Digital Camera Patent Abstract
A highspeed image selecting method for selecting an image photographed
by a digital camera, comprises the steps of: enlarging and feeding
the enlarged thumbnail images sequentially in fast-forward/fast-backward
modes to be sequentially displayed; and, when a desirable thumbnail
image is selected from the enlarged thumbnail images under display,
extending compression image data corresponding to the selected thumbnail
image so as to acquire image data. Digital Camera Patent Claims
What is claimed is:
1. A high speed image selecting method for selecting an image photographed
by a digital camera, comprising the steps of: taking one or more
photographic images with said digital camera to produce corresponding
image data; using said corresponding image data to produce and store;
compressed image data for producing a corresponding one of said
photographic images, and thumbnail image data for producing thumbnail
images in correspondence to said photographic images, wherein each
of said thumbnail images has a respective number of pixels less
than a number of pixels for said image data of said corresponding
one of said photographic images; after said producing of said thumbnail
image data, entering a fast-forward/fast-backward mode comprising:
enlarging said thumbnail images to provide enlarged thumbnail images,
feeding said enlarged thumbnail images sequentially for sequential
display, and in response to a selection operation with respect to
one of said enlarged thumbnail images, extending said compressed
image data corresponding to the selected one of said enlarged thumbnail
images so as to acquire said corresponding image data.
2. The high speed image selecting method as claimed in claim 1,
wherein: the enlarged thumbnail images are indexed to produce corresponding
indexes, and then the enlarged thumbnail images are displayed with
said corresponding indexes during said sequential display.
3. A digital camera for recording, on a recording medium, image
data produced by photoelectrically converting photographing light
and corresponding thumbnail image data thereof, said digital camera
being equipped with a high speed image selecting function, said
digital camera comprising: on said recording medium, for each of
one or more photographic images, corresponding compressed image
data and said corresponding thumbnail image data; a display unit;
data expanding means for expanding said corresponding compressed
image data; enlarged thumbnail image display means for enlarging
said corresponding thumbnail image data and for displaying the enlarged
thumbnail image data on the display unit; thumbnail image selecting
means for feeding the enlarged thumbnail image under display in
fast-forward/fast-backward modes to select a desirable thumbnail
image; image display means for causing said data expanding means
to expand said compressed image data corresponding to said selected
thumbnail image, to provide on said display unit a displayed image;
and image selection defining means for defining the displayed image
as a selection image.
4. The digital camera equipped with a high speed image selecting
function as claimed in claim 3, wherein the fast-forward/fast-backward
feeding operations of the enlarged thumbnail image by the thumbnail
image selecting means are commenced by executing a predetermined
switch operation.
5. The digital camera equipped with a high speed image selecting
function as claimed in claim 3, wherein the fast-forward/fast-backward
feeding operations of the enlarged thumbnail image by the thumbnail
image selecting means are commenced when an instruction is issued
such that forward/backward feeding operations of normal image data
are continuously performed within a predetermined time period.
6. The digital camera equipped with a high speed image selecting
function as claimed in claim 3, wherein the expanding process of
the image data by the data expanding means is carried out in conjunction
with the display process of the enlarged thumbnail image corresponding
thereto.
7. The digital camera equipped with a high speed image selecting
function as claimed in claim 3, further comprising: indexing means
for indexing the enlarged thumbnail image displayed by the thumbnail
enlarged image display means.
8. A recording medium readable by a digital camera for recording
on the recording medium, image data produced by photoelectrically
converting photographing light and also thumbnail image data thereof,
on which a program is recorded and the program is capable of realizing:
a data expanding function for expanding compressed image data to
provide expanded image data; an enlarged thumbnail image display
function for enlarging the thumbnail image data and for displaying
the enlarged thumbnail image data on a display unit; a thumbnail
image selecting function for feeding the enlarged thumbnail image
under display in fast-forward/fast-backward modes to select a desirable
thumbnail image; an image display function for displaying the expanded
image data corresponding to the selected thumbnail image on the
display unit; and an image selection defining function for defining
the displayed image as a selection image.
9. A method of providing a fast image selection mode in a digital
camera, comprising: taking digital images; storing said digital
images as compressed digital images, each of said compressed digital
images corresponding to one of said digital images; producing thumbnail
images based on said digital images, each of said thumbnail images
corresponding to one of said digital images and one of said compressed
digital images, each said thumbnail image having a fewer number
of pixels than a number of pixels for said corresponding compressed
digital image; storing said thumbnail images; detecting an indication
of said fast image selection mode; and in response to said indication
of said fast image selection mode, sequentially displaying on a
display images corresponding to said digital images by: identifying
a current one of said digital images for said displaying, identifying
said thumbnail image corresponding to said current one of said digital
images, enlarging said identified thumbnail image, and displaying
said enlarged thumbnail image on said display.
10. The method of providing a fast image selection mode as set
forth in claim 9, further comprising: providing, for each enlarged
thumbnail image, an index; and displaying, with said enlarged thumbnail
image, said index.
11. The method of providing a fast image selection mode as set
forth in claim 9, further comprising: obtaining a selection of one
of said enlarged thumbnail images; in response to said selection,
expanding said compressed digital image corresponding to said selected
one of said enlarged thumbnail images to provide said corresponding
digital image; and displaying on said display said corresponding
digital image.
12. The method of providing a fast image selection mode as set
forth in claim 9, wherein said indication of said fast image selection
mode is made by a user executing a predetermined switch operation.
13. The method of providing a fast image selection mode as set
forth in claim 9, wherein said indication of said fast image selection
mode comprises detecting that forward/backward feeding operations
of normal image data are continuously performed within a predetermined
time period.
14. A digital camera, comprising: means for taking digital images;
a memory storing said digital images as compressed digital images,
each of said compressed digital images corresponding to one of said
digital images; said memory storing thumbnail images based on said
digital images, each of said thumbnail images corresponding to one
of said digital images and one of said compressed digital images,
each said thumbnail image having a fewer number of pixels than a
number of pixels for said corresponding compressed digital image;
a controller detecting an indication of a fast image selection mode;
in response to said indication of said fast image selection mode,
said controller sequentially displaying on a display images corresponding
to said digital images by: identifying a current one of said digital
images for said displaying, identifying said thumbnail image corresponding
to said current one of said digital images, enlarging said identified
thumbnail image, and displaying said enlarged thumbnail image on
said display.
15. The digital camera as set forth in claim 14, further comprising,
for each enlarged thumbnail image, an index displayed with said
enlarged thumbnail image.
16. The digital camera as set forth in claim 14, further comprising:
means for obtaining a selection of one of said enlarged thumbnail
images; said means for obtaining being responsive to said selection
to expand said compressed digital image corresponding to said selected
one of said enlarged thumbnail images thereby to provide said corresponding
digital image; and said display displaying said corresponding digital
image.
17. The digital camera as set forth in claim 14, wherein said indication
of said fast image selection mode comprises said controller detecting
the execution of a predetermined switch operation.
18. The digital camera as set forth in claim 14, wherein said indication
of said fast image selection mode comprises said controller detecting
that forward/backward feeding operations of normal image data are
continuously performed within a predetermined time period.
Digital Camera Patent Description
BACKGROUND OF INVENTION
The present invention is related to a digital camera, and more
specifically, directed to a highspeed image selecting method and
a digital camera equipped with a highspeed image selecting function,
by which an enlarged thumbnail image is fed in fast-forward/fast-backward
modes when an image is displayed on a display unit such as a liquid
crystal display.
Very recently, digital cameras (electronic still image cameras)
have been developed, and are commercially available, and thus are
gradually popularized.
A digital camera is arranged as follows. Imaging (photographing)
light is photoelectrically converted into image data, and this image
data is recorded on a recording medium, and thereafter is outputted
to an external image processing apparatus, for instance, a personal
computer. Then, the image data is processed by way of a printing
image data forming process in the external image processing apparatus,
and then the formed printing image data is outputted to a printer,
so that a photographed image is printed/reproduced on a print paper.
It should be noted that the most digital cameras are equipped with
liquid crystal displays (LCD) for displaying photographed images
and the like. On the other hand, image data acquired by photoelectric
converting operation are compression-processed to be recorded on
recording media. Normally, the compression process operation is
carried out based on the JPEG (Joint Photographic Image Coding Experts
Group) standard (will be referred to as "JPEG compression"
hereinafter).
In the case that an image is selected on the side of a personal
computer, a plurality of thumbnail images are previously acquired
to be displayed on a monitor, and a user selects a desirable image.
Then, the selected image data is acquired from a digital camera
to be expanded, and the expanded image is displayed on the monitor.
After this expanded image is confirmed by the user, this image is
processed by executing a color printing image data forming process,
and then this processed image is printed out by a printer connected
to the personal computer.
A thumbnail image corresponds to a compressed image which is used
when a desirable image is selected from image data acquired by a
personal computer and the like. Assuming now that a data size (namely
memory capacity) of image data for 1 frame is equal to 1,024.times.768
pixels, a thumbnail image corresponding to this 1-frame image is
such a compressed image having approximately 86.times.60 pixels
by thinning image data from this 1-frame image data. Then the thumbnail
image is recorded on a recording medium of a digital camera.
In such a system that a digital camera is connected to a communication
line and a wireless (radio) unit such as a portable telephone so
as to transmit desirable image data via either a wire line or a
wireless line, and/or in order to directly transmit printing image
data from the digital camera to a printer to be printed out, this
system should be arranged in a manner that the images are reproduced
on a liquid crystal display on the side of the digital camera so
as to select a desirable image.
However, since the image data have been JPEG-compressed to be stored
in the recording medium, these JPEG-compressed image data stored
in this recording medium should be read out and then be expanded,
and thereafter be extended over a frame memory in order to reproduce/display
the images on the liquid crystal display.
When expanding means for compressed data is constituted by a hardware
circuit, expanding/extending process time of these compressed data
may be shortened. However, in popularized digital cameras, expanding
means are normally arranged in a program form (will be referred
to as an "expanding program" hereinafter) so as to reduce
product cost. In such popularized digital cameras, 2 to 3 seconds
are necessarily required to expand a 1-frame image (1,024.times.768
pixels) which has been JPEG-compressed by using this expanding program.
As a result, there is a problem that users have such feelings that
image display time would be prolonged. Moreover, when a desirable
image is selected, image data must be sequentially read out to be
displayed. Under such a circumstance, if a desirable image is stored
in a later order, then a long time duration is actually required
in order to select this desirable image. Thus, there is a further
problem that such a lengthy access time is practically inconvenient.
SUMMARY OF INVENTION
The present invention has been made to solve the above-described
problems, and therefore, has an object to provide a highspeed image
selecting method, and also a digital camera equipped with a highspeed
image selecting function, capable of enlarging a thumbnail image
to feed the enlarged thumbnail image in a fast mode.
To achieve objects, a highspeed image selecting method, according
to a first aspect of the present invention, is featured by such
a highspeed image selecting method for selecting an image photographed
by a digital camera, comprising the steps of: enlarging and feeding
the enlarged thumbnail images sequentially in fast-forward/fast-backward
modes to be sequentially displayed; and when a desirable thumbnail
image is selected from the enlarged thumbnail images under display,
extending compression image data corresponding to the selected thumbnail
image so as to acquire image data.
In this first aspect, the thumbnail image is fed in the fast-forward/fast-backward
modes to be displayed in a high speed. After a desirable thumbnail
image is selected, the compressed image data is expanded, so that
the image can be selected in a high speed.
In accordance with a second aspect of the present invention, in
the highspeed image selecting method of the first aspect, the enlarged
thumbnail images are indexed, and then the enlarged thumbnail images
with the indexes are sequentially fed in the fast-forward/fast-backward
modes to be sequentially displayed.
In this second aspect, the thumbnail images with the indexes are
enlarged and the enlarged thumbnail images are fed in the fast-forward/fast-backward
modes, so that the image can be further easily selected.
In accordance with a third aspect of the present invention, a digital
camera equipped with a highspeed image selecting function is featured
by that in a digital camera for recording on a recording medium,
image data produced by photoelectrically converting photographing
light and thumbnail image data thereof, a digital camera equipped
with a highspeed image selecting function, comprising: a display
unit for displaying an image; data expanding means for expanding
compressed image data; thumbnail enlarged image display means for
enlarging thumbnail image data and for displaying the enlarged thumbnail
image data on the display unit; thumbnail image selecting means
for feeding the enlarged thumbnail image under display in fast-forward/fast-backward
modes to select a desirable thumbnail image; image display means
for displaying image data corresponding to the selected thumbnail
image on the display unit; and selection image defining means for
defining the displayed image as a selection image.
In this third aspect, the thumbnail image is fed in the fast-forward/fast-backward
modes to be displayed in a high speed. After a desirable thumbnail
image is selected, the compressed image data is expanded, so that
the image can be selected in a high speed.
In accordance with a fourth aspect of the present invention, a
digital camera equipped with a highspeed image selecting function
is featured by that the fast-forward/fast-backward feeding operations
of the enlarged thumbnail image by the thumbnail image selecting
means are commenced by executing a predetermined switch operation.
In accordance with the fourth aspect, the enlarging process and
the fast-forward/fast-backward feeding operations of the thumbnail
image can be readily realized by a predetermined switch operation,
so that the thumbnail images can be selected in a high speed.
A digital camera equipped with a highspeed image selecting function
according to a fifth aspect of the present invention, is featured
by that in the digital camera equipped with the highspeed image
selecting function, as described in the third aspect or the fourth
aspect, the fast-forward/fast-backward feeding operations of the
enlarged thumbnail image by the thumbnail image selecting means
are commenced when an instruction is issued such that forward/backward
feeding operations of normal image data are continuously performed
within a predetermined time period.
In accordance with the fifth aspect, when the image selection is
continuously performed within a predetermined time period, the operation
is automatically transferred to the enlarging operation and the
fast-forward/fast-backward operations of the thumbnail image, so
that the thumbnail image can be readily selected in a high speed.
Also, since the enlarged thumbnail image is displayed until the
image data is displayed, the waiting tension given to the user can
be relaxed.
A digital camera equipped with a highspeed image selecting function,
according to a sixth aspect of the present invention, is featured
by that in the digital camera equipped with the highspeed image
selecting function, as described in the third aspect, the fourth
aspect, or the fifth aspect, the expanding process of the image
data by the data expanding means is carried out in conjunction with
the display process of the enlarged thumbnail image corresponding
thereto.
According to the sixth aspect, since the enlarging/display process
operation of the thumbnail image and the expanding process of the
image data are carried out, the image data can be quickly displayed
after the selecting operation.
A digital camera equipped with a highspeed image selecting function,
according to a seventh embodiment of the present invention, is featured
by that the digital camera equipped with the highspeed image selecting
function, as described in any one of the preceding aspects 3 to
6, is further comprised of: indexing means for indexing the enlarged
thumbnail image displayed by the thumbnail enlarged image display
means.
In accordance with the seventh embodiment, since the enlarged thumbnail
images are indexed, the image selection by the fast-forward/fast-backward
operation can be readily performed.
A recording medium, according to an eighth aspect of the present
invention, is featured by such a recording medium readable by a
digital camera for recording on the recording medium, image data
produced by photoelectrically converting photographing light and
also thumbnail image data thereof, on which a program is recorded
and the program is capable of realizing: a data expanding function
for expanding compressed image data; a thumbnail enlarged image
display function for enlarging the thumbnail image data and for
displaying the enlarged thumbnail image data on a display unit;
a thumbnail image selecting function for feeding the enlarged thumbnail
image under display in fast-forward/fast-backward modes to select
a desirable thumbnail image; an image display function for displaying
the expanded image data corresponding to the selected thumbnail
image or the display unit; and a selection image defining function
for defining the displayed image as a selection image.
Since the program recorded on the recording medium according to
the eighth aspect of the present invention is executed, the enlarged
thumbnail image can be fed in the fast-forward/fast-backward operations.
BRIEF DESCRIPTION OF DRAWINGS
FIGS. 1(a) and 1(b) is a block diagram for showing a structural
example of a digital camera equipped with a highspeed image selecting
function according to an embodiment of the present invention;
FIG. 2 is a block diagram for representing a structural example
of highspeed image selecting means;
FIGS. 3(a) and 3(b) show a rear surface portion of the digital
camera;
FIGS. 4(a) and 4(b) are explanatory diagrams for explaining a pixel
interpolation method (simple interpolation method);
FIG. 5 is a flow chart for describing an example of operation of
the highspeed image selecting means;
FIG. 6 is a flow chart for describing an example of operation of
the highspeed image selecting means; and
FIG. 7 is a flow chart for describing an example of operation of
the highspeed image selecting means.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIGS. 1(a) and 1(b) are block diagrams for representing a structural
example of a digital camera according to an embodiment of the present
invention.
In FIG. 1(a), a digital camera 100 is constructed of an optical
system made of a lens and a diaphragm, for entering reflection light
reflected from an imaging object onto a CCD 2; a CCD 2 for converting
the imaging light projected from the optical system 1 into an electric
signal; and an image data forming unit 3 for processing the electric
signal derived from the CCD 2 to be supplied as raster data (image
data) of multiple values (R, G, B) to a frame memory 12A. Furthermore,
the digital camera 100 is arranged by a control unit 4, an input
means 5, a moving picture display control unit 6, an image data
output unit 7, a recording medium control unit 8, a built-in recording
medium 9, an enlarged recording medium 10, an interface 11, an LED
lamp 15 functioning as a display means, and a liquid crystal display
16.
In this digital camera, the control unit 4 controls the executions
of the operation controls, the image processing operations, and
the image compressing/expanding process operations of the image
data forming unit 3, the moving picture display control unit 6,
the image data output unit 7, the recording medium control unit
8, and the highspeed image selecting means 60. The input means 5
is constituted by a button and a switch. The input means 5 inputs
an instruction made by a user by manipulating these button and switch,
and converts the instruction into a digital signal which will be
then supplied to the control unit 4.
The moving picture display control unit 6 outputs the image data
to the liquid crystal display 16 so as to display the moving picture.
In this embodiment, the image data stored in the frame memories
12A and 12B are displayed in a superimpose manner during the normal
display mode. Normally, it should be noted that the image data are
written into the frame memory 12A predetermined times, for example,
30 times, or 60 times per 1 second by the image data forming unit
3, and the image is displayed on the liquid crystal display 16 under
control of the moving picture display control unit 6 in synchronism
with the writing operation of the image data in the same phase.
In the case that a specific button is depressed while displaying
a moving picture to instruct an image recording operation, the image
data output unit 7 converts the R, G, B raster data saved in the
frame memory 12A into a luminance component Y, and color difference
components U and V. Also, the image data output unit 7 subjects
to these luminance/color difference components to the JPEG-compression,
and further executes a compression process operation for producing
a thumbnail image.
Upon receipt of the image data outputted from the image data output
unit 7, the recording medium control unit 8 controls a writing operation
such that JPEG-compressed image data (simply will be referred to
as "image data" hereinafter) and compressed image data
are written into a predetermined position of the built-in recording
medium 9, or the enlarged recording medium 10, and also controls
a reading operation of each of the recorded JPEG image data.
The built-in recording medium 9 and the enlarged recording medium
10 are provided to store thereinto the image data. A serial interface,
or a parallel interface 11 is employed to transmit/receive data
to/from an external apparatus. Also, the LED lamp 15 displays a
condition of a switch, and a functional specification. The liquid
crystal display 16 displays a photographed image, or an object to
be imaged.
Normally, the frame memory 12A is used as an image display memory
of the liquid crystal display 16. The image data is extended in
this frame memory 12A as a bit map image. The frame memory 12B is
employed as a menu display memory, if required. Then, when an image
is displayed on the liquid crystal display 16, the storage contents
of the frame memories 12A and 12B are displayed in a superimpose
manner, if required.
In this embodiment, the built-in recording medium 9 is constructed
of a 4 MB (Megabytes)-flash memory fixed inside the camera 100.
Not only the image data, but also other data such as a program are
stored into the built-in recording medium 9. In this embodiment,
as the enlarged storage medium 10, a 4 to 45 MB-memory card is utilized.
In this case, although a memory card interface (PCMCIA interface
or ATA interface: not shown) is employed, the present invention
is not limited thereto, but other card type memories such as a compact
flash (a trade mark of Sun Disk Inc.) may be utilized.
FIG. 1(b) represents an arrangement of the control unit 4. The
control unit 4 is arranged by a CPU 41, a RAM 42, and a ROM 43.
In this ROM 43, a program group has been previously stored, which
is required to execute a data process operation within the digital
camera 100, for example, the operation control of the digital camera
100, and the data compressing/expanding process operations.
Also, the digital camera 100 transmits the image data stored in
the built-in recording medium 9 via the interface 11 to an external
apparatus, for instance, a computer unit. The digital camera 100
communicates the image data via the modem 300. Furthermore, in such
a case that a printing image data forming process program group
is saved in the digital camera 100, printing image data is formed.
Then the printing image data may be directly transmitted to a printer
400 so as to print out the image.
FIG. 2 is a schematic block diagram for showing a structural example
of the highspeed image selecting means 60 which may constitute a
major portion of the digital camera according to the present invention.
The highspeed image selecting means 60 is constituted by a thumbnail
compression image data expanding means 61, a thumbnail image enlarging/displaying
means 62, a thumbnail image selecting means 63, a compression image
data expanding means 64, an image display means 65, and a selected
image defining means 66.
It should be understood that the high speed image selecting means
60 according to this embodiment is constituted by a software. Alternatively,
the highspeed image selecting means 60 formed in the software may
be arranged to be stored in the ROM 43. Otherwise, the highspeed
image selecting means 60 recorded on an external recording medium
as a software form may be acquired to be saved into the recording
medium 9. When the highspeed image selecting means 60 is executed,
this highspeed image selecting means 60 formed in the software may
be transferred to the RAM 42.
The thumbnail compression image data expanding means 61 cause the
thumbnail image data to be acquired into the RAM 42 so as to execute
the expanding process operation of the compressed thumbnail image
data, and then extends the expanded thumbnail image data into the
RAM 42. Since a pixel number of a thumbnail image is small, even
when all of the thumbnail images are expanded, a total time duration
to execute this expanding process thereof is extremely shorter than
the expanding time of the image data. It should also be noted that
in such an image process system that no compression process operation
is performed to the thumbnail image data, this thumbnail compression
image data expanding means 61 is no longer required.
The thumbnail image enlarging/displaying means 62 enlarges the
expanded thumbnail image data, and transfers the enlarged thumbnail
image data to the frame memory 12A so as to extend the enlarged
thumbnail image data as a picture image. Then, the thumbnail image
enlarging/displaying means 62 causes either an enlarged thumbnail
image 31 or an enlarged thumbnail image 35 to be displayed as an
enlarged image on the liquid crystal display 16 (FIG. 3(a) and FIG.
3(b)).
In this case, when a thumbnail image is simply enlarged to be displayed,
intervals among adjoining pixels become coarse, so that the overall
image is blurred. As a consequence, it is preferable to display
such a thumbnail image produced by interpolating an enlarged image
(see FIGS. 4(a) and 4(b)).
When the button provided near the liquid crystal display 16 is
manipulated by the user, the thumbnail image selecting means 63
judges the implication of this button manipulation, and scrolls
the enlarged thumbnail image 31 or 35 within the display screen
in order that a desirable image by the user is specified.
When the enlarged thumbnail image is displayed, the compression
image data expanding means 64 acquires image data corresponding
to this enlarged thumbnail image from the recording medium so as
to expand this acquired image data to thereby extend the expanded
image data.
The image display means 65 transfers the image data extended in
the RAM 42 to the frame memory 12A, and then extend this transferred
image data as a picture image to thereby display this picture image
on the liquid crystal display 16. As a result, the expanding process
operation of the image data is accomplished, which is specified
while the enlarged thumbnail image displayed in the above-described
manner is observed by the user. Then, the specified/expanded image
data is overwritten into the enlarged thumbnail data, so that clear
image data can be displayed.
When the button provided near the liquid crystal display 16 is
manipulated by the user, the selected image defining means 66 judges
the implication of this button manipulation, and will execute a
subsequent process operation when this button manipulation instructs
the definition of the selected image.
For the sake of an easy explanation, the thumbnail compression
image data expanding means 61 is separately provided with the compression
image data expanding means 64. However, since the image data to
be expanded are different from each other, both the thumbnail compression
image data expanding means 61 and the compression image data expanding
means 64 may be arranged to employ the same data expanding means,
for example, may be arranged as a subprogram.
Also, the above-described highspeed image selecting means 60 may
be employed so as to not only select the image in the digital camera,
but also select the image of the digital camera acquired by the
personal computer.
Now, a description will be made of a pixel interpolating method
that can be employed by the thumbnail image enlarging/displaying
means 62.
Typically, there are the linear interpolation method and the simple
interpolation method (FIGS. 4(a) and 4(b)) as a pixel interpolating
method. The present invention may employ any of these interpolation
methods.
In the linear interpolation method, a resolution conversion is
carried out by performing a linear interpolation between adjoining
two points, so that resolution with a predetermined level can be
maintained.
To the contrary, the simple interpolation method is such an interpolation
method that, as indicated in FIGS. 4(a) and 4(b), while positions
of original pixels A, B, C, and D after being enlarged are calculated,
assuming now that a magnification is selected to be "R"
and "S" (both R and S are positive integers), the original
pixels are copied (R-1) times along the X directions. After the
copying operations of the original pixels along the X direction
are accomplished, the original pixels are copied (S-1) times along
the Y direction to fill the intervals among these original pixels.
In other words, as shown in FIG. 4(a), while an origin is set as
the original pixel "A", if an image constituted by original
pixels A(0,0), B(0,1), C(1,0), and D(1,1,) located adjacent to each
other is first enlarged 4 times along the X direction, and then
is enlarged 5 times along the Y direction, then positions of the
original pixels A, B, C, and D after being enlarged become A(0,0),
B(0,5), C(4,0) and D(4,5) (see FIG. 4(b)). Then, the original pixels
A, B, C, and D are copied only 3 (=4-1) times along the X direction
so as to fill the intervals. When the copy operations of the original
pixels along the X direction are accomplished, the column is copied
only 4 (=5-1) times along the Y direction. As a result of this operation,
as represented in FIG. 4(b), the pixels enlarged by the magnification
of 4.times.5 are formed on the bit map.
In accordance with the linear interpolation method, gradation between
two points may be calculated, and gradation of an enlarged image
can be maintained at a certain level. As a consequence, the image
quality achieved by this linear interpolation method is better than
that achieved by another interpolation method. However, when the
linear interpolation calculation is performed by employing a computer,
a complex dividing calculation is required except for a specific
case, so that a lengthy processing time period is needed. To the
contrary, a processing time period by in the simple interpolation
method requires the shortest time. However, since the gradation
is not adjusted but also pixels are simply copied, the image quality
is coarse. The larger the enlargement ratio becomes, the lower the
quality of the enlarged image is rapidly decreased. Accordingly,
there is a limitation that the enlargement ratio by the simple interpolation
method is selected to be on the order of 4 times.
In accordance with this embodiment, the size of the screen of the
liquid crystal display 16 employed in the digital camera 100 is
limited, and is substantially equal to a size of a thumbnail image.times.4
times. As a consequence, there is no problem as to the image quality.
Moreover, since the interpolation speed achieved by this simple
interpolation method is faster than that of another interpolation
method, the enlarged thumbnail image is interpolated by employing
the simple interpolation method. It should be understood that when
a higher image quality of a displayed image is required, the linear
interpolation method is preferably employed.
FIG. 5 is a flow chart for indicating an example of operations
of the highspeed image selecting means. It is assumed that as an
initial condition, both the thumbnail image data and the image data
have been subjected to the JPEG-compression and the JPEG-compressed
image data have been recorded on the recording medium 9.
As indicated in FIG. 5, when either the button 19 or the button
20 is depressed to commence the highspeed image selection, the thumbnail
compression image data expanding means 61 acquires the thumbnail
image data into the RAM 42, and then expands the JPEG-compressed
thumbnail image data to extend the expanded thumbnail image data
into the RAM 42 (step S1). Subsequently, the thumbnail image emerging/displaying
means 62 sequentially gives index numbers to the expanded thumbnail
image (namely, image with image number 31 in FIG. 3(a)), and then
enlarges/interpolates the thumbnail image data with the index number
(namely, simple interpolation method in this embodiment). Thus,
the interpolated thumbnail image data is displayed as an enlarged
thumbnail image on the liquid crystal display 16 (step S2). Also,
when the user depresses the button 19 or the button 20, the highspeed
image selection process operation is returned to the step S1 (step
S3: YES).
While the button 20 (fast-forward button) provided near the liquid
crystal display 16 is continuously depressed by the user, the thumbnail
image selecting means 63 repeats the process operations defined
at the steps S1 and S2 to successively display the thumbnail images
on the liquid crystal display 16 (fast-forward) in the increment
order. Conversely when this button 20 is released by the user, the
display of this thumbnail image is stopped.
The button 19 is the fast-backward button. While this fast-backward
button 19 is continuously depressed by the user, the thumbnail image
selecting means 63 repeats the process operations defined at the
steps S1 and S2 to successively display the thumbnail images on
the liquid crystal display 16 (fast-backward) in the decrement order.
When this button 19 is released by the user, the display of this
thumbnail image is stopped.
When the image stop time duration has passed for a predetermined
time period (2 seconds in this embodiment), it is assumed that this
image is specified as the selected image. Then, the process operation
is advanced to the next step S4 (step S3 : NO).
At a step S4, when the enlarged thumbnail image is displayed, the
compression image data expanding means 64 acquires the image data
corresponding to this enlarged thumbnail image from the RAM 42 to
expand this acquired image data, and then extends the expanded image
data into this RAM 42. Subsequently, the image display means 65
transfers the image data extended in the RAM 42 to the frame memory
12A so as to be extended as the picture image. Then, the image display
means 65 overwrites this extended image data on the liquid crystal
display 16 (step S5).
When either the button 17 or the button 18 is depressed by the
user, the selected image defining means 66 executes the "next
process" (step S6: YES). When either the button 19 or the button
20 is depressed by the user, the process operation is returned to
the step S1 (step S7 : YES).
Alternatively, in such a case that even when a predetermined time
period (for example, 6 seconds) has passed, either the button 19
or the button 20 is not depressed at the step 6, the selected image
defining means 66 may be arranged to execute the "next process".
It should be understood that as the "next process" after
the image is selected by the highspeed image selecting means 60,
there are a preparation process operation and a printing image data
forming process operation. In this preparation process operation,
this image data is transmitted via the wireless line, or the wire
line. In this printing image data forming process operation, the
printing data is formed in order to directly print out the image
by the printer. These process operations may be executed by another
program separately introduced into the digital camera 100.
FIG. 6 is a flow chart for indicating an example of operations
of the highspeed image selecting means. It is assumed that as an
initial condition, both the thumbnail image data and the image data
have been JPEG-compressed and the JPEG-compressed image data have
been recorded on the recording medium 9.
In the example of FIG. 5, when the-fast-forward key button 20 and
the fast-backward key button 19 are depressed, the fast-forward
operation and the fast-backward operation are commenced. In this
example, the normal reproducing operation is carried out at the
first stage. When either the button 19 or the button 20 is continuously
depressed under a predetermined condition, the operation mode is
transferred to the highspeed image selection mode.
That is, when the normal reproducing operation is carried out (step
S11), if either the button 19 or the button 20 is depressed (step
S12: YES), then the compressed image data expanding means 64 acquires
one preceding image data, or one succeeding image data into the
RAM 42, and expands/extends these acquired image data. Subsequently,
the image display means 65 transfers the image data extended in
the RAM 42 to the frame memory 12A so as to extend this image data
as a picture image which is displayed on the liquid crystal display
16 (step S13).
In this case, if the same button is depressed at the time when
the image reproducing operation is completed (step S14 : YES), the
process operation is advanced to the highspeed image selection mode.
The thumbnail compression image data expanding means 61 acquires
thumbnail image data corresponding to one preceding image data,
or the one succeeding image data into the RAM 42, and then expands
the JPEG-compressed thumbnail image data to extend the expanded
thumbnail image data into the RAM 42. Subsequently, the thumbnail
image enlarging/displaying means 62 enlarges/interpolates the expanded
thumbnail image data (namely, simple interpolation method in this
embodiment). Thus, the interpolated thumbnail image data is displayed
as an enlarged thumbnail image on the liquid crystal display 16
(step S15).
In such a case that the button is further continuously depressed
when this display of the enlarged thumbnail image is completed (step
S16: YES), the process operation is returned to the step S14 at
which one preceding thumbnail image, or one succeeding thumbnail
image is enlarged to be displayed. While the button is continuously
depressed, this process operation is repeatedly carried out, so
that the highspeed image selection can be realized.
On the other hand, when depressing of the button is stopped (step
S16: NO), the enlarged thumbnail image is displayed, the compression
image data expanding means 64 acquires the image data corresponding
to the thumbnail image under display from the RAM 42 to expand this
acquired image data, and then extends the expanded image data into
this RAM 42. Subsequently, the image display means 65 transfers
the image data extended in the RAM 42 to the frame memory 12A so
as to be extended as the picture image. Then, the image display
means 65 overwrites this extended image data on the liquid crystal
display 16 (step S17). Then, the process operation is returned to
the step S12.
While the operations of the highspeed image selection process have
been described, switching of the normal reproduction operation and
the highspeed selection reproduction operation may be executed by
manipulating a predetermined switch, otherwise by any other manners.
FIG. 7 is a flow chart for indicating an example of operations
of the highspeed image selecting means. It is assumed that as an
initial condition, both the thumbnail image data and the image data
have been JPEG-compressed and the JPEG-compressed image data have
been recorded on the recording medium 9.
In the example of FIG. 6, when the fast-forward/fast-backward key
buttons 19/20 are continuously depressed under a predetermined condition,
the process operation is advanced to the highspeed selection mode.
In this example, when either the button 19, or the button 20 is
firstly depressed from the normal reproducing condition, the normal
reproducing operation is carried out. The process operation is advanced
to the highspeed selection mode after the second process operation.
In other words, when the normal reproducing operation is executed
(step S21), a check is made as to whether or not a selection key
of a menu is depressed (step S22). When the selection key is not
depressed (step S22 : YES), after a menu process is executed (step
S23), the process operation is returned to the step S22. On the
other hand, when the button 19, or the button 20 is depressed (step
S24: YES) while the selection key is not depressed (step S22 NO),
since the first button manipulation is executed, the compressed
image data expanding means 64 acquires one preceding image data,
or one succeeding image data into the RAM 42, and expands/extends
these acquired image data. Subsequently, the image display means
65 transfers the image data extended in the RAM 42 to the frame
memory 12A so as to extend this image data as a picture image which
is displayed on the liquid crystal display 16 (step S25).
Next, in such a case that either the button 19 or the button 20
is not depressed for a predetermined time period, e.g., 1 second
or 2 second (step S26: NO, step S27: YES), the process operation
is returned to the step S22. Conversely, when either the button
19 or the button 20 is depressed within a predetermined time period
(step S26: YES), since this is the second key manipulation, the
process operation is advanced to the highspeed image selection mode.
The thumbnail compression image data expanding means 61 acquires
thumbnail image data corresponding to one preceding image data,
or the one succeeding image data into the RAM 42, the thumbnail
image data into the RAM 42, and then expands the JPEG-compressed
thumbnail image data to extend the expanded thumbnail image data
into the RAM 42. Subsequently, the thumbnail image enlarging/displaying
means 62 enlarges/interpolates the thumbnail image data (namely,
simple interpolation method in this embodiment). Thus, the interpolated
thumbnail image data is displayed as an enlarged thumbnail image
on the liquid crystal display 16 (step S28).
After the display of this enlarged thumbnail image is accomplished,
if the button is not depressed within a predetermined time period,
for example, 1 second, or 2 seconds (step S29 : YES), then the process
operation is returned to the step S28 at which either one preceding
thumbnail image or one succeeding thumbnail image is enlarged to
be displayed. When the button is continuously depressed within a
predetermined time period, this process operation is repeatedly
performed, so that the highspeed image selection can be realized.
On the other hand, when the button is not depressed for predetermined
time period (step S19: NO, step S30: YES), the compression image
data expanding means 64 acquires the image data corresponding to
this enlarged thumbnail image from the RAM 42 to expand this acquired
image data, and then extends the expanded image data into this RAM
42. Subsequently, the image display means 65 transfers the image
data extended in the RAM 42 to the frame memory 12A so as to be
extended as the picture image. Then, the image display means 65
overwrites this extended image data on the liquid crystal display
16 (step S31). Then, the process operation is returned to the step
S22.
In FIG. 7, when the fast-forward/fast-backward keys are depressed
after the normal image reproducing operation, the operation mode
is advanced to the highspeed selection mode after the second key
operation. Alternatively, a predetermined flag may be set by executing
the first key operation during the first process operation and the
second process operation, so that the first and second process operations
can be discriminated from the process operations subsequent to the
second process operation. Also, the operation mode is forcibly advanced
to the highspeed selection mode when the second process operation
is carried out. Alternatively, after the first key manipulation,
when a predetermined time period (for example, 1 to 3 seconds) has
passed, it may be judged that the first key manipulation is again
carried out.
While the operations of the highspeed image selection process have
been described, switching of the normal reproduction operation and
the highspeed selection reproduction operation may be executed by
manipulating a predetermined switch, otherwise by any other manners.
Although the various embodiments of the present invention have
been described, the present invention is not limited to the above-explained
embodiments, but may be modified, substituted, or changed.
As previously described in detail, according to the present invention,
the thumbnail images are enlarged to be displayed so as to select
a desirable image. While this desirable thumbnail image is displayed
in the enlarge form, the image data corresponding to this thumbnail
image is expand-processed, and thus the clear image can be displayed.
As a consequence, even when a predetermined time duration is required
to expand the JPEG-compressed image of 1 frame, the user does not
have lengthy time feelings of the image display. Also, since the
thumbnail image can be fed in the fast-forward/fast-backward modes,
the desirable image which is recorded on the recording medium in
the later order can be selected within a short time period.
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