Detection of hanging wires in digital color images

1. A method of detecting and using hanging wire pixels in a digital image, having pixels comprising:

(a) identifying pixels from the digital color image representing one or more sky regions without user intervention;

(b) detecting pixels representing hanging wire regions in the sky regions without user intervention; and

(c) using the detected hanging wire pixels to determine the orientation of the digital image or to replace such hanging wire pixels without user intervention.

2. A method of improving a digital color image having pixels, the method comprising:

(a) identifying pixels from the digital color image representing one or more sky regions without user intervention;

(b) detecting sky occlusion regions by examining the sky regions without user intervention;

(c) developing a model based on the identified sky pixels without user intervention, wherein such model is a mathematical function that has inputs of pixel position and outputs of color;

(d) using the model to operate on the digital color image to replace the values of pixels from the sky occlusion regions with values predicted by the model without user intervention; and

(e) determining when sky occlusion regions are formed by hanging wires and determining the orientation of the image based on the detected hanging wire regions.

3. The method of claim 2 wherein the model is a two-dimensional polynomial of the pixel position in the digital color image.

4. The method of claim 3 wherein the polynomial is a second-order polynomial.

5. The method of claim 2 wherein the step of identifying an initial sky region further comprises:

(i) identifying pixels from the digital color image representing an initial sky region;

(ii) developing a model based on the identified sky pixels, wherein such model is a mathematical function that has inputs of pixel position and outputs of color; and

(iii) and using the model to operate on the digital color image to classify additional pixels not included in the initial sky region as sky.

6. A method of determining the orientation of a digital color image having pixels, the method comprising:

(a) identifying pixels from the digital color image representing one or more sky regions without user intervention;

(b) detecting one or more hanging wire regions by examining the sky regions without user intervention; and

(c) analyzing the hanging wire regions to determine the orientation of the digital color image without user intervention.

7. The method of claim 6 wherein analyzing the hanging wire regions further comprises:

determining the direction of gravity by examining the location of pixels of the hanging wire region with respect to the endpoints of the hanging wire region.

8. A method of removing hanging wire region pixels from detected sky regions in a digital color image having pixels, the method comprising:

(a) identifying pixels from the digital color image representing one or more sky regions without user intervention;

(b) detecting hanging wire regions by examining the sky regions without user intervention;

(c) developing a model based on the identified sky pixels, wherein such model is a mathematical function that has inputs of pixel position and outputs of color without user intervention; and

(d) using the model to operate on the digital color image to replace the values of digital color image pixels associated with the hanging wire regions with values predicted by the model to thereby remove the hanging wire region pixels without user intervention.