1. A method for updating content stored in a cache residing at an internet service provider (ISP) location, the method comprising:
receiving popularity data associated with a first plurality of content assets and indicating the popularity of each content asset in the first plurality of content assets;
generating a manifest that includes a second plurality of content assets that is at least a subset of the first plurality of content assets based on the popularity data and a geographic location associated with the cache; and
transmitting the manifest to the cache for updating one or more content assets stored in the cache based on the manifest.
2. The method of claim 1, further comprising receiving a new manifest from the cache that includes each content asset stored in the cache.
3. The method of claim 2, further comprising transmitting the new manifest to a content control protocol engine that is configured to direct at least one client machine to the cache to access a content asset based on the content assets included in the new manifest.
4. The method of claim 1, wherein the cache includes a manifest service configured to delete at least one content asset stored in the cache that is not included in the manifest.
5. The method of claim 4, wherein the manifest service is further configured to retrieve from a content distribution network at least one content asset that is included in the manifest but not stored in the cache.
6. The method of claim 5, wherein the manifest service is further configured to generate a new manifest that includes the at least one content asset retrieved from the content distribution network, but does not include the at least one deleted content asset.
7. The method of claim 1, wherein the popularity data indicates how frequently each content asset in the first plurality of content assets is requested by users in a user base that spans multiple geographic regions.
8. The method of claim 7, wherein each content asset comprises one or more audiovideo files.
9. A non-transitory computer-readable medium including instructions that, when executed by a processor, cause the processor to update content stored in a cache residing at an internet service provider (ISP) location, by performing the steps of:
receiving a title manifest from a content control service;
comparing content assets included in the title manifest to content assets stored in the cache; and
retrieving from a content delivery network at least one content asset listed in the title manifest and not stored in the cache.
10. The non-transitory computer-readable medium of claim 9, further comprising deleting at least one content asset stored in the cache and not listed in the title manifest.
11. The non-transitory computer-readable medium of claim 10, wherein deleting the at least one content asset comprises marking for deletion the at least one content asset;
temporarily storing the at least one content asset marked for deletion for a given amount of time; and deleting the at least one asset marked for deletion from the cache once the given amount of time has elapsed.
12. The non-transitory computer-readable medium of claim 11, wherein the given amount of time is predetermined.
13. The non-transitory computer-readable medium of claim 9, further comprising generating a new title manifest listing all content assets stored in the cache.
14. The non-transitory computer-readable medium of claim 13, wherein the new title manifest only partially reflects the title manifest.
15. The non-transitory computer-readable medium of claim 13, wherein, after a certain amount of time has elapsed during which all content assets listed in the title manifest and not stored in the cache have been retrieved from the content server and all content assets stored in the cache and not listed in the title manifest have been deleted from the cache, the new title manifest is identical to the title manifest.
16. A system, comprising:
a cache residing at an internet service provider (ISP) location;
one or more content server machines; and
one or more content control server machines configured to transmit to a client machine, in response to a request for a content asset received from the client machine, a customized asset selection indicating that the cache is a primary location from which to request the content asset and that the one or more content server machines are the secondary location from which to request the content asset.
17. The system of claim 16, wherein the customized asset selection includes an internet protocol address associated with the cache and either an internet protocol address or a host name associated with the one or more content server machines.
18. The system of claim 17, wherein the one or content control servers are configured to generate a title manifest that includes a plurality of content assets based on popularity data and a geographic location associated with the cache and to transmit the title manifest to the cache.
19. The system of claim 18, wherein the cache is configured to retrieve from the one or more content server machines content assets listed in the title manifest and not stored in the cache and to delete content assets stored in the cache and not listed in the title manifest.
20. The system of claim 19, wherein the cache is configured to generate a new title manifest based on one more content assets retrieved from the one or more content server machines and one or more content assets deleted from the cache and to transmit the new title manifest to the one or more content control servers.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An optical filtering system comprising:
a first optical element adapted to receive an original image requiring filtering;
a second optical element positioned relative to said first optical element to define an optical region therebetween, said optical region comprising a Fourier transform plane and an optical region outside said Fourier transform plane; and
a positive-definite optical transfer function element having a plurality of non-zero transmission amplitude values positioned within said optical region outside said Fourier transform plane, wherein said positive-definite optical transfer function element introduces a non-positive-definite transfer function on said original image to produce a modified image.
2. The system according to claim 1, wherein an amplitude distribution of said positive-definite optical transfer function element is determined by the position of said positive-definite optical transfer function element relative to said first and second optical elements.
3. The system according to claim 1, wherein the position of said positive-definite optical transfer function element, relative to said first and second optical elements, is determined by a range of complex-valued transfer functions induced by said optical region outside said Fourier transform plane.
4. The system according to claim 1, wherein an amplitude distribution of said positive-definite optical transfer function element is determined using Hermite function expansions.
5. The system according to claim 1, wherein the position of said positive-definite optical transfer function element, relative to said first and second optical elements, is determined using Hermite function expansions.
6. The system according to claim 1, wherein an amplitude distribution of said positive-definite optical transfer function element is determined using approximations.
7. The system according to claim 1, wherein the position of said positive-definite optical transfer function element, relative to said first and second optical elements, is determined using approximations.
8. The system according to claim 1, wherein said positive-definite optical transfer function element comprises a controllable optical modulator.
9. The system according to claim 8, wherein said controllable optical light modulator is controlled by control signals.
10. The system according to claim 1, wherein said original image comprises data, and wherein optical computations of said data are accomplished by said positive-definite optical transfer function element introducing said non-positive-definite transfer function on said data.
11. The system according to claim 10, wherein said optical computations comprise complex-valued arithmetic.
12. The system according to claim 1, wherein said first optical element comprises a lens or graded-index optical medium.
13. The system according to claim 1, wherein said second optical element comprises a lens or graded-index optical medium.
14. The system according to claim 1, wherein said first optical element, said second optical element, and said positive-definite optical transfer function element comprise a monolithic optics device.
15. The system according to claim 1, wherein said first optical element, said second optical element, and said positive-definite optical transfer function element comprise a monolithic, integrated optics device.
16. The system according to claim 1, wherein said original image comprises light.
17. The system according to claim 1, wherein said original image comprises a particle beam.
18. The system according to claim 1, said system further comprising:
a plurality of positive-definite optical transfer function elements positioned within said optical region outside said Fourier transform plane, wherein each of said plurality of positive-definite optical transfer function elements introduce a non-positive-definite transfer function on said original image.
19. The system according to claim 1, said system further comprising:
an image source adapted to generate said original image; and
an observation element adapted to receive said modified image.
20. The system according to claim 19, wherein said image source comprises an optoelectric transducer.
21. The system according to claim 19, wherein said observation element comprises an optoelectric transducer.
22. An optical filtering method comprising:
receiving an original image requiring filtering at a first optical element;
positioning a second optical element relative to said first optical element to define an optical region therebetween, said optical region comprising a Fourier transform plane and an optical region outside said Fourier transform plane;
selecting a positive-definite optical transfer function element based upon which non-positive-definite transfer function is to be applied to said original image; and
positioning said selected positive-definite optical transfer function element within said optical region outside said Fourier transform plane, wherein said positive-definite optical transfer function element introduces a non-positive-definite transfer function on said original image to produce a modified image.
23. The method according to claim 22, wherein an amplitude distribution of said positive-definite optical transfer function element is determined by the position of said positive-definite optical transfer function element relative to said first and second optical elements.
24. The method according to claim 22, wherein the position of said positive-definite optical transfer function element, relative to said first and second optical elements, is determined by a range of complex-valued transfer functions induced by said optical region outside said Fourier transform plane.
25. The method according to claim 22, wherein an amplitude distribution of said positive-definite optical transfer function element is determined using Hermite function expansions.
26. The method according to claim 22, wherein the position of said positive-definite optical transfer function element, relative to said first and second optical elements, is determined using Hermite function expansions.
27. The method according to claim 22, wherein an amplitude distribution of said positive-definite optical transfer function element is determined using approximations.
28. The method according to claim 22, wherein the position of said positive-definite optical transfer function element, relative to said first and second optical elements, is determined using approximations.
29. The method according to claim 22, wherein said positive-definite optical transfer function element comprises a controllable optical modulator.
30. The method according to claim 29, wherein said controllable optical modulator is controlled by control signals.
31. The method according to claim 22, wherein said original image comprises data, and wherein optical computations of said data are accomplished by said positive-definite optical transfer function element introducing said non-positive-definite transfer function on said data.
32. The method according to claim 31, wherein said optical computations comprise complex-valued arithmetic.
33. The method according to claim 22, wherein said first optical element comprises a lens or graded-index optical medium.
34. The method according to claim 22, wherein said second optical element comprises a lens or graded-index optical medium.
35. The method according to claim 22, wherein said first optical element, said second optical element, and said positive-definite optical transfer function element comprise a monolithic optics device.
36. The method according to claim 22, wherein said first optical element, said second optical element, and said positive-definite optical transfer function element comprise a monolithic, integrated optics device.
37. The method according to claim 22, wherein said original image comprises light.
38. The method according to claim 22, wherein said original image comprises a particle beam.
39. The method according to claim 22, said method further comprising:
selecting a plurality of positive-definite optical transfer function elements based upon which non-positive-definite transfer function is to be applied to said original image; and
positioning said selected plurality of positive-definite optical transfer function elements within said optical region outside said Fourier transform plane, wherein each of said plurality of positive-definite optical transfer function elements introduce a non-positive-definite transfer function on said original image.
40. The method according to claim 22, said method further comprising:
adapting an image source to generate said original image; and
an observation element to receive said modified image.
41. The method according to claim 40, wherein said image source comprises an optoelectric transducer.
42. The method according to claim 40, wherein said observation element comprises an optoelectric transducer.
43. An optical filtering method comprising:
receiving an original image requiring filtering at a first optical element;
inducing a Fourier transform plane within an optical region defined by a second optical element positioned relative to said first optical element, said optical region comprising said Fourier transform plane and a region outside said Fourier transform plane;
selecting a positive-definite optical transfer function element based upon which non-positive-definite transfer function is to be applied to said original image; and
introducing a non-positive-definite transfer function on said original image using said selected positive-definite optical transfer function element positioned within said region outside said Fourier transform plane, wherein said introducing of said non-positive-definite transfer function results in a filtered image of said original image.