Non-linear image mapping

• US 9,317,895 B1
• Filed: 08/09/2012
• Issued: 04/19/2016
• Est. Priority Date: 08/09/2012
• Status: Active Grant

• Current Assignee: Xilinx, Inc. (Advanced Micro Devices, Inc.)
• Original Assignee: Xilinx, Inc. (Advanced Micro Devices, Inc.)
• Inventors: Tidwell, Reed P.
• Primary Examiner(s): Pe, Geepy
• Assistant Examiner(s): Adrovel, William
• Application Number:
  US13/571,035
• Time in Patent Office: 1,349 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G01C 21/365 Guidance using head up displays or projectors, e.g. virtual vehicles or arrows projected on the windscreen or on the road itself
• CPC Class Codes: G02B 2027/011 comprising device for correcting geometrical aberrations, distortion
• CPC Class Codes: G02B 2027/014 comprising information/image processing systems
• CPC Class Codes: G02B 27/01 Head-up displays
• CPC Class Codes: G06G 5/00 Devices in which the computing operation is performed by means of fluid-pressure elements such elements in general F15C
• CPC Class Codes: G06T 3/08 Projecting images onto non-planar surfaces, e.g. geodetic screens
• CPC Class Codes: G06T 3/40 Scaling of whole images or parts thereof, e.g. expanding or contracting

Abstract

In an apparatus for digital image processing, a mapper is coupled to receive destination pixel information in terms of a source pixel space, and to provide a 2-dimensional filter kernel with source pixels for the destination pixel information. An oversampled filter includes predetermined coefficients. A filter coefficient module is configured to select phase coefficients from the predetermined coefficients stored in the oversampled filter based on proximity to the source pixels in the filter kernel, and coupled to provide a filter coefficient for each of the source pixels in the filter kernel. A convolution module is coupled to receive the source pixels and the filter coefficients, and to provide a convolution result. The convolution module is configured to apply the filter coefficients to the source pixels in a convolution to provide the convolution result. A normalization module is configured to normalize either the convolution result or the filter coefficients.

Claims

1. An apparatus, comprising:

a mapper configured to receive destination pixel information in terms of a source pixel space, and configured to generate a 2-dimensional filter kernel for source pixels for the destination pixel information;

an oversampled filter including predetermined coefficients having a first grid finer than a second grid of the source pixel space;

the oversampled filter is coupled to the mapper and configured to filter the source pixels to the first grid pattern of the predetermined coefficients for selection of filter coefficients from the predetermined coefficients;

a filter coefficient module configured to select the filter coefficients from the predetermined coefficients stored in the oversampled filter based on proximity to the source pixels in the filter kernel for each of the source pixels in the filter kernel;

the filter coefficient module configured to predistort a digital image associated with the source pixels for non-linear image mapping;

a convolution module coupled to the mapper and the filter coefficient module and configured to receive the source pixels and the filter coefficients, respectively, and configured to apply the filter coefficients to the source pixels in a convolution to generate a convolution result; and

a normalization module configured to normalize either the convolution result or the filter coefficients.

2. The apparatus according to claim 1, wherein:

the oversampled filter is a finite impulse response filter; and

the finite impulse response filter includes a lookup table for storing the predetermined coefficients.

3. The apparatus according to claim 1, wherein the normalization module is configured to receive the convolution result from the convolution module and configured to normalize the convolution result.

4. The apparatus according to claim 1, wherein:

the normalization module is coupled to receive the filter coefficients from the filter coefficient module and configured to generate normalized versions of the filter coefficients;

the normalization module is coupled to provide the normalized versions of the filter coefficients to the convolution module; and

the convolution module is configured for application of the normalized versions of the filter coefficients to the source pixels for the convolution.

5. The apparatus according to claim 1, wherein the mapper is further coupled to receive an X-scaling factor and a Y-scaling factor for the destination pixel information.

6. The apparatus according to claim 1, wherein the oversampled filter is configurable with respect to size, shape, and orientation responsive to scaling and content of an image associated with the destination pixel information.

7. The apparatus according to claim 1, wherein:

the filter coefficient module is configured to store the filter coefficients in a lookup table for retrieval; and

the lookup table is configured to retrieve the filter coefficients responsive to distance from a center of the oversampled filter.

8. The apparatus according to claim 1, wherein:

the oversampled filter is configured to be dynamically shaped responsive to an applied filter; and

the filter coordinates used to look up the predetermined coefficients of the oversampled filter are remappable responsive to the applied filter.

9. The apparatus according to claim 1, wherein:

the filter coefficient module is configured to store the predetermined coefficients in a lookup table with addresses representing distances; and

the lookup table is configured as a one-dimensional, radially addressed lookup table.

10. A vehicle, comprising:

a video and graphics processing module having an image predistorter;

the image predistorter having a filter coefficient module including an oversampled filter configured to predistort a digital image for a non-linear image mapping of a display image to a three dimensional perspective;

the image predistorter including;

a mapper configured to receive destination pixel information in terms of a source pixel space, and configured to generate a 2-dimensional filter kernel for source pixels for the destination pixel information;

wherein the destination pixel information is for the navigation symbology;

the oversampled filter including predetermined coefficients having a first grid finer than a second grid of the source pixel space;

the oversampled filter coupled to the mapper and configured to filter the source pixels to the first grid pattern of the predetermined coefficients for selection of filter coefficients from the predetermined coefficients;

the filter coefficient module configured to select the filter coefficients from the predetermined coefficients stored in the oversampled filter based on proximity to the source pixels in the filter kernel for each of the source pixels in the filter kernel; and

the filter coefficient module configured to predistort the digital image associated with the source pixels for the non-linear image mapping thereof;

a head up display (“

HUD”

) coupled to the video and graphics processing module;

a global positioning system coupled to the video and graphics processing module;

at least one camera coupled to the video and graphics processing module;

wherein the global positioning system is configured to generate navigation symbology for the video and graphics processing module responsive to position information;

wherein the video and graphics processing module is configured to register the navigation symbology from the global positioning system with image information from the at least one camera, and further configured to provide the display image;

wherein the image predistorter is configured to predistort the digital image for projection of the display image onto a windshield in the three dimensional perspective; and

wherein the HUD is configured to receive the predistorted display image for projection thereof.

11. The vehicle according to claim 10, wherein the image predistorter comprises:

a convolution module coupled to the mapper and the filter coefficient module and configured to receive the source pixels from the mapper and the filter coefficients from the filter coefficient module, and configured to apply the filter coefficients to the source pixels in a convolution to generate a convolution result; and

a normalization module coupled to the convolution module or the filter coefficient module and configured to normalize either the convolution result or the filter coefficients, respectively.

12. The vehicle according to claim 10, wherein the HUD is configured to project the predistorted display image onto the windshield in the three dimensional perspective visually aligned with real-world objects viewable by a driver.

13. The vehicle according to claim 10, wherein the HUD is an on-dash HUD.

14. The vehicle according to claim 10, further comprising:

a lenticular material positioned over the HUD;

wherein the display image is not directly viewable due to being obscured by the lenticular material; and

wherein the display image is configured for viewing as a reflected image in the windshield.

15. A vehicle, comprising:

a video and graphics processing module having an image predistorter;

the image predistorter having a filter coefficient module including an oversampled filter configured to predistort a digital image for a non-linear image mapping of a display image to a three dimensional perspective;

the image predistorter including;

a mapper configured to receive destination pixel information in terms of a source pixel space and configured to generate a 2-dimensional filter kernel for source pixels for the destination pixel information;

the oversampled filter including predetermined coefficients having a first grid finer than a second grid of the source pixel space;

the oversampled filter coupled to the mapper and configured to filter the source pixels to the first grid pattern of the predetermined coefficients for selection of filter coefficients from the predetermined coefficients;

the filter coefficient module configured to select the filter coefficients from the predetermined coefficients stored in the oversampled filter based on proximity to the source pixels in the filter kernel; and

the filter coefficient module configured to predistort the digital image associated with the source pixels for the non-linear image mapping thereof;

a head up display (“

HUD”

) coupled to the video and graphics processing module;

at least one sensor camera coupled to the video and graphics processing module;

at least one visual camera coupled to the video and graphics processing module;

wherein the video and graphics processing module is configured to register a sensor image from the at least one sensor camera with a visual image from the at least one visual camera, and further configured to generate the display image;

wherein the image predistorter is configured to predistort the digital image for projection of the display image onto a windshield in the three dimensional perspective; and

wherein the HUD is configured to receive the predistorted display image for projection thereof.

16. The vehicle according to claim 15, wherein the image predistorter includes:

a convolution module coupled to the mapper and the filter coefficient module and configured to receive the source pixels from the mapper and the filter coefficients from the filter coefficient module, and configured to apply the filter coefficients to the source pixels in a convolution to generate a convolution result; and

a normalization module coupled to the convolution module or the filter coefficient module and configured to normalize either the convolution result or the filter coefficients, respectively.

17. The vehicle according to claim 15, wherein the HUD is an in-dash HUD.

18. The vehicle according to claim 15, wherein the HUD is an on-dash HUD.

19. The vehicle according to claim 15, wherein the HUD is configured to project the predistorted display image onto the windshield in the three dimensional perspective visually aligned with real-world objects viewable by a driver.

20. The vehicle according to claim 15, further comprising:

a lenticular material positioned over the HUD;

wherein the display image is not directly viewable due to being obscured by the lenticular material; and

wherein the display image is configured for viewing as a reflected image in the windshield.