Enhancing text in images

1. A computer-implemented method comprising:

receiving, by a computing system, a plurality of images each image including a corresponding version of an identified candidate text region;

aligning, by the computing system, each candidate text region from the plurality of images to a high resolution grid;

compositing, by the computing system, the aligned candidate text regions to create a single superresolution image; and

performing, by the computing system, character recognition on the superresolution image to identify text.

2. The method of claim 1 , where receiving a plurality of images includes receiving images having features associated with text and features associated with non-text image content.

3. The method of claim 2 , further comprising identifying the candidate text region of a received image of the plurality of images by:

dividing the image into a plurality of regions;

detecting features in each region of the plurality of regions;

analyzing detected features in each region; and

determining whether the detected features indicate text.

4. The method of claim 3 , further comprising:

receiving ranging data associated with the received image;

generating a planar map of the received image using the ranging data;

comparing the identified candidate text region with the planar map; and

eliminating the identified candidate text region if the candidate text region is not located on a single plane.

5. The method of claim 1 , where the received images correspond to images of a scene collected from different perspectives.

6. The method of claim 1 , further comprising:

supersampling the candidate text regions from each image of the plurality of images.

7. The method of claim 6 , where supersampling the candidate text regions is performed using bicubic splines.

8. The method of claim 1 , where aligning the candidate text regions comprises aligning pixels of the candidate text regions using block matching.

9. The method of claim 1 , where aligning the candidate text regions includes using range data associated with each image of the plurality of images.

10. The method of claim 1 , where compositing the aligned candidate text regions comprises combining pixels from each candidate text region including:

determining a median value for each pixel value; and

combining the median values for aligned pixels.

11. A computer program product, encoded on a computer-readable medium, operable to cause data processing apparatus to perform operations comprising:

receiving a plurality of images each including a corresponding version of an identified candidate text region;

aligning each candidate text region from the plurality of images to a high resolution grid;

compositing the aligned candidate text regions to create a single superresolution image; and

performing character recognition on the superresolution image to identify text.

12. The computer program product of claim 11 , where receiving a plurality of images includes receiving images having features associated with text and features associated with non-text image content.

13. The computer program product of claim 12 , further comprising:

receiving ranging data associated with the received image;

generating a planar map of the received image using the ranging data;

comparing the identified candidate text region with the planar map; and

eliminating the identified candidate text region if the candidate text region is not located on a single plane.

14. The computer program product of claim 11 , further comprising identifying the candidate text region of a received image of the plurality of images by:

dividing the image into a plurality of regions;

detecting features in each region of the plurality of regions;

analyzing detected features in each region; and

determining whether the detected features indicate text.

15. The computer program product of claim 11 , where the received images correspond to images of a scene collected from different perspectives.

16. The computer program product of claim 11 , further comprising:

supersampling the candidate text regions from each image of the plurality of images.

17. The computer program product of claim 16 , where supersampling the candidate text regions is performed using bicubic splines.

18. The computer program product of claim 11 , where aligning the candidate text regions comprises aligning pixels of the candidate text regions using block matching.

19. The computer program product of claim 11 , where aligning the candidate text regions includes using range data associated with each image of the plurality of images.

20. The computer program product of claim 11 , where compositing the aligned candidate text regions comprises combining pixels from each candidate text region including:

determining a median value for each pixel value; and

combining the median values for aligned pixels.

21. A system comprising:

means for receiving a plurality of images each including a corresponding version of an identified candidate text region;

means for aligning each candidate text region from the plurality of images to a high resolution grid;

means for compositing the aligned candidate text regions to create a single superresolution image; and

means for performing character recognition on the superresolution image to identify text.

22. A system comprising:

one or more data processing apparatus configured to perform operations comprising:

receiving a plurality of images each including a corresponding version of an identified candidate text region;

aligning each candidate text region from the plurality of images to a high resolution grid;

compositing the aligned candidate text regions to create a single superresolution image; and

performing character recognition on the superresolution image to identify text.

23. The system of claim 22 , where receiving a plurality of images includes receiving images having features associated with text and features associated with non-text image content.

24. The system of claim 23 , further comprising:

receiving ranging data associated with the received image;

generating a planar map of the received image using the ranging data;

comparing the identified candidate text region with the planar map; and

eliminating the identified candidate text region if the candidate text region is not located on a single plane.

25. The system of claim 22 , further comprising identifying the candidate text region of a received image of the plurality of images by:

dividing the image into a plurality of regions;

detecting features in each region of the plurality of regions;

analyzing detected features in each region; and

determining whether the detected features indicate text.

26. The system of claim 22 , where the received images correspond to images of a scene collected from different perspectives.

27. The system of claim 22 , further comprising: supersampling the candidate text regions from each image of the plurality of images.

28. The system of claim 27 , where supersampling the candidate text regions is performed using bicubic splines.

29. The system of claim 22 , where aligning the candidate text regions comprises aligning pixels of the candidate text regions using block matching.

30. The system of claim 22 , where aligning the candidate text regions includes using range data associated with each image of the plurality of images.

31. The system of claim 22 , where compositing the aligned candidate text regions comprises combining pixels from each candidate text region including:

determining a median value for each pixel value; and

combining the median values for aligned pixels.