Steganographic encoding

1. A mechanical part comprising:

a metallic surface including a pattern,

the pattern conveying plural-bit auxiliary data in a steganographic manner, and

the pattern provides at least diffuse reflection.

2. The mechanical part of claim 1 , wherein the pattern is provided on the metallic surface with an ink or dye.

3. The mechanical part of claim 2 wherein the metallic surface comprises a first color and the ink or dye comprises a second color, the second color being chosen to help hide or conceal the ink or dye when provided over the first color.

4. The mechanical part of claim 1 wherein the pattern conveying the auxiliary data is provided with digital watermarking.

5. The mechanical part of claim 4 , wherein the auxiliary data is redundantly provided on the metallic surface.

6. The mechanical part of claim 4 , wherein the digital watermarking comprises a component to help resolve distortion introduced during image capture.

7. The mechanical part of claim 1 , wherein the pattern is provided in the metallic surface with small indentations in the surface.

8. The mechanical part of claim 1 in which the pattern comprises a dull finish.

9. An automotive part comprising the mechanical part of claim 1 .

10. The mechanical part of claim 1 , wherein the diffuse reflection approximates Lambertian reflection.

11. A method comprising:

obtaining plural-bit auxiliary data;

creating an original carrier signal representing the plural-bit auxiliary data;

reducing information content of the original carrier signal so that the carrier still conveys the plural-bit auxiliary data, yielding a reduced carrier signal;

hiding the reduced carrier signal in host data.

12. The method of claim 11 wherein the act of hiding is accomplished with digital watermarking.

13. The method of claim 11 wherein the host data resides on a mechanical part.

14. The method of claim 11 wherein the host data comprises audio or video.

15. A computer readable medium comprising instructions stored thereon to cause an electronic processor to perform the method of claim 11 .

16. A programmed computing device comprising instructions stored in memory, said instructions cause said programmed computing device to perform the method of claim 11 .

17. A mechanical part comprising:

a shiny or metallic surface including a pattern,

the pattern including or representing the auxiliary data in a steganographic manner, the pattern providing diffuse or Lambertian reflection.

18. The mechanical part of claim 17 wherein the pattern is provided with an ink or dye and wherein at least one of a coloration or finish of the ink or dye is selected to hide the ink or dye with respect to at least one of a first coloration or a first finish.

19. The mechanical part of claim 17 , wherein the pattern is provided in the shiny or metallic surface through small indentations in the surface.

20. An apparatus comprising:

electronic memory for storing plural-bit auxiliary data;

one or more electronic processors programmed for:

creating an original carrier signal representing the plural-bit auxiliary data;

reducing information content of the original carrier signal so that the carrier still conveys the plural-bit auxiliary data, yielding a reduced carrier signal;

hiding the reduced carrier signal in host data.

21. The apparatus of claim 20 in which the hiding is accomplished with digital watermarking.

22. The apparatus of claim 21 in which the one or more electronic processors are operating to perform at least one of the functions recited therein.

23. The apparatus of claim 20 in which the host data is to reside on a mechanical part.

24. The apparatus of claim 20 in which the host data comprises audio or video.

25. The apparatus of claim 24 in which the one or more electronic processors are operating to perform at least one of the functions recited therein.

26. The apparatus of claim 20 in which the one or more electronic processors are operating to perform at least one of the functions recited therein.