Digital Camera Patent Abstract
A panoramic digital image is produced by providing a digital camera
having a memory and which is operable in a first mode for producing
individual still digital images, and in a second mode for capturing
a series of overlapping digital images to be used in constructing
the panoramic digital image. The digital camera is mounted on a
stand, rotated on the stand through a series of predetermined positions,
and operated in the second mode to capture the series of overlapping
digital images. The series of overlapping digital images corresponding
to the panoramic digital image is stored in a predetermined location
in the memory, and processed to stitch such images together to produce
the panoramic digital image. Digital Camera Patent Claims
What is claimed is:
1. Method of producing a panoramic digital image, comprising the
steps of: (a) providing a digital camera having memory means and
being operable in a panoramic mode for capturing a series of overlapping
digital images to be used in constructing the panoramic digital
image; (b) mounting the digital camera on a stand, the stand including
means for indicating an image number for the series; (c) rotating
the digital camera on the stand through a series of predetermined
positions and operating the digital camera in the panoramic mode
to capture the series of overlapping digital images; (d) storing
the series of overlapping digital images corresponding to the panoramic
digital image in a predetermined location in the memory means; and
(e) automatically stitching the series of stored overlapping digital
images together to produce the panoramic digital image.
2. The method according to claim 1 wherein the storing step includes
storing the series of overlapping digital images in a uniquely named
folder in the memory means.
3. The method according to claim 1 wherein the digital camera includes
a user display indicating the image number.
4. The method according to claim 1 further including the step of
providing instructions to a user to assist the user in taking the
series of overlapping digital images to be used in constructing
the panoramic digital image.
5. The method according to claim 1 further including the steps
of displaying the captured images on a display, and storing instructions
to be displayed on the display to assist a user in capturing the
series of overlapping digital images.
6. The method according to claim 1 further including the step of
automatically setting a compression quality level to enable the
series of overlapping digital images to be stored in the memory
means.
7. Digital camera system for capturing a panoramic digital image,
comprising: (a) a digital camera having memory means and being operable
in a panoramic mode for capturing a series of overlapping digital
images to be used in constructing the panoramic digital image; (b)
a stand for mounting the digital camera, the stand including means
for indicating an image number for the series; (c) means for rotating
the digital camera on the stand through a series of predetermined
positions and operating the digital camera in the panoramic mode
to produce the series of overlapping digital images; and (d) means
for storing the series of overlapping digital images corresponding
to the panoramic digital image in a predetermined location in the
memory means.
8. The digital camera system according to claim 7 wherein the series
of overlapping digital images are stored in a uniquely named folder
in the memory means.
9. The digital camera system according to claim 7 wherein the digital
camera includes a user display indicating the image number.
10. The digital camera system according to claim 7 wherein the
digital camera further includes means for providing instructions
to a user to assist the user in taking the series of overlapping
digital images to be used in constructing the panoramic digital
image.
11. The digital camera system according to claim 7 wherein the
digital camera further includes a display for displaying the captured
images, and means for storing instructions to be displayed on the
display to assist a user in capturing the series of overlapping
digital images.
12. The digital camera system according to claim 7 wherein the
digital camera further includes means for automatically setting
a compression quality level to enable the series of overlapping
digital images to be stored in the memory means.
13. Method of producing a panoramic digital image, comprising the
steps of: (a) providing a digital camera having memory means and
being operable in a panoramic mode for capturing a series of overlapping
digital images to be used in constructing the panoramic digital
image, and fixing the white balance and exposure parameters of the
digital camera in the panoramic mode when capturing the digital
images in the series of overlapping digital images; (b) mounting
the digital camera on a tripod, the tripod including means for indicating
an image number for the series; (c) rotating the digital camera
on the tripod through a series of predetermined positions and operating
the digital camera in the panoramic mode to capture the series of
overlapping white balanced and exposure fixed digital images; (d)
storing the series of overlapping white balance and exposure fixed
digital images corresponding to the panoramic digital image in a
predetermined location in the memory means; and (e) automatically
stitching the series of stored overlapping white balanced and exposure
fixed digit images together to produce the panoramic digital image.
14. The method according to claim 13 wherein the white balance
and exposure fixing step includes storing the white balance and
exposure parameters.
15. The method according to claim 13 wherein the white balance
and exposure parameters are determined using the first image in
the series of overlapping digital images, and wherein such parameters
are used when capturing subsequent digital images in the series.
16. The method according to claim 13 wherein the digital camera
includes a user display indicating the image number.
17. Digital camera system for capturing a panoramic digital image,
comprising: (a) a digital camera having memory means and being operable
in a panoramic mode for capturing a series of overlapping digital
images to be used in constructing the panoramic digital image, and
means for fixing the white balance and exposure parameters of the
digital camera in the panoramic mode when capturing the digital
images in the series of overlapping digital images; (b) a stand
for mounting the digital camera, the stand including means for indicating
an image number for the series; (c) means for rotating the digital
camera on the stand through a series of positions and operating
the digital camera in the panoramic mode to produce the series of
overlapping white balanced and exposure fixed digital images; and
(d) means for storing the series of white balance and exposure fixed
overlapping digital images corresponding to the panoramic digital
image in a predetermined location in the memory means.
18. The digital camera system according to claim 17 wherein the
means for fixing the white balance and exposure of the digital camera
includes means for storing the white balance and exposure parameters
and means for adjusting the white balance and exposure of the series
of overlapping digital images.
19. The digital camera system according to claim 18 wherein the
exposure parameters include lens f-number, exposure time, and analog
gain level.
20. The digital camera system according to claim 17 wherein the
white balance and exposure parameters are determined using the first
image in the series of overlapping digital images, and wherein such
parameters are used when capturing subsequent digital images in
the series.
21. The digital camera system according to claim 17 wherein the
digital camera includes a user display indicating the image number.
22. Method of producing panoramic digital images, comprising the
steps of: (a) providing a digital camera having memory means and
being operable in a panoramic mode for capturing a series of overlapping
digital images to be used in constructing the panoramic digital
image; (b) mounting the digital camera on a stand, the stand including
means for indicating an image number for the series; (c) rotating
the digital camera on the stand through a series of predetermined
positions and operating the digital camera in the panoramic mode
to produce the series of overlapping digital images; (d) selecting
storage locations corresponding to a folder for each series of overlapping
digital images and storing each series of overlapping digital images
in the selected storage locations in the memory means; and (e) selecting
a desired folder corresponding to a desired panoramic digital image
and automatically stitching the series of stored overlapping digital
images in the desired folder together to produce the panoramic digital
image.
23. The method according to claim 22 wherein the digital camera
includes a user display indicating the image number.
24. Method of producing panoramic digital images, comprising the
steps of: (a) providing a digital camera having a removable memory
card and being operable in a panoramic mode for capturing a series
of overlapping digital images to be used in constructing the panoramic
digital image; (b) mounting the digital camera on a stand, the stand
including means for indicating an image number for the series; (c)
rotating the digital camera on the stand through a series of predetermined
positions and operating the digital camera in the panoramic mode
to produce the series of overlapping digital images; (d) selecting
storage locations corresponding to a folder for each series of overlapping
digital images and storing each series of overlapping digital images
in the selected storage locations in the removable memory card;
(e) removing the memory card from the digital camera and inserting
it into a host computer; and (f) selecting on the host computer,
a desired folder corresponding to a desired panoramic digital image
and stitching the series of stored overlapping digital images together
to produce the panoramic digital image.
25. The method according to claim 24 wherein the digital camera
includes a user display indicating the image number.
26. System for capturing and producing a panoramic digital image,
comprising: (a) a digital camera having a removable memory card
and being operable in a panoramic mode for capturing a series of
overlapping digital images to be used in constructing the panoramic
digital image; (b) a stand for mounting the digital camera, the
stand including means for rotating the digital camera through a
series of predetermined positions when the digital camera is operating
in the panoramic mode to produce the series of overlapping digital
images, and means for indicating an image number for the series;
(d) means far selecting a storage location corresponding to a folder
for the series of overlapping digital images and for storing the
series of overlapping digital images in the selected storage location
in the removable memory card; and (e) a host computer having an
interface for receiving the removable memory card and including
means for processing the series of stored digital images in a desired
folder and for stitching such images together to produce the panoramic
digital image.
27. The system according to claim 26 wherein the processing means
further includes means for automatically stitching together the
series of stored digital images when a folder is selected to produce
the panoramic digital image.
28. The system according to claim 26 wherein the digital camera
includes a user display indicating the image number.
29. System for capturing and producing a panoramic digital image,
comprising: (a) a digital camera having a removable memory card
and being operable in a panoramic mode for capturing a series of
overlapping digital images to be used in constructing the panoramic
digital image, and means for fixing the white balance and exposure
parameters of the digital camera in the panoramic mode after the
capture of the first image in the series to be used when capturing
subsequent digital images in the sales of overlapping digital images;
(b) a stand for mounting the digital camera, the stand including
means for rotating the digital camera through a series of predetermined
positions when the digital camera is operating in the panoramic
mode to produce the series of overlapping digital images, and means
for indicating an image number for the series; (d) means for selecting
a storage location corresponding to a folder for the series of overlapping
digital images and for storing the series of overlapping digital
images in the selected storage location in the removable memory
card; and (e) a host computer having an interface for receiving
the removable memory card and including means for automatically
stitching the series of stored white balance and exposure fixed
digit images in a desired folder together to produce the panoramic
digital image.
30. The system according to claim 29 wherein the digital camera
includes a user display indicating the image number.
31. Method of producing a series of overlapping digital images,
comprising the steps of: (a) providing a digital camera having memory
means and being operable in a panoramic mode for capturing a series
of overlapping digital images to be used in constructing a panoramic
digital image; (b) mounting the digital camera on a stand, the stand
including means for indicating an image number for the series; (c)
rotating the digital camera on the stand through a series of predetermined
positions and operating the digital camera in the panoramic mode
to capture the series of overlapping digital images; and (d) storing
the series of overlapping digital images corresponding to the panoramic
digital image in a predetermined location in the memory means.
32. Method of producing a series of overlapping digital images,
comprising the steps of: (a) providing a digital camera having memory
means and being operable in a panoramic mode for capturing a series
of overlapping digital images to be used in constructing a panoramic
digital image, the digital camera including a user display indicating
the image number; (b) mounting the digital camera on a stand, the
stand including means for indicating an image number for the series;
(c) rotating the digital camera on the stand through a series of
predetermined positions and operating the digital camera in the
panoramic mode to capture the series of overlapping digital images;
and (d) storing the series of overlapping digital images corresponding
to the panoramic digital image in a predetermined location in the
memory means.
Digital Camera Patent Description
FIELD OF THE INVENTION
The present invention relates to electronic imaging, and in particular,
to producing panoramic digital images.
BACKGROUND OF THE INVENTION
Photographers electronically capturing panoramic images capture
a scene as a series of overlapping images. This series of overlapping
images represents a greater horizontal field of view, for example,
360 degrees, then could be captured with a single normal photograph.
Digital cameras, such as the Kodak Digital Science DC210.TM. camera
sold by the Eastman Kodak Company, may be used to create 360 degree
panoramic images. This is typically done by mounting the digital
camera on a stand, such as a tripod, and taking numerous images
as the camera is rotated on the stand. Once the desired exposures
are taken by rotating the camera, the images are then downloaded
from the camera to a host computer via a cable or a removable memory
card. A stitching software application, such as PhotoVista.TM. by
LivePicture, may be used to combine the images into a 360 degree
panorama. To accomplish this, each image in the set must be individually
selected and opened. The software then stitches together the various
images to form a panoramic image.
While a professional photographer is able to use the system just
described, it is a challenge for a new user to properly perform
all the steps. For example, the user may forget to take one of the
images at one of the positions, thus leaving a "gap,"
or may take two pictures at the same position. A novice user may
not overlap pictures properly, or may not know how many pictures
are required. In addition, if the files from several different sets
of 360 degree images are recorded on the same memory card, it may
be time consuming for the user to determine which images belong
to which set. This is especially problematic if the user fills up
a memory card during the middle of a set of images, requiring that
a new card be inserted. Also, since the process of taking such sets
of images is complex, it is difficult for a new user to understand
all of the steps necessary to achieve good results.
Furthermore, to provide a suitable panoramic image, the "stitches"
between adjacent images must not be visible. In particular, there
should be no brightness or color shift at the "seam" between
two images. Therefore, it is desirable to maintain the same exposure
and color balance settings for multiple exposures. Current digital
still cameras typically include automatic exposure ("AE")
and automatic white balance ("AWB") functions that set
the exposure parameters (i.e., the lens f-number, exposure time,
and gain) and the AWB separately for each image. Because each picture
taken in the panoramic series may have objects with different reflectances
and colors, the exposure level and AWB settings are usually slightly
different from one picture to the next, as the camera is rotated
on the stand. These slight differences are quite noticeable when
the images are stitched together, since slight differences in brightness
or color are very apparent along the "seams" between two
images. As a result, the stitching software must take elaborate
steps to adjust the individual images during the stitching operation
to minimize the visibility of the seam. This is time consuming and
yields imperfect results.
Some digital cameras, such as the Kodak DCS 420.TM. camera sold
by the Eastman Kodak Company, include the ability to manually select
the exposure parameters (i.e., the lens f-number and exposure time)
and use a "default" white balance setting, such as "daylight
balance," so that all images in the series use the same exposure
parameters. However, since this is a manual operation, the user-selected
exposure and white balance settings may be inappropriate for the
scene that is being captured, so that all of the images in the series
are, for example, overexposed or too reddish in color.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention for inexperienced
digital camera users to quickly and easily produce panoramic digital
images while minimizing the manual operations and the chance for
errors.
This object is achieved by a method of producing a panoramic digital
image, comprising the steps of: (a) providing a digital camera having
memory means and which is operable in a first mode for producing
individual still digital images, and in a second mode for capturing
a series of overlapping digital images to be used in constructing
the panoramic digital image; (b) mounting the digital camera on
a stand; (c) rotating the digital camera on the stand through a
series of predetermined positions and operating the digital camera
in the second mode to capture the series of overlapping digital
images; (d) storing the series of overlapping digital images corresponding
to the panoramic digital image in a predetermined location in the
memory means; and (e) processing the series of stored digital images
to stitch such images together to produce the panoramic digital
image.
It is a further object of the present invention to capture and
produce panoramic digital images having substantially no "seams"
between adjacent images caused by exposure or color shifts.
This object is achieved by a method of producing a panoramic digital
image, comprising the steps of: (a) providing a digital camera having
memory means and which is operable in a first mode for producing
individual still digital images, and in a second mode for capturing
a series of overlapping digital images to be used in constructing
the panoramic digital image, and fixing the white balance and exposure
parameters of the digital camera in the second mode after the capture
of the first image in the series; (b) mounting the digital camera
on a stand; (c) rotating the digital camera on the stand through
a series of predetermined positions and operating the digital camera
in the second mode to capture the series of overlapping digital
images; (d) storing the series of overlapping white balance and
exposure fixed digital images corresponding to the panoramic digital
image in a predetermined location in the memory means; and (e) automatically
stitching the series of stored overlapping white balanced and exposure
fixed digital images together to produce the panoramic digital image.
ADVANTAGES
It is an advantage of the present invention to simplify the capture
of panoramic digital images.
It is another advantage of the present invention to capture and
produce panoramic digital images with substantially reduced errors.
It is yet another advantage of the present invention to automatically
stitch together a series of overlapping digital images stored in
a folder once a desired folder has been selected.
It is a further advantage of the present invention to capture and
produce panoramic digital images with substantially minimized exposure
or color shifts between adjacent images.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a system for capturing and producing
a panoramic digital image in accordance with the present invention;
FIG. 1A shows a portion of the graphical user interface of the
digital still camera of FIG. 1;
FIGS. 2A-2C, when placed together, are a flow diagram of the operation
of the system of FIG. 1 in a panoramic mode to capture and produce
the panoramic digital image;
FIG. 3 is a schematic of the tripod arrangement of FIG. 1;
FIG. 4A is an example of the storage structure of a series of digital
images used to produce the panoramic digital image;
FIG. 4B shows a block diagram depicting the image stitching performed
by the application software of the host computer of FIG. 1; and
FIG. 5 shows a series of "Panoramic Instructions" screens
displayed on the liquid crystal display (LCD) of the digital still
camera of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
Since electronic still cameras employing electronic sensors are
well known, the present description will be directed in particular
to elements forming part of, or cooperating more directly with,
apparatus in accordance with the present invention. Elements not
specifically shown or described may be selected from those known
in the art.
FIG. 1 is a block diagram of system for capturing and producing
a panoramic image in accordance with the present invention. The
system 10 includes a digital still camera 12; a tripod arrangement
14 (shown in FIG. 3) which serves as a stand to secure the digital
still camera 12; and a host computer 16. The host computer 16 includes
a hard drive 18, a central processing unit (CPU) 20, a display monitor
22, and a keyboard/mouse 24.
The digital still camera 12 is used to capture a series of exposures
to produce the panoramic image. As shown in FIG. 1, the digital
still camera 12 includes a zoom lens 26 for directing image light
from a scene (not shown) toward an image sensor 30, and a shutter
28 for regulating exposure time. Both the zoom lens 26 and the shutter
28 are controlled by a microprocessor 32 in response to control
signals received from a plurality of user input buttons 34 including
a shutter release (not shown) for initiating image capture. A flash
unit 36 is used to illuminate the scene when needed.
The image sensor 30 includes a discrete number of photosite elements
or pixels arranged in a two-dimensional array to form individual
photosites corresponding to the pixels of the image. The image sensor
30 can be either a conventional charge coupled device (CCD) sensor,
such as, for example, the Kodak KAF-1600 sensor having 1536 columns
and 1024 rows of photosites, or a complementary metal oxide semiconductor
(CMOS) imager.
The shutter release provided in the user input buttons 34 preferably
has two positions: partially depressed (S1) and fully depressed
(S2). When a user presses the shutter release so that S1 is enabled,
the digital still camera 12 performs autoexposure (AE) using a photodetector
signal from a photodiode 42 to set the f-number of the lens 26,
the exposure time, and the analog gain level of an analog signal
processor (ASP) 38. The AE control of the digital still camera 12
can operate, for example, as described in commonly-assigned U.S.
Pat. No. 5,610,654, entitled "Automatic Camera Exposure Control
Using Variable ISO Sensor," the disclosure of which is herein
incorporated by reference.
After a user fully presses the shutter release so that S2 is enabled,
the zoom lens 26 directs image light from the scene onto the image
sensor 30, and analog image charge information corresponding to
the particular image is produced in respective photosites. The image
sensor 30 converts the charge information to an analog image signal
corresponding to the particular image captured.
The analog image signal output from the image sensor 30 is analog
processed in the ASP 38, and then applied to an analog-to-digital
(A/D) converter 40, which converts the analog image signal into
a digital image signal. The microprocessor 32 initiates and controls
exposure by operation of the shutter 28, by controlling the flash
unit 36, by producing control signals needed for driving the image
sensor 30 and for clocking image information therefrom, and by enabling
the A/D converter 40. The microprocessor 32, which can be, for example,
a Motorola 821 Power PC microprocessor, utilizes a control memory
33 and also responds to the user input buttons 34 for operation
of the digital still camera 12 in a well-known manner. The digital
image signal is stored in buffer memory 44, which is preferably
dynamic random access memory (DRAM).
The digital image signal in the DRAM buffer memory 44 is processed
to provide automatic white balance (AWB) to adjust the white balance
of the digital image signal to correct for the scene illuminant.
The white balance correction is performed by a digital signal processor
46. The digital image signal can be processed to provide AWB as
described, for example, in commonly-assigned U.S. Pat. No. 5,659,357,
entitled "Auto White Adjusting Device," the disclosure
of which is herein incorporated by reference. The digital signal
processor 46 also provides additional processing of the digital
signal, including color correction to correct the camera spectral
sensitivities, tone correction to provide the appropriate opto-electronic
transfer function, and image sharpening to compensate for lens blur
and provide a subjectively sharper image. The digital signal processor
46 also compresses each image according to any one of a number of
known image compression algorithms, such as the well-known JPEG
(Joint Photographic Experts Group) discrete cosine transformation-based
compression algorithm.
The digital signal processor 46 applies a reduced resolution version
of the processed digital image signal to an image display 48, such
as a color liquid crystal display (LCD), where the user can view
the captured image, as well as text and icons. The image display
48 is controlled by the microprocessor 32 in a manner well known.
The digital image signal can be stored in memory located in the
microprocessor 32 within the digital still camera 12 or, if a removable
memory card 54 is present in a memory card slot (not shown) of the
digital still camera 12, can be transferred through a memory card
interface 52 to the removable memory card 54 which is capable of
storing a plurality of digital images.
The removable memory card 54 can be adapted to the CompactFlash
interface standard, such as described in the CompactFlash Specification
Version 1.3, published by the CompactFlash Association, Palo Alto,
Calif., Aug. 5, 1998. Alternatively, the removable memory card 54
can be adapted to the PCMCIA card interface standard, such as described
in the PC Card Standard, Release 2.0, published by the Personal
Computer Memory Card International Association, Sunnyvale, Calif.,
September, 1991. The removable memory card 54 accordingly contains
solid state memory, such as Flash EPROM memory, which the memory
card 54 uses to store image data files. Electrical connection between
the memory card 54 and the digital camera 12 is maintained through
a card connector (not shown) positioned in the memory card interface
52. The memory card interface 52 and the card connector provide,
e.g., an interface according to the aforementioned CompactFlash
or PCMCIA card interface standard.
The removable memory card 54 can also be inserted into a memory
card reader 56 in the host computer 16 which is also adapted to
the CompactFlash or PCMCIA interface standard. This enables images
stored on the memory card 54 to be downloaded into the host computer
16. The digital image signals can also be sent to a serial interface
(not shown) of the host computer 16 through either a cable (not
shown), which is connected to the digital camera 12 through a host
computer interface 58, or a wireless interface, such as an infrared
interface (not shown).
The digital camera 12 further includes a plurality of image display
buttons 60 (shown in FIG. 1A) on the LCD 48 that together with the
LCD 48 form a graphical user interface (GUI). A portion of the GUI
of the digital still camera 12 is shown in FIG. 1A. As shown, the
image display buttons 60 include a menu up button 60a, a select
button 60b, and a menu down button 60c.
In accordance with the present invention, the digital still camera
12 is operable in a normal mode and a panoramic mode. In the normal
mode, the digital still camera 12 captures and produces individual
still digital images in a manner well known to those skilled in
the art. In the panoramic mode, the digital still camera captures
a series of overlapping digital images to be used in constructing
a panoramic image. The firmware memory 50 of the digital still camera
12, which is preferably Flash EPROM, stores the instructions for
the digital signal processor 46 for implementing the panoramic mode.
As shown in FIG. 1A, on a first screen 70 of the LCD 48, a user
can select various features for the operation of the normal mode
for capturing individual still digital images by using the menu
up button 60a, the select button 60b, and the menu down button 60c.
As shown in FIG. 1A, these various features include "Quality
level," "Flash setting," and "Time lapse."
By selecting the "Quality level" feature, the user can
select different compression image quality levels, such as high
quality, standard quality, and low quality. By selecting the "Flash
setting" feature, the user can choose to turn the flash on
for all pictures, to not use the flash at all, or to set the flash
to an automatic mode in which the flash is turned on only when the
ambient light level is low. By selecting the "Time lapse"
feature, the user can capture a series of time lapse images. The
time lapse mode allows the user to take a picture, for example,
every minute for a total of 10 pictures. As shown in FIG. 1A, the
user also has the option of selecting a "Panoramic photos"
feature on the first screen 70 of the LCD 48. By selecting the "Panoramic
photos" feature, the user can operate the digital still camera
12 in the panoramic mode for capturing a series of overlapping digital
images to be used in constructing a panoramic image. The values
of these settings are maintained in the control memory 33 by the
microprocessor 32.
FIGS. 2A-2C, when placed together, are a flow diagram of the operation
of the system 10 in the panoramic mode. In operation, the user selects
the "Panoramic photos" mode on the first screen 70 of
the LCD 34 as shown in FIG. 1A (block 200). Four options are then
displayed on a second screen 72 of the LCD 34: "Instructions,"
"Automatic capture," "Manual capture," and "Settings."
By selecting "Instructions" (block 202), a series of screens
100-110 (shown in FIG. 5) is displayed on the LCD 48. These screens
100-110 describe how to use the "Panoramic photos" mode,
as well as panoramic picture taking hints. The user then attaches
the digital still camera 12 to the stand 14 (block 204).
Referring briefly to FIG. 3, a schematic of the tripod arrangement
14 which serves as a stand to secure the digital still camera 12
is shown. As shown, the stand 14 includes a tripod 75, a camera
holder 76 for attaching the digital still camera 12 to the stand
14, and a rotatable indexing head 74 which is attached to the top
of the tripod 75. The rotatable indexing head 74 is used to rotate
the digital still camera 12 the same angle between successive image
captures in order to obtain a series of images which can be combined
to produce a corresponding panoramic image. Preferably, the rotating
indexing head 74 enables the digital still camera 12 to be positioned
every 30 degrees to obtain a series of 12 horizontal images or every
22.5 degrees to obtain a series of 16 vertical images. The number
of images required for a 360 degree panoramic image depends on the
field-of-view of the lens 26 and the optical format of the image
sensor 30.
As shown in FIG. 3, the stand 14 further includes a dial 78 attached
to the rotatable indexing head 74 for indicating the current image
number, and a base 80 to support the dial 78 and the rotating indexing
head 74. The digital still camera 12 can be mounted to the stand
14 in either the portrait (i.e., vertical) orientation or the landscape
(i.e., horizontal) orientation. However, mounting the digital still
camera 12 in the portrait orientation is preferable since it provides
the largest possible vertical field of view. For a more detailed
description of the stand 14, see commonly assigned U.S. Pat. No.
5,870,642, entitled "Panoramic Support For Camera Permits Horizontal-Format
And Vertical-Format Image Recording" by Mittelstaedt et al.,
the disclosure of which is herein incorporated by reference.
Referring again to FIGS. 2A-2C, once the digital still camera 12
is mounted to the stand 14 (block 204), the user again selects the
"Panoramic photos" mode on the first screen 70 of the
LCD 34 (block 206), and then selects either "Automatic capture"
or "Manual capture" on the second screen 72 of the LCD
34 (block 208), as shown in FIG. 1A. Upon selection of either mode,
the zoom lens 26 is automatically set to the widest angle and infinity
focus position by the microprocessor 32 (block 210). A warning is
also displayed on the LCD 48 of the digital still camera 12 if there
is insufficient memory available in the removable memory card 54
to take a full series of images (block 212). When there is insufficient
memory, the microprocessor 32 automatically modifies the compression
quality level setting, if there is enough memory to store all the
images at the lower quality level. Alternatively, the user can override
this automatic setting and can remove the current memory card 54
and replace it with a memory card 54 having sufficient available
memory space; delete existing files on the memory card 54, reduce
the size of the panoramic image, or exit the panoramic mode.
A settings screen 86, shown in FIG. 1A, can be used to change the
number of digital images in the panoramic digital image. Preferably,
the default setting of the digital still camera 12 in the panoramic
mode equals the number of position settings of the rotating indexing
head 74 for the camera orientation selected in screen 90 to enable
the user to produce a 360 degree panoramic digital image. However,
the user can also use screen 88 to produce a 90 degree, 180 degree,
or 270 degree panoramic digital image.
By selecting "Manual capture," a list of steps is then
displayed on screen 82 (shown in FIG. 1A) of the LCD 48 directing
the user to set the digital still camera 12 to position 1 on the
rotatable indexing head 74 of the tripod arrangement 14, to press
the shutter button, and to then wait until prompted (block 214),
as shown in FIG. 1A. Once the user presses the shutter button, a
first exposure is taken after a predetermined delay, preferably
approximately two seconds (block 216). The delay provides sufficient
time for the user to remove his/her hand from the shutter button
to reduce possible movement of the digital still camera 12 during
exposure. Before the exposure is taken, the microprocessor 32 of
the digital still camera 12 determines the scene light level and
sets the proper exposure parameters, i.e., the lens f-number, exposure
time, and analog gain level of the ASP 38, to provide the proper
exposure for the first picture in a manner well known to those skilled
in the art. These exposure parameters are stored in the control
memory 33 by the microprocessor 32, and are used for all of the
remaining exposures in the series to match the exposure levels in
order to prevent seams from appearing at the boundary between any
two images that are stitched together caused by different exposure
levels (block 217).
Once the first image in the series is captured, the analog signal
is processed in the ASP 38, digitized in the A/D converter 40, and
stored in the buffer memory 44. The digital image signal in the
buffer memory 44 is processed by the digital signal processor 46
to provide white balance correction, for example, by applying red
(g.sub.R), green (g.sub.G), and blue (g.sub.B) gain factors to the
red, green, and blue digital image signals. Once these g.sub.R,
g.sub.G, and g.sub.B AWB parameters are determined for the first
captured image in the series, the parameters are stored in the control
memory 33 by the microprocessor 32 (block 218). During capture of
subsequent images in the series, the AWB parameters are recalled
from the control memory 33 by the microprocessor 32 and used to
process subsequent digital images in the series of overlapping digital
images to produce the panoramic digital image.
It should be noted that determining the AE and AWB parameters for
the first captured image, storing the parameters, and recalling
such parameters for use in subsequent images can also be used in
the time lapse mode of the digital still camera 12.
Referring briefly to FIG. 4A, an example is shown of the storage
structure of the series of digital images used to produce the panoramic
digital image. Once the first exposure is taken (block 216 in FIG.
2A), a folder 60 is created on the removable memory card 54, and
the first image of the series is stored in the folder 60 (block
219 in FIG. 2B). The folders can be automatically named by the digital
still camera 12, or manually named and selected by the user as described
in commonly-assigned U.S. Pat. No. 5,633,678, entitled "Electronic
Still Camera For Capturing And Categorizing Images," the disclosure
of which is herein incorporated by reference. The name of the image
files is selected to indicate which folder it is stored in. For
example, as shown in FIG. 4A, the folder 60 can be named "NODE001,"
and the first image can be named "N001P01.JPG." Once the
first image is stored, the LCD 48 of the digital still camera 12
prompts the user to rotate the digital still camera 12 to the second
position on the rotatable indexing head 74 and to press the shutter
button (block 220). Once the user presses the shutter button, the
second exposure is taken after a predetermined delay of approximately
two seconds (block 222). In accordance with the present invention,
the second exposure is taken using the same AWB parameters, and
the same AE parameters (i.e., lens f-number, exposure time, and
analog gain level) as was used for the first exposure to eliminate
"seams" between the images when they are stitched together.
Such AE and AWB parameters are recalled from the control memory
33 by the microprocessor 32. The second image is then stored in
the folder 60 which contains the first image (block 224). In the
example above and as shown in FIG. 4A, the second image can be named
as "N001P02.JPG" and would be stored in folder "NODE001"
along with the first image "N001P01.JPG."
The user is then prompted to take the remaining exposures in the
left to right circular sequence (block 226) in the same manner as
for the second exposure. Each image is stored in the same folder
60 as the first and second images. After the final exposure of the
series is taken, the LCD 48 displays "Panoramic Photo completed"
(block 228). At this point, the user may choose to take additional
panoramic images by moving the tripod arrangement 14 to additional
locations and taking additional series of images (block 230). In
this case, if second and third series of images were to be taken,
new folders 62 and 63, respectively, would be created and named,
for example, "NODE002" and "NODE003," respectively,
as shown in FIG. 4A.
If the user selects the "Automatic capture" mode rather
than the "Manual capture" mode, the user only presses
the shutter button once, and the digital still camera 12 automatically
takes pictures, for example, every 5 seconds, as the user rotates
the digital still camera 12 on the stand 14 after hearing the shutter
28 close as each image is taken. Screen 84 of the LCD 48, shown
in FIG. 1A, indicates to the user which frame is being taken.
After all desired exposures have been taken, the user removes the
removable memory card 54 containing the images stored in the folders
from the digital still camera 12, and inserts the memory card 54
into the host computer 16 (block 232). Alternatively, the digital
still camera 12 can be attached to the host computer 16 using a
wire interface using, for example, a USB or RS-232 interface. Conventional
application program software for stitching the series of selected
images together to produce a panoramic image in accordance with
the present invention is incorporated into the hard drive 18 of
the host computer 16, and then downloaded to a computer random access
memory (RAM) (not shown) when the program is used by the CPU 20.
Stitching software is well known in the art, but such software should
be modified in accordance with the present invention. An example
of a commercially available stitching software application is PhotoVista.TM.
provided by LivePicture.
FIG. 4B shows a block diagram depicting the image stitching performed
by the application software of the host computer 16. On the host
computer 16, the user launches the stitching application (block
234) and selects the desired folder of images to be stitched to
create the panoramic image (block 236), as shown in FIG. 4B. Once
the folder is selected, the application software automatically opens
the images in sequential order from left to right (block 238). The
application software also rotates the image data to be in the horizontal
orientation since the images were captured with the digital still
camera 12 positioned in the vertical orientation (block 240). The
application software then automatically stitches the images together
to provide the panoramic image as shown in FIG. 4B (block 242).
The resulting panoramic image can be viewed on the display monitor
22, and can then be stored on the hard drive 18 or the removable
memory card 54 (block 244), printed on a local printer (not shown),
or added to a web page in a manner well known to those skilled in
the art.
The panoramic mode is turned off when the user either inactivates
the panoramic mode, or when the digital camera 12 is turned off.
Alternatively, the panoramic mode can be turned off when all images
in a given series have been captured.
The invention has been described in detail with particular reference
to a preferred embodiment thereof. However, it will be appreciated
that variations and modifications can be effected by a person of
ordinary skill in the art without departing from the spirit and
scope of the invention. For example, the control memory 33 could
be incorporated into the microprocessor 32 or the frame memory 44,
the white balance correction gain factors could be applied by the
ASP 38, or the digital still camera 12 could store unprocessed image
data from the frame memory 44, and the image processing performed
by the digital signal processor 46, including the AWB processing,
could be performed by the CPU 20 of the host computer 16. In addition,
as was previously described, the process of determining AE and AWB
parameters for a first captured image, or prior to storing a first
captured image, storing the parameters, and recalling the parameters
for use in subsequent images is also useful for time lapse or burst
image features. These features capture a series of images with the
digital still camera pointing in the same direction, using either
a relatively long delay between successive images (for time delay
feature) or a very short delay between images (for burst image feature).
These features do not require the panoramic mode or panoramic stitching
software.
Parts List 10 system 12 digital still camera 14 stand 16 host computer
18 hard drive 20 central processing unit 22 display monitor 24 keyboard/mouse
26 zoom lens 28 shutter 30 image sensor 32 microprocessor 33 control
memory 34 user buttons 36 flash unit 38 analog signal processor
40 analog-to-digital converter 42 photodiode 44 frame memory 46
digital signal processor 48 image display 50 firmware memory 52
memory card interface 54 removable memory card 56 memory card reader
58 host interface 60 image display buttons 60a menu up button 60b
select button 60c menu down button 70 first LCD screen 72 second
LCD screen 74 rotatable indexing head 75 tripod 76 camera holder
78 dial 80 mount 82 "Manual capture" LCD screen 84 "Automatic
capture" LCD screen 86 "Settings" LCD screen 88 "Capture
Angle" LCD screen 90 "Camera Orientation" LCD screen
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