Progressive still frame mode
First Claim
1. A method for transmitting a representation of a still image from a first location to a second location using a communications channel on which a videoconference call has been established between the first location and the second location, the second location having received a first set of data representing the still image as a first image at a first quality level, the method comprising:
- selectively enabling a still mode;
when the still mode is not enabled, storing a series of images in succession, and storing the first image in a memory as a stored image when the still mode is enabled, the first image being one of the series of images as the still image to be transmitted;
computing difference information representing a difference between a function of the stored image and the still image;
encoding the difference information in a format capable of being processed at the second location as a second set of data;
outputting the second set of data for transmission over the communications channel;
constructing a second image based on the stored image and the difference information, the second image having a second quality level higher than the first quality level;
storing the second image in the memory as the stored image; and
repeating the process of computing the difference information, encoding the difference information, outputting the encoded difference information, constructing the second image, and storing the second image, increasing the second quality level with each iteration until the second quality level satisfies a quality threshold.
4 Assignments
0 Petitions
Accused Products
Abstract
A still image is progressively transmitted over a communications channel by computing, encoding, and outputting for transmission difference information representing the difference between the still image and a lower quality representation of the still image that has been received by a remote location. This process is repeated, with additional difference information being generated to supplement the image received at the remote location, such that the quality of the image at the remote location improves over time. The difference information may be encoded in a format compatible with existing video compression standards and processed by a receiving terminal regardless of the presence of still mode capability.
27 Citations
49 Claims
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1. A method for transmitting a representation of a still image from a first location to a second location using a communications channel on which a videoconference call has been established between the first location and the second location, the second location having received a first set of data representing the still image as a first image at a first quality level, the method comprising:
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selectively enabling a still mode; when the still mode is not enabled, storing a series of images in succession, and storing the first image in a memory as a stored image when the still mode is enabled, the first image being one of the series of images as the still image to be transmitted; computing difference information representing a difference between a function of the stored image and the still image; encoding the difference information in a format capable of being processed at the second location as a second set of data; outputting the second set of data for transmission over the communications channel; constructing a second image based on the stored image and the difference information, the second image having a second quality level higher than the first quality level; storing the second image in the memory as the stored image; and repeating the process of computing the difference information, encoding the difference information, outputting the encoded difference information, constructing the second image, and storing the second image, increasing the second quality level with each iteration until the second quality level satisfies a quality threshold. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. For use in transmitting a still image with a desired quality using a communications channel, a system comprising:
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a still mode control block configured and arranged to selectively enable a still mode; a first memory configured and arranged to, when the still mode is not enabled, store a series of images in succession, and, when the still mode is enabled, store one of the series of images as the still image; a variable quality encoder configured and arranged to encode difference information representing a difference between a reconstructed image and the still image as a set of data representing the difference information with variable quality that is successively increased until a quality threshold is satisfied; an image reconstructor configured and arranged to construct the reconstructed image as a function of the difference information; a second memory configured and arranged to store the reconstructed image; and a difference information generator configured and arranged to generate the difference information and to provide the difference information to the variable quality encoder. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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30. A method for generating a still image having a desired quality at a receiving terminal based on data received from a communications channel on which a videoconference call is established, the method comprising:
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selectively enabling a still mode; constructing a reconstructed image based on the data when the still mode is enabled, the reconstructed image representing the still image with a first quality lower than the desired quality; storing the reconstructed image in a memory; receiving difference information from the communications channel; constructing a new reconstructed image based on the reconstructed image and on the difference information, the new reconstructed image representing the still image with a second quality higher than the first quality; storing the new reconstructed image in the memory; and repeating the process of receiving difference information, constructing a new reconstructed image, and storing the new reconstructed image, including using a summing block and iteratively incorporating difference information to generate an updated image having the second quality higher than the first quality, such that the quality of the updated image is progressively improved as additional difference information is received, the second quality being increased at each iteration until the second quality equals the desired resolution. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37, 38, 39)
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40. A system for generating a still image having a desired quality based on data received from a communications channel on which a videoconference call is established between a local location and a remote location, the system comprising:
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a still mode enabler, configured and arranged to selectively enable a still mode; a decoder, responsive to the communications channel and configured and arranged to decode the data; an image constructor, responsive to the decoder and including a summing block for iteratively incorporating difference information into a stored image having a first quality to generate an updated image having a second quality higher than the first quality, such that the quality of the updated image is progressively improved as additional difference information is received; and a memory, responsive to the image constructor and configured and arranged to store the updated image as the stored image. - View Dependent Claims (41, 42, 43, 44, 45, 46, 47, 48)
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49. An arrangement for communicating a representation of a still image using a communications channel on which a videoconference call has been established between a first location and a second location, the second location using a program causing a video decoder to decode received data sets as a sequence of video images representing live video and the second location having received a first set of data representing the still image as a first image at a first quality level, the arrangement comprising:
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a still mode control block configured and arranged to selectively enable a still mode; a first video terminal located at the first location having a processor programmed for encoding and sending to the second location difference information representing a difference between the first image and the still image when the still mode is enabled; a second video terminal located at the second location having a processor including a program for decoding the difference information and constructing therefrom a second image having a second quality level higher than the first quality level; and wherein said first video terminal and said second video terminal are configured to repeatedly, respectively, encode and send and decode and construct to obtain a reconstructed second image having an acceptable quality level.
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Specification