Re-sizing image sequences
AssigneeSnell Limited
InventorMichael James Knee
Life of this patent
Estimating the term…
Abstract
To modify the aspect ratio of images in a video sequence, a measure of image energy is provided at or around each pixel, for example by taking differences between adjacent pixels. A minimum energy path of contiguous pixels is then identified which extends across the image from one edge to another, for example vertically if the width of the picture is to be modified. Information concerning the location of a path in one image is used in the identification of a path in the next image, for example by biasing the energy measure of the path. The aspect ratio of each image is then modified by removing or by replicating the minimum energy path of contiguous pixels.
Claims30
A method in an image processor of changing the size of a first image, forming part of a sequence of images, the method comprising the steps of:
- selecting a low spatial-frequency-energy region in the first image;
- and
- removing or enlarging the selected low spatial-frequency-energy region in the first image,
- wherein the selection of the region in the first image to be removed or enlarged is biased towards the position of a low spatial-frequency-energy region in a second image in the sequence.
A method in an image processor of changing the size of a first image, forming part of a sequence of images, the method comprising the steps of:
- selecting a low spatial-frequency-energy region in the first image;
- and
- removing or enlarging the selected low spatial-frequency-energy region in the first image,
- wherein the selection of the region in the first image to be removed or enlarged is biased towards the position of a low spatial-frequency-energy region in a second image in the sequence, and
- where the selection of the region in the first image to be removed or enlarged is biased towards a motion compensated position of a low spatial-frequency-energy region in a second image in the sequence and the motion compensation compensates for movement between the first and second images.
A method in an image processor of changing the size of a first image, forming part of a sequence of images, the method comprising the steps of:
- selecting a low spatial-frequency-energy region in the first image;
- and
- removing or enlarging the selected low spatial-frequency-energy region in the first image,
- wherein the selection of the region in the first image to be removed or enlarged is biased towards the position of a low spatial-frequency-energy region in a second image in the sequence, and
- where a set of pixel shift values dependant upon the location of one or more low-spatial-frequency energy regions is derived for the pixels of one or more images in the sequence so that the translation of input pixels necessary to produce respective changed-size output images is defined by the respective pixel shift values, and the respective images are changed in size by applying the respective pixel shift values to their pixels.
A method in an image processor of changing the size of an image, the method comprising the steps of:
- processing a set of pixels that represent the image so as to find a low spatial-frequency-energy path between points on opposite edges of the image including a sub-set of the said set of pixels;
- evaluating the total spatial-frequency energy of the said sub-set of pixels;
- using the evaluated total spatial-frequency energy of the said sub-set of pixels to determine the magnitude of a one-dimensional expansion or contraction such that a larger expansion or contraction is applied where the evaluated total spatial-frequency energy of the said sub-set of pixels is lower and a smaller expansion or contraction is applied where the evaluated total spatial-frequency energy of the said sub-set of pixels is higher;
- and
- applying said expansion or contraction to those parts of the said image that lie on the said path.
A method in an image processor of processing a sequence of pixel based images to modify the aspect ratio of the images, the method comprising the steps of:
- providing at or around each pixel a measure of image energy;
- identifying for each image a low energy path of contiguous pixels extending across the image from one edge of the image to a different edge of the image, wherein information concerning the location of a path in one image is used in the identification of a path in the next image of the sequence;
- and
- modifying the aspect ratio of each image by removing or by replicating said low energy path of contiguous pixels.
A non-transitory computer-readable medium including instructions for a processor, the instructions implementing a method comprising the steps of:
- providing at or around each pixel a measure of image energy;
- identifying for each image a low energy path of contiguous pixels extending across the image from one edge of the image to a different edge of the image, wherein information concerning the location of a path in one image is used in the identification of a path in the next image of the sequence;
- and
- modifying the aspect ratio of each image by removing or by replicating said low energy path of contiguous pixels.
Dependencies are inferred from the claim text.