U.S. patent application number 12/694899 was filed with the patent office on 2010-06-03 for diagnostic device, system and method for reduced data transmission.
Invention is credited to Dov AVNI, Arkady Glukhovsky, Eli Horn, Gavriel Meron, Ofra Zinaty.
Application Number | 20100134606 12/694899 |
Document ID | / |
Family ID | 32587529 |
Filed Date | 2010-06-03 |
United States Patent
Application |
20100134606 |
Kind Code |
A1 |
AVNI; Dov ; et al. |
June 3, 2010 |
DIAGNOSTIC DEVICE, SYSTEM AND METHOD FOR REDUCED DATA
TRANSMISSION
Abstract
A device, system and method may enable the obtaining of in vivo
images from within body lumens or cavities, such as images the
gastrointestinal (GI) tract, where the data such as image data is
typically transmitted or otherwise sent to a receiving system in
compressed or diluted form. The image may be reconstructed and for
example displayed to a user.
Inventors: |
AVNI; Dov; (Haifa, IL)
; Meron; Gavriel; (Petach Tikva, IL) ; Horn;
Eli; (Kiryat Motzkin, IL) ; Zinaty; Ofra;
(Haifa, IL) ; Glukhovsky; Arkady; (Santa Clarita,
CA) |
Correspondence
Address: |
Pearl Cohen Zedek Latzer, LLP
1500 Broadway, 12th Floor
New York
NY
10036
US
|
Family ID: |
32587529 |
Appl. No.: |
12/694899 |
Filed: |
January 27, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10551436 |
Jul 17, 2006 |
7664174 |
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PCT/IL2004/000287 |
Mar 29, 2004 |
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12694899 |
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Current U.S.
Class: |
348/65 ;
348/E7.085 |
Current CPC
Class: |
A61B 1/041 20130101;
H04N 19/59 20141101; A61B 1/00016 20130101; H04N 5/3456
20130101 |
Class at
Publication: |
348/65 ;
348/E07.085 |
International
Class: |
H04N 7/18 20060101
H04N007/18 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 31, 2003 |
IL |
155175 |
Claims
1. An in vivo device comprising: an imager for capturing in vivo
image data, the imager comprising rows of pixels; a controller to
receive the in vivo image data, and to dilute the image data using
a dilution pattern, wherein said dilution pattern is repeated in
every four rows of the captured image data, such that every second
green pixel is selected from a first row, every second blue pixel
is selected from a second row, and every second red pixel is
selected from a third row; and a transmitter to transmit diluted
image data.
2. The device of claim 1 wherein the dilution pattern used to
dilute the image data is modified based on operating conditions of
the device.
3. The device of claim 2 wherein the operating conditions are
selected from a group consisting of position of the in vivo device,
pH, temperature, ambient lighting or color conditions.
4. The device of claim 1 wherein the dilution pattern further
comprises selecting a same amount of red pixels and blue pixels and
twice that amount of green pixels.
5. The device of claim 1 wherein the dilution pattern further
comprises selecting every second green pixel from said second row,
and selecting no pixels from a fourth row.
6. The device of claim 1 wherein the dilution pattern further
comprises selecting every second red pixel from a fourth row, such
that a same amount of green pixels and blue pixels are selected and
twice that amount of red pixels are selected.
7. A system for dilution of in vivo image data for subsequent
reconstruction thereof, the system comprising a data compression
module to: receive image data acquired by an in-vivo imager, the
imager comprising rows of pixels; and dilute said image data using
a dilution pattern, wherein said dilution pattern is repeated in
every four rows of the image data, such that every second green
pixel is selected from a first row, every second blue pixel is
selected from a second row, and every second red pixel is selected
from a third row.
8. The system of claim 7 wherein said data compression module is
implemented as part of a transmitter in an in vivo device.
9. The system of claim 8 further comprising a receiver to receive
the diluted image data.
10. The system of claim 7 wherein said dilution pattern further
comprises selecting a same amount of red pixels and blue pixels and
twice that amount of green pixels.
11. The system of claim 7 wherein said dilution pattern further
comprises selecting every second green pixel from said second row,
and selecting no pixels from a fourth row.
12. The system of claim 7 wherein said dilution pattern further
comprises selecting every second red pixel from a fourth row, such
that a same amount of green pixels and blue pixels are selected and
twice that amount of red pixels are selected.
13. A method for dilution of in vivo image data comprising:
capturing in vivo image data by an in vivo imager, the data
arranged in rows of pixels; diluting the captured image data
according to a dilution pattern, wherein the dilution pattern
wherein the dilution pattern is repeated in every four rows of the
image data, such that every second green pixel is selected from a
first row, every second blue pixel is selected from a second row,
and every second red pixel is selected from a third row; and
transmitting the diluted image data to a receiver.
14. The method of claim 13 wherein said dilution pattern further
comprises selecting every second red pixel from a fourth row, such
that a same amount of green pixels and blue pixels are selected and
twice that amount of red pixels are selected.
15. The method of claim 13 comprising reconstructing an image from
the diluted image data.
16. The method of claim 13 wherein the dilution pattern is
predetermined.
17. The method of claim 13 wherein the dilution pattern is created
by a component of an in vivo device comprising the imager, based on
operating conditions selected from: the position of the device in
the gastro-intestinal tract, pH, temperature surrounding the
device, ambient lighting or color.
18. The method of claim 13 wherein the dilution pattern further
comprises averaging the value of a selected pixel of a certain
color with the value of a nearby pixel of the same color.
19. The method of claim 13 wherein the averaging is activated or
deactivated by a control bit.
20. The method of claim 13 wherein the in vivo imaging device is a
swallowable capsule.
Description
PRIOR APPLICATIONS DATA
[0001] This application is a continuation of U.S. patent
application Ser. No. 10/551,436, entitled "DIAGNOSTIC DEVICE,
SYSTEM AND METHOD FOR REDUCED DATA TRANSMISSION", filed Jul. 17,
2006, published on Nov. 23, 2006 as United States Patent
Application Publication No. 2006/0262186, which is hereby
incorporated by reference in its entirety, and which is a National
Phase Application of International Application No.
PCT/IL2004/000287, entitled "DIAGNOSTIC DEVICE, SYSTEM AND METHOD
FOR REDUCED DATA TRANSMISSION", filed Mar. 29, 2004, published on
Oct. 14, 2004 as International Application Publication No. WO
2004/088448, which is hereby incorporated by reference in its
entirety, and claims priority and benefit from Israeli Patent
Application Number 155175, entitled "DIAGNOSTIC DEVICE, SYSTEM AND
METHOD FOR REDUCED DATA TRANSMISSION", filed on Mar. 31, 2003,
which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to an in vivo device, system
and method such as for imaging the digestive tract; more
specifically, to an in vivo device, system and method where
information transmitted or sent, is compressed.
BACKGROUND OF THE INVENTION
[0003] Devices and methods for performing in-vivo imaging of
passages or cavities within a body, and for gathering information
other than or in addition to image information (e.g., temperature
information, pressure information), are known in the art. Such
devices may include, inter glia, various endoscopic imaging systems
and devices for performing imaging in various internal body
cavities.
[0004] An in-vivo imaging device may include, for example, an
imaging system for obtaining images from inside a body cavity or
lumen, such as the GI tract. The imaging system may include, for
example, an illumination unit, such as a set of light emitting
diodes (LEDs), or other suitable light sources. The device may
include an imaging sensor and an optical system, which focuses the
images onto the imaging sensor. A transmitter and antenna may be
included for transmitting the images signals. A receiver/recorder,
for example worn by the patient, may record and store image and
other data. The recorded data may then be downloaded from the
receiver/recorder to a computer or workstation for display and
analysis. Such imaging and other devices may transmit data such as
image data or other data during a certain period of time. It may be
desirable to limit the amount of time spent transmitting image
data, and also the bandwidth required for such a transmission. The
time spent transmitting limits the amount of image or other data
that may be transmitted. Other in-vivo diagnostic units need not
transmit by radio waves, for example, image or other data collected
may be sent via wire.
[0005] Therefore, there is a need for an in-vivo diagnostic device,
such as an imaging device, which more efficiently transmits
data.
SUMMARY OF THE INVENTION
[0006] An embodiment of the device, system and method of the
present invention enables the obtaining of in vivo images from
within body lumens or cavities, such as images of the
gastrointestinal (GI) tract, where the data such as image data is
typically transmitted or otherwise sent to a receiving system.
According to one embodiment of the invention, the data transmitted,
including, for example, image information, is compressed. The data
may be reconstructed using suitable methods and, for example,
displayed to a user.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1A shows a schematic diagram of an in vivo imaging
system according to one embodiment of the present invention;
[0008] FIG. 1B shows a schematic diagram of an in vivo imaging
system according an embodiment of the present invention;
[0009] FIG. 1C shows a schematic diagram of an in vivo imaging
system according an embodiment of the present invention;
[0010] FIG. 1D shows a schematic diagram of an in vivo imaging
system according to an embodiment of the present invention;
[0011] FIG. 2 depicts a series of steps of a method according to an
embodiment of the present invention;
[0012] FIG. 3 depicts a schematic diagram of a first exemplary
dilution pattern for selecting pixels according to an embodiment of
the present invention;
[0013] FIG. 4 depicts a schematic diagram of a second exemplary
dilution pattern for selecting pixels according to an embodiment of
the present invention;
[0014] FIG. 5 depicts a schematic diagram of pixels of one color
selected according to an exemplary dilution pattern in accordance
with the present invention;
[0015] FIG. 6 depicts a schematic diagram of partial reconstruction
of an image based on pixels selected according to an exemplary
dilution pattern in accordance with the present invention; and
[0016] FIG. 7 depicts a series of steps of a method for
reconstructing a diluted image according to an embodiment of the
present invention.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0017] In the following description, various aspects of the present
invention will be described. For purposes of explanation, specific
configurations and details are set forth in order to provide a
thorough understanding of the present invention. However, it will
also be apparent to one skilled in the art that the present
invention may be practiced without the specific details presented
herein. Furthermore, well-known features may be omitted or
simplified in order not to obscure the present invention.
[0018] Embodiments of the system and method of the present
invention may be preferably used in conjunction with an imaging
system or device such as described in U.S. Pat. No. 5,604,531 to
Iddan et al. and/or in application number WO 01/65995 entitled "A
Device And System For In Vivo Imaging", published on 13 Sep., 2001,
both of which are hereby incorporated by reference. However, the
device, system and method according to the present invention may be
used with any device providing imaging or other data from a body
lumen or cavity. In alternate embodiments, the system and method of
the present invention may be used with devices capturing
information other than image information within the human body; for
example, temperature, pressure or pH information, information on
the location of the transmitting device, or other information.
[0019] Reference is made to FIGS. 1A-1D, which show schematic
diagrams of in vivo imaging system according to embodiments of the
present invention. In an exemplary embodiment shown in FIG. 1A, a
device 40 may be an ingestible capsule capturing images, but may be
another sort of device and may collect information other than image
information. Typically, device 40 may include at least one sensor
such as an imager 46, for capturing images, a processing chip or
circuit 47 that processes the signals generated by the imager 46,
and one or more illumination sources 42, for example one or more
"white LEDs" or any other suitable light source, for illuminating
the body lumen. An optical system 50, including, for example, one
or more optical elements (not shown), such as one or more lenses or
composite lens assemblies (not shown), one or more suitable optical
filters (not shown), or any other suitable optical elements (not
shown), may aid in focusing reflected light onto the imager 46 and
performing other light processing. Processing chip 47 need not be a
separate component; for example, processing or a processing chip
may be integral to the imager 46. A non-image sensor 49, for
example, such as a temperature sensor, a pH sensor, or a pressure
sensor may be included. In an alternate embodiment of the present
invention sensor 46 may be a non-image sensor such as a temperature
sensor, a pH sensor, or a pressure sensor.
[0020] Device 40 typically includes a transmitter 41, for
transmitting image and possibly other information (e.g., control
information, non-image data, etc.) to a receiving device, and a
compression module 600, for compressing data. The transmitter 41
may typically be an ultra low power radio frequency (RF)
transmitter with high bandwidth input, possibly provided in chip
scale packaging. The transmitter may transmit via an antenna 48.
The transmitter 41 may act as a controller may also include
circuitry and functionality for controlling the device 40.
Typically, the device may include a power source 45, such as one or
more batteries. For example, the power source 45 may include silver
oxide batteries, lithium batteries, or other electrochemical cells
having a high energy density, or the like. Other suitable power
sources may be used.
[0021] Other components and sets of components may be used. For
example, the power source may be an external power source
transmitting power to the capsule, for example as described in a
patent application with International Publication Number WO
02/080753 A2, and a controller separate from the transmitter 41 may
be used.
[0022] In one embodiment, the imager 46 may be a complementary
metal oxide semiconductor (CMOS) imaging camera. The CMOS imager
may typically be an ultra low power imager and may be provided in
chip scale packaging (CSP). One suitable CMOS camera may be, for
example, a "camera on a chip" CMOS imager specified by Given
Imaging Ltd. of Israel and designed by Photobit Corp. of
California, USA, with integrated active pixel and post processing
circuitry. Other types of CMOS imagers may be used. In another
embodiment, another imager may be used, such as a CCD imager, or
another imager.
[0023] Typically, the device 40 is swallowed by a patient and
traverses a patient's GI tract, however, other body lumens or
cavities, such as blood vessels, the female reproductive tract,
etc., may be imaged or examined. The device 40 transmits image and
possibly other data to components located outside the patient's
body, which may receive and process the data. Preferably, located
outside the patient's body in one or more locations, may be a
receiver 12, preferably including or attached to an antenna or
antenna array 15, for receiving image and possibly other data from
device 40, and a controller or processor 113, a receiver storage
unit 16, for storing image and other data, a data processor 14, a
data processor storage unit 19, a data decompression module 610 for
decompressing data, and an image monitor 18, for displaying, inter
alia, the images or reconstructed versions of the images
transmitted by the device 40 and recorded by the receiver 12.
Typically, the receiver 12 and receiver storage unit 16 may be
small and portable, and may be worn on the patient's body during
recording of the images. Preferably, data processor 14, data
processor storage unit 19 and monitor 18 may be part of a personal
computer or workstation, which includes, for example, standard
components such as a processor 13, a memory (e.g., storage 19, or
other memory), a disk drive, and input-output devices, although
alternate configurations are possible. In alternate embodiments,
the data reception and storage components may be of another
suitable configuration. Further, image and other data may be
received in other manners, by other sets of components. Typically,
in operation, image data may be transferred to the data processor
14, which, in conjunction with processor 13 and software, may
store, possibly process, and display the image data on monitor 18.
Other systems and methods of storing and/or displaying collected
image data may be used. Any of data processor 14, processor 13,
receiver 12, controller 113, or another component or set of
components, may act as or include a suitable controller or
processor for, inter alia, controlling the receipt and transfer of
data, reconstructing data, decompressing data, etc.
[0024] Typically, the device 40 transmits image information in
discrete portions. Each portion typically corresponds to an image
or frame. Other transmission methods are possible. For example, the
device 40 may capture an image once every half second, and, after
capturing such an image, may transmit the image to the receiving
antenna. Other capture rates may be possible. Typically, the image
data recorded and transmitted may be a digital color image data,
although in alternate embodiments other image formats (e.g., black
and white image data) may be used. In one embodiment, each frame of
image data includes 256 rows of 256 pixels each, each pixel
including data for color and brightness, according to known
methods. For example, in each pixel, color may be represented by a
mosaic of four sub-pixels, each sub-pixel corresponding to
primaries such as red, green, or blue (where one primary is
represented twice). In other embodiments, each pixel may capture
only one color. The brightness of the overall pixel may be recorded
by, for example, a one byte (i.e., 0-255) brightness value. Other
data formats may be used.
[0025] In some embodiments of the device, system and method of the
present invention, diagnostic data need not be transmitted, but may
be sent via another method, such as via wire. For example, in an
endoscope device, an imaging device at one end may send the data
via wire to a receiving device.
[0026] It may be desirable to limit the amount of time spent
transmitting image data, and/or the bandwidth required for such a
transmission. Embodiments of the system and method of the present
invention may compress image and possibly other data before
transmission. Since compressed data may take less time to transmit,
more data may be transmitted, and more zo frames of image data may
be transmitted per time unit, without increasing, foe example, the
bandwidth of the transmitter. Alternatively, the same amount of
data may be transmitted using less bandwidth. Another aspect of the
data transmission relates to the transmission systems with limited
energy source. In this case smaller amount of bits needed to be
transmitted may enable more energy per bit in the transmission.
Data other than or in addition to image data may be transmitted and
compressed. For example, control information may be compressed.
Furthermore, in devices transmitting telemetric information other
than image information, such as pressure or pH information, such
information may be compressed. In further embodiments, image data
need not be transmitted in discrete portions corresponding to
images.
[0027] Thus, for example, if the bandwidth of a transmission
mechanism permits an uncompressed frame relay rate of, for example,
two frames per second at a specified bit rate, the same
transmission mechanism may be able to support the transmission of a
greater number of frames per second using the same bit rate if the
transmitted data is compressed or diluted prior to compression, and
then reconstructed after transmission. Thus, according to one
embodiment, for areas of the gastro-intestinal tract where a
greater number of frames per second may be desired (for example,
the esophagus, which may be traversed quickly by a capsule), the
imaging device may operate in a "fast mode" which transmits
compressed or diluted data and may therefore be capable of
transmitting a greater number of frames per second than
uncompressed data. In one embodiment, data may be added by for
example interpolation and/or other methods to produce completed
images or images that may be presented as completed images.
[0028] In an exemplary embodiment of the present invention, device
40 includes a data compression module 600 for compressing data
transmitted from the device 40 and for providing the data to the
transmitter 41, possibly via intermediate circuitry. Data
compression module 600 may be implemented as part of a
microprocessor or ASIC or other micro-computing device, as part of
the imager 46 or processing chip 47, or in another suitable manner.
In alternate embodiments the functions of the data compression
module 600 may be taken up by other structures and may be disposed
in different parts of the device 40. For example, the transmitter
41 may include data compression capability, or data compression
module 600 may be a stand-alone unit, or may be implemented in
software. In one embodiment, transmitter 41 may include, for
example, a modulator 70 for receiving the video signal from the
imager 46, a radio frequency (RF) amplifier 72, and an impedance
matcher 74. The modulator may convert the input image signal having
a cutoff frequency of, for example, f.sub.c of less than 5 MHz to
an RF signal having a carrier frequency f.sub.r, typically in the
range of 1 GHz (other ranges may be used). While in one embodiment
the signal is an analog video signal, the modulating signal may be
another signal, for example digital rather than analog. The carrier
frequency may be in other bands, e.g. a 400 MHz band. The modulated
RF signal may have a bandwidth of f.sub.t. The impedance matcher
may match the impedance of the circuit to that of the antenna.
Other suitable transmitters or arrangements of transmitter
components may be used, utilizing different signal formats and
frequency ranges. For example, alternate embodiments may not
include a matched antenna or may include a transmitter without a
matching circuit. In one embodiment of such an imaging device 40,
transmission may occur at a frequency of 434 MHz, using Phase Shift
Keying (PSK). In alternate embodiments, other transmission
frequencies and methods (such as AM or FM) may be used.
[0029] The receiver 12 may preferably detect a signal having the
carrier frequency f.sub.r and the bandwidth f.sub.c described
herein. The receiver 12 may be similar to those found in
televisions or for example it may be one similar to those described
on pages 244-245 of the book Biomedical Telemetry by R. Stewart
McKay and published by John Wiley and Sons, 1970. The receiver may
be digital or analog. In alternate embodiments, other receivers,
responding to other types of signals, may be used.
[0030] The receiver 12 preferably includes a data decompression
module 610 for decompressing data received from the device 40. In
exemplary embodiment data decompression module 610 may be a
microprocessor or other micro-computing device and may be part of
the receiver 12. In alternate embodiments the functions of the data
decompression (decoding) module 610 may be taken up by other
structures and may be disposed in different parts or more than one
part of the system; for example, data decompression module 610 may
be implemented in software and/or be part of data processor 14. The
receiver 12 may receive compressed data without decompressing the
data and store the compressed data in the receiver storage unit 16.
The data may be later decompressed by, for example data processor
14.
[0031] Preferably, the transmitter 41 may provide overall control
of the device 40; in alternate embodiments control may be provided
by other modules. Preferably, the data compression module 600 may
interface with the transmitter 41 to receive and compress image
data; other units may provide other data to data compression module
600. In addition, the data compression module 600 may provide the
transmitter 41 with information such as, for example, start or stop
time for the transfer of image data from the data compression
module 600 to the transmitter 41, the length or size of each block
of such image data, and the rate of frame data transfer. The
interface between the data compression module 600 and the
transmitter 41 may be handled, for example, by the data compression
module 600. Typically, the data compression module 600 may compress
image information in discrete portions. Each portion may typically
correspond to an image or frame. Other compression methods or
sequences are possible, and other units of compression and
transmission are possible. In one embodiment, to compress the image
data, subsequent images may be compared, and to only differences
between these images may be transmitted rather than each image.
Assuming that in most cases the subsequent images may be similar,
the difference between the images may contain much less information
than the image itself.
[0032] In alternate embodiments, the data exchanged between the
data compression module 600 and the transmitter 41 may be
different, and in different forms. For example, size information
need not be transferred. Furthermore, in embodiments having
alternate arrangements of components, the interface and protocol
between the various components may also differ. For example, in an
embodiment where a data compression capability is included in the
transmitter 41 and the imager 46 transfers un-compressed data to
the transmitter 41, no start/stop or size information may be
transferred. In another embodiment of the invention, a data
compression module 601 may be implemented as part of an imager 46',
such as in for example, device 40 shown in FIG. 1B. In one
embodiment of the invention, imager 46' or another component within
device 40 may produce a selection of input data to form a diluted
image. In such a case, a transmitter 41' may be a transmitter
without compression capability; however, using selections of data
and compression may be performed together. In another embodiment of
the invention, a compression module 602 may be part of a processing
chip 47' such as in for example, device 40 shown in FIG. 1C.
Processing chip 47 and 47' may be for example, a microprocessor,
ASIC, or another suitable micro-computing device. In yet another
embodiment of the invention, a compression module 603 may be
included as a stand-alone unit such as in for example, device 40
shown in FIG. 1D.
[0033] The data compression module for example, module 600 (or 601,
602 or 603), and data decompression module 610, may use various
data compression formats and systems. Compression formats used may
include compression formats where some data may be lost during
compression and compression formats where data may not be lost
during compression. Typically, the data compression module 600 and
decompression module 610 may include circuitry and/or software to
perform such data compression. For example, if the data compression
module 600 or decompression module 610 (or other compression or
decompression systems) are implemented as a computer on a chip or
ASIC, data compression module 600 or decompression module 610 may
include a processor operating on firmware which includes
instructions for a data compression algorithm. If data
decompression module 610 is implemented as part of data processor
14 and/or processor 13, the decompression may be implemented as
part of a software program. It will be evident to those of skill in
the art that compression module need not be a physically separate
component, but rather, that its functionality may be performed by
another component, such as imager 46'.
[0034] The amount of imager data to be sent may be, for example,
over 1.35 Megabits per second. Compression may reduce this amount.
After compression, and before transmission, other operations such
as randomization may occur (performed, for example, by the
transmitter 41). For example, the occurrence of the digital signals
("0" and "1") may be randomized so that transmission may not be
impeded by a recurring signal of one type.
[0035] FIG. 2 depicts a series of steps of a method according to an
embodiment of the present invention. Referring to FIG. 2, in block
200, an in-vivo device, such as a swallowable capsule, captures
image data. Typically, an imager within the device may capture
image data of a gastrointestinal tract, but other image data may be
captured, for example, image data from other body lumens or
cavities. Data other than or in addition to image data may be
captured. The image data from the imager may be passed to other
units for processing.
[0036] In block 210, the image data is compressed. Such compression
or other processing may be performed by a processing unit such as,
for example, transmitter 41. The image data is typically received
from the imager or via another unit. Such compression may be
typically in response to a process receiving input data
corresponding to an image. In the embodiment shown in FIG. 2,
compression may be accomplished by diluting the captured data, or
by selecting only a pattern of pixels for transmission. Such
creation of a selection of data, where the selection is typically
less data than the original data, may be, for example, performed
according to a dilution pattern. Alternately, only the differences
between for example, pixels or regions of subsequent images may be
transferred. The image data may be first loaded or transferred from
the imager to a compression module, or, alternately or
additionally, may be compressed at the imager. If applicable, data
other than or in addition to image data may be compressed; in block
215, for example, sensor data other than image sensor data, control
data, etc. In one embodiment of the invention, for example, data
may be selected for transmission by the imager and then further
compressed, for example, by JPEG or another algorithm before
transmission. The selected data is typically less data than the
original data.
[0037] In block 220, the data may be transmitted to a receiver.
Typically, the data, such as for example image data, may be
transmitted, for example, using radio waves (RF channel) to a
receiver external to the body, but other methods may be used. In
alternate embodiments, the image or other data may be sent by other
methods, such as by wire.
[0038] In block 230, the data may be decompressed, enabling
reconstruction of the image. Reconstruction may include further
elements such as pre-processing, post-processing, etc.
Reconstructed image data may be, for example, displayed or stored
for later use. Alternately, the compressed image data may be stored
for later image reconstruction.
[0039] Other suitable steps or series of steps may be used than
those described in the above blocks.
[0040] The data compression methods described herein may be
lossless or lossy. Lossless data compression may enable precise
(with no distortion) decoding of the compressed data. The
compression ratio of lossless methods may however be limited. Lossy
compression methods may not enable precise decoding of the
compressed information. However the compression ration of lossy
methods may be much higher than of the lossless method. In many
cases the data distortion of the lossy methods may be
non-significant, and the compress ratio may be high. Without
limitation of generality, the description of data compression
schemes herein may be applicable both to lossless and to lossy
methods.
[0041] In an embodiment of the present invention, compression may
be accomplished by transmitting only portions of the captured image
selected according to, for example, a dilution pattern. While this
may result in some loss of quality in the resulting image, proper
selection of pixels according to a suitable dilution pattern,
together with proper reconstruction of the diluted image, may
preserve the quality of the transmitted image and rehabilitate the
image to lossless or near-lossless condition. The dilution pattern
may for example be predetermined, may be selected or created by a
component of the device based on operating conditions related, for
example, to its position in the gastro-intestinal tract or other
surrounding conditions such as pH, temperature, ambient lighting or
color conditions, or may be created using other methods. Data may
be selected for transmission by means other than a dilution
pattern.
[0042] Embodiments of the invention are presented herein with
different dilution patterns, although those of skill in the art
will recognize that other dilution patterns may be used for
compressed transmission in accordance with the present invention.
In the below exemplary dilution patterns presented, there is
assumed an imager with 256 rows and 256 columns of pixels, each
pixel representing one of the colors red, blue or green. The
embodiments also show an imager having twice as many green pixels
as red or blue pixels. It will be recognized by those of skill in
the art that the invention may be practiced with imagers of
different configurations, sizes, and color patterns. For example, a
black and white imager may be used.
[0043] FIG. 3 depicts one exemplary dilution pattern in accordance
with embodiments of the invention that may be used in an imager
having, for example, pixels representing red (R) 302, green (G)
304, and blue (B) 306 in the arrangement shown. In this first
exemplary dilution pattern shown, the imaging device may transmit
every, for example, fourth pixel in each row, where, typically, all
pixels chosen in any row represent the same color. In the case of
three colors, e.g., red, blue and green, one color selected for
transmission may repeat every second row, while the selection of
the other two colors alternates every fourth row. Thus, for
example, in the example shown, in two of each four consecutive
rows, the color red 308 may be selected, while in the remaining two
rows, blue 310 and green 312 may alternate every fourth row. Thus,
if the array of pixels in the imager includes 256 rows and 256
columns, the device may transmit only 64 pixels, or every fourth
pixel, for each row.
[0044] FIG. 4 depicts another exemplary dilution pattern that may
be used in accordance with embodiments of the invention. In this
second exemplary dilution pattern, a pattern may be repeated every
four rows, in which no pixels may be transmitted from a first row,
every fourth pixel may be transmitted from each of the next two
rows, and every second pixel may be transmitted from the fourth
row. In this embodiment, it will be recognized that twice as many
green pixels 402 may be transmitted than red pixels 404 or blue
pixels 406.
[0045] According to some embodiments of the present invention, the
device may transmit for some or all pixels the difference between
the actual value and a predicted value based on the already
determined values of other pixels, for example, neighboring pixels.
The receiver may determine the predicted value based on the values
of the other pixels, and modify the predicted value by the
difference transmitted, thereby reconstructing the original actual
value for the pixel. It will be recognized that this embodiment of
the invention may be implemented as lossless or lossy. For example,
in one embodiment, for each pixel there may be transmitted either a
value or an exact difference based on a predicted value for the
pixel. In such an embodiment, no image quality in the reconstructed
image will be lost. In another example, there may be set a
threshold, wherein a difference between the predicted value and the
actual value that may be less than the threshold may not be
transmitted. In this latter example, some image quality in the
reconstructed image may be compromised.
[0046] It will be recognized by those of skill in the art that
while only several dilution patterns have been discussed at length,
any suitable dilution pattern that selects some pixels or areas for
transmission while omitting others may be used in accordance with
embodiments of this invention. In one embodiment of the invention,
producing selected data includes for example modifying at least one
input datum by reference to at least one other input datum to
produce selected data.
[0047] Optionally, devices in accordance with embodiments of the
invention may operate in a "simple" fast mode, an "averaging" fast
mode or other suitable mode corresponding to any suitable dilution
pattern, including, for example, the modes discussed herein. In
"averaging" mode, the value transmitted for a selected pixel of a
certain color may be summed or averaged or otherwise affected by
the value of a nearby pixel, typically a pixel of the same color.
For example, in FIG. 3, a pixel 308 selected by the particular
dilution pattern for transmission may be averaged by the imager
with a neighboring pixel of the same color 302 prior to
transmission. Averaging may be performed by the compression module,
for example, the imager, or by another component. This "averaging
mode" may be activated or deactivated, for example, by a control
bit intrinsic or extrinsic to the compression module, for example,
the imager. It will be appreciated by those of skill in the art
that any modification of an input pixel by reference to one or more
neighboring pixels, for example a weighted average, may be used in
accordance with the present invention.
[0048] Also optionally, in an embodiment of the present invention,
there may be provided an error correction mechanism for detecting
and correcting errors. In some embodiments, control or "overhead"
information may be transmitted in addition to the pixels of each
image, for example, information contained in a prefix header and/or
suffix word. This control information may or may not be compressed.
Various techniques of error correction are known, any of which may
be used in connection with any embodiment of the present invention.
In some embodiments of the invention, the imager may perform error
correction encoding.
[0049] At the receiver end, various methods may be used in
accordance with embodiments of the present invention to reconstruct
an image from the diluted data transmitted. The method of
reconstruction may vary, for example, depending on the dilution
pattern chosen.
[0050] In an embodiment of the invention employing the first
exemplary dilution pattern, a full matrix of color values for each
pixel may be reconstructed from the selected pixels using various
methods. In some embodiments of the invention, interpolation or
weighted interpolation between selected data may be used for
reconstructing the diluted image. Other suitable methods for
reconstructing the data may be used in addition to interpolation or
instead of interpolation. In one embodiment of the invention, edge
detection may be used to determine weights for weighted
interpolation when reconstructing an image from a diluted image.
For example, as shown in FIG. 5, the sampled red pixels 502 in the
first dilution pattern may be in a rhomboid pattern. In one
embodiment of the present invention, some or all of the values of
four pixels 602 forming a rhomboid may be used to calculate a value
for the pixel at the center of the rhomboid, as depicted by the
pixels 604 in FIG. 6. While in one embodiment of the present
invention, the four values surrounding a rhomboid center may be
averaged, other embodiments are of course possible. For example,
edge detection or other suitable methods may be used to locate
pixels that may be on the edge of an object. For pixels that may be
determined to be on the edge, the center value may be determined by
for example a weighted average of, for example, the four
surrounding pixels. Whether the pixel may be on an edge may, for
example, be determined based on the gradient at that pixel.
Alternately or additionally, the center value may be determined by
a weighted average of a subset of the surrounding pixels. In one
embodiment, the center value may be determined based on the median
of some or all of the surrounding pixels. In one embodiment, the
interpolation may be on a grid not necessarily in the shape of a
square. For example, the orthogonal values between the pixels may
be obtained by interpolation of the four surrounding pixels. Any
suitable method may be used for this interpolation, for example,
linear, quadratic, bicubic, polynomial, weighted average, or other
interpolation. The remaining pixels, which may be located on
diagonals between originally selected pixels, may be interpolated
using known methods. Interpolating typically helps to produces
additional image data, eventually resulting in a reconstructed
image.
[0051] With respect to the remaining two colors in the first
dilution pattern, the missing pixels may be interpolated from the
square pattern shown in FIG. 6 by any suitable method of
interpolation, for example, linear, quadratic, bicubic, polynomial
or other interpolation. The remaining pixels, which may be located
on diagonals between originally selected pixels, may be for
example, interpolated using known methods. While only some methods
of interpolation of missing pixels have been enumerated, it will be
understood by those of skill in the art that any suitable method of
interpolation may be used consistent with any embodiment of the
present invention.
[0052] With respect to reconstructing image data in accordance with
the second exemplary dilution pattern, a similar reconstruction
process may be used as the one described. Thus, for example, the
rhomboid pattern created by the sampled green pixels may be similar
to the rhomboid pattern of the red pixels in the first exemplary
dilution pattern, and the pixels of the remaining two colors are in
a square pattern. It will be understood by those of skill in the
art that the present invention is not limited in the respect of the
exemplary dilution patterns (and reconstruction schemes) described
above, and that many others may be used in accordance with the
present invention.
[0053] In some embodiments of the present invention, there may be
further enhancement or refinement of the reconstructed image. In
some embodiments of the present invention, the resulting image may
be smoothed by modifying the color values of the originally
selected pixels, for example, by replacing the original value by a
weighted average of the original value taken together with some or
all values of the surrounding selected pixels, for example, a
median value of the surrounding pixels.
[0054] The various compression and/or dilution methods discussed
herein need not be used with a device having more than one mode, or
a "fast mode", but may be utilized for various other purposes.
Further, compression and dilution of pixels need not be used
together.
[0055] Typically, a compression and/or dilution process is carried
out by control circuitry in the device 40, such as transmitter 41.
Similarly, reconstruction and/or decompression may be carried out
by for example, data processor 14, decompression module 610,
processor 13, etc., or by structures in the receiver 12. Of course,
in other embodiments, such processes may be carried out by other
components, and of course the methods discussed herein may be
carried out in devices having structures other than that of devices
40, receiver 12, and data processor 14. For example, control
processes such as producing the selection of input data may be
carried out by an imaging component, or another component. For
example, a portion of a controller may be considered to be within
the imaging unit.
[0056] Furthermore, in some embodiments of the present invention,
enhancement may be made by for example modifying the intensity
values of the image to restore them to near the original values.
For example, the intensity of a reconstructed pixel may be
calculated using only or predominantly the values of nearby
originally selected pixels. In another embodiment, intensity for
each pixel may be obtained by using the values of pixels of only
one color, for example, green. It will be recognized that other
methods of obtaining intensity values for reconstructed pixels may
be used consistent with embodiments of this invention.
[0057] In some embodiments of the present invention, there may be
lessening of color artifacts due to the process of dilution and
reconstruction of the image, for example, by suppressing colors of
pixels located on edges found in the image. In some embodiments of
the invention, color suppression may also be used to correct
color-saturated pixels during, for example, reconstruction.
[0058] In some embodiments of the present invention, a
pre-processing block may be added for the original samples. For
example, in one embodiment, a gradient evaluation for enhancing
edges may be added. Additionally, in one embodiment of the
invention, a post-processing block may be added for enhancing
reconstruction, for example, for correcting interpolation
artifacts, for example, periodic artifacts. In one embodiment,
these artifacts may be corrected in the frequency domain by
convolution or median filter.
[0059] FIG. 7 depicts a series of steps of a method for
reconstructing a diluted image or other suitable data according to
an embodiment of the present invention. Referring to FIG. 7, in
block 700, selected data, for example a diluted image data, may be
received. For example, the data may be received at a receiver 12, a
data processor 14, or other suitable structure. In block 710
pre-processing may be performed on data or selected data.
Pre-processing may include for example, clearing errors with error
correction code, reducing noise, performing a gradient evaluation
for detecting and enhancing edges, calculating intensity, etc.
Other suitable pre-processing may be used. In step 730,
interpolation may be performed to, for example, fill in gaps
between data. Interpolation may include, for example, linear,
quadratic, bicubic, polynomial, weighted average, or other suitable
interpolation. Edge information may be used to weight differently
each of the samples. For example, pixels along directions with high
gradient (possibly close to an edge) may, for example, not be
included in interpolation. Other suitable weighting factors may be
included. In one embodiment of the invention, intensity may be
calculated and used during interpolation for maintaining the ratio
between color and intensity during interpolation. Other suitable
interpolation methods may be implemented. After interpolation,
post-processing may be performed on interpolated data in block 760
to, for example enhance reconstructed image. Post-processing for
enhancing a reconstructed image may include, for example image
sharpening, color suppression, intensity adjustment, convolution or
a median filter. Other suitable post-processing techniques may be
implemented.
[0060] Embodiments of the present invention may include apparatuses
for performing the operations herein. Such apparatuses may be
specially constructed for the desired purposes (e.g., a "computer
on a chip" or an ASIC), or may include general purpose computers
selectively activated or reconfigured by a computer program stored
in the computers. Such computer programs may be stored in a
computer readable storage medium, such as, but is not limited to,
any type of disk including floppy disks, optical disks, CD-ROMs,
magnetic-optical disks, read-only memories (ROMs), random access
memories (RAMs), electrically programmable read-only memories
(EPROMs), electrically erasable and programmable read only memories
(EEPROMs), magnetic or optical cards, or any other type of media
suitable for storing electronic instructions.
[0061] The processes presented herein are not inherently related to
any particular computer or other apparatus. Various general purpose
systems may be used with programs in accordance with the teachings
herein, or it may prove convenient to construct a more specialized
apparatus to perform the desired method. The desired structure for
a variety of these systems appears from the description herein. In
addition, embodiments of the present invention are not described
with reference to any particular programming language. It will be
appreciated that a variety of programming languages may be used to
implement the teachings of the invention as described herein.
[0062] Unless specifically stated otherwise, as apparent from the
discussions herein, it is appreciated that throughout the
specification discussions utilizing terms such as "processing",
"computing", "calculating", "determining", or the like, typically
refer to the action and/or processes of a computer or computing
system, or similar electronic computing device (e.g., a "computer
on a chip" or ASIC), that manipulate and/or transform data
represented as physical, such as electronic, quantities within the
computing system's registers and/or memories into other data
similarly represented as physical quantities within the computing
system's memories, registers or other such information storage,
transmission or display devices.
[0063] While the invention has been described with respect to a
limited number of embodiments, it will be appreciated that many
variations, modifications and other applications of the invention
may be made. Embodiments of the present invention may include other
apparatuses for performing the operations herein. Such apparatuses
may integrate the elements discussed, or may comprise alternative
components to carry out the same purpose. It will be appreciated by
persons skilled in the art that the appended claims are intended to
cover all such modifications and changes as fall within the true
spirit of the invention.
* * * * *