further comprise configuring the
motion analyzer with dimension register arrays adapted to code a
position of the pixels located in the foreground of the digital
picture image frame. Additionally, the method may further comprise
configuring the motion analyzer with a comparator array comprising
exclusive OR computer-graphic logic adapted to separate the
background pixel group from the foreground pixel group.
Furthermore, the method may further comprise configuring the motion
analyzer as a mini Cathode Ray Tube Controller (CRTC). Preferably,
the configuration of the motion analyzer is variable. Also, the
captured image is preferably recorded only when a motion or a
difference between the captured image and the reference image is
detected.
[0008] Another embodiment provides a system for recording digitally
stored surveillance images, wherein the system comprises a series
of continuous digital picture image frames dividable according to
timing intervals; a motion analyzer adapted to store a reference
image; a motion detector operatively connected to the motion
analyzer, wherein the motion detector is adapted to detect a motion
difference between a captured image and the reference image; an
image differentiator operatively connected to the motion analyzer,
wherein the image differentiator is adapted to attribute a motion
code and time stamp on the captured image; and a recorder
operatively connected to the motion analyzer, wherein the recorder
is adapted to record the captured image when the motion code and
time stamp match a predetermined threshold.
[0009] Preferably, the motion analyzer further comprises a
dimension register array adapted to code a position of pixels
located in a foreground of a digital picture image frame; a frame
buffer adapted to store the coded positions of the pixels located
in the foreground of the digital picture image frame; a comparator
adapted to separate a background pixel group from a foreground
pixel group in the digital picture image frames based on the coded
positions; and an image compressor adapted to compress the pixels
in the foreground pixel group. Preferably, the motion analyzer
comprises a comparator array comprising exclusive OR
computer-graphic logic adapted to separate the background pixel
group from the foreground pixel group. Furthermore, the motion
analyzer may comprise a mini CRTC. Moreover, the configuration of
the motion analyzer is preferably variable. Additionally, the
captured image is preferably recorded only when a motion or a
difference between the captured image and the reference image is
detected.
[0010] These and other aspects of the embodiments herein will be
better appreciated and understood when considered in conjunction
with the following description and the accompanying drawings. It
should be understood, however, that the following descriptions,
while indicating preferred embodiments and numerous specific
details thereof, are given by way of illustration and not of
limitation. Many changes and modifications may be made within the
scope of the embodiments herein without departing from the spirit
thereof, and the embodiments herein include all such
modifications.
BRIEFDESCRIPTION OF THE DRAWINGS
[0011] The embodiments herein will be better understood from the
following detailed description with reference to the drawings, in
which:
[0012] FIG. 1 illustrates a schematic diagram of a conventional
digital surveillance system architecture;
[0013] FIG. 2 illustrates a graphical representation of a motion
picture frame;
[0014] FIG. 3 illustrates a schematic diagram of a motion detection
based compression architecture according to an embodiment
herein;
[0015] FIG. 4 illustrates a schematic diagram of a motion analysis
controller architecture according to an embodiment herein;
[0016] FIG. 5 illustrates a computer system diagram according to an
embodiment herein; and
[0017] FIG. 6 is a flow diagram illustrating a preferred method of
an embodiment herein.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0018] The embodiments herein and the various features and
advantageous details thereof are explained more fully with
reference to the non-limiting embodiments that are illustrated in
the accompanying drawings and detailed in the following
description. Descriptions of well-known components and processing
techniques are omitted so as to not unnecessarily obscure the
embodiments herein. The examples used herein are intended merely to
facilitate an understanding of ways in which the embodiments herein
may be practiced and to further enable those of skill in the art to
practice the embodiments herein. Accordingly, the examples should
not be construed as limiting the scope of the embodiments
herein.
[0019] As mentioned, there remains a need for a new technique for
analyzing digitally-stored surveillance images. The embodiments
herein achieve this by providing a technique for making the digital
recording surveillance system object based instead of time based.
Referring now to the drawings, and more particularly to FIGS. 2
through 6, where similar reference characters denote corresponding
features consistently throughout the figures, there are shown
preferred embodiments.
[0020] As illustrated in FIG. 2, most picture frames 200 have the
following characteristics: (1) most of the pictures 200 have a
large portion of the "background" 210 that is relatively static,
such as a flower bed or parking lot; (2) there are usually
relatively small but relatively fixed shaped "foreground" objects
220 that move inside the picture frames 200; and (3) since it is a
time based system, the motion search and analysis of conventional
techniques is generally performed by linearly searching through
human eyes.
[0021] The embodiments herein operate according to FIG. 3 in the
following manner. First, as images are processed, the time domain,
such as the date, time, and location of the image, is separated
into timing intervals such as per minutes (for example, per 10
minutes, etc.), recording the first image as a reference image
(I-Picture). Then, all of the other images (F-pictures) are
compared with this I-picture. Essentially, only the I-picture is
fully transmitted, the rest of the pictures, F-pictures (forward
pictures) and B-pictures (backward pictures), are only transmitted
for their difference with the I-pictures, whereby the difference is
much smaller than the entire picture, especially when the
difference is based on 8.times.8=64 pixel blocks. Preferably, this
is facilitated by hardware (basically combiner/integrator 401 built
from adder logic), which functions as a motion estimator.
Generally, this technique combines the difference vectors of the
two blocks of pixels on the luminance and chrominance and sends out
the difference vectors, whereby the difference vectors are
transmitted instead of the original pixel information.
[0022] The recording is not performed until a motion or a
difference is detected and analyzed. Second, the reference frame
(I-frame) is stored in a separate background frame buffer 310 as a
comparing reference frame. Preferably, the frame buffer 310 is
embodied as a block of computerized random access memory (RAM)
based memory (for example, a linear or block shape 4 MB RAM) that
stores the entire frame 200 of one picture. The time interval can
be dynamically adjusted according to the particular situation
(using, for example, adaptive algorithms).
[0023] Third, every captured frame is compared with the I-picture
buffered image; whereby the difference is fed into a motion
analyzer 302 that is operatively connected to the background frame
buffer 310. In this context, the "difference" refers to the
difference of luminance and chrominance, in the size of a
8.times.8=64 pixel block. More specifically, two vectors, luminance
difference and chrominance difference, are fed into the motion
analyzer 302. These vectors are fed by direct input into a hardware
comparator (combiner/integrator) 401 of the motion analyzer 302 as
shown in FIG. 4. Then, a specified set of motion codes is marked on
each of the frames along with time stamps 315. The motion codes
come from the output of the motion analyzer 302; more specifically,
the output of the comparator 401. The image then is marked with
only the difference vector instead of its pixels. An example of the
motion code is (value=3 [position -1, +2]; value=-15), (luma diffs
with position code, chrom diffs). The motion codes may be coded in
a standard way or in anyway that a system designer desires.
[0024] Fourth, the motion analyzer 302 then analyzes the input
(i.e., captured images) from the motion detector 306 and an image
differentiator 321. The output of the image differentiator 321 is
the difference between the stored reference images and the new
input image to make a decision if the image has to be recorded.
Element 320 (logic) operates on top of the foreground frame buffer
312 (memory). Thus, every frame 200 is marked with a certain motion
code associated with it. The compression of pixels occurs because
only selected frames have to be recorded, wherein the remainder of
the frames, which is the majority of the time--anywhere from 50% to
99%--can simply be discarded.
[0025] Preferably, the motion analyzer 302 comprises a small to
medium sized frame buffer 312 to store the foreground object images
220 and motion codes. The block of image pixels that are being
processing is preferably a 8.times.8=64 pixel block. Additionally,
the motion analyzer 302 preferably comprises dimension register
arrays 322 adapted to code the position of the foreground buffer
312. The dimension register array 322 is preferably configured as a
set of memory cells specifically formatted to record the motion
code. Moreover, the motion analyzer 302 preferably comprises a
comparator array (exclusive OR) 401 to distinguish the moving
object area 220 from the background 210. The comparator array 401
preferably comprises exclusive OR logic to differentiate the two or
more inputs to generate a same or not judgment assessment.
Furthermore, the motion analyzer 302 preferably combines the input
of the output of a sprite buffer 300 with the motion detector 306
in the fashion of an AND function. This occurs by combining those
two sets of parameters to form a set of formatted code.
[0026] The motion analyzer 302 may be designed as a mini CRTC, with
a small frame buffer 312. The CRTC is adapted to control the scan
of pixels across the display on a CRT, including the horizontal and
vertical position of the pixel and the value of the pixel. The
shape of the motion analyzer 302 can be of any shape, such as
rectangular, or could be circle or any other shape, even variable
one, as long as the shape position parameters 320 can be easily
coded. In this context, the "shape" of the motion analyzer 302 is
the size of the motion analyzer 302. Preferably, the motion
analyzer 302 is a hardware component.
[0027] The sprite buffer 300 provides the means of the motion
analysis that separates the picture frames 200 with only time stamp
marks 315 and at the same time, associates the frames 200 with a
motion code, thus drastically increasing the editing and analysis
speed by searching for a motion code in combination with a time
stamp 315. This increases the speed so one does not have to search
linearly as in conventional techniques by time stamp only.
Accordingly, the embodiments herein facilitate searching or editing
by motions, locations, and other particular features that a user
can define. A digitally recoded image is much faster for searching
and consumes much less space than analog data, and also provides
much better image quality as well as durability. The digital image
then can be copied without degradation to the quality unlimited
times, which is more durable then analog images, which can
generally only be copied once or twice with reasonable degradation;
and with fast searching the editing efficiency is increased at
least by ten times to one hundred times. Moreover, the image
quality is improved by two times to four times as a digital zoom
can be applied to the images 200.
[0028] Components 401, 403, 405, and 407 are roughly the building
blocks of the CRTC. The pixels of the picture 200 are fed into the
motion detector 403 to get the size and location of the moving
part; thus the "sprite area" (i.e., small portion of pixels cut
from the main picture) is identified. The picture is also fed into
the pattern recognition mechanism 405 to get the location and size
information of the characteristics of the moving part of the
picture (for example, a moving car or person) so that an
intelligent motion code can be transmitted. The picture is also fed
into a database search matching mechanism 407 to get background
information to see if a previously-stored pattern matches the
sprite information so that an even more intelligent motion code can
be programmed into the difference vectors that the
combiner/integrator 401 will integrate. Finally, the
combiner/integrator 401 combines this information from the output
of elements 403, 405, and 407 to get a difference vector code to
form a transmitted code.
[0029] The techniques provided by the embodiments herein may be
implemented on an integrated circuit chip (not shown). The chip
design is created in a graphical computer programming language, and
stored in a computer storage medium (such as a disk, tape, physical
hard drive, or virtual hard drive such as in a storage access
network). If the designer does not fabricate chips or the
photolithographic masks used to fabricate chips, the designer
transmits the resulting design by physical means (e.g., by
providing a copy of the storage medium storing the design) or
electronically (e.g., through the Internet) to such entities,
directly or indirectly. The stored design is then converted into
the appropriate format (e.g., GDSII) for the fabrication of
photolithographic masks, which typically include multiple copies of
the chip design in question that are to be formed on a wafer. The
photolithographic masks are utilized to define areas of the wafer
(and/or the layers thereon) to be etched or otherwise
processed.
[0030] The resulting integrated circuit chips can be distributed by
the fabricator in raw wafer form (that is, as a single wafer that
has multiple unpackaged chips), as a bare die, or in a packaged
form. In the latter case the chip is mounted in a single chip
package (such as a plastic carrier, with leads that are affixed to
a motherboard or other higher level carrier) or in a multichip
package (such as a ceramic carrier that has either or both surface
interconnections or buried interconnections). In any case the chip
is then integrated with other chips, discrete circuit elements,
and/or other signal processing devices as part of either (a) an
intermediate product, such as a motherboard, or (b) an end product.
The end product can be any product that includes integrated circuit
chips, ranging from toys and other low-end applications to advanced
computer products having a display, a keyboard or other input
device, and a central processor.
[0031] The embodiments herein can take the form of an entirely
hardware embodiment, an entirely software embodiment or an
embodiment including both hardware and software elements.
Preferably, the embodiments are implemented in software, which
includes but is not limited to firmware, resident software,
microcode, etc.
[0032] Furthermore, the embodiments herein can take the form of a
computer program product accessible from a computer-usable or
computer-readable medium providing program code for use by or in
connection with a computer or any instruction execution system. For
the purposes of this description, a computer-usable or computer
readable medium can be any apparatus that can comprise, store,
communicate, propagate, or transport the program for use by or in
connection with the instruction execution system, apparatus, or
device.
[0033] The medium can be an electronic, magnetic, optical,
electromagnetic, infrared, or semiconductor system (or apparatus or
device) or a propagation medium. Examples of a computer-readable
medium include a semiconductor or solid state memory, magnetic
tape, a removable computer diskette, a RAM, a read-only memory
(ROM), a rigid magnetic disk and an optical disk. Current examples
of optical disks include compact disk-read only memory (CD-ROM),
compact disk-read/write (CD-R/W) and DVD.
[0034] A data processing system suitable for storing and/or
executing program code will include at least one processor coupled
directly or indirectly to memory elements through a system bus. The
memory elements can include local memory employed during actual
execution of the program code, bulk storage, and cache memories
which provide temporary storage of at least some program code in
order to reduce the number of times code must be retrieved from
bulk storage during execution.
[0035] Input/output (I/O) devices (including but not limited to
keyboards, displays, pointing devices, etc.) can be coupled to the
system either directly or through intervening I/O controllers.
Network adapters may also be coupled to the system to enable the
data processing system to become coupled to other data processing
systems or remote printers or storage devices through intervening
private or public networks. Modems, cable modem and Ethernet cards
are just a few of the currently available types of network
adapters.
[0036] A representative hardware environment for practicing the
embodiments herein is depicted in FIG. 5. This schematic drawing
illustrates a hardware configuration of an information
handling/computer system in accordance with the embodiments herein.
The system comprises at least one processor or central processing
unit (CPU) 10. The CPUs 10 are interconnected via system bus 12 to
various devices such as a RAM 14, ROM 16, and an I/O adapter 18.
The I/O adapter 18 can connect to peripheral devices, such as disk
units 11 and tape drives 13, or other program storage devices that
are readable by the system. The system can read the inventive
instructions on the program storage devices and follow these
instructions to execute the methodology of the embodiments herein.
The system further includes a user interface adapter 19 that
connects a keyboard 15, mouse 17, speaker 24, microphone 22, and/or
other user interface devices such as a touch screen device (not
shown) to the bus 12 to gather user input. Additionally, a
communication adapter 20 connects the bus 12 to a data processing
network 25, and a display adapter 21 connects the bus 12 to a
display device 23 which may be embodied as an output device such as
a monitor, printer, or transmitter, for example.
[0037] FIG. 6 is a flow diagram illustrating a method of recording
digitally stored surveillance images according to an embodiment
herein, wherein the method comprises dividing (601) a series of
continuous digital picture image frames according to timing
intervals; storing (603) a reference image in a frame buffer 312 of
a motion analyzer 302; detecting (605) a motion difference between
a captured image and the reference image; attributing (607) a
motion code and time stamp 315 on the captured image; and recording
(609) the captured image when the motion code and time stamp 315
match a predetermined threshold. The method may further comprise
coding a position of pixels located in a foreground 220 of a
digital picture image frame 200; sending the coded positions of the
pixels located in the foreground 220 of the digital picture image
frame 200 to the frame buffer 312 of the motion analyzer 302;
separating a background pixel group 210 from a foreground pixel
group 220 in the digital picture image frames 200 based on the
coded positions; and compressing the pixels in the foreground pixel
group 220.
[0038] Moreover, the method may further comprise configuring the
motion analyzer 302 with dimension register arrays 322 adapted to
code a position of the pixels located in the foreground 220 of the
digital picture image frame 200. Additionally, the method may
further comprise configuring the motion analyzer 302 with a
comparator array 401 comprising exclusive OR computer-graphic logic
adapted to separate the background pixel group 210 from the
foreground pixel group 220. Furthermore, the method may further
comprise configuring the motion analyzer 302 as a mini CRTC.
Preferably, the configuration of the motion analyzer 302 is
variable. Also, the captured image is preferably recorded only when
a motion or a difference between the captured image and the
reference image is detected.
[0039] The foregoing description of the specific embodiments will
so fully reveal the general nature of the embodiments herein that
others can, by applying current knowledge, readily modify and/or
adapt for various applications such specific embodiments without
departing from the generic concept, and, therefore, such
adaptations and modifications should and are intended to be
comprehended within the meaning and range of equivalents of the
disclosed embodiments. It is to be understood that the phraseology
or terminology employed herein is for the purpose of description
and not of limitation. Therefore, while the embodiments herein have
been described in terms of preferred embodiments, those skilled in
the art will recognize that the embodiments herein can be practiced
with modification within the spirit and scope of the appended
claim.
* * * * *