Digital Camera Patent Abstract
A digital camera includes a button to renew a displayed image. If
an operator depresses the renewing button for 2 seconds or longer,
then a continuous reproducing mode is set. If a finger is released
from the renewing button, the mode is switched from the continuous
reproducing mode to a normal reproducing mode. A CPU, in the continuous
reproducing mode, expands thumbnail image data and magnifies the
expanded data to display the thumbnail images on an LCD. In the
normal reproducing mode, on the other hand, original image data
is expanded, and an expanded original image is displayed on the
LCD. That is, the thumbnail images are reproduced in a continuous
manner during depression of a reproducing button by the operator,
while the thumbnail image is turned into an original image if the
operator releases his finger from the reproducing button. Digital Camera Patent Claims
What is claimed is:
1. A digital camera for reproducing on a monitor screen any one
of a first image of a first resolution and a second image of a second
resolution lower than said first resolution, comprising: a mode
setter for setting any one of a normal reproducing mode and a continuous
reproducing mode; a first image reproducer for reproducing each
of the first images when the normal reproducing mode is set; and
a second image reproducer for enlarging each of the second images
and reproducing each of the enlarged second images in a continuous
manner when the continuous reproducing mode is set, wherein a size
of the enlarged second image is equal to a size of said monitor
screen.
2. A digital camera according to claim 1, wherein said mode setter
is capable of alternately setting said modes by use of only a single
button.
Digital Camera Patent Description
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to digital cameras, and more particularly
to a digital camera adapted to reproduce any one of thumbnail image
and original image recorded through compression.
Description of the Prior Art
The conventional digital cameras are arranged to expand original
image data in each of a normal reproducing mode and a continuous
reproducing mode so that the expanded data can be displayed on an
LCD.
However, it takes as long as about three seconds to expand the
original image data. Therefore, there has been a difficulty in shortening
the period of renewing the image in the continuous reproducing mode.
SUMMARY OF THE INVENTION
Therefore, it is an primary object of this invention to provide
a digital still camera which is capable of shortening the time period
of reproduced-image renewal in a continuous reproducing mode.
According to this invention, a digital camera adapted to reproduce
any one of thumbnail image and original image, comprises: a mode
setting means for setting any one of a normal reproducing mode and
a continuous reproducing mode; an original image reproducing means
for reproducing an original image in the normal reproducing mode;
and a thumbnail image reproducing means for reproducing thumbnail
images in a continuous manner in the continuous reproducing mode.
When a normal reproducing mode is set, an original image is reproduced
by the original image reproducing means. On the other hand, when
the continuous reproducing is set, thumbnail images are reproduced
by the thumbnail image reproducing means.
In one aspect of this invention, a reproducing mode is switched
over between the normal reproducing mode and the continuous reproducing
mode, depending upon an operation of the indicating button used
to indicate reproduced-image renewal.
In another aspect of this invention, the flag is set when the indicating
button is in an on state, and the flag is reset when the indicating
button is in an off state. A state of setting the flag is representative
of the continuous reproducing mode, while a state of resetting the
flag being representative of the normal reproducing mode.
In one embodiment of this invention, the flag is set when the on
state of the indicating button continues for a predetermined time
period. In this setting state, the thumbnail images are reproduced
in a continuous manner. Incidentally, the thumbnail images are magnified
to a size of the original image.
In another embodiment, the flag is reset when the indicating button
is turned to the off state. In the setting state is produced the
same original image as the thumbnail image lastly reproduced when
the flag is reset. The original image is renewed each time the indicating
button is depressed.
According to this invention, the thumbnail images are reproduced
in the continuous reproducing mode. Accordingly, it takes less time
to expand data, thereby shortening the period of reproduced-image
renewal. Further, in the normal reproducing mode an original image
is reproduced, thereby preventing against degradation in image quality.
The above described objects and other objects, features, aspects
and advantages of the present invention will become more apparent
from the following detailed description of the present invention
when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing one embodiment of this invention;
FIG. 2 is an illustrative view showing image file forms;
FIG. 3 is a flowchart showing part of operation in the FIG. 1 embodiment;
FIG. 4 is a flowchart showing another part of the operation in
the FIG. 1 embodiment;
FIG. 5 is a flowchart showing a further part of the operation in
the FIG. 1 embodiment;
FIG. 6 is a flowchart showing still another part of the operation
in the FIG. 1 embodiment; and
FIG. 7 is an illustrative view showing part of operation in the
FIG. 1 embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a digital camera 10 of this embodiment includes
a barrier 11 formed at a front of a main body thereof. If this barrier
11 is opened, a photographing mode is set. At the same time, an
optical image incident upon a lens 12 is given to a CCD imager 14
through a color filter having C.sub.y, Y.sub.e, M.sub.g and G arranged
in a mosaic form.
When outputting a motion picture through a monitor 34, the CCD
imager 14 performs so-called well-known pixel mixing readout to
supply a resulting pixel signal to a CDS/AGC circuit 16. The CDS/AGC
circuit 16 performs well-known noise removal and level adjustment
on the inputted pixel signal. The pixel signal processed by this
CDS/AGC circuit 16 is then converted by an A/D converter 18 into
digital data, i.e. pixel data. A first signal processing circuit
20 performs color separation and YUV-conversion on the pixel data
outputted from the A/D converter 18.
The Y, U and V data thus created is written by a memory control
circuit 26 into a memory area 24a of a DRAM 24 through a bus 22.
Since this data to be written to the memory area 24a is progressive-scan
data, the data in its form cannot be outputted through an interlace-scan
schemed LCD 34. For this reason, the memory control circuit 26 temporarily
writes the Y, U and V data into the memory area 24a. The Y, U and
V data are thereafter read out by the same memory control circuit
26 according to an interlace-scan method.
When outputting a motion picture, the second signal processing
circuit 30 performs predetermined horizontal and vertical interpolations
on the Y, U and V data (motion picture data) read out of the DRAM
24 so that these data become suited for a display-screen size of
the LCD 34. The motion picture data, outputted from the second signal
processing circuit 30, is then converted by a D/A converter 32 into
an analog signal. This analog signal is supplied to the LCD 34,
and also outputted through an output terminal 36. As a result, a
motion picture is displayed on the LCD 34.
When a shutter button 40 is depressed by an operator, a 4-bit micro-computer
42 supplies a control signal to a CPU 28 through an interrupt terminal
28a. In response thereto, the CPU 28 controls the CCD imager 14
to perform so-call all-pixel readout. The CCD imager 14 outputs
pixel signals every line by the progressive scan method. Since the
CCD imager 14 is mounted with a color filter in a mosaic form, C.sub.y
and Y.sub.e are alternately outputted at an odd line, while M.sub.g
and G are alternately outputted at an even line. The CDS/AGC circuit
16 performs noise removal and level adjustment on the pixel signal,
similarly to the above. The A/D converter 18 converts the pixel
signal from the CDS/AGC circuit 16 into digital data, i.e. pixel
data. The CCD imager 14 is disabled after outputting 1 frame of
pixel signals. The 1-frame pixel data created by the A/D converter
18 is directly supplied onto a bus 22 without processed by the first
signal processing circuit 20. This 1-frame pixel data is written
into the memory area 24a by the memory control circuit 26.
The CPU 28 performs color separation and YUV-conversion on the
image data stored in the memory area 24a with using a working area
24b. The converted Y, U and V data, i.e. photographed image data,
are compressed according to a JPEG format. The compressed data is
accommodated within an image file. The image file, in turn, is recorded
in a memory card 46. Incidentally, where no memory card 46 is applied
to the digital still camera 10, the image file is recorded on a
flash memory 38.
The memory control circuit 26 also reads Y.sub.e, C.sub.y, M.sub.g
and G of the pixel data out of the memory area 24a by the interlace
scan method, and supplies them to a second signal processing circuit
30. The second signal processing circuit 30, when a shutter button
40 is depressed, performs color separation and YUV-conversion on
the inputted pixel data, thereby outputting a photographed image
(freeze image) on the LCD 34.
The image file recorded in the memory card 46 is put with a marker,
of as shown FIG. 2, at a predetermined address thereof. "SOI"
is a start marker for an image file. Markers "APP0" and
"APP12" are respectively start markers for a thumbnail
image data area and an image information area, which have been contemplated
by the present applicant. "DQT" is a start marker for
a quantization table data area. "SOF" is a start marker
for a parameter area concerning frames. "DHT" is a start
marker for a Huffman coding table data area. "SOS" is
a start marker for a parameter area concerning components. "EOI"
is an end marker for the image file. Incidentally, an original image
data area is provided following the parameter area concerning components.
The frame-related parameter area is written with the number of
pixels of the image data. If the number of pixels is 640 pixels.times.480
lines, the information means that the resolution is at VGA. If the
number of pixels is 1024 pixels.times.768 lines, it means that the
resolution is at XGA. The image information area is written with
a photographing date, a photographing condition such as on/off of
a not-shown strobe, the presence or absence of protection setting,
and so on. The thumbnail image data area is recorded with thumbnail
image data under compression. The original image data is recorded
with compressed original image data (photographed image data).
If a reproduce/photograph switch 52 is switched to a reproducing
mode, a reproducing mode is set. The reproducing mode involves a
normal reproducing mode and a continuous reproducing mode. In the
normal reproducing mode, renewal is made for a displayed original
image each time the operator once depresses a forward feed button
48 or reverse feed button 50. That is, the CPU 28 reads original
image data out of a desired image file recorded in the memory card
46. The CPU 28 also performs expansion on the read image data by.using
a working area 24c, and stores the expanded original image data
(YUV data) into the memory area 24a. The stored original image data
is read out of the memory area 24a by the interlace-scan method.
A second signal processing circuit 30 performs horizontal and vertical
interpolations on the read original image data. As a result, a reproduced
image is displayed on the LCD 34.
Incidentally, where no memory card 46 is applied, original image
data is read from a desired image file recorded in an incorporated
flash memory 38. However, the below explanations will be made principally
on a case that the memory card 46 is applied.
If the operator continues to depress the forward feed button 48
or reverse feed button 50 for 2 seconds or longer, then a continuous
reproducing mode is set. At this time, the CPU 28 reads thumbnail
image data from respective image files at a predetermined interval
and expands the read thumbnail image data, in order, with using
the working area 24c. The expanded thumbnail image data is subjected
by the second signal processing circuit 30 to horizontal and vertical
interpolations and expanded to the screen size of the LCD 34. As
a result, expanded thumbnail images are displayed for a predetermined
time period on the LCD 34. In this manner, while the forward feed
button 48 or reverse feed button 50 is being depressed, expanded
thumbnail images are reproduced in a continuous manner.
When the operator releases his finger from the forward feed button
48 or reverse feed button 50, the continuous reproducing mode is
switched to the normal reproducing mode. The CPU 28 reproduces the
original image data corresponding to the thumbnail image being displayed
immediately before switching over of the mode. Therefore, if the
operator releases his finger from the forward feed button 48 or
reverse feed button 50 at an instance that a desired thumbnail image
is being displayed, the thumbnail image displayed on the LCD 34
turns into an original image, line by line, from a top thereof.
During continuous reproduction, thumbnail image data smaller in
data amount is read out. Due to this, the period of renewing the
reproduced image is shortened, thereby enabling high-speed reproduction.
On the other hand, when the forward feed button 48 or reverse feed
button 50 is turned off during displaying a desired thumbnail image,
the thumbnail image being displayed turns into the original image.
As a result, the quality of image display is improved.
The flash memory 38 is stored with a program corresponding to flowcharts
shown in FIG. 3 to FIG. 6. When the reproducing mode is set, the
4-bit micro-computer 42 makes timer interruptions at a interval
of 0.1 second to process on the flowchart shown in FIG. 3, and the
CPU 28 processes on the flowcharts shown in FIG. 4 to FIG. 6.
Referring to FIG. 3, the 4-bit micro-computer 42 determines at
a step S61 whether the forward feed button 48 is depressed or not.
If "NO", the 4-bit microcomputer 42 resets, at a step
S71, a measuring counter 42b, and resets a button flag 28f at a
step S73, to end the process. On the other hand, if "YES"
is determined at the step S61, the 4-bit micro-computer 42 causes
a count value M of a counter 42a to increment at the step S65, and
determines at a step S67 whether the count value M is exhibiting
a value corresponding to 2 seconds.
The flowchart shown in FIG. 3 is executed by timer interruptions
at an interval of 0.1 second, wherein the count value M is reset
at a time that the forward feed button 48 or reverse feed button
50 is turned off. To achieve this, it is determined whether or not
2 seconds or more has elapsed after depressing the forward feed
button 48 depending upon whether the count value M is exhibiting
"20" or greater or not. If "YES" at the step
S67, the 4-bit micro-computer 42 outputs, at a step S69, a control
signal to set a button flag 28f, thereby ending the process. If
"NO" at the step S67, the 4-bit micro-computer 42 outputs,
at a step S73, a control signal to reset the button flag 28f to
end the process.
With the flowchart configured like this, the button flag 28f is
set at the time that the operator continues depressing the forward
feed button 48 for 2 seconds, thereby setting the continuous reproducing
mode. On the other hand, if the operator releases his finger from
the forward feed button 48, the button flag 28f is promptly reset,
returning the mode to the normal reproducing mode.
Incidentally, although the above explanation was based on the operation
by the depression of the forward feed button 48, the process is
carried out in a similar manner where the reverse feed button is
depressed. That is, the depression of the reverse feed button 50
for 2 seconds or longer causes setting of the continuous reproducing
mode, and releasing the finger from the reverse feed button 50 returns
the mode to the continuous reproducing mode.
Referring to FIG. 4 to FIG. 6, the CPU 28 in the reproducing mode
first determines at a step S1 whether a memory card 46 is applied
to a slot 44 or not. If the determination here is "NO",
reproduction is made for the image data from the flash memory 38,
detailed explanation thereof being omitted here. On the other hand,
if "YES" at the step S1, the CPU 28 resets, at a step
S3, the total counter 28b, the PIC counter 28c and the table address
counter 28d. The CPU 28 then reads, at a step S5, any one of the
image file names out of the memory card 46, and enters the read
image file name to a last address of the entry table 28e at a step
S7.
At a step S9, the image file names entered in the entry table 28e
are sorted according to their file numbers, and then a count value
T of the total counter is incremented at a step S11. The CPU 28
subsequently determines at a step S13 whether all the image file
names have been read out of the memory card 46 or not. If "NO",
the process returns to the step S5, while if "YES", the
process proceeds to a step S15.
If the shifting to the reproducing mode is made when the image
files are recorded, for example, in the order as shown in FIG. 7(A),
in the memory card 46, these image file names are entered as shown
in FIG. 7(B), i.e. in an order of power ascending in file number.
Referring to FIG. 5, the CPU 28 sets, at a step S15, a count value
TA of the table address counter 28d at "1". At a step
S17, original image data is read out of an image file corresponding
to a current count value TA (=the entry table 28e number). The original
image data thus read is expanded according to a JPEG format. The
expanded original image data is displayed on the LCD 34 at a step
S19. That is, if the mode is shifted to the reproducing mode, reproduction
is first made for an image file smallest in file number. The CPU
28 subsequently determines at a step S21 whether the forward feed
button 48 is depressed or not. If "YES", the count value
TA is incremented at a step S23. At a step S25, original image data
is read out of an image file corresponding to a current count value,
and the read original image data is expanded according to a JPEG
format. The original image is displayed on the LCD 34.
It takes about 3 seconds from the determination "YES"
at the step S21 to the completion of the process at the step S27.
Accordingly, the CPU 28 executes the step S29 after a lapse of about
3 seconds from the operation of the forward feed button 48. At a
step S29, it is determined whether the button flag 28f is set or
not.
The button flag 28f is set at a time that the depressing time period
(on time period) of the forward feed button 48 exceeds 2 seconds.
However, if the depression time period is kept for about 3 seconds,
"YES" is determined at the step S29. Thereupon, the CPU
28 executes a process for the continuous reproducing mode at steps
S31-S41.
On the other hand, if the operator releases his finger immediately
after depressing the forward feed button 48, the flag 28f is set.
Due to this, the CPU 28 determines "NO" at the step S29,
to repeat the process for the normal reproducing mode by executing
the steps S21-S29. That is, the original image is renewed each time
the forward feed button 48 is depressed.
At a step S31, the CPU 28 increments the count value TA, and then
determines at a step S32 whether the count value TA is greater than
the number of recorded images. If the determination here is "NO",
the process advances directly to a step S34, while if "YES",
the count value is set at "1" at a step S33 and the process
proceeds to the step S34. Accordingly, after a lastly-arranged image
is reproduced. A firstly-arranged image is displayed. At the step
S34, thumbnail image data is read out of an image file corresponding
to a current count value TA to executing an expansion process. The
thumbnail image data has pixels in number, i.e. 80 pixels.times.60
lines. On the other hand, the LCD 34 has pixels in number of 704
pixels.times.432 lines. Accordingly, the CPU 28 performs, at a step
S35, a magnifying zoom process on the thumbnail image data to thereby
create magnified thumbnail image data having 704 pixels.times.432
lines. That is, the second signal processing circuit 30 is caused
to execute such a zoom process. Thus, magnified thumbnails are displayed
on the LCD 34 at a step S37. At step S39, it is determined whether
or not 0.5 second has elapsed from a time executing the step S31.
If 0.5 seconds is elapsed, it is determined at a step S41 whether
the button flag 42c is still being set or not. If "YES",
the process returns to the step S31 to repeat the process as stated
above. Due to this, magnified thumbnail images are each displayed
for 0.5 second in a continuous manner.
The display of an original image requires a time period of approximately
3 seconds, whereas the display of thumbnail image data takes not
longer than 0.5 second. It is therefore possible to continuously
reproduce thumbnail images at a high speed while the forward feed
button 48 is kept in depression.
If the forward feed button 48 is turned off, the button flag 42c
is immediately reset so that the CPU 28 determines "NO"
at a step S41. Because the count value TA is maintained at a same
value without incrementation, the CPU 28 reads at a step S43 original
image data from the same image file and expands the image data according
to a JPEG format. Thereafter, the expanded data is outputted on
the LCD 34 at a step S45, and the process returns to the step S21.
That is, if the operator finds a desirable thumbnail image and releases
his finger from the forward feed button 48, an original flag 42c
is reset to thereby return the mode from the continuous reproducing
mode to the normal reproducing mode. At this time, the thumbnail
image being displayed on the LCD 34 is changed to an original image
line by line, thus providing image representation with improved
quality.
Incidentally, although the process by depressing the forward feed
button 48 was explained based on FIG. 4 to FIG. 6, the depression
of the reverse forward button 50 decrements the count value TA.
In also this case, thumbnail images are reproduced in a continuous
manner.
According this embodiment, since thumbnail images are reproduced
in a continuous reproducing mode, it is possible to reduce the data
expansion time and hence the renewing time period required for image
production. Also, in the normal reproducing mode, an original image
is reproduced, thereby preventing against degradation in image quality.
Incidentally, the memory card may use various cards such as SSFDC
(Solid State Floppy Disc Card). Although in this embodiment a complementary-colored
filter was used that has Y.sub.e, C.sub.y, M.sub.g and G arranged
in a mosaic form, a primary-colored filter may be used that has
R, G and B arranged in a mosaic form. Further, although FIG. 4 to
FIG. 6 were explained using the memory card 46, the process will
be similarly made for a case that a plurality of images are recorded
on the flash memory 38.
Although the present invention has been described and illustrated
in detail, it is clearly understood that the same is by way of illustration
and example only and is not to be taken by way of limitation, the
spirit and scope of the present invention being limited only by
the terms of the appended claims. |