Method and system for classifying painted road markings in an automotive driver-vehicle-assistance device

1. For use in a vehicle, an automated, computerized method for processing an image, comprising the steps of:

receiving from a digital camera mounted on the vehicle, an image file depicting pixels of an image of a scene related to vehicle operation on a road, each one of the pixels having N band color values;

transforming the N bands to log color space values in a log color space;

generating a log chromaticity plane in the log color space;

identifying pixels meeting criteria indicating suitability for use in determining an accurate orientation for the log chromaticity plane, according to a BIDR model and based upon an analysis of the pixels of an image of a scene related to vehicle operation on a road, wherein the pixel analysis is based upon an estimate of lit road color;

calculating an orientation for the log chromaticity plane, according to a BIDR model, as a function of the identified pixels;

projecting the log color space values to the chromaticity plane to provide chromaticity representation values corresponding to the pixels of the image; and

using the chromaticity representation values corresponding to the pixels to generate an illumination invariant image of the scene.

2. The method of claim 1 including the further step of using the illumination-invariant representation of the image to analyze the scene for painted road markings.

3. For use in a vehicle, an automated, computerized method for processing an image, comprising the steps of:

receiving from a digital camera mounted on the vehicle, an image file depicting pixels of an image of a scene related to vehicle operation on a road, each one of the pixels having N band color values;

transforming the N bands to log color space values in a log color space;

generating a log chromaticity plane in the log color space;

identifying pixels meeting criteria indicating suitability for use in determining an accurate orientation for the log chromaticity plane, according to a BIDR model and based upon an analysis of the pixels of an image of a scene related to vehicle operation on a road, wherein the pixel analysis is based upon an estimate of lit road color;

calculating an orientation for the log chromaticity plane, according to a BIDR model, as a function of the identified pixels;

projecting the log color space values to the chromaticity plane to provide chromaticity representation values corresponding to the pixels of the image;

using the chromaticity representation values corresponding to the pixels to generate an illumination invariant image of the scene;

receiving from the digital camera a series of image files, to depict a road video; and

performing a multi-thread operation, in a first thread, performing the step to calculate the orientation, and in a second thread, performing the steps to generate the illumination invariant image of the scene.

4. The method of claim 3 wherein the first thread operates on a subset of the series of image files, and the second thread operates on all of the series of image files.

5. The method of claim 3 including the further step of using the illumination-invariant representation of the image to analyze the scene for painted road markings.

6. A device comprising:

a computer system adapted to be coupled to a digital camera adapted for mounting on a vehicle to record an image of a scene related to vehicle operation on a road; and

the computer system including a memory storing an image file comprising pixels of an image of the scene;

the computer system being arranged and configured to execute a routine to:

receive from the memory, an image file depicting pixels of an image of a scene related to vehicle operation on a road, each one of the pixels having N band color values;

transform the N bands to log color space values in a log color space;

generate a log chromaticity plane in the log color space;

identify pixels meeting criteria indicating suitability for use in determining an accurate orientation for the log chromaticity plane, according to a BIDR model and based upon an analysis of the pixels of an image of a scene related to vehicle operation on a road, wherein the pixel analysis is based upon an estimate of lit road color;

calculate an orientation for the log chromaticity plane, according to a BIDR model, as a function of the identified pixels;

projecting the log color space values to the chromaticity plane to provide chromaticity representation values corresponding to the pixels of the image; and

using the chromaticity representation values corresponding to the pixels to generate an illumination invariant image of the scene.

7. A computer program product, disposed on a non-transitory computer readable media, the product including computer executable process steps operable to control a computer to:

receive an image file depicting pixels of an image of a scene related to vehicle operation on a road, in a computer memory, each one of the pixels having N band color values;

transform the N bands to log color space values in a log color space;

generate a log chromaticity plane in the log color space;

identify pixels meeting criteria indicating suitability for use in determining an accurate orientation for the log chromaticity plane, according to a BIDR model and based upon an analysis of the pixels of an image of a scene related to vehicle operation on a road, wherein the pixel analysis is based upon an estimate of lit road color;

calculate an orientation for the log chromaticity plane, according to a BIDR model, as a function of the identified pixels;

projecting the log color space values to the chromaticity plane to provide chromaticity representation values corresponding to the pixels of the image; and

using the chromaticity representation values corresponding to the pixels to generate an illumination invariant image of the scene.