Image transmission with divided image signal transmission through selected channels

• US 5,541,657 A
• Filed: 12/02/1994
• Issued: 07/30/1996
• Est. Priority Date: 08/13/1991
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Mashimo, Hiroshi, Kikuchi, Takayuki, Yamamoto, Mitsuru
• Primary Examiner(s): Kostak, Victor R.
• Assistant Examiner(s): Flynn, Nathan J.
• Application Number:
  US08/352,211
• Time in Patent Office: 606 Days
• Field of Search: 348/388, 348/394, 348/398, 348/432
• US Class Current: 348/388.1
• CPC Class Codes: G06T 3/40 Scaling of whole images or parts thereof, e.g. expanding or contracting
• CPC Class Codes: G06T 3/4092 Image resolution transcoding, e.g. by using client-server architectures
• CPC Class Codes: H04N 19/00 Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
• CPC Class Codes: H04N 19/20 using video object coding
• CPC Class Codes: H04N 19/30 using hierarchical techniques, e.g. scalability H04N19/63 takes precedence
• CPC Class Codes: H04N 19/39 involving multiple description coding [MDC], i.e. with separate layers being structured as independently decodable descriptions of input picture data
• CPC Class Codes: H04N 19/503 involving temporal prediction adaptive coding with adaptive selection between spatial and temporal predictive coding H04N19/107; adaptive coding with adaptive selection among a plurality of temporal predictive coding modes H04N19/109
• CPC Class Codes: H04N 19/98 Adaptive-dynamic-range coding [ADRC]
• CPC Class Codes: H04N 21/21805 enabling multiple viewpoints, e.g. using a plurality of cameras
• CPC Class Codes: H04N 21/234363 by altering the spatial resolution, e.g. for clients with a lower screen resolution
• CPC Class Codes: H04N 21/2365 Multiplexing of several video streams
• CPC Class Codes: H04N 21/23655 Statistical multiplexing, e.g. by controlling the encoder to alter its bitrate to optimize the bandwidth utilization
• CPC Class Codes: H04N 21/2383 Channel coding or modulation of digital bit-stream, e.g. QPSK modulation arrangements for detecting or preventing errors in the information received by adapting the channel coding H04L1/0009; analogue front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/4347 Demultiplexing of several video streams
• CPC Class Codes: H04N 21/4382 Demodulation or channel decoding, e.g. QPSK demodulation analog front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/4438 Window management, e.g. event handling following interaction with the user interface
• CPC Class Codes: H04N 5/45 Picture in picture , e.g. displaying simultaneously another television channel in a region of the screen
• CPC Class Codes: H04N 7/0806 the signals being two or more video signals H04N7/0803, H04N7/081 take precedence
• CPC Class Codes: H04N 7/15 Conference systems
• CPC Class Codes: H04N 7/152 Multipoint control units therefor

Abstract

When dynamic image signals from a plurality of dynamic image signal sources are simultaneously received by a plurality of receivers, a dynamic image signal to be transmitted is transmitted while being divided into one or a plurality of partial dynamic image signals. In each of the plurality of dynamic image output devices, a desired number of received partial dynamic image signals are displayed in a desired size, thereby preventing a decrease in transmission efficiency caused by transmission of a large amount of dynamic image information exceeding the capacity of a transmission path.

Claims

1. An image transmission apparatus comprising:

signal dividing means for dividing an image signal to be transmitted into one or a plurality of image signals;

transmission control means for transmitting the divided image signals to image output devices through selected transmission channels among a plurality of transmission channels, each of the divided image signals corresponding to one of said selected transmission channels;

selection means for selecting a desired number of divided image signals from the image signals transmitted by said transmission control means;

means for setting an output size of an image to be output from said image output devices according to the number of divided image signals selected by said selection means; and

means for reconstructing an image signal from the transmitted image signal corresponding to the output size.

2. The apparatus according to claim 1, wherein said signal dividing means divides an image to be transmitted into pixel units each including N pixels (N is an integer), a pixel set consisting of N pixels constituting the pixel unit is represented by P₀, an average value of image signals of pixels belonging to said pixel set P₀ is represented by m₀₁, said pixel set P₀ is divided into two partial pixel sets P₁ and Q₁, average values of image signals of pixels belonging to said partial pixel sets P₁ and Q₁ are represented by m₂₁ and n₂₁, said partial pixel set Q₁ is divided into two pixel sets P₂₂ and Q₂₂, average values of image signals of pixels belonging to said pixel sets P₂₂ and Q₂₂ are represented by m₂₂ and n₂₂, average values m and n of pixels belonging to the pixel sets are calculated until the number of pixels in each of pixel sets P and Q becomes 1, and N values k respectively represented by following formulas are determined as partial image signals using obtained N values m and N-1 values n:

k₀₁ =m₀₁

k₁₁ =m₁₁ -m₀₁

k₂₁ =m₂₁ -m₁₁

k₂₂ =m₂₂ -n₁₁

k₃₁ =m₃₁ -m₂₁

k₃₂ =m₃₂ -n₂₁

k₃₃ =m₃₃ -m₂₂

k₃₄ =m₃₄ -n₂₂.

3. The apparatus according to claim 1, wherein said transmission control means comprises:

means for determining an encoding level of the image signal to be transmitted according to the number of empty channels of said plurality of transmission channels; and

means for modulating the image signal at a frequency corresponding to the encoding level.

4. The apparatus according to claim 3, wherein when said plurality of transmission channels do not include empty channels, said transmission control means waits until a channel used at a predetermined encoding level is ready.

5. The apparatus according to claim 1, wherein said transmission control means utilizes an optical transmission system as a transmission system of a dynamic image signal.

6. An image transmission apparatus comprising:

input means for inputting an image signal;

signal dividing means for dividing the image signal into a plurality of image signals; and

transmission control means for transmitting the divided image signals through selected transmission channels among a plurality of transmission channels, each of the divided image signals corresponding to one of the selected transmission channels,

wherein said transmission control means selects the transmission channels in accordance with instructions from an external device.

7. The apparatus according to claim 6, wherein the image signal to be transmitted is a dynamic image signal and said signal dividing means divides a dynamic image to be transmitted into pixel units each including n pixels (N is an integer), a pixel set consisting of N pixels constituting the pixel unit being represented P₀, and an average value of image signals of pixels belonging to said pixel set P₀ being represented by M₀₁, said pixel set P₀ being divided into two partial pixel sets P₀ and Q₁, average values of image signals of pixels belonging to said partial pixel sets P₀ and Q₁ being represented by m₂₁ and n₂₁, said partial pixel set Q₁ being divided into two pixel sets P₂₂ and Q₂₂, average values of image signals of pixels belonging to said pixel sets P₂₂ and Q₂₂ being represented by m₂₂ and n₂₂, average values m and n of pixels belonging to the pixel sets being calculated until the number of pixels in each of pixel sets P and Q becomes 1, and N values k respectively represented by following formulae are determined as partial dynamic image signals using obtained N values m and n-1 values n:

k₀₁ =m₀₁

k₁₁ =m_11- m₀₁

k₂₁ =m₂₁ -m₁₁

k₂₂ =m₂₂ -n₁₁

k₃₁ =m₃₁ -m₂₁

k₃₂ =m₃₂ -n₂₁

k₃₃ =m₃₃ -m₂₂

k₃₄ =m₃₄ -n₂₂.

8. An image transmission apparatus, comprising:

input means for inputting an image signal;

signal dividing means for dividing the image signal into a plurality of image signals; and

transmission control means for transmitting the divided image signals through selected transmission channels among a plurality of transmission channels, each of the divided image signals corresponding to one of the selected transmission channels,

wherein said transmission control means comprises;

means responsive to each divided image signal for determining an encoding level of the image signal to be transmitted according to a number of unselected channels of said plurality of transmission channels; and

means for modulating the image signal for which the encoding level has been determined at a frequency corresponding to the encoding level.

9. The apparatus according to claim 8, wherein when said plurality of transmission channels does not included unselected channels, said transmission control means waits until a selected channel being used at a predetermined encoding level is ready.

10. An image transmission apparatus comprising:

input means for inputting an image signal;

signal dividing means for dividing the image signal into a plurality of image signals; and

transmission control means for transmitting the divided image signals through selected transmission channels among a plurality of transmission channels, each of the divided image signals corresponding to one of the selected transmission channels,

wherein said transmission control means utilizes an optical transmission system as a transmission system of an image signal.

11. An image transmission apparatus, comprising:

input means for inputting an image signal;

signal dividing means for dividing the image signal into a plurality of image signals; and

transmission control means for transmitting the divided image signals through selected transmission channels among a plurality of transmission channels, each of the divided image signals corresponding to one of the selected transmission channels,

wherein said transmission control means comprises;

means responsive to each divided image signal for determining an encoding level of the image signal to be transmitted according to a number of unselected channels of said plurality of transmission channels; and

means for encoding the image signal corresponding to the determined encoding level.