Navigation using fourier phase technique

1. A method for controlling a cursor on a screen, comprising:

determining at least one dimension for a first sub-slice and for a second sub-slice;

extracting, using a computer processor, the first and second sub-slices from first and second image slices, respectively, wherein each of the first and second image slices capture an image of a portion of a finger and wherein the first and second image slices overlap in a first overlapping region and the first and second sub-slices overlap in a second overlapping region;

computing a shift between the first image slice and the second image slice based information included in the second overlapping region while ignoring at least a portion of information included in the first overlapping region that is outside of the second overlapping region; and

determining a displacement of the cursor on the screen based on the computed shift.

2. The method of claim 1 , wherein the computing step comprises:

computing a PHAse Transform of the first and second sub-slices.

3. The method of claim 1 , wherein the computing step comprises:

computing a correlation between the first and second sub-slices.

4. The method of claim 1 , further comprising:

repeating the extracting, the computing, and the determining steps.

5. The method of claim 1 , further comprising:

receiving the first image slice from a scanner; and

retrieving the second image slice from a memory.

6. The method of claim 5 , further comprising:

storing the first image slice in the memory.

7. The method of claim 6 , wherein the storing step comprises:

overwriting the second image slice with the first image slice in the memory.

8. A system for controlling a cursor on a screen, comprising:

a memory; and

a processor coupled to the memory and configured to execute a plurality of modules, wherein the modules include:

a shift determining module configured to determine a shift between a first image slice and a second image slice, wherein each of the first and second image slices capture an image of a portion of a finger, the shift determining module comprising:

a control module configured to determine at least one dimension for a first sub-slice and for a second sub-slice:

an extraction module configured to extract the first and second sub-slices from the first and second image slices, respectively, wherein the first and second image slices overlap in a first overlapping region and the first and second sub-slices overlap in a second overlapping region; and

a shift computation module configured to compute the shift between the first and second image slices based on information included in the second overlapping region while ignoring at least a portion of information included in the first overlapping region that is outside of the second overlapping region; and

a cursor movement module configured to determine a displacement of the cursor on the screen based on the determined shift.

9. The system of claim 8 , wherein the shift computation module is configured to compute a PHAse Transform of the first and second sub-slices.

10. The system of claim 8 , wherein the shift computation module is configured to compute a correlation between the first and second sub-slices.

11. The system of claim 8 , further comprising:

a sensor configured to output image slices;

wherein the shift determining module is configured to receive the first image slice from the sensor and the second image slice from the memory.

12. The system of claim 11 , wherein:

the control module is configured to overwrite the second image slice with the first image slice.