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Claims  |
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What is claimed is:
1. In an electronic still image camera comprising:
an optical lens,
a shutter mechanism operably associated with said lens,
an array of discrete light sensing pixel elements, each pixel element being
responsive when said shutter mechanism is operated to incident
illumination from a subject image radiating through said lens and shutter
mechanism to generate an analog picture information signal corresponding
to said subject image,
pixel multiplexing means responsive to each array of pixel elements for
separating an output from each pixel element into its primary color
components,
analog to digital converter means responsive to the outputs of said pixel
multiplexing means for converting said analog picture information signal
into corresponding digital data information signals,
removably mounted memory means for storing said digital data information
signals,
the improvement comprising output data control means for selecting one of a
plurality of different output data format codes prerecorded in said camera
to be associated with each said digital data information signals where
each of said plurality of output data format codes corresponds
respectively to one of a like plurality of different data formats for
different types of computer apparatus, and
logic means responsive to said output data control means for determining
the output data format of said digital data information signals in
accordance with a selected one of said plurality of different output data
format codes.
2. The improved electronic still camera of claim 1 further comprising
picture image resolution determining means and digital data compression
means for selectively determining which of a plurality of compression
algorithm parameters are to be applied to said digital data information
signals in response to an operator activated switch means.
3. The improved electronic still image camera of claim 2 wherein said
removably mounted memory means comprises digital diskette means having
thereon a plurality of selectively addressable magnetic sector and track
sections for recording said digital data information signals.
4. The improved electronic still image camera of claim 3 hwerein said
digital compression algorithm of said digital data compression means is
also recorded in its entirety on said diskette means and further
comprising record marking means for recording a digital coded mark for
indicating the compression alogorithm parameters utilized in compressing
each said digital data information signals.
5. The improved electronic still image camera of claim 2 further comprising
record marking means for recording a unique digital mark indicating the
compression alogorithm parameters utilized in compressing each said
digital data information signals.
6. The improved electronic still camera of claim 2 further comprising
record marking means for generating and recording with each said digital
data information signals a coded mark indicating the compression algorithm
parameters utilized in compressing said digital data information signals.
7. The improved electronic still image camera of claim 1 further comprising
memory formatting means operable during the camera power-up routine to
automatically format said memory means in acccordance with one of a
plurality of output data formats.
8. The improved electronic still image camera of claim 1 further comprising
audio recording means for simultaneously recording digital audio signals
associated with each subject image and memory file correlation means for
associating in said memory means the respective storage locations of said
audio signals with its associated image signals.
9. The improved electronic still image camera of claim 1 further comprising
switch activated control means for improving the image signal storage
efficiency by selectively determining the amount of storage of said
removably mounted memory means to be associated with storage of each
picture image.
10. An electronic still image camera comprising:
an optical lens,
a shutter mechanism operably associated with said lens,
an array of discrete light sensing pixel elements, each pixel element being
responsive when said shutter mechanism is operated to incident
illumination from a subject image radiating through said lens to generate
an analog picture information signal corresponding to said subject image,
pixel multiplexing means responsive to said array of pixel elements for
separating an output from each pixel element into its primary color
components,
analog to digital converter means responsive to the output of said pixel
multiplexing means for converting said analog picture information signal
into corresponding digital data information signals,
removably mounted memory means for temporarily storing said digital data
information signals,
output data format control means for storing in said camera at least one of
a plurality of different output data format codes where each of said
plurality of output data format codes corresponds respectively to one of a
like plurality of different data formats for different types of computer
apparatus, and
logic means responsive to said format control means for selectively
controlling the formatting of said digital data information signals in
accordance with a selected one of said plurality of different output data
codes.
11. The electronic still image camera of claim 10 further comprising memory
formatting means operable to automatically format said removably mounted
memory means in accordance with one of a plurality of operator selectable
data storage formats.
12. The electronic still image camera of claim 10 further comprising image
resolution determining means for selectively determining which of a
plurality of compression algorithm parameters are to be applied to said
digital data information signals.
13. The electronic still image camera of claim 12 further comprising record
marking means for indicating which one of said plurality of compression
alogorithm parameters were utilized to compress said digital data
information signals.
14. The electronic still image camera of claim 10 wherein said removably
mounted memory means comprises digital data diskette means and further
comprising selectable diskette formatting means for automatically
formatting diskette means in accordance with one of a plurality of
operator selectable data formats.
15. The electronic still image camera of claim 10 further comprising remote
activation means for selectively activating said camera and logic means
responsive to said remote activation means for intiating an output data
format check of said removably mounted memory means.
16. A process for storing an electronically sensed video image comprising
the steps of:
generating an analog image signal corresponding to the imagewise pattern of
radiant light incident on a plurality of light sensing pixel elements,
converting the analog image signals into digital electronic information
signals wherein a distinct digital electronic signal corresponds to the
analog image signals corresponding to the intensity of radiant light
falling on the light sensing pixel elements,
temporarily storing the digital electronic information signals,
recording in selectable addressible memory means at least one of a
plurality of different digital output data format codes where each of said
plurality of output data format codes corresponds respectively to one of a
like plurality of different data formats for different types of computer
apparatus,
selecting from said selectable addressible memory means one of said
different digital output data format codes to be associated with each said
digital electronic information signals, and
storing said digital electronic information signals in a digital memory in
accordance with said selected output data format code.
17. The process of claim 16 further including steps of:
detecting the presence at an electronic still camera of a remotely
generated activating signal, and
activating said generating of said analog signal in response to the
detecting of said activating signal.
18. An electronic video image signal output data format translator
comprising:
input means for receiving image signals corresponding to sensed picture
information,
converter means for converting said image signals to digital image signals,
buffer storage means for temporarily storing said digital image signals,
output data format selection means for selecting one of a plurality of
different data format codes stored in the translator to be associated with
each said digital image signals where each of said plurality of different
data format codes corresponds respectively to one of a like plurality of
different data formats for different types of computer apparatus, and
output memory means for storing said digital image signals formatted in
accordance with said selected data format code. |
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Claims |
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Description |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to an electronic still video camera and in
particular to an improved electronic still camera which converts a still
picture of an object or scene into an operator selectable compressed
digital signal format for storage utilizing a compression/decompression
algorithm, such as the Joint Photographic Experts Group (JPEG) algorithm
standard for example, formatted into Personal Computer (PC) compatible
format retaining the images' color information, and stored on a PC
compatible memory diskette. For example, the diskette can be a three and a
half (31/2) inch digital diskette. The digital diskette is removeable from
the electronic camera for direct insertion into a PC which contains the
previously loaded corresponding decompression algorithm whereby the
digital image is in a format compatible for immediate use with word
processing, desk top publishing, data base, and multi-media applications.
2. Description of the Prior Art
FIG. 1 is a schematic block diagram showing structure of a conventional
prior art electronic still camera system, in which a CCD image sensor
element 1a converts a still image of an object into an analog color video
signal when the shutter control circuitry 2a is activated. The output
color video signal of the image sensor element is then routed to the
signal processing subsystem 3a where the signal is converted to National
Television System Committee (NTSC) or other composite video formats (such
as the European video standard Phase Alternating Line-PAL) and logged in
analog format onto a mass memory storage device such as an analog video
floppy disk, Electrically Erasable Programmable Read Only Memory (EEPROM),
analog audio cassette, bubble memory, or other storage device 5a. Power is
supplied by a rechargeable/removable battery system 4a.
An electronic camera that converts an image into electronic image signals
and transferred to a memory storage device is disclosed in the following:
U.S. Pat. No. 4,131,919; U.S. Pat. No. 4,456,931; U.S. Pat. No. 4,758,883;
U.S. Pat. No. 4,803,554; and U.S. Pat. No. 4,837,628.
Conventional prior art electronic still cameras, for example of the types
disclosed in the aforementioned references, produce an electronic signal
corresponding to a desired image in analog format such as the National
Television System Committee (NTSC) or similar on magnetic or electronic
storage media for either permanent or temporary storage to facilitate
viewing on a television or video monitor. With the current state of the
art, it is expensive and time consuming to convert the analog image
equivalent to a digital format for direct utilization with PC software
applications. Currently, to convert an image captured on an electronic
still camera to a PC compatible format one must convert the signal back to
either a composite NTSC or RGB video signal and use a conversion device
such as a "frame grabber" (a digital circuit board installed into PCs that
convert video images into PC compatible formats) of the type sold
commercially by Aapps Corporation, Orange Micro, RasterOps, and others or
convert the image to a hard-copy print (a photograph) and utilize an
electronic "scanner", a piece of equipment that connects to a PC, which
converts an image into a digital format. The later technique is employed
extensively within the desktop publishing industry.
SUMMARY OF THE INVENTION
It is the object of this invention to provide an improved electronic still
camera with operator selectable picture compression in one of a plurality
of operator selectable digital data formats recordable on a standard
removeable magnetic diskette common to personal computers.
It is a further object of this invention to provide an improved electronic
still camera that provides digital image files for immediate and direct
incorporation into popular word processing, desktop publishing, and other
software programs on PCs.
It is another object of this invention is to provide an improved electronic
still camera that, under user selection, can record and store still images
selectively compressed in a directly insertable digital memory storage
device into a PC in either color or black and white formats thus
facilitating storage of a large number of images with the signal flag
indicating the degree of compression selected by the operator as well as
the color/black and white mode selection being stored as digital values on
the digital memory storage device with each image frame.
An additional object of this invention to provide an electronic still
camera device that can rapidly capture a series of images automatically as
well as singularly. Also, this camera provides multiple outputs in both
video format for monitor and display of images and digital formats to
facilitate data transmission, additional processing, or storage to a
variety of storage media.
It is still another object of this invention is to provide a more efficient
electronic still camera that can take a still picture with operator
selectable high, medium, or low resolution in either color or black and
white by electronic shutter and exposure control by utilizing a variety of
electro-optical sensors including Charge Coupled Devices (CCD), Infrared
(IR), and Ultra Violet (UV) which can be directly or remotely controlled
by analog, digital, or radio frequency (RF) control signals.
A further object of this invention is to provide a programmable video
picture translator device for efficiently converting electronic still
images in analog composite video format into digital data format readable
by a PC. This translator device also provides additional video inputs and
outputs for capturing video images, monitoring video images on monitors
and displays, and can transmit either compressed or unprocessed digital
image data through a variety of output I/O channels in various formats
such as serial, parallel, etc. Also, this invention can incorporate
sound/voice with images thru additional interface circuitry and audio
digitizers.
Finally, it is the object of this invention to provide an electronic still
camera that is efficient in design and permits extended periods of
portable operation and which provides the user with operational status
through the use of continuous internal self-test software routines and
operator displays.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block diagram of a conventional prior art electronic
still camera.
FIG. 2 is a schematic block diagram of the overall structure of an
electronic still camera embodying the present invention.
FIG. 2A is an illustration showing one embodiment of an audio data file,
data format flag, compression level, and color/black and white mode
selection values stored on a digital memory diskette storage device.
FIG. 3 is a flowchart showing the power-up and continuous self-test
sequence in accordance with one aspect of the present invention.
FIG. 4 is an example of a 1/2" CCD array utilizable in accordance with one
aspect of the present invention.
FIG. 5A is a schematic block diagram showing the image signal to digital
signal conversion logic in accordance with one aspect of the present
invention.
FIG. 5B is a logic and timing diagram for the image signal to digital
signal conversion logic in accordance with one aspect of the present
invention.
FIG. 6 is an example of the control panel logic in accordance with one
aspect of the present invention.
FIG. 6A is an example of one embodiment of switch logic of the control
panel switches and controls utilizable in accordance with one aspect of
the present invention.
FIG. 6B is an example of the PICT image file format based upon the
published standard provided by Apple Computer, Inc.
FIG. 6C is an alternate embodiment of the current invention embodying
remote operation.
FIG. 7 is a simplified block diagram of the digital control unit in
accordance with one aspect of the present invention.
FIG. 8 is a flowchart showing the steps of the image compression algorithm
in accordance with one aspect of the present invention.
FIG. 9 is a block diagram of a video format translator device in accordance
with one aspect of the present invention.
FIG. 10 is a block diagram illustrating the operation of a translator
device in accordance with one aspect of the present invention.
FIG. 11 is an alternative embodiment of the video format translator in
accordance with another aspect of the present invention showing additional
video inputs and data outputs.
FIG. 12 is an alternate embodiment of the invention showing an optional
diskette format utility flowchart.
FIG. 13 is an alternate embodiment of a frame buffer utilizable in
accordance with another aspect of the present invention showing a frame
buffer stack permitting multiple shot mode.
FIG. 14A is a block diagram of an embodiment of the format select logic in
accordance with one aspect of the present invention.
FIG. 14B is a flow diagram illustrating the steps of the format selection
logic operations.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 2 is a schematic block diagram of the preferred embodiment of an
electronic still camera in accordance with the principals of the
invention. Referring to FIG. 2, an image optical pick-up element 1, which
for example could be a Charge Coupled Device (CCD) (or an Infrared (IR) or
Ultraviolet (UV) sensor), converts a still image of an object into an
electric signal when a picture "shoot" command is initiated by the
operator via control panel 2. When taking a picture, focusing and shutter
speed are controlled by a lens system and shutter speed selection
mechanism under control of the digital control unit 9. The camera, like
other still video cameras, employs an electronic shutter system that
controls a charge storage time in a CCD array onto which an image of an
object is focused through the lens system.
When the "shoot" control 6 is half depressed (see FIG. 6), a power supply
voltage is supplied from the rechargeable batteries 4 to the electronic
circuits and digital control unit 9, control panel 2, and the disk drive
assembly 5. The exposure control circuitry not shown generates appropriate
horizontal and vertical transfer pulses as well as field shift pulses
under control of the reference clock timing and control signals provided
by the digital control unit 9 type for driving the CCD device and
pre-processing circuitry. This design may be of any type well known in the
art for example those cited in U.S. Pat. Nos. 4,131,919 and 4,456,931 and
any similar designs well known in the prior art.
An alternate embodiment of the present invention that provides remote
operation of the camera is shown in FIG. 6C. When remote "Shoot" control
30 is activated by any means for example manually, or by radiant, or
electronic energy, a control signal is generated and routed through the
external jack 31, located on the external camera body. The external
control 30 is electrically connected to the external jack 31 by a
twisted-pair conductive cable assembly that is familiar to those skilled
in the art. Upon receipt of the externally generated "shoot" command, the
relay switch 32 is activated and provides internal switch closure. This
closure of switch 32 then initiates the process previously described and
provides the half V+ voltage previously described. The full V+ is provided
via the fixed delay 33, the value chosen to allow the diskette drive
assembly 5 (FIG. 2) and associated control circuitry to initialize prior
to receiving image data.
When the "shoot" control is fully depressed in either embodiment, the
shutter controller 15 (FIG. 6) generates a shutter pulse that generates
control signals for the A/D converters 8 allowing the image/picture data
signal in the sample and hold circuitry of the pixel multiplexer 7 to be
converted into a digital signal. Control and address instructions of the
type well known in the art are generated from the digital control unit 9
to facilitate the storage of the digital image data within the pixel
buffer 10 and frame buffer 11. Upon completion of image conversion, the
contents of the frame buffer are transferred to the compression processor
12 which for example may be of the many versions currently offered
commercially such as C-Cube's (San Jose, Calif.) four chip Application
Specific Integrated Circuit (ASIC) set. In the compression processor 12,
the Joint Photographic Experts Group (JPEG), a part of the International
Standards Organization (ISO) which is a subset of the International
Telegraph and Telephone Committee (CCITT), image compression algorithm
fully described in Report # JTC1/SC2/WG8 dated 1985 is performed under
control of the digital control unit 9 to compress the size of the image. A
variable selectable compression ratio of up to 50:1 is performed on the
digital image frame. Other compression ratios are operator selectable via
the control panel 2 switches 14A and 14B (FIG. 6). The compressed digital
frame is then formatted into either an IBM PC/Clone (such as GIFF) or
Apple Macintosh (such as PICT II) image file format depending on the
setting selected by the operator for a user switch 17 (FIG. 6) position on
the control panel 2. After formatting, the file is written into a
temporary memory buffer within the disk input/output (I/O) interface
circuit 13 which, under the command of the digital control unit 9,
controls the high density (1.4 Mbyte storage capacity) disk drive unit 5.
Following file transfer to the diskette e.g., the frame counter display 22
on the control panel 2 is updated by appropriate control signals and the
camera is ready to undergo the same procedure for the next image. Power to
the electronic circuits and disk drive system is terminated following
release of the "shoot" control switch 6.
In accordance with the preferred embodiment of this invention, it is
permissible for the user to select various resolution quality image
recording levels with the higher levels being at the expense of memory
diskette storage capacity. The position of switches 14A and 14B for
example could represent a unique digital mark or word that denotes the
respective switch position and is sensed during initial power application
and periodically during operation. FIG. 6A illustrates typical logic AND
gate circuits 60a and 60b utilizable in conjunction with switches 14A and
14B or switch 17 to generate appropriate signals to designate respective
switch positions and generate appropriate control signals from. The switch
positioned in the High position for high resolution allows only four to
five images to be stored, while Med. switch position for medium resolution
allows approximately twenty five images to be stored, and Low for low
resolution allows up to fifty images to be stored on a single diskette.
Also, by selecting black and white mode instead of color via switch 14B,
the operator may select additional storage capacity since storage is
increased by a factor greater than three (one element per pixel versus
three for color). Various image resolution combinations are permissible
because the operator can select a different resolution and mode setting
for each image prior to image signal capture. This is accomplished by
marking or "tagging" each image frame data information signal with the
resolution and mode of each image as it is written onto the memory
diskette in any suitable manner, for example as shown in FIG. 2A. With
reference to FIG. 2A, diskette 50 has tracks 51a, 52b, . . . 52n. With
reference to track 52b there is shown a representative portion of segment
53 depicting a typical image file information format having digital bit 54
depicting color mode, and digital bits 55 representing compression
resolution level markings or tags. With reference to color mode tag 54 it
can be seen that if switch 14B is in the color position tag 54 is recorded
as a logical "one" or true-conversely if bit 54 is recorded as a logical
"zero" it corresponds to the black and white position of switch 14B.
Similarly as shown switch 14A would record in memory position 55 a binary
"zero" for low resolution, a binary "one" for medium resolution and a
binary "two" for high resolution selections by the operator. By
incorporating this "tagging" approach, it is possible for the
decompression algorithm, loaded into any PC prior to use or written onto
the memory storage diskette along with the image data, to automatically
determine the appropriate level of compression associated with image file
and execute decompression efficiently.
Still another alternate embodiment in accordance with this invention
incorporates an acoustic digitizer circuit which digitizes sound. There
are several digitizers commercially available such as the Apple Computer
Inc. Musical Instrument Data Interface (MIDI) adaptor. The output of this
digitizer may be selectively connected to the CPU 20 (FIG. 7) via an
additional I/O interface similar to the auxiliary I/O interface 80. The
sound or audio associated with each image can be recorded, digitized, and
stored on the diskette device on available tracks in an identical manner
previously described (FIG. 2A). An image file in accordance with this
embodiment would be appropriately marked or tagged with the corresponding
digitized audio file 56 (FIG. 2A). Upon playback on a sound configured PC,
both the image and the corresponding audio would then be viewed and heard
simultaneously.
It should be noted that a major advantage a camera in accordance with the
present invention has over conventional still video cameras is that a
camera according to this invention is capable of storing multiple digital
images in semiconductor memory temporarily at a rapid rate while,
simultaneously, the image compression processor 12, file formatter
software algorithm, and disk I/O interface 13 that stores formatted files
continue to function in concert together at a slower rate. This efficient
design coupled with VLSI low power, high speed semiconductor memory
devices (10 and 11 FIG. 5A and 24 FIG. 7) allows this operational
capability.
Like most other still video and conventional film cameras, when the "shoot"
control 6 (FIG. 6) is fully depressed, a control signal is generated from
the digital control unit 9 that generates a trigger signal on the control
panel 2 to cause a flash unit 16 (FIG. 6) to irradiate a flash of light
onto the subject image.
During initial camera operation, the user first inserts a diskette such as
a standard three and a half inch or similar storage medium. Various memory
diskette sizes and formats are suitable for the invention. However, for
the preferred embodiment either a double-density (800 Kbytes of storage)
or a high-density (1.4 Mbytes of storage) diskette in a three and a half
inch format which are readily available from various commercial sources
such as Sony, Maxell, and Verbatim. The user must then select the desired
PC format (IBM PC/Clone or Apple Macintosh, etc.) via switch 17 (FIG. 6)
on the control panel 2. As shown in FIG. 3.; after turning on the power
switch or inserting a diskette 50, the digital control unit 9 performs a
self test of all internal circuitry, battery, disk drive unit, and control
panel. Should any failures be detected, an appropriate error indicator is
illuminated on the control panel. During the power-on sequence (see FIG. 3
and FIG. 12), the inserted diskette 50 is automatically checked for
formatting consistencies in accordance with the format selected by the
format switch 17 on the control panel 2 (IBM/Apple/etc.) and for available
storage space by checking the boot block on the diskette, a technique that
will be familiar to those skilled in the art. Should any inconsistencies
be detected, an error indicator is illuminated on the control panel (ie,
disk full, unformatted, etc.). The operator frame counter display 22 (FIG.
6) is then updated to show the maximum number of pictures available based
upon indicated operator selections (color/black and white), diskette type
(double versus high density), and capacity (partially full versus empty
diskette). During operation, the operator can selectively erase a frame
and record over it if desired by selecting the erase mode of operation
from the control panel and toggling the forward/reverse control.
The optics for the preferred embodiment of the invention is a commercially
available one-half inch (1/2") color CCD device having a pixel grid array
of 780.times.488 as pictorially depicted in FIG. 4. This results in
380,640 pixel elements which results in a commercially acceptable quality
resolution image as will be understood by those skilled in the art. In a
color imaging device (CCD array) photoelectric elements, such as
photodiodes, are arranged in a two dimensional array with optical filters
for R (red), G (green), and B (blue). Various arrangements of optical
filters are well known and the arrangement of optical filters is not
limited to a particular one with this invention. During operation each
pixel stores a charge corresponding to the amount of incident light. The
RGB components of each pixel's charge is sequentially read out via a
horizontal/vertical addressing scheme that will be familiar to those
skilled in the art.
As shown in FIG. 5A; each charge, when addressed, is amplified and
processed in a sample and hold (S/H) circuit 18. The analog voltage in
each S/H circuit is digitized by an associated analog to digital (A/D)
converter 8. The digital values are routed and collected in the pixel
buffer 10. Following completion of discrete pixel element conversion and
subsequent formatting in the pixel buffer which is under Control Processor
Unit (CPU) 20 software control, the output of the full pixel buffer is
routed to the frame buffer 11 by digital control unit 9. This process
continues until a complete frame is collected within the frame buffer. The
general digital logic and timing and control signals for this circuitry is
shown in FIG. 5B. The timing is provided by a master clock that is an
integral part of the CPU microprocessor. For example, the MOTOROLA 68040
microprocessor has a clock speed of approximately 40 Megahertz (MHZ) which
results in a clock period of 25 nanoseconds (nsec.). This clock pulse is
used by the function and address decoder 19 (FIG. 6) to generate the
address and control signals shown in FIG. 5B as would be understood by
those skilled in the art. The circuit of the present invention may be
designed by one skilled in the art to function with a variety of
microprocessor architectures and is not limited to any one in particular.
One can see from the timing chart that the S/H circuit is allowed (via the
SE command) to charge to a voltage level indicative of the analog voltage
impinging upon the pixel element (via the PS command). After a fixed time
period, the A/D converters are enabled (via the CE command) to begin
conversion of the analog voltage value on the S/H. Upon completion of
conversion, a conversion completion signal (CC) is generated by the A/D
and routed back to the S/H circuit (via the SC command which is generated
by the function and address controller 19) to discharge the stored analog
voltage in anticipation of the next pixel element conversion process.
Next, the output of the A/D converter 8 is clocked into the pixel buffer
10 (via the PB command). When the pixel buffer 10 is full, the output is
clocked out to the frame buffer 11 (via the FB command) and the pixel
multiplexer address circuitry selects the next pixel for conversion. Reset
signals (RST) are sent to all circuit elements to | | |
