U.S. patent application number 09/064125 was filed with the patent office on 2001-11-22 for data transmission with receiver side control.
Invention is credited to HIEDA, TERUO.
Application Number | 20010043744 09/064125 |
Document ID | / |
Family ID | 14516548 |
Filed Date | 2001-11-22 |
United States Patent
Application |
20010043744 |
Kind Code |
A1 |
HIEDA, TERUO |
November 22, 2001 |
DATA TRANSMISSION WITH RECEIVER SIDE CONTROL
Abstract
This invention provides communication method, communication
device, transmitting device, receiving device, communication
system, and memory medium which can take high quality pictures and
communicate efficiently. According to one aspect, this invention is
a communication method for supplying moving picture data sent from
a transmitter to a receiver side through a transmission channel,
characterized by the transmitter sends moving picture data of a
predetermined resolution and/or frame rate based on an instruction
from the receiver.
Inventors: |
HIEDA, TERUO; (YOKOHMA-SHI,
JP) |
Correspondence
Address: |
FITZPATRICK CELLA HARPER & SCINTO
30 ROCKEFELLER PLAZA
NEW YORK
NY
10112
US
|
Family ID: |
14516548 |
Appl. No.: |
09/064125 |
Filed: |
April 22, 1998 |
Current U.S.
Class: |
382/232 ;
375/E7.013 |
Current CPC
Class: |
H04N 21/2662 20130101;
H04N 21/25808 20130101; H04N 21/6373 20130101; H04N 21/440227
20130101; H04N 21/234363 20130101; H04N 21/234327 20130101; H04N
21/84 20130101 |
Class at
Publication: |
382/232 |
International
Class: |
G06K 009/36; G06K
009/46 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 25, 1997 |
JP |
109683/1997 |
Claims
What is claimed is:
1. Communication method for supplying moving picture data sent from
a transmitter to a receiver through a transmission channel,
comprising: receiving an instruction at the transmitter from the
receiver concerning frame rate of the moving picture data; and
sending the moving picture data from the transmitter to the
receiver at a frame rate based on the instruction from said
receiver.
2. Communication method according to claim 1, wherein the
transmitted image data is formatted hierarchically.
3. Communication method according to claim 2, wherein said
transmitter transmits a part of the hierarchical moving picture
data which includes a layer corresponding to the instruction from
said receiver.
4. Communication method according to claim 1, wherein said
transmitter transmits the moving picture data obtained from an
object.
5. Communication method according to claim 1, wherein said
transmitter transmits a sequence of moving picture data, of an
identity which is based on the instruction from said receiver, from
among plural sequences of moving picture data.
6. Communication method according to claim 1, wherein said receiver
displays an image based on the moving picture data from said
transmitter.
7. Communication method for supplying moving picture data to a
receiver through a transmission channel, comprising: receiving an
instruction from the receiver concerning frame rate of the moving
picture data; and sending the moving picture data to the receiver
at a frame rate based on the instruction from said receiver.
8. Communication method according to claim 7, wherein the
transmitted image data is formatted hierarchically.
9. Communication method according to claim 8, wherein a part of the
hierarchical moving picture data includes a layer corresponding to
the instruction from said receiver.
10. Communication method according to claim 7, wherein said
transmitter transmits the moving picture data obtained from an
object.
11. Communication method according to claim 7, wherein the moving
picture data is selected, based on the instruction from said
receiver, from among plural sequences of moving picture data.
12. Communication method according to claim 7, wherein said
receiver displays an image based on the moving picture data from
said transmitter.
13. Communication method for receiving moving picture data from a
transmitter to a receiver through a transmission channel,
comprising: sending an instruction to the transmitter concerning
frame rate of the moving picture data; and receiving the moving
picture data from the transmitter at a frame rate based on the
instruction.
14. Communication method according to claim 13, wherein the
transmitted image data is formatted hierarchically.
15. Communication method according to claim 14, wherein said
transmitter transmits a part of the hierarchical moving picture
data which includes a layer corresponding to the instruction.
16. Communication method according to claim 13, wherein said
transmitter transmits the moving picture data obtained from an
object.
17. Communication method according to claim 13, wherein said
transmitter transmits the moving picture data, of which kind is
based on the instruction from said receiver, from among plural
sequences of moving picture data.
18. Communication method according to claim 13, wherein an image is
displayed based on the moving picture data from said
transmitter.
19. Communication method for supplying moving picture data sent
from a transmitter to a receiver side through a transmission
channel, characterized by said transmitter sends moving picture
data of a predetermined frame rate based on the instruction from
said receiver.
20. Communication method according to claim 19, wherein said
transmitter transmits a part of the hierarchical moving picture
data which includes a layer corresponding to the instruction from
said receiver.
21. Communication method according to claim 19, wherein said
receiver instructs the resolution or frame rate to said
transmitter.
22. Communication method according to claim 19, wherein said
transmitter transmits the moving picture data obtained from an
object.
23. Communication method according to claim 19, wherein said
transmitter transmits the moving picture data, of which kind is
based on the instruction from said receiver, from among plural
sequences of moving picture data.
24. Communication method according to claim 19, wherein said
receiver displays an image based on the moving picture data from
said transmitter.
25. Communication method between a transmitter which produces
digital moving picture data and a receiver which receives digital
moving picture data through a network and displays, notifying the
resolution or frame rate, which is set at said receiver, to said
transmitter; and supplying the moving picture data having the
predetermined resolution and frame rate to said receiver by said
transmitter, the moving picture data is obtained from hierarchical
data based on the notification.
26. Communication method between a transmitter which produces
digital moving picture data and a receiver which receives digital
moving picture data through a network and displays, notifying the
frame rate, which is set at said receiver, to said transmitter; and
supplying the moving picture data having the predetermined frame
rate to said receiver by said transmitter side, the moving picture
data is obtained based on the notification.
27. Communication apparatus which supplies moving picture data sent
from transmitting means to receiving means through a transmission
channel, comprising: wherein said transmitting means includes
obtaining means for obtaining moving picture data; and sending
means for sending the moving picture data obtained by said
obtaining to a transmission channel, and wherein said sending means
sends the moving picture data of a predetermined resolution or
frame rate obtained from hierarchical data based on the instruction
from said receiving means.
28. Communication apparatus according to claim 27, wherein said
sending means includes producing means for producing hierarchical
data based on the moving picture data obtained by said obtaining
means, and wherein said sending means sends a part of the
hierarchical data which includes a layer corresponding to the
instruction from said receiving means.
29. Communication method according to claim 27, wherein said
receiving means includes input means for inputting a resolution or
frame rate and said receiving means instructs the resolution or
frame rate to said sending means.
30. Communication method according to claim 27, wherein said
obtaining means includes image capturing means for taking pictures
of an object and generates moving picture data.
31. Communication method according to claim 27, wherein said
obtaining means includes memory means for storing plural sequences
of moving picture data, and said sending means sends a selected
sequence of moving picture data based on the instruction of said
receiving means from among the plural sequences of moving picture
data stored in said memory means.
32. Communication method according to claim 27, wherein said
receiving means includes means for displaying an image based on the
moving picture data from said transmitting means.
33. Communication apparatus which supplies moving picture data sent
from transmitting means to receiving means through a transmission
channel, comprising: wherein said transmitting means includes
obtaining means for obtaining moving picture data; and sending
means for sending the moving picture data obtained by said
obtaining to a transmission channel, and wherein said sending means
sends the moving picture data of a predetermined frame rate which
is based on the instruction from said receiving means.
34. Communication apparatus according to claim 33, wherein said
sending means includes producing means for producing hierarchical
data based on the moving picture data obtained by said obtaining
means, and wherein said sending means sends a part of the
hierarchical data which includes a layer corresponding to the
instruction from said receiving means.
35. Communication method according to claim 33, wherein said
receiving means includes input means for inputting a resolution or
frame rate and said receiving means instructs the resolution or
frame rate to said sending means.
36. Communication method according to claim 33, wherein said
obtaining means includes image capturing means for taking pictures
of an object and generates moving picture data.
37. Communication method according to claim 33, wherein said
obtaining means includes memory means for storing plural sequences
of moving picture data, and said sending means sends a selected
sequence of moving picture data based on the instruction of said
receiving means from among the plural sequences of moving picture
data stored in said memory means.
38. Communication method according to claim 33, wherein said
receiving means includes means for displaying an image based on the
moving picture data from said transmitting means.
39. Communication apparatus which includes transmitting means for
generating digital moving picture data and receiving means for
displaying an image based on the digital moving picture data
through a transmission channel, wherein said receiving means
notifies the resolution or frame rate, which is set, to said
transmitting means, and said transmitting means supplies, to said
receiving means, the digital moving picture data of a predetermined
resolution or frame rate obtained from hierarchical data based on
the instruction from said receiving means.
40. Communication apparatus which includes transmitting means for
generating digital moving picture data and receiving means for
displaying an image based on the digital moving picture data
through a transmission channel, wherein said receiving means
notifies the frame rate, which is set, to said transmitting means,
and said transmitting means supplies, to said receiving means, the
digital moving picture data of a predetermined frame rate obtained
from hierarchical data based on the instruction from said receiving
means.
41. Transmitting apparatus which sends moving picture data to sent
to a transmission channel, comprising: obtaining means for
obtaining moving picture data; and sending means for sending the
moving picture data to the transmission channel, wherein said
sending means sends the moving picture data of a predetermined
resolution or frame rate obtained from hierarchical data based on
the instruction supplied through the transmission channel.
42. Transmitting apparatus according to claim 41, wherein said
sending means includes producing means for producing hierarchical
data based on the moving picture data obtained by said obtaining
means, and wherein said sending means sends a part of the
hierarchical data which includes a layer corresponding to the
instruction.
43. Transmitting apparatus according to claim 41, wherein said
obtaining means includes image capturing means for taking pictures
of an object and generates the moving picture data.
44. Transmitting apparatus according to claim 41, wherein said
obtaining means includes memory means for storing plural sequences
of moving picture data, and said sending means sends a selected
sequence of moving picture data based on the instruction from among
plural sequences of moving picture data stored in said memory
means.
45. Transmitting apparatus which sends moving picture data to sent
to a transmission channel, comprising: obtaining means for
obtaining moving picture data; and sending means for sending the
moving picture data to the transmission channel, wherein said
sending means sends the moving picture data of a predetermined
frame rate based on the instruction supplied through the
transmission channel.
46. Transmitting apparatus according to claim 45, wherein said
sending means includes producing means for producing hierarchical
data based on the moving picture data obtained by said obtaining
means, and wherein said sending means sends a part of the
hierarchical data which includes a layer corresponding to the
instruction.
47. Transmitting apparatus according to claim 45, wherein said
obtaining means includes image capturing means for taking pictures
of an object and generates the moving picture data.
48. Transmitting apparatus according to claim 45, wherein said
obtaining means includes memory means for storing plural sequences
of moving picture data, and said sending means sends a selected
sequence of moving picture data based on the instruction from among
the plural sequences of moving picture data stored in said memory
means.
49. Receiving apparatus which receives moving picture data from a
transmitter through a transmission channel, comprising; instructing
means for instructing a resolution or a frame rate to said
transmitter; and receiving means for receiving the moving picture
data of a predetermined resolution or frame rate obtained from
hierarchical data based on the instruction by said instructing
means.
50. Receiving apparatus according to claim 49, wherein said
receiving means a part of the hierarchical data which includes a
layer corresponding to the instruction by said instructing
means.
51. Receiving apparatus according to claim 49, further comprising
input means for inputting a resolution or a frame rate, wherein
said instructing means instructs the resolution or frame rate input
by input means to said transmitter.
52. Receiving apparatus according to claim 49, wherein said
receiving means receives the moving picture data obtained by taking
pictures of an object.
53. Receiving apparatus according to claim 49, wherein said
receiving means receives a selected sequence of moving picture data
based on the instruction of said receiving means from among the
plural sequences of moving picture data.
54. Receiving apparatus according to claim 49, further comprising
means for displaying an image based on the received moving picture
data.
55. Receiving apparatus which receives moving picture data from a
transmitter through a transmission channel, comprising: instructing
means for instructing a frame rate to said transmitter; and
receiving means for receiving the moving picture data of a
predetermined frame rate based on the instruction by said
instructing means.
56. Receiving apparatus according to claim 55, wherein said
receiving means a part of the hierarchical data which includes a
layer corresponding to the instruction by said instructing
means.
57. Receiving apparatus according to claim 55, further comprising
input means for inputting a resolution or a frame rate, wherein
said instructing means instructs the resolution or frame rate input
by input means to said transmitter.
58. Receiving apparatus according to claim 55, wherein said
receiving means receives the moving picture data obtained by taking
pictures of an object.
59. Receiving apparatus according to claim 56, wherein said
receiving means receives a selected sequence of moving picture data
based on the instruction of said receiving means from among the
plural sequences of moving picture data.
60. Receiving apparatus according to claim 56, further comprising
means for displaying an image based on the received moving picture
data.
61. A computer-executable program product stored on a computer
readable medium, the computer-executable program product for
supplying moving picture data sent from a transmitter to a receiver
through a transmission channel, said computer program product
including: computer readable program code means to receive an
instruction at the transmitter from the receiver concerning frame
rate of the moving picture data; and computer readable program code
means to send the moving picture data from the transmitter to the
receiver at a frame rate based on the instruction from said.
62. A computer-executable program product stored on a computer
readable medium, the computer-executable program product for
supplying moving picture data to a receiver through a transmission
channel, said computer program product including: computer readable
program code means to receive an instruction from the receiver
concerning frame rate of the moving picture data; and computer
readable program code means to send the moving picture data to the
receiver at a frame rate based on the instruction from said
receiver.
63. A computer-executable program product stored on a computer
readable medium, the computer-executable program product for
receiving moving picture data from a transmitter to a receiver
through a transmission channel, said computer program product
including: computer readable program code means to send an
instruction to the transmitter concerning frame rate of the moving
picture data; and computer readable program code means to receive
the moving picture data from the transmitter at a frame rate based
on the instruction.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to communication method,
communication apparatus, transmitting apparatus, receiving
apparatus, communication system, and memory medium. For example,
this invention relates to communicating moving picture data through
a transmission channel.
[0003] 2. Description of the Related Art
[0004] In recent years, with the spread of personal computers, the
use of network, internet and modem communications has increased
dramatically, for transmitting various kinds of information.
[0005] For example, it is possible for pictures obtained by
video-cameras to be supplied to personal computers and stored as
moving picture data. Further, making use of communication software,
the moving picture data may be sent to other personal computers and
host computers through a network, such as Ethernet or other
transmission channel such as by modems.
[0006] There are difficulties, however, when the above-mentioned
image data is transmitted by known communication methods.
[0007] First, a bit rate of transmission is very high when moving
picture is sent from video-cameras to personal computers, owing to
the large amount of data for moving pictures.
[0008] For example, consider a case where a single frame of a
moving picture has 640 pixels in a horizontal direction and 480
pixels in a vertical direction and has 8 bits for each of R, G, B.
If the moving picture is transmitted at the rate of 30 frames per
second, the transmission bit rate is
640.times.480.times.30.times.3.times.8=221184000 bit. That is about
220 M bit/s.
[0009] When a moving picture data of such a high bit rate is
transmitted, the loads at the sender side, the transmission
channel, and the receiver side become very large. Therefore, in the
prior art, when moving picture data is transmitted, transmission
capability (bandwidth) of the transmission channel is monopolized
by the transmission. Then the number of communications which can
occur over the channel at the same time decreases. Other
communications are also impeded.
[0010] Also, at the receiver side, the personal computer uses most
of its capabilities in order to receive the moving picture data,
and can not conduct other calculations. Particularly, in order to
confirm the received moving picture data, sometimes it is reduced
and displayed. According to the prior art, even for confirmation by
display on a monitor, the whole moving picture data is transmitted
and the load of the receiver side remains heavy.
[0011] In order to solve the above-mentioned problem, there are
known communication methods which compress the picture, reduce the
resolution and/or reduce the frame rate. However, according to
these methods, if the received picture is enlarged for display at
the receiver side, the picture quality is not good.
SUMMARY OF THE INVENTION
[0012] Therefore, this invention was made in order to address the
above-mentioned shortcomings, and its purpose is to provide
communication method, communication device, transmitting device,
receiving device, communication system, and memory medium which can
take high quality pictures and communicate efficiently.
[0013] Especially, it is an object of the present invention to
provide an efficient transmission of moving picture data.
[0014] In one aspect, the present invention involves communication
in which moving picture data is sent from a transmitter to a
receiver side through a transmission channel, characterized by the
transmitter side sending the moving picture data at a resolution
and/or frame rate determined based on an instruction from the
receiver side. Preferably, the image data is arranged
hierarchically, and is transmitted at a level in the hierarchy
determined based on the instruction.
[0015] More concretely, the communication between a transmitter
side which produces digital moving picture data and a receiving
side which receives digital moving picture data through a
transmission channel and displays an image based on the data,
involves notification of the resolution or frame rate, which is set
at the receiving side, to the transmitter side; and supply of the
moving picture data to the receiver side by the transmitter side.
The resolution and frame rate of the moving picture data is
obtained from hierarchically arranged image data based on the
notification. Preferably, the transmitter side transmits a part of
the hierarchical moving picture data which includes a layer
corresponding to the notification instruction from said receiver
side. The receiver side may instruct either the resolution or frame
rate, or both, to the transmitter side. The transmitter side
transmits the moving picture data obtained from an object. The
transmitter side may also transmit moving picture data of a kind
selected from among plural kinds based on the instruction from the
receiver side. At the receiver side, an image is displayed based on
the moving picture data from the transmitter side.
[0016] In another aspect, the present invention involves
communication of moving picture data sent from a transmitter to a
receiver side through a transmission channel, characterized by the
transmitter side sending the moving picture data at a frame rate
determined based on an instruction from the receiver side.
[0017] More concretely, the communication between a transmitter
side which produces digital moving picture data and a receiving
side which receives digital moving picture data through a
transmission channel and displays an image based on the data,
involves notification of the frame rate, which is set at said
receiving side, to the transmitter side; and supply of the moving
picture data to the receiver side by the transmitter side. The
frame rate of the moving picture data is obtained based on the
notification. The moving picture data is preferably arranged
hierarchically. Preferably, the transmitter side transmits a part
of the hierarchical moving picture data which includes a layer
corresponding to the notification instruction from the receiver
side. The receiver side may instruct either the resolution or frame
rate, or both, to the transmitter side. The transmitter side
transmits the moving picture data obtained from an object. The
transmitter side may also transmit a sequence of the moving picture
data whose identity is selected from among plural different
sequences based on the instruction from the receiver side. At the
receiver side an image is displayed based on the moving picture
data from the transmitter side.
[0018] The present invention can be applied to a transmitter side
only and also a receiver side only.
[0019] This summary has been provided so that the nature of the
invention may be understood quickly. A more complete understanding
of the invention can be obtained by reference to the followed
detailed description of the preferred embodiments thereof in
connection with the attached Figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 shows a block diagram of the structure of a
communication system according to one embodiment of the present
invention.
[0021] FIG. 2 shows a block diagram of the structure of a
video-camera included in the communication system.
[0022] FIG. 3 shows one example of hierarchical data produced by a
hierarchical data producing circuit included in the communication
system.
[0023] FIG. 4 is a flow-chart for explaining the operation of the
communication system.
[0024] FIG. 5 shows a block diagram of the structure of a
communication system according to another embodiment of the present
invention.
[0025] FIG. 6 is a flow-chart for explaining the operation of the
communication system shown in FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] (First Embodiment)
[0027] FIG. 1 shows a communication system 100 embodying the
present invention.
[0028] Communication system 100 includes a sending apparatus
comprised by video-camera 110 having a network communication
function. Four personal computers 120, 130, 140, 150 each having a
network communication function are receiving apparatuses.
Video-camera 110 and four personal computers 120, 130, 140, 150 are
connected to each other by network 160 which constitutes a
transmission channel.
[0029] FIG. 2 is a block diagram showing the construction of video
camera 110. As shown in FIG. 2, video-camera 110 includes lens 111,
which is part of an optical system for image capture, image
capturing device 112, to which the light from lens 111 is focused,
signal processing circuit 113, to which the output of image
capturing device 112 is supplied, hierarchical data producing
circuit 114, to which the output of signal processing circuit 113
is supplied, memory 115, to which the output of hierarchical data
producing circuit 114 is supplied, control circuit 116, to which
the output of memory 115 is supplied, network interface circuit
118, which is connected to control circuit 116, and network
connecting terminal 119, which is connected to network interface
circuit 118. Video-camera 110 is connected to network 160 in FIG. 1
via connecting terminal 119.
[0030] Each computer 120.about.150 has a different function, for
example, different data process ability, different display
resolution or different image display ability.
[0031] First, a sequence of operation of communication system 100
will be explained as follows.
[0032] In video-camera 110, a light from an object, not shown in
the figure, is focused to image capturing device 112 through lens
111. Image capturing device 112 comprises, for example, a CCD
(charge coupled device), which generates video signals by
photo-electrically converting the light from lens 111 and supplies
the video signals to signal processing circuit 113. Signal
processing circuit 113 performs a predetermined process on the
video signals from image capturing device 112, generates moving
picture signals and supplies the moving picture signals to
hierarchical data producing circuit 114. Hierarchical data
producing circuit 114 converts the moving picture signals from
signal processing circuit 113 into image data hierarchically
structured both in pixel number dimension and in time-axis
dimension (herein after "hierarchical data"). The image data is
temporarily stored in memory 115. Control circuit 116 communicates
with each computer 120.about.150, which is connected to network
160, through network interface circuit 118 and network connecting
terminal 119 by using commands.
[0033] Further, control circuit 116 sends the image data stored in
memory 115 to each computer 120.about.150 through network interface
circuit 118 and network connecting terminal 119. In this case,
control circuit 116 does not send all image data stored in memory
115, but only a part of the image data, which corresponds to the
requested resolution and frame rate, based on the commands from
each computer 120.about.150. Accordingly, the image data, which
corresponds to the requested resolution and frame rate, is supplied
to each computer 120.about.150 based on the commands from them
through network 160.
[0034] Computer 120.about.150 stores the supplied image data or
displays an image based on the image data.
[0035] Next, the hierarchical data, which is generated by
hierarchical data producing circuit 114 and stored in memory 115,
will be explained in detail.
[0036] Consider four frames (frame 1 to 4) of moving picture
signals supplied to hierarchical data producing circuit 114 from
signal processing circuit 113. Hierarchical data producing circuit
114 produces, from the supplied moving picture signals of four
frames, digital image data D1 (composed of data D1-1, D1-2, D1-3),
digital image data D2 (composed of data D2-1, D2-2, D2-3), digital
image data D3 (composed of data D3-1, D3-2, D3-3), and digital
image data D4 (composed of data D4-1, D4-2, D4-3) as shown in FIG.
3.
[0037] Image data D1 represents frame 1, which may be a starting
frame or reset frame of the moving picture. Image data D2
represents frame 2, which is a next successive frame of frame 1.
Image data D3 represents frame 3, which is a next successive frame
of frame 2. Image data D4 represents frame 4, which is a next
successive frame of frame 3.
[0038] Image data D1 includes the entirety of information of frame
1, in compressed or uncompressed format. However, image data D2
only includes information of the difference between frame 1 and
frame 2. Likewise, image data D3 only includes information of the
difference between frame 2 and frame 3, and image data D4 only
includes information of the difference between frame 3 and frame
4.
[0039] In image data D1, data D1-1 represents the lowest resolution
image, which includes least number of pixels. Data D1-2 represents
a middle resolution image, and is stored as difference data between
data D1-1 and data representing a middle resolution image which
includes more pixels than the lowest resolution image. The
difference data is obtained by removing data D1-1 from the data
representing the middle image. Data D1-3 represents a higher
resolution image, and is stored as difference data which is
obtained by removing the data D1-1 and D1-2 from data representing
a higher resolution image which includes more pixels than the
middle resolution image.
[0040] Image data D2.about.D4, as well as image data D1,
respectively include three resolution image data, such as data
Dx-1, Dx-2, Dx-3. The hierarchical image data D1.about.D4 are
stored in memory 115.
[0041] In this embodiment, there are three layers of resolutions.
However, the number of layers is not limited to three. It can be
determined in accordance with the process ability or necessity of
the system. Preferably, it is within 2 layers .about.10 layers. For
example, in a case where the lowest resolution is 16 pixel.times.16
pixel, which is usually used for an icon display by a personal
computer, the other resolutions can be 80 pixel.times.60 pixel, 160
pixel.times.120 pixel, 240 pixel.times.180 pixel, 320
pixel.times.240 pixel, 640 pixel.times.480 pixel.
[0042] In this example, the number of frames is four (frame
1.about.frame 4) and the hierarchical image data to be produced are
D1.about.D4. However, the number of frames are not limited to this
embodiment. It can be determined in accordance with the process
ability or necessity of the system. Preferably, it is within 4
frames.about.30 frames per second. In that case, even if the number
of frames are different, the structure of data representing whole
one frame is similar to D1-1, D1-2, D1-3. Difference data which is
similar to D2-1, D2-2, D2-3 succeeds D1-1, D1-2, D1-3. Difference
data Dn-1, Dn-2, Dn-3 (n: maximum frame number) succeeds D2-1,
D2-2, D2-3.
[0043] Next, the operational timing of video-camera and computer
120.about.150 will be explained in detail.
[0044] A memory medium comprised by a program memory is provided
for each of computers 120.about.150, one of which is shown at 220
in FIG. 1 for computer 120, to store a communication program. Each
computer is arranged to communicate with video-camera 110 by
reading-out the communication program from its respective program
memory and executing it.
[0045] Likewise, program memory 210 is connected to control circuit
116 and is included in video-camera 110 as shown in FIG. 2. Control
circuit 116 is arranged to communicate with video-camera 110 and
computers 120.about.150 by reading-out the communication program
from program memory 210 and executing it.
[0046] Process steps executed by the communication program executed
in video-camera 110 are shown in FIG. 4(a). Process steps executed
by the communication programs executed in computers 120.about.150
are shown in FIG. 4(b).
[0047] In this embodiment, program memory 210 is provided inside of
video-camera 110. However, it can be connected from outside as an
external memory apparatus. Likewise, program memory 220 can be
located inside or outside of computer 120.
[0048] In FIG. 4, a solid line expresses a flow of control, and a
dotted line expresses a flow of commands and data in network
160.
[0049] Briefly, the process steps in FIG. 4 for computer 120
operate to send an instruction to video-camera 110 concerning
resolution and/or frame rate of the moving picture data and to
receive the moving picture data from video-camera at a resolution
and/or frame rate based on the instruction. For video-camera 110,
the process steps operate to receive an instruction from computer
120 concerning resolution and/or frame rate of the moving picture
data and to send the moving picture data to computer 120 at a
resolution and/or frame rate based on the instruction from computer
120. Overall, the process operate to receive an instruction at the
transmitter from the receiver concerning resolution and/or frame
rate of the moving picture data to send the moving picture data
from the transmitter to the receiver at a resolution and/or frame
rate based on the instruction from the receiver.
[0050] In more detail, in step S211, video-camera 110 waits for a
communication request. Flow remains at step S211 until control
circuit 102 receives the communication request.
[0051] In step S221, one of the computers, for example, computer
120, sends a communication request through network 160 to
video-camera 110. Control circuit 116 in video-camera 110 responds
in step S212 by sending an allowance of communication through
network 160 to computer 120.
[0052] Upon receipt of the allowance of communication message from
video-camera 110, computer 120 sends an image data request through
network 160 to video-camera 110 (step S222).
[0053] Next, control circuit 116 in video-camera 110 sends an
inquiry of resolution and frame rate through network 160 to
computer 120 in response to the image data request (step S213).
Computer 120 responds by sending its desire for frame rate and
resolution through network 160 to video-camera 110 (step S223).
[0054] Computer 120 can obtain its desire for frame rate and
resolution automatically such as with default values, but more
preferably, the frame rate and/or resolution are obtained manually,
with operator interaction. For example, computer 120 can display a
message for instructing a user to input information such as a size
of a display area, setting values in response to the inquiry from
video-camera 110. In response to the message, the user can input
information such as the size of the display area, setting values by
operating a mouse or a key board. For example, a size of the
display area for displaying moving pictures can be input. Computer
120 sends the answer for the resolution and the frame rate through
network 160 to video-camera 110 based on the operation of the
user.
[0055] Next, control circuit 116 in video-camera 110 sets the
nearest resolution and frame rate to the answer from computer 120
(step S214). Concretely, for example, values of a plurality of
combinations of resolutions and frame rates are stored in memory
115 in advance, in correspondence with the hierarchical data shown
in FIG. 3. Accordingly, control circuit 116 selects and sets the
setting values of the nearest resolution and frame rate to the
answer from computer 120 from among the plurality of
combinations.
[0056] Control circuit 116 reads out only the image data
corresponding to the set resolution and frame rate from among the
image data stored in memory 115 and sends it through network 160 to
computer 120 (step S215). Accordingly, computer 120 receives the
image data sent by video-camera 110 and displays an image based on
the received image data (step S224).
[0057] In this example, interaction between only video-camera 110
and computer 120 was explained. Of course, other computers
130.about.150 can communicate with video-camera 110 in the same
way. When a communication request is sent from each of the
computers to video-camera 100, video-camera 110 performs the
process of step S211.about.S215 for each of the computers.
[0058] In a case where new information of resolution or frame rate
is sent from a user of the computer during the transmission of
image data in step S215 and S224, video-camera 110 may change the
resolution or frame rate to the new one.
[0059] In this way, when the user of the computer inputs the new
resolution or frame rate, the image data sent to the computer is
changed in response to the input. Accordingly, the user of the
computer can change the resolution or frame rate and obtain the
image of the desired resolution and frame rate as desired.
[0060] As explained above, according to the first embodiment, one
video-camera 110 sends image data to each of computers
120.about.150. In that case, the number of pixels, the number of
colors and the number of frames are matched to the request from
each of computers 120.about.150. According to this, it is possible
to reduce the total data amount flowing in network 160 compared
with the case where the image data is sent to the computer
(receiver side) at the maximum number of pixels and maximum frame
rate and the computer modifies the received image data for display.
Also it is possible to reduce the internal process load of
video-camera 110 and computer 120.about.150. Further it is possible
for a user of computer to obtain a desired image quality, such as a
low resolution image for display and a high resolution image for
enlarging because he can set or change, as needed, the resolution
and frame rate requested to video-camera 110. Accordingly, it is
possible to transmit image data efficiently and to obtain a desired
image quality.
[0061] (Second Embodiment)
[0062] In this embodiment, the present invention is embodied in
communication system 300 shown in FIG. 5.
[0063] In communication system 300 shown in FIG. 5, the elements
which have substantially the same functions as the communication
system 100 shown in FIG. 1, are labeled with the same number. In
communication system 300, moving picture server 310 is provided
instead of video-camera 110. Disk apparatus 320 is connected to
moving picture server 310.
[0064] Moving picture server 310 includes CPU 311, memory 312,
hard-disk 313 for temporarily storing program and data, and
interfaces 314 and 315 to network 160 and disk apparatus 320
respectively.
[0065] Disk apparatus 320 comprises an opto-magnetic disk, CDROM
(Compact Disk Read Only Memory) or a large hard-disk and stores
hierarchical data in a format such as that shown in FIG. 3.
[0066] In communication system 300, the hierarchical data (image
data) pre-stored in disk apparatus 320 is read-out in a desired
resolution and frame rate, and sent to each of the computers
120.about.150 by moving picture server 310 in response to the
request.
[0067] In the first embodiment, one piece of image data, which is
being captured in real-time by video-camera, is sent from
video-camera. However, in this embodiment, a plurality of image
data is pre-stored in disk apparatus 320 and each of the image data
is sent in different timings in response to the request of each of
computers 120.about.150. In particular, plural different sequences
of moving picture data are stored, each with an identification by
which any one of the sequences can be selected.
[0068] Concretely, a communication program is stored in a memory
medium such as hard-disk 313 included in moving picture server 310.
The communication program is read-out and executed by CPU 311
included in moving picture server 310 so that moving picture server
310 may communicate with each of computers 120.about.150.
[0069] On the other hand, a communication program is stored in a
memory medium such as program memory 220 connected to computer 120.
The communication program is read-out and executed by computer 120
so that computer 120 may communicate with moving picture server
310.
[0070] Other computers 130, 140, 150 also communicate with moving
picture server 310 by executing corresponding communication
programs.
[0071] The process steps executed by the communication program in
moving picture server 310 are shown in FIG. 6(a). The process steps
executed by the communication programs executed in each of
computers 120.about.150 are shown in FIG. 6(b).
[0072] Briefly, the process steps in FIG. 6 for computer 120
operate to send an instruction to server 310 concerning resolution
and/or frame rate of the moving picture data and to receive the
moving picture data from server 310 at a resolution and/or frame
rate based on the instruction. For server 310, the process steps
operate to receive an instruction from computer 120 concerning
resolution and/or frame rate of the moving picture data and to send
the moving picture data to computer 120 at a resolution and/or
frame rate based on the instruction from computer 120. Overall, the
process operate to receive an instruction at the transmitter from
the receiver concerning resolution and/or frame rate of the moving
picture data to send the moving picture data from the transmitter
to the receiver at a resolution and/or frame rate based on the
instruction from the receiver.
[0073] In this embodiment, hard-disk 313 is provided inside of
server 310 instead of video-camera 110. However, it can be
connected from outside as an external memory apparatus. Likewise,
program memory 220 can be located inside or outside of computer
120.
[0074] In FIG. 6, a solid line expresses a flow of control, and a
dotted line expresses a flow of commands and data in network
160.
[0075] The operation of communication system 300 will be explained
by using FIGS. 5 and 6.
[0076] In step S411, picture server 310 waits for a communication
request. Flow remains at step S411 until server 310 receives the
communication request.
[0077] In step S421, one of the computers, for example, computer
120, sends a communication request through network 160 to moving
picture server 310.
[0078] Moving picture server 310 responds in step S412 by sending
an allowance of communication through network 160 to computer
120.
[0079] Upon receipt of the allowance message from server 310,
computer 120 sends an image data request through network 160 to
moving picture server (step S422).
[0080] Next, moving picture server 310 sends an inquiry of sequence
identity, resolution and frame rate of an image through network 160
to computer 120 in response to the image data request (step S413).
Computer 120 responds by sending its desire for frame rate and
resolution, and identification of moving picture data, through
network 160 to server 310 (step S423). Computer 120 can obtain its
desire for frame rate and resolution, and sequence identification,
automatically such as in accordance with default values. More
preferably, however, the frame rate and resolution, and sequence
identity, are obtained manually, with operator interaction. For
example, computer 120 can display a message for instructing a user
to input information such as a size of a display area, setting
values in response to the inquiry from moving picture server 310.
In response to the message, the user can input information such as
the size of the display area, setting values by operating a mouse
or a key board. For example, a kind of an image and a size of the
display area for displaying moving pictures can be input. Computer
120 sends the answer of the kind of the image, the resolution and
the frame rate through network 160 to moving picture server 310
based on the operation of the user.
[0081] Next, moving picture server 310 sets the kind of the image,
the nearest resolution and frame rate to the answer from computer
120 (step S414). Moving picture server 310 then reads-out only the
image data, which corresponds to the set kind of image, resolution
and frame rate among the image data stored in memory 320. The
read-out image data is temporarily stored in internal hard disk 313
(step S415).
[0082] Moving picture server 310 converts the stored image data
into image data without having the hierarchical data structure
(step S416), and sends it through network 160 to computer 120 (step
S417).
[0083] Next, computer 120 temporarily stores the image data without
having the hierarchical data structure in internal memory (step
S424).
[0084] Next, computer 120 judges whether whole image data has been
received or not (step S425). Computer 120 continues to perform
receiving operation of step S424 until the whole image data has
been received.
[0085] After computer 120 has been received the whole image data,
computer 120 displays a moving picture based on the image data
stored in the internal memory (step S426).
[0086] In this example, interaction between only moving picture
server 310 and computer 120 was explained. Of course, other
computers 130.about.150 can communicate with moving picture server
310 in the same way. When a communication request is sent from each
of the computers to moving picture server 310, moving picture
server 310 performs the process of step S411.about.S415 for each of
the computers.
[0087] In the above embodiment, the image data from moving picture
server 310 is transmitted to computer 120, temporarily stored in
computer 120, and reproduced after the whole of the image data is
received by computer 120. The transmission method is called an
asynchronous transmission method. However, a synchronous
transmission method, in which image data of a predetermined number
of frames is sent from moving picture server 310 to computer 120 in
a predetermined time interval, can be used for the transmission. In
that case, image display may start before computer 120 receives the
whole image data.
[0088] Also, in the above embodiment, moving picture server 310
converts image data into non-hierarchical image data. However, the
conversion can be performed when the image data is received by
computer 120. Also, the conversion can be performed after the
reception of the image data by computer 120. In this way, it is
possible to reduce the process load of moving picture server
310.
[0089] Further in the above embodiment, the display based on the
received image data starts after the reception of the whole image
data by computer 120. However, it may start after the reception of
a part of the image data, for example, image data of a
predetermined time.
[0090] In this case, computer 120 does not have to wait for the
reception of the whole image data. Accordingly, it is possible to
shorten the time period between the start of the reception of the
image data and the start of the display based on the image data. As
a result, computer 120 can save on the amount of memory needed for
storing the image data.
[0091] According to the second embodiment, it is possible to supply
a plurality of different sequences of moving pictures to each of
computers 120.about.150 at a plurality of different timings in
addition to the effect of the first embodiment.
[0092] Because a plurality of different sequences of moving
pictures are stored in disk apparatus 320 at the sender side,
moving picture server 310 can send image data of preferred image
sequence, number of pixels, colors and frame rate based on the
request from each of computer 120.about.150.
[0093] Also according to this embodiment, it is possible to reduce
the process load of computers 120.about.150. This is because the
conversion to image data of non-hierarchical data structure occurs
at moving picture server 310 side.
[0094] In the first and second embodiment, input image data is
converted to the image data hierarchically structured both in pixel
number direction (in resolution) and in time-axis direction.
However, the conversion may be only in one of pixel number
direction (in resolution) and in time-axis direction.
[0095] In this case, a sender side (video-camera 110 or moving
picture server 310) reads all data and converts it based on the
resolution and frame rate answered from a receiver side (computer
120.about.150).
[0096] It is preferable for the sender side to have high processing
capability for conversion of resolution and frame rate, since it is
easy to store moving picture data when it is stored in such as disk
apparatus 320 as shown in the second embodiment. It is especially
effective to use this method, in a case where moving picture data
has already been produced.
[0097] In the first and second embodiment, a sender side sets the
nearest value to the resolution and frame rate answered by a
receiver side. However, the same resolution and frame rate as the
answer can be set for the transmission.
[0098] In this case, if the resolution and frame rate of image data
which is held by a sender side is completely the same as the answer
from a receiver side, the sender side sends the image data as it
is. On the other hand, if the answer is different, the sender side
converts the image data based on the answer and sends the converted
image data.
[0099] A sender side can set the nearest resolution and frame rate
to the answer from a receiver side and send the image data
corresponding to the set values if the receiver side can convert,
before display or other processing, the received image data into
the image data of the same resolution and frame rate that a use
expects.
[0100] In this way, at the receiver side, a user can obtain the
ideal image based on his settings. Also, is possible to re-convert
the image data easily, since the image data is sent to the receiver
side as the nearest form to the user's settings.
[0101] (Other Embodiment)
[0102] Modifications of the above embodiments are included in the
scope of this invention.
[0103] The present invention can be applied to not only a system
comprising a plurality of devices (for example, a plurality of
computers, memory device, video-camera) as shown in FIGS. 1 and 5,
but also to a single device (for example, a computer having an
image capturing device).
[0104] The purpose of the present invention can be achieved by
providing program codes of software for realizing the above
mentioned function into a computer in the apparatus or the system
connected to a various device, and making the computer (ex. CPU,
MPU) in the apparatus or the system operate in accordance with the
stored program, in order to realize the function of the above
mentioned embodiments.
[0105] In this case, the program codes of said software themselves
are used to realize the above mentioned function of the embodiment.
The program codes themselves and means for supplying them to the
computer, for example, the memory medium storing the program codes,
comprise the invention. For example, floppy disks, hard disks,
optical disks, opto-magnetic disks, CD-ROM, CD-R, magnetic tapes,
non-volatile memory card, ROM can be used as the memory medium
storing the program codes.
[0106] Needless to say, the above mentioned function of the
embodiment can be realized not only by the computer which executes
the supplied program codes but also by the computer which executes
the supplied program codes together with the operating system under
which the computer is operated or other application software.
[0107] Further, the supplied program codes can be stored in the
memory provided in a function extension board or a function
extension unit connected to the computer. After that the CPU and so
on, mounted on the function extension board or the function
extension unit, may execute a part of or all of the processing
based on the instruction of the program codes.
[0108] While present invention is described above with respect to
what is currently considered to be its preferred embodiments, it is
to be understood that the invention is not limited to the disclosed
embodiments. To the contrary, the invention is intended to cover
various modifications and equivalent arrangements included within
the spirit and scope of the appended claims.
* * * * *