Method and system for correcting a distorted input image
First Claim
1. An image acquisition system comprising:
- a first memory for storing at least a portion of a distorted input image acquired from an image sensor and a lens system;
a second memory for storing a corrected output image; and
an interpolator module connected to said first memory for reading distorted input image information and to said second memory for writing corrected output image information, said interpolator comprising;
a bi-cubic interpolator; and
a pair of bi-linear interpolators and being switchable between a first high quality mode and a second high speed mode where,in said first high quality mode, for each pixel for said output image, said interpolator is arranged to read a 4×
4 pixel window from said first memory and with said bi-cubic interpolator to interpolate said 4×
4 pixel window to provide said output pixel value, andin said second high speed mode, for each pair adjacent output pixels for said corrected output image, said interpolator is arranged to read a 4×
4 pixel window from said first memory, said 4×
4 pixel window bounding a pair of 2×
2 pixel windows, each of which are interpolated in parallel by said pair of bi-linear interpolators to provide said output pixel values.
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Accused Products
Abstract
A method for correcting a distorted input image comprises determining a local region of an image to be displayed and dividing said region into an array of rectangular tiles, each tile corresponding to a distorted tile with a non-rectangular boundary within said input image. For each tile of the local region, maximum and minimum memory address locations of successive rows of said input image sufficient to span said boundary of said distorted tile are determined. Successive rows of the distorted input from between said maximum and minimum addresses are read. Distortion of the non-rectangular portion of said distorted input image is corrected to provide a tile of a corrected output image which is stored.
21 Citations
17 Claims
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1. An image acquisition system comprising:
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a first memory for storing at least a portion of a distorted input image acquired from an image sensor and a lens system; a second memory for storing a corrected output image; and an interpolator module connected to said first memory for reading distorted input image information and to said second memory for writing corrected output image information, said interpolator comprising;
a bi-cubic interpolator; and
a pair of bi-linear interpolators and being switchable between a first high quality mode and a second high speed mode where,in said first high quality mode, for each pixel for said output image, said interpolator is arranged to read a 4×
4 pixel window from said first memory and with said bi-cubic interpolator to interpolate said 4×
4 pixel window to provide said output pixel value, andin said second high speed mode, for each pair adjacent output pixels for said corrected output image, said interpolator is arranged to read a 4×
4 pixel window from said first memory, said 4×
4 pixel window bounding a pair of 2×
2 pixel windows, each of which are interpolated in parallel by said pair of bi-linear interpolators to provide said output pixel values. - View Dependent Claims (2, 3, 4, 5)
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6. A method for correcting a distorted input image comprising:
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a) determining a local region of an image to be displayed and dividing said region into an array of tiles, each tile having a boundary defined by a plurality of nodes, each node having a set of coordinates within an image space; b) for each tile of the local region, transforming node coordinates according to a first local transformation to take into account a local distortion of said input image in said local region; c) determining a perspective transformation applicable to at least a portion of the nodes of said local region of an image, said perspective transformation comprising multiplying node coordinates u,v transformed according to said first local transformation with the following matrix transformation; - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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Specification