Claims
- 1. A method of implementing continuous zoom to a digital image, the method comprising the steps of:
- a) receiving a digital image signal;
- b) inputting a desired zoom ratio;
- c) using the input zoom ratio to select at least one interpolation filter having a predetermined cut-off frequency from at least one set of interpolation filters to provide at least one interpolation filter, the cut-off frequencies of at least some of the interpolation filters in the set being logarithmically spaced;
- d) applying said selected interpolation filter to the digital image signal to effect the desired zooming; and
- e) providing an output digital signal to which the desired zooming has been applied.
- 2. A method according to claim 1, wherein step c) includes selecting a vertical filter coefficient.
- 3. A method according to claim 1, wherein step c) includes selecting a horizontal filter coefficient.
- 4. Digital image signal spatial interpolation apparatus for continuous zoom of a digital image comprising:
- means for receiving a digital image signal:
- means for inputting a desired zoom ratio;
- a discrete set of filters for one spatial dimension, said set of filters having a plurality of cut-off frequencies; and
- means responsive to said inputted desired zoom ratio for applying a selected filter from said discrete set of filters to the digital image signal to effect a corresponding desired zooming operation.
- 5. The spatial interpolation apparatus of claim 4 in which at least some of said cut-off frequencies are logarithmically spaced.
- 6. Digital image signal spatial interpolation apparatus for continuous zoom of a digital image comprising:
- means for receiving a digital image signal:
- means for inputting a desired zoom ratio;
- a first discrete set of filters for a first spatial dimension;
- a second discrete set of filters for a second spatial dimension, at least one of said first and second discrete sets of filters having a plurality of cut-off frequencies; and
- means responsive to said inputted desired zoom ratio for applying a selected filter from at least one of said first and second discrete sets of filters to the digital image signal to effect a corresponding desired zooming operation.
- 7. The spatial interpolation apparatus of claim 6 in which both of said discrete sets of filters have said plurality of cut-off frequencies.
- 8. The spatial interpolation apparatus of claim 6 or 7 in which at least some of said cut-off frequencies are logarithmically spaced.
Priority Claims (1)
Number |
Date |
Country |
Kind |
9311942 |
Jun 1993 |
GBX |
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Parent Case Info
This is a Divisional of application Ser. No. 08/241,311, filed May 10, 1994 abandoned.
US Referenced Citations (9)
Foreign Referenced Citations (1)
Number |
Date |
Country |
WO9107848 |
May 1991 |
WOX |
Divisions (1)
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Number |
Date |
Country |
Parent |
241311 |
May 1994 |
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