GB2281835A - Phase locking system for video signals - Google Patents
Phase locking system for video signals Download PDFInfo
- Publication number
- GB2281835A GB2281835A GB9318646A GB9318646A GB2281835A GB 2281835 A GB2281835 A GB 2281835A GB 9318646 A GB9318646 A GB 9318646A GB 9318646 A GB9318646 A GB 9318646A GB 2281835 A GB2281835 A GB 2281835A
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- Prior art keywords
- output
- pixels
- input
- images
- producing
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Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N7/00—Television systems
- H04N7/01—Conversion of standards, e.g. involving analogue television standards or digital television standards processed at pixel level
- H04N7/0135—Conversion of standards, e.g. involving analogue television standards or digital television standards processed at pixel level involving interpolation processes
- H04N7/014—Conversion of standards, e.g. involving analogue television standards or digital television standards processed at pixel level involving interpolation processes involving the use of motion vectors
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/04—Synchronising
- H04N5/06—Generation of synchronising signals
- H04N5/067—Arrangements or circuits at the transmitter end
- H04N5/073—Arrangements or circuits at the transmitter end for mutually locking plural sources of synchronising signals, e.g. studios or relay stations
- H04N5/0736—Arrangements or circuits at the transmitter end for mutually locking plural sources of synchronising signals, e.g. studios or relay stations using digital storage buffer techniques
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/14—Picture signal circuitry for video frequency region
- H04N5/144—Movement detection
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N7/00—Television systems
- H04N7/01—Conversion of standards, e.g. involving analogue television standards or digital television standards processed at pixel level
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N7/00—Television systems
- H04N7/01—Conversion of standards, e.g. involving analogue television standards or digital television standards processed at pixel level
- H04N7/0105—Conversion of standards, e.g. involving analogue television standards or digital television standards processed at pixel level using a storage device with different write and read speed
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Synchronizing For Television (AREA)
- Television Signal Processing For Recording (AREA)
- Television Systems (AREA)
Abstract
A system for synchronising an input video signal having an asynchronous frame sync frequency comprises the step of temporally interpolating output fields from the input fields, at the appropriate temporal positions. A specific embodiment disclosed, allows the input signal to be stored in a video memory at the asynchronous frame rate and read from memory at the asynchronous frame rate. The drift in write and read sync rates can cause frames to be skipped or repeated and this effect is compensated for by temporally interpolating the fields in a transition period when this effect occurs. Interpolation can be motion compensated. <IMAGE>
Description
METHOD AND APPARATUS FOR SYNCHRONISING VIDEO SIGNALS
The present invention relates to a method and apparatus for synchronisation of video signals and more particularly for frame synchronising video signals between unlocked sources and destinations.
Video synchronisation is a well known requirement for "locking" two asynchronous video sources, for example when an outside broadcast vehicle produces a signal with a local sync generator which is then relayed back to a studio which operates with its own station reference synchronisation.
In practice, the two frame sync frequencies will be very close, typically one part in four million, but the phase and exact frequency will differ slightly, as shown in
Figure 1 of the appended drawings.
Typically, synchronisation is achieved by using a buffer memory as shown in Figure 2 of the appended drawings.
A write pointer writes input video data into the buffer in synchronism with the input video signal and a read pointer reads out that stored data in synchronism with an external output sync reference. However, when the input and output synchronisation signals have different frequencies, the read and write pointers drift relative to one another. In particular, when the position of the read pointer is overtaken by the writer pointer, a video skip occurs in which a frame is dropped causing a sudden jump in moving sequences. Furthermore, when the write pointer is overtaken by the read pointer, the same video sequence is output twice so that a frame is repeated, resulting in hesitation of movement of the image.
The portion of the video sequence repeated or dropped is usually 2 fields (one frame) for component video, 4 fields for NTSC or 8 fields for PAL due to the need to maintain the SC-H phase relationship in the last two cases.
Clearly, when synchronizers of the above type drop or repeat frames, a visual discontinuity is introduced into the moving sequences. Furthermore, this discontinuity will draw attention to any auditory disturbances when both the audio and video signals are being simultaneously synchronised.
It is an object of the present invention to provide a method/apparatus for synchronising video signals without introducing the disturbances of dropped or repeated frames as produced by the above described method.
According to the present invention there is provided a method of producing, from a video signal of consecutive input images, a video signal of consecutive output images synchronised to an external synchronising signal, the method comprising the steps of:
forming output pixels of an output image according to a) the values of corresponding neighbouring pixels of corresponding adjacent input images and b) the temporal relationship of an external synchronising signal to the synchronising signals of the corresponding input images; and
producing the output image in synchronism with the external synchronisation signal.
According to the present invention there is also provided an apparatus for producing, from a video signal of consecutive input images, a video signal of consecutive output images synchronised to an external synchronising signal, the apparatus comprising:
means for forming output pixels of an output image according to (a) the values of corresponding neighbouring pixels of corresponding adjacent input images and (b) the temporal relationship of an external synchronising signal to the synchronising signals of the corresponding input images; and
means for producing the output image in synchronism with the external synchronisation signal.
Thus, by continuously forming output data on the basis of its temporal relationship to related input data, the output data is continuously adjusted and data dropping or repeating is avoided.
While this avoids such problems, either expensive and complicated processes must be used for this continuous phase adjustment or some degradation of the output image quality will occur.
Thus, preferably the method is such that the input images are stored in a buffer and normally read out in synchronism with the external synchronisation signal and wherein, when the buffer approaches being either full or empty of previously unread input pixel data, a predetermined number of output images are formed by the above method.
Thus, this allows video data to pass unprocessed for the vast majority of the time, but then implements a gradual "smooth" transition over a series of fields/frames in which a field/frame would otherwise have been repeated or dropped.
The invention will be more clearly understood from the following description, given by way of example only with reference to the accompanying drawings in which:
Figure 1 shows the relative positions of input and output fields in vertical/temporal space;
Figure 2 shows a block diagram of a known video synchroniser using a buffer memory;
Figure 3 shows a block diagram of a vertical/temporal interpolater for use in the first embodiment of the present invention;
Figure 4 shows a block diagram of a motion compensated conversion system for use with the second embodiment of the present invention;
Figure 5 shows interpolation in static picture area according to the motion adaptive interpolation embodiment of the present invention;
Figure 6 shows interpolation in moving picture areas according to the motion adaptive interpolation embodiment of the present invention;;
Figure 7 shows a block diagram of the motion adaptive interpolation embodiment of the present invention;
Figure 8 shows the switching characteristic for the motion adaptive interpolation embodiment of the present invention;
Figure 9 shows a block diagram of the local interpolation embodiment of the present invention;
Figure 10 shows the relationship between a known output synchroniser and that shown in Figure 9 when a frame is dropped;
Figure 11 shows the relationship between a known synchroniser output and that of Figure 9 when a frame is repeated.
The most straightforward embodiment of the present invention is illustrated in Figure 3. In this embodiment, the input signal is merely subjected to vertical/temporal interpolation. By this process, each output pixel is calculated from the surrounding vertical and temporal input pixels. The input and output synchronisation extraction circuits 8,9 obtain the input and output synchronisations and, from these, the relative temporal position of each output pixel in relation to the surrounding input pixels may be calculated. This information is used in conjunction with the coefficient selection circuit 10 to control the interpolater circuit 5 to produce the output pixel by linear vertical/temporal interpolation. Thus, as the relative position of output pixels vary with the input pixels, so the interpolator 5 varies the contribution of the surrounding input pixels to the output pixels.Hence, there is never the need for dropping or repeating data.
This apparatus is relatively straightforward, but vertical and temporal resolution is usually slightly impaired by the processing.
Figure 4 shows a system based on the technique of motion compensated conversion and, whilst this particular system represents a video standards rate converter, it illustrates the principles behind using such techniques in another embodiment for continuously adjusting the phase/frequency of the output video signal.
According to simple linear interpolation, if a feature of an image moves between two positions, the resulting interpolated image will comprise faded representations of the feature in both positions. However, according to the motion compensated conversion, vectors are calculated which indicate movement of the image and the resulting interpolation produces a representation of the feature between its two positions. As with the embodiment described above, the motion compensated conversion process is used to produce output pixels calculated from surrounding input pixels on the basis of the temporal phase difference between the input and output synchronisation signals such that it is not necessary to ever drop or repeat information.
While this embodiment overcomes the problems of the first embodiment of maintaining vertical and temporal resolution, it is at the expense of relatively high cost and complexity.
A third embodiment is now described with reference to
Figures 5 to 8. This embodiment is based on the realisation that, since the number of lines in the input images is the same as the resynchronised output images, the conversion from input data to output data is principally temporal and therefore it is possible to simplify the method and apparatus of conversion.
Where the input image/picture or areas of the picture are static from, for instance, frame to frame, it is not necessary to introduce any vertical interpolation. Thus, in essence, this embodiment uses a motion adaptive approach in which it is determined whether the image is static or in motion and, where picture areas are static, vertical resolution is preserved and, where picture areas are moving, vertical/temporal interpolation is used to produce the output images.
When a picture area is detected as moving, it is not essential to the invention what type of interpolation is used, but, preferably this embodiment uses a motion adaptive combination of two dimensional linearly interpolated samples and intra-frame one dimensional interpolation to provide a high quality interpolated output with modest processing complexity.
Figure 5 illustrates vertical/temporal space for a picture area with no motion. In this case, the output samples can be generated directly by either previous field replacement, averaging the samples in adjacent fields or producing a weighted combination of the samples on either side. For the case of weighted combination, for instance, PO may be calculated from its adjacent pixels according to the formula:
i.e. the value of PO is formed according to its proximity to the two adjacent input pixels.
Referring to Figure 6, when the picture area is determined to be moving, the output may be formed by a weighted combination of the input samples around the required output sample, the interpolater generally using 4 or 16 samples surrounding the site of the value to be estimated.
Figure 7 shows a block diagram of a system for implementing the above process.
Motion detector 18 produces an output K which takes the value "0" for a static part of the image and the value "1" for fully moving areas. The value of any one output pixel is simultaneously estimated by both blocks 12 and 13, corresponding to the two methods of interpolation based on static and moving images respectively. Multipliers 15 and 16 multiply the outputs of blocks 12 and 13 respectively and the two multiplied outputs are passed to the adder 17 to produce the estimate of the required pixel. The output K is arranged to have a "soft" switching characteristic as shown in Figure 8 and this arrangement allows for a smooth transition from the static to motion processing when K takes a value between 0 and 1.Thus the motion detector may determine the degree of motion for each pixel in turn such that the various areas of a single video field can be formed from either blocks 12 or 13 according to their individual degree of motion.
All of the above embodiments still suffer from the disadvantage that by virtue of the continuous processing and interpolation to produce the output data, the output quality suffers.
The fourth embodiment provides a method and apparatus which avoids the degradation resulting from the continuous processing used in the previous embodiment.
With reference to Figure 9, the method and apparatus of this embodiment, for the majority of the time, allows video image information to be buffered in the same way as described in relation to the prior art. However, when the buffer approaches the situation in which a frame must be dropped or repeated, according to the present embodiment, the system operates over a plurality of frames spanning the frame which would have been repeated or dropped so as to implement a gradual "smooth" transition at the discontinuity.
Since, over the period of transition, more significant interpolation is required than with the embodiments described above, the smoothness of motion at these points may not be quite so good. However, this embodiment does have the benefit of not degrading the vast majority of program material by processing.
Figure 9 shows the implementation of the system in which the video memory 6, address generator 7 and synchronisation extractors 8 and 9 are essentially the same as shown in the known synchroniser of Figure 2. However, in addition, there are also provided an interpolater 5, together with coefficient selector 10 and a switch 11 under control of the address generator 7. Switch 11 selects either the normal output from the video memory 6 or else the output of the interpolater 5 during the transition period associated with a dropped or repeated sequence of fields.
By way of example, Figures 10 and 11 show a comparison of the frames produced by a known synchroniser and those produced by the present synchroniser. Considering the required coefficient values for the transition period of a repeated frame (Fig. 11), the frames output from the present synchroniser may be calculated from those of the previous synchroniser as follows:
FA = 3/4 F5 + 1/4 F6,
FB = 1/2 F6 + 1/2 F7,
FC = 3/4 F7 + 1/4 F6,
FD = 3/4 F7 + 1/4 F8,
FE = 1/2 F7 + 1/2 F8,
FF = 3/4 F9 + 1/4 F8.
In this example, in order to provide hardware of minimum complexity, simple coefficient values have been chosen together with a combination of fields of only the same polarity. However, with a general vertical/temporal interpolater there is not normally a restriction on the coefficient values or mixing portions of fields of different polarities.
Similar schemes exist when dropping video sequences as illustrated in Figure 10.
The implementation of this system can be relatively straightforward and has been considered in a simplified format in relation to the BKPF-108C using easy binary coefficients of 0.25, 0.5 and 0.75 and only combining fields of same polarity to soften the transition. Note also that in practice, the switch 11 in Figure 9 can be implemented "virtually" by selecting interpolator 5 coefficient 1 and 0.
The techniques are equally applicable to all video standards but only 625/50 Hz has been considered by way of example.
Claims (20)
1. A method of producing, from a video signal of consecutive input images, a video signal of consecutive output images synchronised to an external synchronising signal, the method comprising the steps of:
forming output pixels of an output image according to a) the values of corresponding neighbouring pixels of corresponding adjacent input images and b) the temporal relationship of an external synchronising signal to the synchronising signals of the corresponding input images; and
producing the output image in synchronism with the external synchronisation signal.
2. A method according to claim 1 wherein the input images and the output images are of identical format.
3. A method according to claim 1 or 2 wherein said output pixels are formed by linear vertical/temporal interpolation of said corresponding neighbouring input pixels.
4. A method according to claim 1 or 2 wherein said output pixels are formed by motion compensated conversion of said corresponding neighbouring input pixels.
5. A method according to any preceding claim further comprising the step of determining whether an area of adjacent input images is moving and wherein said step of forming is only used where the area is determined to be moving.
6. A method according to claim 5 wherein where the area is determined to be static, output pixels of the output image are generated by one of a) previous field replacement, b) averaging the pixels of adjacent fields and c) producing a weighted combination of the pixels on either side.
7. A method according to claim 5 or 6 wherein when the area is determined to be moving, output pixels are formed from a weighted combination of the vertically/temporally surrounding input pixels.
8. A method according to claim 5, 6 or 7 wherein the step of determining is applied to determine individually whether each input pixel is static or moving.
9. A method of producing, from a video signal of consecutive input images, a video signal of consecutive output images synchronised to an external synchronising signal, the method comprising the steps of:
storing consecutive input images in a memory buffer;
determining whether the buffer is approaching a state of being one of full and empty of previously unread input pixel data;
where said buffer is not approaching said state, producing an output image in synchronism with the external synchronisation signal by reading the buffer; and
where the buffer is approaching said state, producing a predetermined number of output images by the method according to any preceding claim.
10. An apparatus for producing, from a video signal of consecutive input images, a video signal of consecutive output images synchronised to an external synchronising signal, the apparatus comprising:
means for forming output pixels of an output image according to (a) the values of corresponding neighbouring pixels of corresponding adjacent input images and (b) the temporal relationship of an external synchronising signal to the synchronising signals of the corresponding input images; and
means for producing the output image in synchronism with the external synchronisation signal.
11. An apparatus according to claim 10 for producing output images of identical format to the input images.
12. An apparatus according to claim 10 or 11 wherein, in use, said forming means forms output pixels by linear/temporal interpolation of said corresponding neighbouring input pixels.
13. Apparatus according to claim 10 or 11 wherein, in use, said forming means forms said output pixels by motion compensated conversion of said corresponding neighbouring input pixels.
14. An apparatus according to any one of claims 10 to 13 further comprising means for determining whether an area of adjacent input images is moving and wherein, in use, said forming means only forms output pixels where the area is determined to be moving.
15. An apparatus according to claim 14, further comprising generating means and wherein, in use, where the area is determined to be static, output pixels of the output image are generated by the generating means by one of a) previous field replacement, b) averaging the pixels of adjacent fields and c) producing a weighted combination of the pixels on either side.
16. An apparatus according to claim 14 or 15 comprising second forming means and wherein, in use, when the area is determined to be moving, said second forming means forms output pixels from a weighted combination of the vertically/temporally surrounding input pixels.
17. An apparatus according to claim 14, 15 or 16 wherein, in use, said determining means determines individually whether each pixel is static or moving.
18. An apparatus for producing, from a video signal of consecutive input images, a video signal of consecutive output images synchronised to an external synchronising signal, the apparatus comprising:
a memory buffer for storing consecutive input images;
means for determining whether the buffer is approaching a state of being one of full and empty of previously unread input pixel data;
means for producing, where said buffer is not approaching said state, an output image in synchronism with the external synchronisation signal by reading the buffer; and
an apparatus according to any preceding claim for producing, where the buffer is approaching said state, a predetermined number of output images
19. A method of synchronising video signals substantially as hereinbefore described with reference to and as illustrated by the accompanying drawings.
20. An apparatus for synchronising video signals constructed and arranged substantially as hereinbefore described with reference to and as illustrated by the accompanying drawings.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9318646A GB2281835B (en) | 1993-09-08 | 1993-09-08 | Method and apparatus for synchronising video signals |
| JP20224894A JP3946780B2 (en) | 1993-09-08 | 1994-08-26 | Video signal synchronizer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9318646A GB2281835B (en) | 1993-09-08 | 1993-09-08 | Method and apparatus for synchronising video signals |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB9318646D0 GB9318646D0 (en) | 1993-10-27 |
| GB2281835A true GB2281835A (en) | 1995-03-15 |
| GB2281835B GB2281835B (en) | 1998-04-22 |
Family
ID=10741721
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9318646A Expired - Fee Related GB2281835B (en) | 1993-09-08 | 1993-09-08 | Method and apparatus for synchronising video signals |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP3946780B2 (en) |
| GB (1) | GB2281835B (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0875882A2 (en) * | 1997-04-15 | 1998-11-04 | Genesis Microchip Inc. | Multi-scan video timing generator for format conversion |
| EP0973329A2 (en) * | 1998-07-06 | 2000-01-19 | General Instrument Corporation | HDTV video frame synchronizer that provides clean digital video without variable delay |
| EP1292139A1 (en) * | 2000-06-09 | 2003-03-12 | Sharp Kabushiki Kaisha | Recorder/player apparatus |
| EP1843587A1 (en) | 2006-04-05 | 2007-10-10 | STMicroelectronics S.r.l. | Method for the frame-rate conversion of a digital video signal and related apparatus |
| WO2007129257A1 (en) * | 2006-05-04 | 2007-11-15 | Koninklijke Philips Electronics N.V. | Controlled frame rate conversion |
| EP2033434A1 (en) * | 2006-05-05 | 2009-03-11 | Miranda Technologies Inc. | Method and apparatus for synchronizing a graphics signal according to a reference signal |
| GB2525137A (en) * | 2013-08-30 | 2015-10-21 | Amberfin Ltd | Conversion of video frame rate |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001309202A (en) * | 2000-04-19 | 2001-11-02 | Matsushita Electric Ind Co Ltd | Frame synchronizer |
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| GB2018064A (en) * | 1978-03-08 | 1979-10-10 | Nippon Electric Co | Phase locking system for television signals |
| US4439786A (en) * | 1978-09-29 | 1984-03-27 | The Marconi Company Limited | Apparatus and method for processing television picture signals and other information |
| GB2231226A (en) * | 1989-04-27 | 1990-11-07 | Sony Corp | Motion dependent video signal processing |
| GB2231743A (en) * | 1989-04-27 | 1990-11-21 | Sony Corp | Motion dependent video signal processing |
| GB2255254A (en) * | 1991-03-28 | 1992-10-28 | Matsushita Electric Ind Co Ltd | Television standard conversion apparatus |
| GB2259212A (en) * | 1991-08-27 | 1993-03-03 | Sony Broadcast & Communication | Standards conversion of digital video signals |
| GB2265275A (en) * | 1992-03-18 | 1993-09-22 | Sony Broadcast & Communication | Digital video signal processing for standards conversion |
-
1993
- 1993-09-08 GB GB9318646A patent/GB2281835B/en not_active Expired - Fee Related
-
1994
- 1994-08-26 JP JP20224894A patent/JP3946780B2/en not_active Expired - Fee Related
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2018064A (en) * | 1978-03-08 | 1979-10-10 | Nippon Electric Co | Phase locking system for television signals |
| US4439786A (en) * | 1978-09-29 | 1984-03-27 | The Marconi Company Limited | Apparatus and method for processing television picture signals and other information |
| GB2231226A (en) * | 1989-04-27 | 1990-11-07 | Sony Corp | Motion dependent video signal processing |
| GB2231743A (en) * | 1989-04-27 | 1990-11-21 | Sony Corp | Motion dependent video signal processing |
| GB2255254A (en) * | 1991-03-28 | 1992-10-28 | Matsushita Electric Ind Co Ltd | Television standard conversion apparatus |
| GB2259212A (en) * | 1991-08-27 | 1993-03-03 | Sony Broadcast & Communication | Standards conversion of digital video signals |
| GB2265275A (en) * | 1992-03-18 | 1993-09-22 | Sony Broadcast & Communication | Digital video signal processing for standards conversion |
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0875882A2 (en) * | 1997-04-15 | 1998-11-04 | Genesis Microchip Inc. | Multi-scan video timing generator for format conversion |
| EP0875882A3 (en) * | 1997-04-15 | 1998-12-09 | Genesis Microchip Inc. | Multi-scan video timing generator for format conversion |
| US6177922B1 (en) | 1997-04-15 | 2001-01-23 | Genesis Microship, Inc. | Multi-scan video timing generator for format conversion |
| EP0973329A2 (en) * | 1998-07-06 | 2000-01-19 | General Instrument Corporation | HDTV video frame synchronizer that provides clean digital video without variable delay |
| EP0973329A3 (en) * | 1998-07-06 | 2000-10-25 | General Instrument Corporation | HDTV video frame synchronizer that provides clean digital video without variable delay |
| US7295768B2 (en) | 2000-06-09 | 2007-11-13 | Sharp Kabushiki Kaisha | Recording and reproducing apparatus |
| EP1292139A4 (en) * | 2000-06-09 | 2004-11-10 | Sharp Kk | Recorder/player apparatus |
| EP1292139A1 (en) * | 2000-06-09 | 2003-03-12 | Sharp Kabushiki Kaisha | Recorder/player apparatus |
| USRE43897E1 (en) | 2000-06-09 | 2013-01-01 | Sharp Kabushiki Kaisha | Recording and reproducing apparatus |
| EP1843587A1 (en) | 2006-04-05 | 2007-10-10 | STMicroelectronics S.r.l. | Method for the frame-rate conversion of a digital video signal and related apparatus |
| US8259790B2 (en) | 2006-04-05 | 2012-09-04 | Stmicroelectronics S.R.L. | Method for the frame-rate conversion of a video sequence of digital images, related apparatus and computer program product |
| US8861595B2 (en) | 2006-04-05 | 2014-10-14 | Stmicroelectronics S.R.L. | Method for the frame-rate conversion of a video sequence of digital images, related apparatus and computer program product |
| WO2007129257A1 (en) * | 2006-05-04 | 2007-11-15 | Koninklijke Philips Electronics N.V. | Controlled frame rate conversion |
| EP2033434A1 (en) * | 2006-05-05 | 2009-03-11 | Miranda Technologies Inc. | Method and apparatus for synchronizing a graphics signal according to a reference signal |
| EP2033434A4 (en) * | 2006-05-05 | 2010-03-24 | Miranda Technologies Inc | Method and apparatus for synchronizing a graphics signal according to a reference signal |
| GB2525137A (en) * | 2013-08-30 | 2015-10-21 | Amberfin Ltd | Conversion of video frame rate |
Also Published As
| Publication number | Publication date |
|---|---|
| GB9318646D0 (en) | 1993-10-27 |
| GB2281835B (en) | 1998-04-22 |
| JPH07107331A (en) | 1995-04-21 |
| JP3946780B2 (en) | 2007-07-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20110908 |