Method of generating motion vectors of images of a video sequence
First Claim
Patent Images
1. A method of generating signals representing absolute motion vectors of an image of a video sequence, the method comprising:
- defining horizontal and vertical weighing functions with values over pixels belonging to a first portion of the image being larger than values over pixels outside the first portion of the image;
computing horizontal and vertical characteristic curves of the image and of a preceding image in the video sequence;
determining a horizontal global displacement between the two images that minimizes a weighted average, calculated using the horizontal weighing function, of an absolute value of a difference between taps of the horizontal characteristic curve of the current image and of a translated replica of the horizontal characteristic curve of the preceding image in the sequence;
determining a vertical global displacement between the two images that minimizes a weighted average, calculated using the vertical weighing function, of an absolute value of a difference between taps of the vertical characteristic curve of the current image and of a translated replica of the vertical characteristic curve of the preceding image in the sequence;
aligning the image with the preceding image in the sequence and calculating relative motion vectors between the aligned images; and
generating the signals representing absolute motion vectors between the images as a vector sum of the relative motion vectors and the horizontal and vertical global displacement.
1 Assignment
0 Petitions
Accused Products
Abstract
A digital image processing system and method for removing motion effects from images of a video sequence, and generating corresponding motion compensated images.
30 Citations
24 Claims
-
1. A method of generating signals representing absolute motion vectors of an image of a video sequence, the method comprising:
-
defining horizontal and vertical weighing functions with values over pixels belonging to a first portion of the image being larger than values over pixels outside the first portion of the image; computing horizontal and vertical characteristic curves of the image and of a preceding image in the video sequence; determining a horizontal global displacement between the two images that minimizes a weighted average, calculated using the horizontal weighing function, of an absolute value of a difference between taps of the horizontal characteristic curve of the current image and of a translated replica of the horizontal characteristic curve of the preceding image in the sequence; determining a vertical global displacement between the two images that minimizes a weighted average, calculated using the vertical weighing function, of an absolute value of a difference between taps of the vertical characteristic curve of the current image and of a translated replica of the vertical characteristic curve of the preceding image in the sequence; aligning the image with the preceding image in the sequence and calculating relative motion vectors between the aligned images; and generating the signals representing absolute motion vectors between the images as a vector sum of the relative motion vectors and the horizontal and vertical global displacement. - View Dependent Claims (2, 3, 4, 5)
-
-
6. A method of filtering an image of an input video sequence, the method comprising:
-
defining horizontal and vertical weighing functions with values over pixels belonging to a first portion of the image being larger than values over pixels outside the first portion of said image; computing horizontal and vertical characteristic curves of the image and of a preceding image in the sequence; determining a horizontal global displacement between the two images that minimizes a weighted average, calculated using the horizontal weighing function, of an absolute value of a difference between taps of the horizontal characteristic curve of the current image and of a translated replica of the horizontal characteristic curve of the preceding image in the sequence; determining a vertical global displacement between the two images that minimizes a weighted average, calculated using the vertical weighing function, of an absolute value of a difference between taps of the vertical characteristic curve of the current image and of a translated replica of the vertical characteristic curve of the preceding imagein the sequence; and generating a filtered output image by filtering out the horizontal and vertical global displacements from the current image.
-
-
7. A method of filtering an image of an input video sequence, the method comprising:
-
computing horizontal and vertical characteristic curves of the image and of a preceding image in the sequence, then generating corresponding high-pass replicas thereof using a high-pass filter; calculating a horizontal global displacement between the two images that minimizes an average of an absolute value of a difference between taps of the horizontal high-pass replica characteristic curve of the current image and of a translated replica of the high-pass replica horizontal characteristic curve of the preceding image in the sequence; calculating a vertical global displacement between the two images that minimizes an average of an absolute value of a difference between taps of the vertical high-pass replica characteristic curve of the current image and of a translated replica of the vertical high-pass replica characteristic curve of the preceding image in the sequence; and generating a filtered output image by filtering out the horizontal and vertical global displacements from the current image. - View Dependent Claims (8, 9)
-
-
10. A method of filtering an image of an input video sequence, comprising:
-
computing horizontal and vertical characteristic curves of the image and of a preceding image in the sequence, then generating corresponding band-pass replicas thereof using a Butterworth IIR band-pass filter; calculating a horizontal global displacement between the two images that minimizes an average of an absolute value of a difference between taps of the horizontal band-pass replica characteristic curve of the current image and of a translated replica of the horizontal band-pass replica characteristic curve of the proceding image in the sequence; calculating a vertical global displacement between the two images that minimizes an average of an absolute value of a difference between taps of the vertical band-pass replica characteristic curve of the current image and of a translated replica of the vertical band-pass replica characteristic curve of the preceding image in the sequence; and generating a filtered output image by filtering out the horizontal and vertical global displacements from the current image. - View Dependent Claims (11)
-
-
12. A method of filtering an image of an input video sequence, comprising the steps of:
-
computing horizontal and vertical characteristic curves of the image and of a preceding image in the sequence, then generating corresponding high-pass replicas thereof; calculating a horizontal global displacement between the two images that minimizes an average of an absolute value of a difference between taps of the horizontal high-pass replica characteristic curve of the current image and of a translated replica of the horizontal high-pass replica characteristic curve of the proceding image in the sequence; calculating a vertical global displacement between the two images that minimizes an average of an absolute value of a difference between taps of the vertical high-pass replica characteristic curve of the current image and of a translated replica of the vertical high-pass replica characteristic curve of the preceding image in the sequence; and generating a filtered output image by filtering out the horizontal and vertical global displacements from the current image. - View Dependent Claims (13, 14, 15, 16)
-
-
17. A system to process digital images, comprising:
-
a Bayer sensor configured to generate Bayer pattern images of captured scenes; a curve generator configured to generate characteristic curves of the Bayer pattern images; a memory storing the Bayer pattern images and the respective characteristic curves; and a digital signal processor configured to generate absolute global motion vectors based on the Bayer images and the respective characteristic curves. - View Dependent Claims (18, 19)
-
-
20. A computer readable memory medium comprising contents that cause a computing device to implement a method of processing a digital image, the method including:
-
defining horizontal and vertical weighing functions with values over pixels belonging to a first portion of the image being larger than values over pixels outside the first portion of the image; computing horizontal and vertical characteristic curves of the image and of a preceding image in the video sequence; determining a horizontal global displacement between the two images that minimizes a weighted average, calculated using the horizontal weighing function, of an absolute value of a difference between taps of the horizontal characteristic curve of the current image and of a translated replica of the horizontal characteristic curve of the preceding image in the sequence; determining a vertical global displacement between the two images that minimizes a weighted average, calculated using the vertical weighing function, of an absolute value of a difference between taps of the vertical characteristic curve of the current image and of a translated replica of the vertical characteristic curve of the preceding image in the sequence; aligning the image with the preceding image in the sequence and calculating relative motion vectors between the aligned images; and generating the signals representing absolute motion vectors between the images as a vector sum of the relative motion vectors and the horizontal and vertical global displacement.
-
-
21. A method of generating signals representing absolute motion vectors of an image of a video sequence, the method comprising:
-
defining horizontal and vertical weighing functions with values over pixels belonging to a first portion of the image being larger than values over pixels outside the first portion of the image; computing horizontal and vertical characteristic curves of the image and of a preceding image in the video sequence; determining a horizontal global displacement between the two images that minimizes a weighted average, calculated using the horizontal weighing function, of an absolute value of a difference between taps of the horizontal characteristic curve of the current image and of a translated replica of the characteristic curve of the preceding image in the sequence; determining a vertical global displacement between the two images that minimizes a weighted average, calculated using the vertical weighing function, of an absolute value of a difference between taps of the horizontal characteristic curve of the current image and of a translated replica of the characteristic curve of the preceding image in the sequence; aligning the image with the preceding image in the sequence and calculating relative motion vectors between the aligned images; and generating the signals representing absolute motion vectors between the images as a vector sum of the relative motion vectors and the horizontal and vertical global displacement. - View Dependent Claims (22, 23, 24)
-
Specification