Method and system for transforming an image of a biological surface

• US 7,356,169 B2
• Filed: 06/19/2002
• Issued: 04/08/2008
• Est. Priority Date: 06/27/2001
• Status: Active Grant

• Current Assignee: Activcard Ireland, Limited
• Original Assignee: Activcard Ireland, Limited
• Inventors: Hamid, Laurence
• Primary Examiner(s): Bella; Matthew C.
• Assistant Examiner(s): Lu; Tom Y
• Application Number:
  US10/173,754
• Publication Number:
  US 20030007670A1
• Time in Patent Office: 2,120 Days
• Field of Search: 382/124, 382/126
• US Class Current: 382/124
• CPC Class Codes: G06V 40/12 Fingerprints or palmprints
• CPC Class Codes: G06V 40/1347 Preprocessing; Feature extraction

Abstract

Provided is a method of transforming an image of a biometric surface comprising the steps of sensing a biometric surface to provide biometric image data, receiving data relating to a plurality of parameters for use in transforming image data different parameters for resulting in differently transformed image data for a same biometric image data, the data received from another processor, transforming the biometric image data in accordance with the received data to provide transformed biometric image data in a format relating to the received data, and providing the transformed biometric image data as output image data having the format, wherein the transformed biometric image data is different for different parameters enabling provision of images of a same biometric surface having different image formats. There is further provided a biometric imaging device for executing the above described method, as well as memory for storing data, relevant to the above-described method.

Claims

1. A method of transforming an image of a biometric surface, comprising the steps of:

sensing the biometric surface using a contact imaging device to provide sensed biometric image data having at least two rows and two columns and image parameters including at least image resolution;

receiving transform data relating to a plurality of transform parameters including at least image resolution for use in transforming the sensed biometric image data, wherein different transform parameters result in differently transformed image data for a same biometric image data;

transforming the sensed biometric image data in accordance with the received transform data to provide transformed biometric image data in a biometric imaging data format other than a biometric imaging data format of the sensed biometric image data; and

providing the transformed biometric image data as output image data,

wherein the transformed biometric image data is different for different transform parameters enabling provision of images of a same biometric surface having different biometric imaging data formats.

2. A method for imaging a biometric surface according to claim 1, further comprising the steps of:

sensing a plurality of partial images using a contact swipe imager; and

constructing a composite image from said partial images to provide a sensed biometric image.

3. A method for imaging a biometric surface according to claim 2, further comprising the step of capacitively sensing biometric image data of a biometric surface.

4. A method for imaging a biometric surface according to claim 2, wherein the transformed biometric image data represents a framed feature of the biometric surface.

5. A method for imaging a biometric surface according to claim 4, wherein the framed feature is transformed according to at least one of resolution, orientation, and line width.

6. A method for imaging a biometric surface according to claim 2, wherein the transformed biometric image data is transformed according to its frame size.

7. A method for imaging a biometric surface according to claim 2, wherein the transformed biometric image data is transformed according to a feature indicated in the parameters.

8. A method for imaging a biometric surface according to claim 2, wherein the output image data is provided to one of a plurality of different compatible analysis applications.

9. A method for imaging a biometric surface according to claim 8, wherein the step of transforming involves a same transform process for different ones of the compatible analysis applications, the same transform process transform result being variable in dependence upon the parameters.

10. A method for imaging a biometric surface according to claim 2, wherein the captured image data are provided according to industry standard biometric imaging data formats.

11. A method for imaging a biometric surface according to claim 2, wherein the biometric surface is a fingerprint.

34. A method for imaging a biometric surface according to claim 1, wherein the received transform data includes transform data for the transformed biometric image data, the transform data including a horizontal resolution r_h, a vertical resolution r_v, a number of pixels a_h in a horizontal direction, a number of pixels a_v in a vertical direction, and a data point depth d_bit, comprising the steps of:

determining an image area within the biometric surface for the sensed biometric image data, the image area having A_h pixels in a horizontal direction and A_v pixels in a vertical direction;

determining an image resolution of the sensed biometric image data, the image having a horizontal resolution R_h and a vertical resolution R_v;

determining a data point depth D_bit for the sensed biometric image data; and

determining an area of interest within the image area,

wherein the transforming step comprises the step of transforming at least one of A_h to a_h, A_v to a_v, R_h to r_h, R_y to r_y, and D_bit to d_bit for the area of interest.

35. A method for imaging a biometric surface according to claim 34, wherein if A_h/R_h>

A_h/r_h, then calculating A_h(A_h/R_h−

A_h/r_h)/2 as a representation of a number of pixels to be trimmed from both horizontal sides of the output image data.

36. A method for imaging a biometric surface according to claim 34, wherein if A_v/R_v>

A_v/r_v, then calculating A_v(A_v/R_v−

A_v/r_v)/2 as a representation of a number of pixels to be trimmed from both vertical sides of the output image data.

37. A method for imaging a biometric surface according to claim 36, wherein data points are removed in proportion to the number of pixels to be trimmed.

38. A method for imaging a biometric surface according to claim 36, wherein data points are interpolated to reconstruct the output image data as it would have been sensed if it were sensed at the transformed resolution.

39. A method for imaging a biometric surface according to claim 34, wherein if A_h/R_h<

A_h/r_h, then calculating A_h(A_h/R_h−

A_h/r_h)/2 as a representation of a number of pixels to be added to both horizontal sides of the output image data.

40. A method for imaging a biometric surface according to claim 34, wherein if A_v/R_v<

A_v/r_v, then calculating A_v(A_v/R_v−

A_v/r_v)/2 as a representation of a number of pixels to be added to both vertical sides of the output image data.

41. A method for imaging a biometric surface according to claim 40, wherein data points are interpolated to reconstruct the output image data as it would have been sensed if it were sensed at the transformed resolution.

42. A method for imaging a biometric surface according to claim 1, wherein the transforming step comprises the steps of:

determining an image of a known area relative to a feature of the sensed biometric image data;

during said transforming step, maintaining a resolution of said known area;

rotating the image area relative to the feature; and

transforming a resolution of said image area such that a number of pixels along each axis is in accordance with a desired image size.

12. A method of transforming an image of a biometric surface for use in identification of a person, comprising the steps of:

sensing the biometric surface using a contact imaging device to provide sensed biometric image data having at least two rows and two columns and image parameters including at least image resolution;

receiving transform data relating to a plurality of transform parameters including at least image resolution for use in transforming sensed biometric image data, wherein different transform parameters result in differently transformed image data for a same biometric image data;

transforming the sensed biometric image data in accordance with the received transform data to provide transformed biometric image data in a biometric imaging data format other than a biometric imaging data format of the sensed biometric image data;

providing the transformed biometric image data as output image data,

wherein the transformed biometric image data is different for different transform parameters enabling provision of images of a same biometric surface having different biometric imaging data formats;

providing template image data of a predetermined biometric surface; and

comparing the output image data to template image data for identifying the person.

13. A biometric imaging device for imaging a biometric surface, comprising:

a memory that stores a plurality of transform parameters including at least image resolution, wherein different transform parameters result in different transformed image data when used to transform for a same image data;

a sensing device that senses the biometric surface and that provides sensed biometric image data relating to an image of the biometric surface, said biometric image data having at least two rows and two columns and image parameters including at least image resolution; and

a processor that transforms the sensed biometric image data into transformed data in one of a number of biometric imaging data formats in accordance with the plurality of transform parameters,

wherein the transformed sensed biometric image data is different for different received transform parameters enabling provision of images of a same biometric surface having different biometric imaging data formats from a same biometric imaging device.

14. A biometric imaging device according to claim 13, wherein the sensing device is a contact swipe imager that senses data in the form of a plurality of partial images.

15. A biometric imaging device according to claim 14, further comprising a processor that constructs a composite image from said plurality of partial images.

16. A biometric imaging device according to claim 15, wherein the processor that transforms the sensed data is a same processor as the processor that constructs the composite image.

17. A biometric imaging device according to claim 13, wherein the sensing device is a capacitive sensing device.

18. A biometric imaging device according to claim 13, wherein the sensing device is a fingerprint sensor.

19. A biometric image interface for interfacing a biometric sensing device with an image analysis device, the biometric image interface comprising:

a memory that receives and stores a plurality of transform parameters from the image analysis device, the transform parameters including at least image resolution, wherein different transform parameters result in different transformed image data when used to transform for a same image data; and

a processor that executes instructions for the biometric sensing device in accordance with the received transform parameters, transforms biometric data from the biometric sensing device into one of a number of biometric imaging data formats in accordance with the transform parameters, and transmits to the image analysis device output image data transformed in accordance with the received transform parameters , wherein transforming is performed differently for different transform parameters, thereby enabling provision of images of a same biometric surface having different biometric imaging data formats using a same biometric sensing device.

20. A biometric image interface according to claim 19, wherein the sensing device is a contact swipe imager that senses data in the form of a plurality of partial images.

21. A biometric image interface according to claim 19, wherein the sensing device is a capacitive sensing device.

22. A biometric image interface according to claim 19, wherein the sensing device is a fingerprint sensor.

23. A biometric image interface according to claim 19, wherein the image analysis device compares the transmitted output image data with template image data.

24. A computer readable medium having stored therein data relating to instructions for execution on a processor, the instructions for performing the steps of:

receiving transform data relating to a plurality of transform parameters including at least image resolution for use in transforming image data where different transform parameters result in differently transformed image data for a same biometric image data;

transforming the biometric image data in accordance with the received transform data to provide transformed biometric image data in a biometric imaging data format relating to the received transform data; and

providing the transformed biometric image data as output image data having the biometric imaging data format relating to the received transform data,

wherein the transformed biometric image data is different for different transform parameters enabling provision of images of a same biometric surface having different biometric imaging data formats.

25. A computer readable medium according to claim 24, the data including instructions for performing the steps of:

sensing a plurality of partial images using a contact swipe imager; and

constructing a composite image from said partial images.

26. A computer readable medium according to claim 24, the data including instructions for performing the step of capacitively sensing image data of a biometric surface.

27. A computer readable medium according to claim 24, wherein the transformed biometric image data represents a framed feature of the biometric surface.

28. A computer readable medium according to claim 27, wherein the framed feature is transformed according to at least one of resolution, orientation, and line width.

29. A computer readable medium according to claim 24, wherein the transformed biometric image data is transformed according to its frame size.

30. A computer readable medium according to claim 24, wherein the transformed biometric image data is transformed according to a feature indicated in the parameters.

31. A computer readable medium according to claim 24, wherein the output image data is provided to one of a plurality of different compatible analysis applications.

32. A computer readable medium according to claim 31, wherein the step of transforming involves a same transform process for different ones of the compatible analysis applications, the same transform process transform result being variable in dependence upon the parameters.

33. A computer readable medium according to claim 24, wherein the captured image data is provided according to industry standard biometric imaging data formats.

43. A computer readable medium according to claim 24, wherein the received transform data includes transform data for the transformed biometric image data, the transform data including a horizontal resolution r_h, a vertical resolution r_v, a number of pixels a_h in a horizontal direction, a number of pixels a_v in a vertical direction, and a data point depth d_bit, the data further including instructions for performing the steps of:

determining an image area within the biometric surface for the biometric image data, the image area having A_h pixels in a horizontal direction and A_v pixels in a vertical direction;

determining an image resolution of the biometric image data, the image having a horizontal resolution R_h and a vertical resolution R_v;

determining a data point depth D_bit for the biometric image data; and

determining an area of interest within the image area,

wherein the transforming step comprises the step of transforming at least one of A_h to a_h, A_v to a_v, R_h to r_h, R_y to r_y, and D_bit to d_bit for the area of interest.

44. A computer readable medium according to claim 43, wherein if A_h/R_h>

A_h/r_h, then instructions are further included for calculating A_h(A_h/R_h−

A_h/r_h)/2 as a representation of a number of pixels to be trimmed from both horizontal sides of the output image data.

45. A computer readable medium according to claim 43, wherein if A_v/R_v>

A_v/r_v, then instructions are further included for calculating A_v(A_v/R_v−

A_v/r_v)/2 as a representation of a number of pixels to be trimmed from both vertical sides of the output image data.

46. A computer readable medium according to claim 45, further including instructions for removing data points in proportion to the number of pixels to be trimmed.

47. A computer readable medium according to claim 45, further including instructions for interpolating the data points to reconstruct the output image data as it would have been sensed if it were sensed at the transformed resolution.

48. A computer readable medium according to claim 43, wherein if A_h/R_h<

A_h/r_h, then instructions are further included for calculating A_h(A_h/R_h−

A_h/r_h)/2 as a representation of a number of pixels to be added to both horizontal sides of the output image data.

49. A computer readable medium according to claim 43, wherein if A_v/R_v<

A_v/r_v, then instructions are further included for calculating A_v(A_v/R_v−

A_v/r_v)/2 as a representation of a number of pixels to be added to both vertical sides of the output image data.

50. A computer readable medium according to claim 49, further including instructions for interpolating data points to reconstruct the output image data as it would have been sensed if it were sensed at the transformed resolution.

51. A computer readable medium according to claim 24, wherein the transforming step comprises the steps of:

determining an image of a known area relative to a feature of the biometric image data;

during said transforming step, maintaining a resolution of said known area;

rotating the image area relative to the feature; and

transforming a resolution of said image area such that a number of pixels along each axis is in accordance with a desired image size.