Image analysis – Applications – Motion or velocity measuring
Reexamination Certificate
1998-10-28
2001-04-17
Bella, Matthew C. (Department: 2621)
Image analysis
Applications
Motion or velocity measuring
C356S027000, C073S488000
Reexamination Certificate
active
06219436
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to motion vector estimation and detection of covered/uncovered image parts. The invention also relates to motion-compensated interpolation, and to a display apparatus comprising means for carrying out such a motion-compensated interpolation.
2. Description of the Related Art
The paper “Motion estimation method using the spatio-temporal characteristics of moving objects”, presented at the International Workshop on HDTV, Los Angeles, October, 1996, by H. Sonehara et al., discloses a motion vector detection method which takes account of the spatio-temporal continuity of motion vectors and the local characteristics of pictures. Motion vector trajectories are traced to assess the spatio-temporal continuity of motion vectors. To remove erroneous motion vectors detected in the covered/uncovered background of the contour area of moving objects, motion vectors are estimated by means of a detection-area hierarchy and the correlation of luminance signals. It is necessary to identify, in two sequential fields, the area (covered and uncovered background area) in which the picture correlation becomes indeterminate. For this, a detection block is set in the current field and vectors are detected in relation to the next field. Then a detection block is set in the next field and vectors are detected in relation to the current field. In short, motion vectors are detected two-way.
European Patent Specification EP-B-0,535,066 discloses a method of assigning the appropriate one (if any) of a plurality of possible motion vectors to pixels of a video signal consisting of a series of pictures, the method comprising the steps of: a backwards assignment operation in which a first input picture is shifted by each of a plurality of possible vectors and compared to a second, succeeding picture to determine assignment errors for each vector at each pixel; a forward assignment operation in which the second picture is shifted by each of a plurality of possible vectors and compared to the first picture to determine assignment errors for each vector at each pixel; and using, for each pixel, the assignment errors determined in both forward assignment and backwards assignment operations to determine whether any of the vectors is appropriate for that pixel. The method may further comprise comparing the assignment errors for the forward and backwards assignment operations for a pixel to determine whether the pixel may relate to revealed or obscured background. This combined vector assignment flags regions of both revealed and obscured background as ‘no match’ so that a fallback interpolation technique can be used. This fallback interpolation technique has not been described. In an alternative method, vectors from the instant of an input picture are converted to an output picture at a different instant in time by projecting the input vectors forward in time (allowing for their motion). Several problems are inherent in projecting vectors forward in time. While these problems are not insurmountable the technique of combined forward and backward assignment is simpler and therefore more attractive.
SUMMARY OF THE INVENTION
It is, inter alia, an object of the invention to provide a reliable motion detection/motion-compensated interpolation. To this end, a first aspect of the invention provides a motion vector estimation method and device for an image to be interpolated between neighboring previous and next input images. A second aspect of the invention provides an interpolation method using said motion vector estimation method. A third aspect of the invention provides a display apparatus using said device for estimating motion vectors. A fourth aspect of the invention provides a method of and device for detecting covered and uncovered parts in an image to be interpolated.
A primary aspect of the invention provides a method of detecting covered and uncovered parts in an image to be interpolated between neighboring previous and next input images, in which backward motion vectors from the next input image to the previous input image, and having corresponding backward estimation errors, and forward motion vectors from the previous input image to the next input image, and having corresponding forward estimation errors, are determined, uncovered and covered parts are detected in the neighboring previous and next input images, respectively, in the thus detected uncovered parts, uncovered parts in the image to be interpolated are detected by determining second backward estimation errors by comparing both neighboring previous and next input images when partially shifted over the backward motion vectors to a temporal location of said image to be interpolated, and by comparing the second backward estimation errors to a threshold, and in the thus detected covered parts, covered parts in the image to be interpolated are detected by determining second forward estimation errors by comparing both neighboring previous and next input images when partially shifted over the forward motion vectors to a temporal location of the image to be interpolated, and by comparing the second forward estimation errors to the threshold.
Another aspect of the invention provides a method of estimating motion vectors for an image to be interpolated between neighboring previous and next input images, in which motion from the next input image to the previous input image is detected to obtain backward motion vectors having corresponding backward estimation errors, motion from the previous input image to the next input image is detected to obtain forward motion vectors having corresponding forward estimation errors, uncovered and covered parts are detected in the image to be interpolated, motion vectors are furnished for the uncovered parts in dependence upon the forward motion vectors taken from locations wholly and/or partly shifted over the backward motion vector, and motion vectors for the covered parts are furnished in dependence upon the backward motion vectors taken from locations wholly and/or partly shifted over the forward motion vectors.
These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.
REFERENCES:
patent: 5978030 (1999-11-01), Jung et al.
patent: 5995080 (1999-11-01), Biro et al.
patent: 6026217 (2000-02-01), Adiletta
patent: 535066 B1 (1993-07-01), None
patent: 2279531 (1995-01-01), None
patent: 9120155A1 (1991-12-01), None
patent: 9628931A2 (1996-09-01), None
patent: 9628931A3 (1996-09-01), None
De Haan Gerard
Pelagotti Anna
Bella Matthew C.
Choobin M.
U.S. Philips Corporation
Vodopia John F.
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