External user interface for head worn computing

1. A method, comprising:

presenting, via a see-through display of a wearable device, a virtual line as a guide for alignment of one or more input strokes written by a wearer of the wearable head device;

tracking a motion of a pen held by the wearer as the pen moves along a surface relative to the virtual line, wherein the tracking comprises:

receiving, via an IMU located on the pen, a signal indicative of movement of the pen; and

obtaining images of the pen as the pen moves relative to the virtual line;

determining, based on the signal, a first relative motion between a tip of the pen and the virtual line;

determining, based on the images, a second relative motion between the tip of the pen and the virtual line; and

determining an input sequence corresponding to the one or more input strokes, wherein the input sequence is determined based on a comparison of the first relative motion and the second relative motion.

2. The method of claim 1 , wherein the virtual line is presented as a portion of a note.

3. The method of claim 1 , wherein the virtual line is presented as a portion of a message template.

4. The method of claim 1 , wherein the virtual line is presented as a portion of an email template.

5. The method of claim 1 , wherein the virtual line is presented as a portion of a writing teaching platform.

6. The method of claim 1 , wherein the virtual line is presented as a portion of a painting teaching platform.

7. The method of claim 1 wherein the virtual line is presented as a portion of a drawing teaching platform.

8. The method of claim 1 , wherein the input sequence is presented via the see-through display relative to the virtual line.

9. The method of claim 8 , wherein the presentation is in real time.

10. The method of claim 1 , wherein determining the input sequence of the pen includes determining a relative position between the tip of the pen and the virtual line.

11. The method of claim 1 , wherein tracking the motion of the pen held by the wearer as the pen moves along the surface relative to the virtual line further comprises receiving surface images captured by a pen tip camera located on the pen.

12. The method of claim 11 , wherein determining the input sequence of the pen further comprises determining, based on the surface images, a third relative motion between the tip of the pen and the virtual line and in accordance with a discrepancy between the first relative motion and the second relative motion, determining the input sequence of the pen further based on the third relative motion.

13. A non-transitory computer-readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by one or more processors of one or more electronic devices, cause the electronic devices to:

present, via a see-through display of a wearable device, a virtual line as a guide for alignment of input strokes written by a wearer of the wearable head device;

track a relative motion of a pen held by the wearer as the pen moves along a surface relative to the virtual line, wherein the tracking comprises:

receiving, via an IMU located on the pen, a signal indicative of movement of the pen; and

obtaining images of the pen as the pen moves relative to the virtual line;

determine, based on the signal, a first relative motion between a tip of the pen and the virtual line;

determine, based on the images, a second relative motion between the tip of the pen and the virtual line; and

determine an input sequence corresponding to the one or more input strokes, wherein the input sequence is determined based on a comparison of the first relative motion and the second relative motion.

14. The non-transitory computer-readable storage medium of claim 13 , wherein determining the input sequence of the pen includes determining a relative position between the tip of the pen and the virtual line.

15. The non-transitory computer-readable storage medium of claim 13 , wherein tracking the relative motion of the pen held by the wearer as the pen moves along the surface relative to the virtual line further comprises receiving surface images captured by a pen tip camera located on the pen.

16. The non-transitory computer-readable storage medium of claim 15 , wherein determining the input sequence of the pen further comprises determining, based on the surface images, a third relative motion between the tip of the pen and the virtual line and in accordance with a discrepancy between the first relative motion and the second relative motion, determining the input sequence of the pen further based on the third relative motion.

17. The non-transitory computer-readable storage medium of claim 13 , wherein the input sequence is presented via the see-through display relative to the virtual line.

18. The non-transitory computer-readable storage medium of claim 17 , wherein the presentation is in real time.

19. The non-transitory computer-readable storage medium of claim 13 , wherein the virtual line is presented as a portion of at least one of a note, a message template, and an email.

20. The non-transitory computer-readable storage medium of claim 13 , wherein the virtual line is presented as a portion of at least one of a writing teaching platform, a painting teaching platform, and a drawing teaching platform.