Digital image rate converting method and device

• US 6,094,227 A
• Filed: 01/27/1998
• Issued: 07/25/2000
• Est. Priority Date: 02/03/1997
• Status: Expired due to Fees

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Guimier, Stephane-Pascal
• Primary Examiner(s): Lee, Michael H.
• Application Number:
  US09/014,173
• Time in Patent Office: 910 Days
• Field of Search: 348/441, 348/443, 348/459, 348/792, 348/793, 348/17, 348/18, 345/89, 345/94
• US Class Current: 348/459
• CPC Class Codes: G06F 3/153 using cathode-ray tubes
• CPC Class Codes: G09G 2340/0435 Change or adaptation of the frame rate of the video stream
• CPC Class Codes: G09G 3/2018 by time modulation using two or more time intervals
• CPC Class Codes: G09G 3/2025 the sub-frames having all the same time duration
• CPC Class Codes: H04N 7/01 Conversion of standards , e.g. involving analogue television standards or digital television standards processed at pixel level

Abstract

A digital signal converting method and device for converting an input image rate into an output image rate, is applied to input images which are formed by a plurality of input data frames. The method storing the input frames, calculating a sliding average over a plurality of stored frames, and deriving the averages for producing output images with a timing fixed by the output image rate.

Claims

1. A digital signal converting method for converting a series of input images at an input image rate I into a series of output images at an output image rate O=M*I, where M is an integer greater than one, each input image being formed by a series of a fixed number K of input data frames, where K=P*M, K and P being integers greater than one, said method comprising:

storing input data frames either individually or as combinations of C input data frames each, where C is an integer that is less than or equal to P,

calculating a sliding average over K stored individual data frames or K/C stored data frame combinations, and

successively deriving said averages to produce the output images with a timing fixed by the output image rate O.

2. The method as claimed in claim 1, wherein the calculation of the sliding average is preceded by triggering the calculation of an arithmetical average.

3. A method as claimed in claim 1, wherein K=16 and the input images have a format that is compatible with a liquid crystal display screen.

4. A method as claimed in claim 2, wherein M=8 and the series of output images is transmitted to a display monitor.

5. A digital signal converting device for converting a series of input images at an input image rate I into a series of output images at an output image rate O+M*I, where M is an integer greater than one, each input image being formed by a series of a fixed number K of input data frames, where K=P*M, K and P being integers greater than one, said device comprising:

storage means for storing input data frames either individually or as combinations of C input data frames each, where C is an integer that is greater than one and less than or equal to P,

a calculation means for calculating a sliding average over K stored frames or K/C stored data frame combinations, and for successively deriving said averages and for producing the output images with a timing fixed by the output image rate O.

6. The device as claimed in claim 5, wherein the calculation means further comprises

a control device for triggering the calculation of the arithmetical average.

7. A device as claimed in claim 5, wherein K=16 and the series of input images is produced by the device for generating images on a liquid crystal display screen.

8. A device as claimed in claim 7, wherein M=8 and the series of output images is transmitted to a display monitor.