Real-time software video/audio transmission and display with content protection against camcorder piracy

• US 20050265577A1
• Filed: 05/18/2005
• Published: 12/01/2005
• Est. Priority Date: 02/26/2002
• Status: Active Grant

• Current Assignee: OL Security LLC (Intellectual Ventures LLC)
• Original Assignee: Truelight Technologies, LLC
• Inventors: DeCegama, Angel
• Granted Patent: US 7,630,569 B2
• Time in Patent Office: Days
• US Class Current: 382/100
• CPC Class Codes: H04N 19/107 between spatial and temporal predictive coding, e.g. picture refresh
• CPC Class Codes: H04N 19/132 Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking
• CPC Class Codes: H04N 19/137 Motion inside a coding unit, e.g. average field, frame or block difference
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/18 the unit being a set of transform coefficients
• CPC Class Codes: H04N 19/48 using compressed domain processing techniques other than decoding, e.g. modification of transform coefficients, variable length coding [VLC] data or run-length data motion estimation in a transform domain H04N19/547; processing of decoded motion vectors H04N19/513
• CPC Class Codes: H04N 19/587 involving temporal sub-sampling or interpolation, e.g. decimation or subsequent interpolation of pictures in a video sequence
• CPC Class Codes: H04N 19/59 involving spatial sub-sampling or interpolation, e.g. alteration of picture size or resolution
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/63 using sub-band based transform, e.g. wavelets
• CPC Class Codes: H04N 19/635 characterised by filter definition or implementation details
• CPC Class Codes: H04N 19/647 using significance based coding, e.g. Embedded Zerotrees of Wavelets [EZW] or Set Partitioning in Hierarchical Trees [SPIHT]
• CPC Class Codes: H04N 19/70 characterised by syntax aspects related to video coding, e.g. related to compression standards
• CPC Class Codes: H04N 19/86 involving reduction of coding artifacts, e.g. of blockiness
• CPC Class Codes: H04N 2005/91392 using means for preventing making copies of projected video images
• CPC Class Codes: H04N 21/6125 involving transmission via Internet transmission by internet of broadcast information H04H60/82

Abstract

The invention presents new methods of compression, transmission, and decompression of video signals providing increased speed and image quality and for protecting against camcorder piracy. Methods based on selecting an anchor frame, wavelet transformation with decimation and time stamping can provide one-pass encoding of signals in which the amount of bits of information needed to be transmitted can be substantially reduced, thereby increasing the speed of transmission of digital signals over networks. Decompressing signals, along with interpolation methods to re-create portions of images of lesser importance in visual perception, can provide coordinated video and audio presentations of high quality in real-time over all kinds of networks and frame interpolation resulting in a displayed frame rate significantly higher than 30 fps. The use of randomly selected anchor frames can render reconstructed transmitted images of poor quality for pirates who do not have access to identities of anchor frames.

Claims

1. A system for transmitting audio and video via a communication medium, comprising:

an audio input;

a video input;

an image capture mechanism operably linked to said video input;

an audio encoder operably linked to said audio input;

a wavelet transform image encoder operably linked to said image capture mechanism, said encoder adapted to select anchor frames using a random selection process;

an inverse wavelet transform image decoder operably linked to said communication medium, said decoder operating on said randomly selected anchor frame;

an audio and video synchronizer; and

a receiver for replaying said audio and decoded video images.

2. The system of claim 1, further comprising:

a coefficient selection mechanism for determining a range of coefficient values between a maximum value per level of wavelet transform, and a minimum value specified as a significance threshold; and

an encoder for encoding each coefficient with a number of bits allocated for each coefficient range, said encoder adapted to encode a signal identifying a randomly selected anchor frame.

3. The system of claim 1, wherein said decoder comprises:

a receiver for receiving an encoded digital image, previously encoded from an original image using a wavelet transform and a randomly selected anchor frame;

an image expander for expanding the encoded image along one of a vertical or a horizontal axis, to create an interim image that approximates the low frequency side of a wavelet transform of the original image; and

an image enhancer, for

calculating the vertical wavelet transform of the interim image;

enhancing local maxima of the wavelet transform; and

replacing the coefficient of the result with those of the encoded image.

4. The system of claim 1, further comprising:

a communication speed specification mechanism for specifying the transmission speed of a communication medium used by a first user;

an image encoder for selecting and encoding an image from said stream of images using a wavelet transform, said encoder adapted to match transmission speed of the communication medium used by the first user;

an image decoder for receiving the encoded images via the communication medium, and decoding the selection of images using their inverse wavelet transform; and

an expander.

5. The system of claim 4, further comprising:

a communication speed specification mechanism for specifying the transmission speed of a communication medium used by a second user; and

an image encoder for selecting and encoding an image from said stream of images using a wavelet transform, said encoder adapted to match transmission speed of the communication medium used by the second user.

6. The system of claim 1, wherein said wavelet transform image encoder has asymmetrical filters for differentially decimating low-frequency signals and high-frequency signals.

7. The system of claim 1, further comprising:

a quality threshold input; and

means for decimating low-frequence signals and high-frequency signals in said frame based on said quality threshold input.

8. The system of claim 1, further comprising a video input including an input video image;

a receiver of wavelet-transformed, asymmetrically filtered, decimated video information containing low-frequency and high-frequency coefficients from a frame of a video image, said frame being identified relative to said anchor frame;

an inverse wavelet transform-based device for producing a decoded video image; and

a comparator for comparing said decoded video image to said frame of said input video image.

9. A device for encoding a sequence of digital images to meet a video quality threshold value, comprising:

(a) a video input;

(b) a video capture mechanism;

(c) a quality threshold input specifying an image quality threshold;

(d) an encoded first frame image, produced by;

(i) receiving a first frame of image data from a sequence of digital images and making said first frame an anchor frame selected randomly;

(ii) selecting a first frame position located within said frame at which to fix an anchor frame calculation; and

(iii) calculating a wavelet transform for said first frame;

(e) an encoded second frame image;

produced by;

(i) receiving a second frame of image data from said sequence of digital images;

(ii) selecting a position located within said second frame, said position being the same as the position in said first frame; and

(iii) calculating a wavelet transform for said second frame; and

(f) a comparator for determining at said selected position whether the wavelet transform of said first frame position and the wavelet transform of said second frame is greater than the quality threshold value.

10. A method of transmitting one of a digital image or a video image via a communication medium, comprising the steps of:

(a) providing an input stream of video or image data including at least one digital image;

(b) capturing an image frame from said stream;

(c) compressing and encoding said image frame using a wavelet transform to create an encoded frame;

(d) transmitting said encoded frame via said communication medium to a decoder; and

(e) decoding and expanding said encoded frame using an inverse wavelet transform relative to a randomly selected anchor frame, to create an output stream including a decoded, expanded digital image.

11. The method of claim 10, further comprising:

(f) receiving a quality threshold value corresponding to the maximum allowed difference between said anchor frame and a subsequent image frame;

(g) receiving a signal identifying said randomly selected anchor frame;

(h) selecting a position located within said anchor frame at which to fix an anchor frame calculation;

(i) calculating a wavelet transform for said anchor frame;

0) receiving a second frame of image data from said sequence of digital images;

(k) calculating a wavelet transform for said second frame;

(l) determining at the selected position located within said frame of image data whether the difference between said first and second frames is greater than the quality threshold value, and if so;

then (m) making the second frame a new anchor frame.

12. The method of claim 10, further comprising the steps of:

(f) determining a set of high frequency coefficients of the wavelet transform of the image;

(g) determining a maximum value per level of wavelet transform;

(h) specifying a significance threshold as a minimum value;

(i) determining a range of coefficient values between said maximum and minimum values;

(j) allocating a number of data bits to each range;

(k) encoding each coefficient with the specified number of bits allocated to each range and wherein said digital image is related to a randomly selected anchor frame.

13. The method of claim 10, further comprising the steps of:

(f) receiving an encoded image frame, previously encoded from an original frame using a wavelet transform;

(g) expanding the encoded image frame along a vertical axis to create an interim image frame approximating the low frequency side of a wavelet transform of the original image frame;

(h) calculating the vertical wavelet transform of the interim image frame;

(i) enhancing the coefficient of the result obtained in step (h) with those of the encoded image frame; and

(j) expanding the encoded image frame along a horizontal axis and repeating steps (a)-(e) to create the decoded and enhanced image frame.

14. The method of claim 10, further comprising variably compressing a digital image for transmission to different users, comprising the steps of:

(f) receiving an input as to the speed of a first communications medium used by a first user;

(g) compressing and encoding an image frame from said stream of images using a wavelet transform, said compressing and encoding adapted to match the transmission speed of the communication medium used by said first user; and

(h) decoding the selection of images using an inverse wavelet transform; and

(i) expanding said selection of images produced by step (h).

15. The method of claim 14, further comprising the steps of:

(j) receiving an input as to the speed of a second communications medium used by a second user;

(k) compressing and encoding an image frame from said stream of images using a wavelet transform, said compressing and encoding adapted to match the transmission speed of the communication medium used by said second user; and

(l) decoding the selection of images using an inverse wavelet transform; and

(m) expanding said selection of images produced by step (l).