Digital Camera Patent Abstract
A digital camera is provided with a display for displaying an image
of an object and a specifying unit for specifying a plurality of
measuring points on the display. An actual area of a region surrounded
by the plurality of measuring points specified by the specifying
unit are calculated by a calculator. Digital Camera Patent Claims
What is claimed is:
1. A digital camera, comprising: a display for displaying an image
of an object; a specifying unit for specifying a plurality of measuring
points on said display; and a calculator for calculating an actual
area of a region surrounded by said plurality of measuring points
specified by said specifying unit.
2. The digital camera as recited in claim 1, further comprising
a distance measuring device for measuring a distance from said digital
camera to said measuring points, wherein said calculator calculates
said actual area based on distance information on said plurality
of measuring points.
3. The digital camera as recited in claim 2, wherein said calculator
calculates said actual area based on distance information on said
plurality of measuring points and a focal length of a photographing
lens.
4. The digital camera as recited in claim 2, wherein said calculator
calculates said actual area based on distance information on said
plurality of measuring points and angle information on said measuring
points.
5. The digital camera as recited in claim 2, wherein said specifying
unit includes a cursor movable on said display, and wherein said
distance measuring device measures said distance regarding the image
pointed by said cursor.
6. The digital camera as recited in claim 1, wherein said display
shows a calculated result of said calculator.
7. The digital camera as recited in claim 1, wherein said display
displays a segment connecting said measuring points specified by
said specifying unit.
8. The digital camera as recited in claim 1, wherein a calculated
result of said calculator is recorded in recording medium together
with a photographed image.
9. The digital camera as recited in claim 8, wherein said display
displays said calculated result together with the photographed image
when the photographed image recorded in said recording medium is
reproduced.
10. A method for calculating an area of an object in a digital
camera, including the steps of: displaying an image of the object
on a display; calculating a distance from said digital camera to
each of a plurality of measuring points specified on said display;
calculating an angle of each of said plurality of measuring points
relative to said camera; and calculating an actual area of a region
surrounded by said plurality of measuring points based on said calculated
distances and said angles.
11. A digital camera, comprising: a display for displaying an image
of an object; a specifying unit for specifying a plurality of measuring
points on said display; a first detector for detecting a distance
from said digital camera to each of said plurality of measuring
points of the object; a second detector for detecting an angle of
each of said plurality of measuring points relative to said camera;
a third detector for detecting a photographing direction; and a
calculator for calculating a relative position of each of said plurality
of measuring points relative to a photographing position based on
detected results of said first, second and third detectors.
12. The digital camera as recited in claim 11, wherein said second
detector detects said angle based on distance information on said
plurality of measuring points and a focal length of a photographing
lens.
13. The digital camera as recited in claim 11, wherein said third
detector detects a photographing angle relative to a reference plane.
14. The digital camera as recited in claim 13, wherein a projected
area of a region surrounded by said plurality of measuring points
relative to said reference plane is calculated based on a relative
position of said measuring points calculated by said calculator.
15. The digital camera as recited in claim 14, wherein said display
displays said calculated area information.
16. The digital camera as recited in claim 14, wherein said calculated
area information is recorded in a recording medium together with
a photographed image.
17. The digital camera as recited in claim 14, wherein said display
displays said calculated area information together with the image
when the image recorded in said recording medium is reproduced.
18. The digital camera as recited in claim 11, wherein said display
displays a segment connecting said measuring points specified by
said specifying unit.
19. The digital camera as recited in claim 11, wherein said specifying
unit includes a cursor movable on said display, and wherein said
first detector measures a distance from said digital camera to the
image pointed by said cursor.
20. A method for calculating a relative position of an object relative
to a digital camera, including the steps of: displaying an image
of the object on a display; calculating a distance from said digital
camera to each of a plurality of measuring points specified on said
display; detecting an angle of each of said plurality of measuring
points relative to said camera; detecting a photographing direction;
and calculating a relative position of said measuring points relative
to the photographing position based on information on the detected
distance of the object, angles and photographing direction.
Digital Camera Patent Description
The present invention claims a priority based on the Japanese Patent
Application No. H11-51730, the contents of which is incorporated
hereinto by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a digital camera.
2. Description of Related Art
As it is well known, there are many digital cameras equipped with
a distance measuring mechanism for measuring a distance from the
camera to the object to automatically focus an optical image of
the object passed through a photographing lens onto a light receiving
surface of an image pick-up element such as a charge-coupled device
(hereinafter referred to as "CCD"). In details, in such
digital cameras, a distance from the camera to the object is measured
by the distance measuring mechanism, and the image pick-up lens
is driven in a direction of the optical axis thereof depending on
the measured distance to automatically focus the optical image of
the object onto the light receiving surface of the CCD. Then, the
optical image of the object focused on the CCD is photoelectrically
converted into analog signals. The analog signals are converted
into digital signals which are then subjected to a prescribed image
processing to form image data. The image data are displayed as a
photographed image on the liquid crystal display (hereinafter referred
to as "LCD").
In the mean time, it has been proposed that a digital camera has
not only a function for recording and reproducing the photographed
image but also a function for recording measured information on
a distance from the camera to the object utilizing the aforementioned
distance measuring mechanism.
Conventionally, a digital camera having such a measuring function
is disclosed in, for example, Unexamined Laid-open Japanese Patent
Publication Nos. 5-153467, 5-153468, 5-79820, 5-56389, 5-45124,
5-45125, 5-30412, 5-26622, 5-22661, 5-18748, 5-14779, etc.
Some of these digital cameras can record the distance information
of the object or the size information of the object calculated based
on the distance information and the photographing angle information
in a recording medium together with the photographed image of the
object.
By the way, in order to accelerate a development of a measuring
function of such digital cameras, it has been expected that a digital
camera which can measure an area of a certain region of a place
away from the photographing position, i.e., the camera position,
is realized. However, in a digital camera having a conventional
measuring function, the function is limited to measure a size of
the object. None of the aforementioned prior arts discloses technique
for calculating the aforementioned area and recording the calculated
information.
Furthermore, none of the prior arts fails to disclose or suggest
any concept utilizing a depression angle or an elevation angle of
the photographing direction (the direction of the photographing
lens). Therefore, it was impossible to calculate the relative position
of the measuring point relative to the photographing camera position
because it was unable to specify a reference plane such as a horizontal
plane in a photographing image. As a result, a height of an object
such as a height of a building cannot be measured precisely.
SUMMARY OF THE INVENTION
A first object of the present invention is to provide a digital
camera by which a user can easily know an area of a certain region
of a place away from a photographing position.
A second object of the present invention is to provide a digital
camera by which a relative position of a specified measuring point
relative to a photographing position can be specified to enable
a measurement of a height of an object or the like.
A third object of the present invention is to provide a method
to be employed in a digital camera by which an area of a certain
region of a place away from a photographing position can easily
be known.
A fourth object of the present invention is to provide a method
to be employed in a digital camera by which a relative position
of a specified measuring point relative to a photographing position
can be specified to enable a measurement of a height of an object
or the like.
According to a first aspect of the present invention, a digital
camera includes a display for displaying an image of an object,
a specifying unit for specifying a plurality of measuring points
on the display, and a calculator for calculating an actual area
of a region surrounded by the plurality of measuring points specified
by the specifying unit.
With this digital camera, since the actual area of a region surrounded
by the plurality of measuring points specified by the specifying
unit can be measured, a user can easily know an area of any desired
place away from the photographing position.
According to a second aspect of the present invention, a digital
camera includes a display for displaying an image of an object,
a specifying unit for specifying a plurality of measuring points
on the display, a first detector for detecting a distance from the
digital camera to each of the plurality of measuring points of the
object, a second detector for detecting a camera angle of each of
the plurality of measuring points, a third detector for detecting
a photographing direction, and a calculator for calculating a relative
position of each of the plurality of measuring points relative to
a photographing position, based on detected results of the first,
second and third detectors.
With this digital camera, since a reference plane such as a horizontal
plane can be specified in a photographing image by detecting the
photographing direction, the relative position of a measuring point
relative to the photographing position can be measured, which enables
a measurement of a height of an object or the like.
According to a third aspect of the present invention, a method
for calculating an area of an object in a digital camera includes
the steps of displaying an image of the object on a display, calculating
a distance from the digital camera to each of a plurality of measuring
points specified on the display, calculating an angle of each of
the plurality of measuring points relative to said camera, and calculating
an actual area of a region surrounded by the plurality of measuring
points, based on the calculated distances and the angles.
With this method, since the actual area of the region surrounded
by the plurality of measuring points can be calculated, a user can
easily know an area of a region of any desired place away from the
photographing position.
According to a fourth aspect of the present invention, a method
for calculating a relative position of an object relative to a digital
camera includes the steps of displaying an image of the object on
a display, calculating a distance from the digital camera to each
of a plurality of measuring points specified on the display, detecting
an angle of each of the plurality of measuring points relative to
said camera, detecting a photographing direction, and calculating
a relative position of the measuring points relative to the photographing
position, based on information on the detected distance of the object,
angles and photographing direction.
With this method, since a reference plane such as a horizontal
plane can be specified in a photographing image by detecting the
photographing direction, the relative positions of the measuring
points relative to the photographing position can be obtained. This
enables a measurement of a height of an object or the like.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features, and advantages of the present
invention will be apparent from the following detailed description
of the preferred embodiments with reference to the attached drawings,
wherein:
FIG. 1 is a principle explanatory diagram of a main portion of
a digital camera according to an embodiment of the present invention;
FIG. 2 is an explanatory diagram of a screen display when an angle
of each of the measuring points shown in FIG. 1 is detected;
FIG. 3 is a front view of the digital camera;
FIG. 4 is a rear view of the digital camera;
FIG. 5 is a bottom view of the digital camera;
FIG. 6 is a block diagram showing a control system of the digital
camera;
FIG. 7 illustrates a screen display when a measuring mode is selected
in the digital camera;
FIG. 8 illustrates a screen transient display showing a method
for specifying measuring points in a measuring mode;
FIG. 9 illustrates an explanatory diagram showing a memory structure
of a memory card used in the digital camera; and
FIG. 10 illustrates a screen display in a reproduction mode of
the digital camera.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of a digital camera according to the present invention
will be explained with reference to the drawings.
Principle
With reference to FIG. 1, the principle of the present invention
will be explained in the case where a projected area S of the triangular
shaped land (.DELTA.P1P2P3) located at a slope is measured.
In a three-dimensional coordinate (x, y, z), it is assumed that
a digital camera 1 is located on the origin O. The reference letter
"Z" denotes a vertical direction, and the xy-plane corresponds
to a horizontal plane. The reference letters "P1," "P2"
and "P3" denote three measuring points specified for calculating
the area of the region surrounded by segments connecting the aforementioned
three measuring points, wherein these measuring points P1, P2 and
P3 are assumed to be located at an inclined land.
In order to calculate the area of the triangular shaped land .DELTA.P1P2P3,
the aforementioned measuring points P1, P2 and P3 are specified
on the screen of the LCD display 10. Then, the distance from the
origin 0 to each of the measuring points P1, P2 and P3 is calculated
by utilizing the distance measuring mechanism for an automatic focusing.
Next, each position of P1, P2 and P3 on the LCD display 10 is specified.
The angle formed between the segment O-P1 and the segment O-P2 (the
angle P1-O-P2) can be calculated from the focal length of the photographing
lens 301 and the distance between the measuring point P1 and the
measuring point P2 on the screen. The actual distance between the
measuring point P1 and the measuring point P2 can be calculated
from the distance between the origin O and the measuring point P1,
the distance between the origin O and the measuring point P2 and
the angle P1-O-P2. Similarly, the actual distances between the measuring
point P3 and the measuring point P2 and between the measuring point
P3 and the measuring point P1 can be calculated. Accordingly, the
area of the triangular shaped land .DELTA.P1P2P3 can be calculated.
As apparent from the above, since it is possible to calculate the
area of the triangular shaped land .DELTA.P1P2P3, an area of any
land (object) of any shape can be calculated by increasing measuring
points to be specified and dividing the shape into a plurality of
triangular shapes.
Next, a projection of the photographing central direction C of
the digital camera 1 on the xy-plane is defined as a central direction
Ca, and the coordinate system is set such that the projected central
direction Ca coincides with the y-axis.
When the elevation angle (or the depression angle) .theta. which
is an angle formed between the photographing central direction C
and the horizontal plane (reference plane) is detected, the coordinates
of P1, P2 and P3 can be specified in the xyz-coordinate system.
As a result, the height of the measuring points P1, P2 and P3 (the
value on the z-axis) can be obtained.
Furthermore, the actual area S of the region surrounded by the
segments connecting the projected measuring points P1a, P2a and
P3a on the horizontal plane can also be obtained.
As it is obvious from the above explanation, if only an area of
a region surrounded by the segments connecting the measuring points
P1, P2 and P3 is to be calculated, it is only required to know each
distance between two measuring points P1, P2 and P3 and each relative
angle thereof. Therefore, it is not necessarily required to obtain
the elevation angle (or the depression angle) .theta. of the photographing
central direction C. Furthermore, instead of obtaining the elevation
angle (or the depression angle) .theta. relative to the center of
the photographing view of the digital camera 1, an elevation angle
(or depression angle) relative to any specified point of a photographing
view may be obtained.
Explanation of a Digital Camera
A digital camera according to one embodiment of the present invention
will be explained with reference to FIGS. 3-5.
As shown in FIG. 3, the digital camera 1 comprises a box-shaped
camera main body 2 and an image sensing unit 3 having an elongated
rectangular parallelepiped shape. The image sensing unit 3 is detachably
connected to the right side of the camera main body 2 in the front
view shown in FIG. 3.
In the image sensing unit 3, an image pick-up circuit 302 including
a CCD color area sensor 303 as one example of an image pick-up element,
is disposed at an appropriate portion behind a zoom lens 301 as
an image taking lens as shown in FIG. 6. In the image sensing unit
3, a light-quantity adjusting circuit 304 (see FIG. 6) connected
to a light-adjusting sensor 305 for receiving the light of the flash
5 reflected from the object, is provided at an appropriate position.
The light-adjusting sensor 305 is positioned at an appropriate position
of the front end surface of the image sensing unit 3. In the image
sensing unit 3, a gyro J for detecting the elevation angle (or the
depressing angle) .theta. (see FIG. 1) of the zoom lens 301 of the
digital camera 1 is provided.
Furthermore, as shown in FIG. 6, provided in the image sensing
unit 3 are a zoom motor M1 for changing the zoom ratio of the zoom
lens 301 and for moving the zoom lens between the stand-by position
and the image taking position and an automatic focusing motor (AF
motor) M2 for automatically focusing the optical image of the object
onto the light receiving surface of the CCD 303. The zoom motor
Ml and the AF motor M2 are rotatably driven by a zoom motor driving
circuit 215 and an AF motor driving circuit 216, respectively.
Furthermore, the image sensing unit 3 is provided with an optical
finder 31 used in a silver halide lens shutter camera.
As shown in FIGS. 3 to 5, the camera main body 2 has a display
10, such as an LCD (Liquid Crystal Display), a slot 17 for receiving
a memory card 8, and a connection terminal 13 for connecting the
digital camera 1 to a personal computer 19 (see FIG. 6) or the like.
The image signal taken by the image sensing unit 3 is subjected
to a prescribed image processing in the camera main body 2. The
processed image is displayed on the LCD 10, recorded in the memory
card 8 and/or transferred to the personal computer 19. At a rear
surface side of the LCD 10, a back-light 16 (see FIG. 6) is provided.
A grip 4 is formed in the left-hand side of the front face of the
camera main body 2, and a built-in flash lamp 5 is provided in the
right-hand upper side at an appropriate position. Frame forwarding
and backwarding switches 6 and 7 are provided near the center of
the top face of the main body 2. The forwarding switch 6 (hereinafter
referred to as "UP switch") feeds the frame in the direction
that the frame number increases in the photographed order, and is
referred to as an UP switch 6. The backwarding switch 7 (hereinafter
referred to as "DOWN switch") feeds the frame in the direction
that the frame number decreases. A delete switch D for deleting
the images recorded in the memory card 8 is provided on the left
side of the DOWN switch 7, and a shutter button 9 is provided on
the right side of the UP switch 6 in the rear view shown in FIG.
4.
An LCD 10 is provided in the middle of the left-hand side of the
rear face of the camera main body 2. The LCD 10 functions as a view
finder during image taking, and as a display during the reproduction
of the recorded image. Provided at the lower side of the LCD 10
is a compression rate setting switch 12 for switching the compression
rate K of the image data to be recorded in the memory card 8. Provided
at the upper side of the LCD 10 are a power switch PS and a flash
lamp (which may be abbreviated as "FL") mode setting switch
11. At a side face of the main body 2, a connection terminal 13
is provided.
A photographing/reproduction mode setting switch 14 for switching
between a "photographing mode" and a "reproduction
mode" is positioned at the top right of the rear face of the
main body 2. Digital pictures are taken in the photographing mode.
In the reproduction mode, the digital images recorded in the memory
card 8 are reproduced and displayed on the LCD 10. The photographing/reproduction
mode setting switch 14 is also a bicontact slide switch. For example,
if the switch is shifted to the right, the reproduction mode is
selected, and if shifted to the left, the photographing mode is
selected.
Provided at the right side of the rear face of the camera main
body 2 is a four-gathered button Z (Z1-Z4). By selectively pressing
these buttons Z1-Z4, the cursor K displayed on the finder display
image in an overlap manner can be moved in any direction including
a right-and-left direction and up-and-down direction.
As shown in FIG. 5, a battery cavity 18 and a slot 17 for receiving
a memory card 8 are provided on the bottom face of the main body
2. The battery cavity 18 and the slot 17 are covered with a clam-shell
type cover 15. The digital camera 1 according to this embodiment
has a power supply source E consisting of four AA batteries connected
in series.
Function keys F1, F2 corresponding to the menu displayed on the
LCD 10 are provided at the rear face of the camera main body 2.
FIG. 6 is a block diagram of the control system of the digital
camera 1.
First, the inner structure of the image sensing unit 3 will be
explained. In the image sensing unit 3, the CCD 303 photoelectrically
converts the optical image of the object focused by the macrozoom
lens 301 into image signals of three color components R (red), G
(green) and B (blue), and outputs the image signals to the signal
processor 313. This image signal consists of sequence of pixel signals
received by the respective pixels. A timing generator 314 generates
various timing pulses for controlling and driving the CCD 303.
Since the diaphragm of the image sensing unit 3 is fixed, the exposure
of the image sensing unit 3 is controlled by adjusting the quantity
of exposure of the CCD 303, that is, the charge accumulation time
of the CCD 303, which corresponds to the shutter speed. If the luminance
of the object is too low to select to an appropriate shutter speed,
the level of the image signal output from the CCD 303 is adjusted
in order to compensate for the insufficient exposure. In other words,
at low luminance, the exposure is controlled by adjusting both the
shutter speed and the gain. The level of the image signal is adjusted
by controlling the gain of the AGC circuit in the signal processor
313.
The timing generator 314 generates various driving control signals
for the CCD 303 based on the reference clock supplied from the timing
control circuit 202. The signals generated by the timing generator
314 includes a timing signal for starting and finishing integration
(i.e., exposure), and clock signals (horizontal synchronization
signals, vertical synchronization signals, transfer signals, etc.)
for controlling the reading timing of the light-receiving signals
from the respective pixels.
These signals are supplied to the CCD 303.
The signal processor 313 applies a prescribed analogue signal processing
to the analog image signal output from the CCD 303. The signal processor
313 has a CDS (correlation double sampling) circuit for reducing
the noise of the image signal and an AGC (automatic gain control)
circuit for adjusting the level of the image signal by controlling
the gain of this AGC circuit.
The light-quantity adjusting circuit 304 sets the light emission
of the built-in flash lamp 5 to a predetermined level determined
by the general controller 211 when the flash lamp 5 is used when
taking an image. During the flash photographing, the flash light
reflected from the object is received by the light-adjusting sensor
305 upon starting exposure. When the quantity of light received
by the sensor 305 reaches a predetermined level, the light-quantity
adjusting circuit 304 supplies a flash stop signal to the flash
control circuit 214 via the general controller 211. In response
to the flash stop signal, the flash control circuit 214 forcibly
stops the light emission of the built-in flash lamp 5, whereby the
light emission amount of the built-in flash lamp 5 can be regulated
to the prescribed level.
The aforementioned image sensing unit 3 and the camera main body
2 are electrically connected each other by way of seven groups of
connection terminals 334a, 334b, 334c, 334d, 334e, 334f, 334g provided
at the connection surface 334 of the image sensing unit 3 and seven
groups of connection terminals 234a, 234b, 234c, 234d, 234e, 234f,
234g provided at the connection surface 234 of the camera main body
2.
Next, the inner structure of the camera main body 2 will be explained.
The A/D converter 205 provided in the main body 2 of the digital
camera 1 converts each pixel signal (i.e., analog signal) of the
image signal sequence into a 10-bit digital signal based on the
A/D conversion clock supplied from the timing control circuit 202.
The timing control circuit 202 generates a reference clock and
a clock for the timing generator 314 and the A/D converter, and
is controlled by the general controller 211.
A black level correction circuit 206 corrects the black level of
the digitalized pixel signal (hereinafter referred to as "pixel
data") converted by the A/D converter 205 to the reference
black level. A white balance circuit (hereinafter referred to as
"WB circuit") 207 converts the level of the pixel data
of each color component of R, G or B, so that the white balance
can be adjusted after .gamma. (gamma) correction. The WB circuit
207 converts the level of the pixel data of each color component
R, G, B using a level conversion table input from the general controller
211. The conversion coefficient (the slope of the characteristic
line) for each color component in the level conversion table is
set each taken image by the general controller 211.
The .gamma. (gamma) correction circuit 208 corrects for the .gamma.
(gamma) characteristic of the pixel data. An image memory 209 stores
the pixel data output from the .gamma. (gamma) correction circuit
208. The memory capacity of the image memory 209 corresponds to
one frame data. Accordingly, if the CCD 303 has an n.times.m pixel
matrix, the image memory 209 has a memory capacity of n.times.m
pixel data, and each pixel data is stored in the corresponding pixel
position in the image memory 209.
A VRAM 210 is a buffer memory for storing the image data which
is to be reproduced and displayed on the LCD 10. The memory capacity
of the VRAM 210 corresponds to the number of pixels of the LCD 10.
In the image taking preparation mode, each pixel data of the image
taken by the image sensing unit 3 every 1/30 second is subjected
to the prescribed signal processing by the sequence from the A/D
converter 205 to the .gamma. (gamma) correction circuit 208, and
stored in the image memory 209. This pixel data is simultaneously
transferred to the VRAM 210 via the general controller 211, and
displayed on the LCD 10 (live-view display). The user can recognize
the photographed object on the LCD 10. In the reproduction mode,
the image read out from the memory card 8 is subjected to the prescribed
signal processing by the general controller 211, which is then transferred
to the VRAM 210, and displayed on the LCD 10.
A card I/F 212 is an interface for writing the image data into
the memory card 8 or reading the image data from the memory card
8. A communication I/F 213 is an interface based on the USB standard
for example, or an interface for connecting a personal computer
19.
A flash control circuit 214 controls the light emission of the
built-in flash lamp 5. In particular, the flash control circuit
214 controls the quantity of flash light, the flash timing, and
so on, based on the control signal supplied from the general controller
211. The flash control circuit 214 also brings the light emission
to zero based on the flash stop signal input from the light-quantity
adjusting circuit 304.
An RTC (Real Time Clock) 219 is a time circuit for keeping the
track of the date and time of each photograph, which is driven by
a separate power source (not shown).
An operation unit 250 has switches corresponding to the UP switch
6, the DOWN switch 7, the shutter button 9, the FL mode setting
switch 11, the compression rate setting switch 12, the photographing/reproduction
mode setting switch 14, the four gathered button Z and the function
keys F1, F2.
The shutter button 9 is of a two-step type which can detect a half-pressed
state (hereinafter referred to as "S1 state") and a full-pressed
state (hereinafter referred to as "S2 state"), which is
generally used in a silver-halide camera. When the shutter button
9 is half pressed (S1 state) in the image taking preparation state,
the general controller 211 controls the AF motor M2 via the AF motor
driving circuit 216 so that the contrast of the image data of the
image memory 209 becomes maximum to execute the automatic focus
processing of the image taking lens 310. When the shutter button
9 is released from the S1 state, the focus is locked at the position.
The distance from the camera to the object can be obtained based
on the moving 25 amount of the AF motor M2 from the reference position,
and is stored in an inner memory (not shown) of the general controller
211.
The power switch PS is connected to a self holding circuit PSH
connected to the general controller 211 via a voltage check circuit
W. In a power-off state, since the self holding circuit PSH maintains
a power-on state by pressing the power switch PS one time, the power
supply to the general controller 211 and each block is maintained.
On the other hand, in a power-on state, when the power switch PS
is pressed, the pressing of the power switch PS is detected by the
general controller 211. Simultaneously, the general controller 211
stops the power supply to the blocks not required to drive the zoom
motor M1, and drives the zoom motor M1 by way of the zoom motor
driving circuit 215 for a certain time to return the zoom lens 301
to the stand-by position. Then, the general controller 211 stops
the power supply to the blocks required to drive the zoom motor
M1 and itself.
The general controller 211 comprises a micro computer, and it organically
controls the driving timing of each element in the image sensing
unit 3 and the camera main body 2 so as to generally control the
photographing operation of the digital camera 1. The general controller
211 includes an area calculation portion 2112 comprising an inner
CPU, etc. for measuring the area S of the region surrounded by segments
connecting each measuring points.
Furthermore, the general controller 211 has a luminance detector
for determining an exposure control value (i.e., a shutter speed
SS), and a shutter speed setting unit. In the image taking standby
mode, the luminance detector detects the luminance of the object
based on the image taken by the CCD 303 every 1/30 second. In other
words, the luminance detector determines the luminance of the object
from the image data updated and stored in the image memory 209.
The shutter speed setting unit determines the shutter speed SS
(that is, the integral time of the CCD 303) based on the luminance
of the object detected by the luminance detector.
The general controller 211 has a filter for filtering the photographed
image and a recording image generator for generating a thumb nail
image and a compressed image for recording the photographed image.
Further provided to the general controller 211 is a reproduction
image generator for generating a reproduction image for reproducing
images recorded in the memory card 8 on the LCD 10.
The filter corrects the high frequency components of the image
to be recorded by a digital filer to correct the contour of the
image.
The recording image generator reads the pixel data out of the image
memory 209, and generates a thumb nail image and a compressed image
which are to be recorded in the memory card 8. To be more precise,
the recording image generator scans the image memory 209 in the
raster direction, and reads out every 8 pixels in both the horizontal
and vertical directions to create a thumb nail image and record
the thumb nail image.
The recording image generator also reads out the entire pixel data
from the image memory 209, and applies a prescribed data compression
process to these pixel data based on a JPEG method, such as two-dimensional
DCT conversion or Hoffmann encoding, to create a compressed image
data. The compressed image data is recorded in the primary image
area of the memory card 8.
If, in the image taking mode, the shutter button 9 is pressed to
start taking images, the general controller 211 creates a thumb
nail image from the image taken in the image memory 209 after the
instruction for taking images, and the compressed image created
by a JPEG method at the compression rate set by the compression
rate setting switch 12. A tag information (such as the frame number,
exposure value, shutter speed, compression rate, date and time,
flash ON/OFF data, scene information, judged result of the image,
etc), the compressed image and the thumb nail image, are stored
in the memory card 8.
As shown in FIG. 9, the memory card 8 can store forty frames of
images taken by the digital camera 1 at a 1/20 compression rate.
Each of the frames 81-85 has tag information, high-resolution image
data (640.times.480 pixels) compressed by a JPEG method, and thumb
nail image data (80.times.60 pixels).
When the photographing/reproduction mode setting switch 14 is set
to the reproduction mode, the image data having the largest frame
number is read out of the memory card 8. The read out image data
is extended, and transferred to the VRAM 210 so that the image data
having the largest frame number, or the newest photographed image
is displayed on the LCD 10. By operating the UP switch 6, the image
data having a larger frame number is displayed. On the other hand,
by operating the DOWN switch, the image data having a smaller frame
number is displayed.
Explanation of the Operation
When the power is turned on by pressing the power switch PS while
pressing the function key F1, the mode is set to the setup mode.
The LCD 10 displays the screen as shown in FIG. 7. By pressing the
button Z3, Z4, the normal photographing mode and the measuring mode
can be selected in a cyclic manner. In this state, when the function
key F1 corresponding to "OK" is pressed, the mode changes.
In the measuring mode, as shown in FIG. 8, the plus-shaped cursor
K is displayed on the LCD 10 together with the live-view.
If the button Z1 is pressed, the cursor K moves left, and if the
button Z2 is pressed, the cursor K moves right. If the button Z3
is pressed, the cursor K moves upward, and if the button Z4 is pressed,
the cursor K moves downward. The focusing mechanism focuses the
image on the position P1 of the cursor K, and the distance from
the digital camera to the position P1 is measured from the displacement
amount of the focusing motor M2 from the initial position, and is
displayed on the upper right portion of the screen 8A. The aforementioned
focusing and the distance measuring will be repeated as the cursor
K moves, and the distance display is updated whenever the cursor
K moves.
Furthermore, the angle formed between the segment connecting the
camera position O and the measuring point P1 and the photographing
direction C is calculated from the focus length of the image taking
lens 301 (since the lens is a zoom lens, the displacement amount
of the zoom motor M1 from the reference position corresponds to
the focus length) and the positional difference of each position
of the measuring points P1, P2 and P3 relative to the central direction
C on the LCD 10. In addition, the elevation angle (or depression
angle) .theta. of the photographing direction C is detected by the
signal from the gyro J.
From the distance information of the measuring point P1, the angle
information relative to the photographing direction C and the elevation
angle (or depressing angle) .theta. of the photographing direction
C, the position P1 (x, y, z) of the measuring point P1 in the coordinate
system (x, y, z) shown in FIG. 1 is calculated, and is temporarily
stored in the memory provided in the general controller 211.
In this state (screen 8A), if the function key F1 is pressed or
the shutter button 9 is half-pressed, the first measuring point
P1 is fixed, and the next measuring point P2 becomes ready to set
(screen 8B).
In specifying the measuring point P2 on the screen 8B, the four-gathered
buttons Z1-Z4 controls the cursor K in the same manner as mentioned
above. The segment connecting the measuring point P1 and the measuring
point P2 is displayed on the screen.
In the screen 8B, the distance between the measuring point P1 and
the measuring point P2 is calculated by obtaining the position of
the measuring point P2, and is displayed on the right upper portion
of the screen.
In this state (screen 8B), if the function key F1 is pressed or
the shutter button 9 is half-pressed, the second measuring point
P2 is fixed, and the next measuring point P3 becomes ready to set
(screen 8C).
In specifying the measuring point P3 on the screen 8C, the four-gathered
buttons Z1-Z4 controls the cursor K in the same manner as mentioned
above. The segment connecting the measuring points P1 and P2 and
the segment connecting the measuring points P2 and P3 are displayed
on the screen. Furthermore, a triangular shape connecting the measuring
points P1, P2 and P3 is also displayed on the screen. In the screen
8C, the area calculation portion 2112 calculates the area of .DELTA.P1P2P3
by obtaining the relative position of the measuring point P3, and
is displayed on the right upper portion of the screen. Thus, the
photographer can immediately confirm the area S of the specified
region.
At this stage, the area to be displayed on the LCD 10 may be the
actual area corresponding to .DELTA.P1P2P3 shown in FIG. 1, or may
be the projected actual area of .DELTA.P1P2P3 projected on the horizontal
plane xy (the actual area of .DELTA.P1aP2aP3a shown in FIG. 1).
These switching may be added to the menu of the setup mode shown
in FIG. 7.
In a case where the actual area corresponding to .DELTA.P1P2P3
is measured, each distance between the measuring points may be calculated
from the distance information of each measuring point and the mutual
angle information on the measuring points, and then the actual area
corresponding to .DELTA.P1P2P3 may be calculated. In this case,
it is not necessarily required to obtain the position of each measuring
position in the xyz-coordinate system shown in FIG. 1.
As mentioned above, if three measuring points P1, P2 and P3 are
specified arbitrarily on the screen of the LCD 10, the triangular
shaped area surrounded by the segments connecting these measuring
points P1, P2 and P3 can be easily calculated.
Furthermore, since the horizontal plane (xy-plane) can be specified
in the photographing view by obtaining the elevation angle (or depressing
angle) .theta. relative to the photographing direction C, the height
of each measuring point P1, P2 or P3 can be easily measured. If
necessary, the height may be displayed on the LCD 10.
To specify the fourth measuring point, the function key F1 is pressed,
or the shutter button 9 is half-pressed on the screen 8C shown in
FIG. 8 after specifying the three measuring points P1, P2 and P3.
Similarly, the fifth and sixth measuring points P5, P6 can be specified.
Whenever a triangular shape is specified, the area thereof can be
measured. Therefore, even an area of a polygonal shape other than
a triangle shape or an irregular shape can be easily measured.
In the screens 8B, 8C, 8D, when the function key F2 corresponding
to the display "cancel" is pressed, the screen returns
to the previous one. Therefore, even if it fails to specify the
measuring point, the measuring point can be specified again immediately.
In the screens (8A-8D), when the shutter button 9 is fully pressed,
the recording message shown in the screen 8E is displayed, and the
image data when the shutter button 9 is pressed and the measuring
status are recorded in the memory card 8. By this record, the photographer
can utilize the measured information at any time.
The memory card 8 has a format as shown in FIG. 9, and records
the image data of each frame in the photographing order. The image
data of each frame is recorded in the memory card 8 as the image
data of high resolution, the reduced image data of the thumb nail
image and the tag information.
Recorded in the tag are the number of measuring points n, the relative
position information P1 (x, y, z), . . . Pn(x, y, z) of n measuring
points, the distance between the measuring points (in a case where
it is recorded by fully pressing the shutter button 9 in the screen
8B), and the area of the region surrounded by segments connecting
the measuring points P1, . . . Pn (in a case where it is recorded
by fully pressing the shutter button 9 in the screen 8C or subsequent
screens).
On the other hand, in a case where the photographed image is read
out of the memory card 8 and reproduced on the LCD, as shown in
FIG. 10, the region surrounded by segments connecting the measuring
points is displayed so as to easily be recognized, and is displayed
together with the photographed image in an overlapped manner. By
pressing the function key F1, the display of the measuring points
and the area are turned on and off so as to display only the photographed
image. Since the measured results are displayed together with the
photographed image in an overlapped manner, the measured results
can be easily recognized by comparing to the photographed image.
In the aforementioned embodiment, although the horizontal plane
is set to the reference plane by detecting the elevation angle or
depressing angle of the photographing direction C, the reference
plane is not limited to the horizontal plane.
As mentioned above, according to the above embodiment, since the
actual area of the region surrounded by the segments connecting
the measuring points is measured based on the distance information
and the angle information on the measuring points, an area of any
desired place away from the photographing position can be easily
recognized.
Since the reference plane such as a horizontal plane can be specified
in the photographing view by detecting the angle of the photographing
direction relative to the reference plane, the relative position
of the measuring point relative to the photographing position can
be calculated. Therefore, the height of the object or the like can
be measured.
Furthermore, since the measured information is displayed on the
LCD, the photographer can immediately recognize the measured information.
In addition, since the measured information is recorded together
with the photographed image, the image of the object and the measured
information recorded can be utilized at any time.
Furthermore, the measured information is displayed on the LCD when
reproducing the photographed image, it is not required to reproduce
only the measured information, and the measured information and
the photographed image can be recognized in comparison to each other.
The measuring specifying unit is provided with a cursor movable
on the screen of the LCD, and the focusing mechanism focuses the
image on the cursor position. Therefore, the measuring point can
be easily and simply specified by using the cursor.
Since the segments connecting the measuring points are displayed
on the screen of the LCD, the user can easily recognize the specified
region which area is to be measured.
The terms and descriptions in this specification are used only
for explanatory purposes and the present invention is not limited
to these terms and descriptions. It should be appreciated that there
are many modifications and substitutions without departing from
the spirit and the scope of the present invention which is defined
by the appended claims.
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