DESC:DETERMINATION OF ROTARY CENTER OF ROTATABLE MEMBERS ,CLAIMS:1. A method comprising:
capturing an image of a rotatable member (102) that is to be used for holding a gemstone for its machining, the rotatable member (102) comprising a rotary center about which the rotatable member (102) is rotatable, wherein the rotary center is marked such that it has a pixel color value lesser than a threshold in the image;
determining a position of the rotary center in the image based on its pixel color value being lesser than the threshold; and
comparing the position of the rotary center in the image with a position of the rotary center in a reference image of the rotatable member (102), wherein the position of the rotary center the reference image is a reference position for the rotary center, for identifying the position of the rotary center relative to the reference position.

2. The method as claimed in claim 1, wherein the comparing comprises overlaying the image on the reference image.

3. The method as claimed in claim 1, wherein determining the position of the rotary center is performed using an edge detection technique.

4. The method as claimed in claim 1 comprising determining a ratio of pixels in the image to microns.

5. The method as claimed in claim 4 comprising:
determining a displacement between the position of the rotary center in the image and the position of the rotary center in the reference image based on the ratio of pixels in the image to microns; and
moving the rotatable member (102) for the displacement such that the rotary center coincides with the position of the rotary center in the reference image.

6. The method as claimed in claim 5 comprising:
holding the gemstone at the rotary center;
rotating the rotatable member (102); and
illuminating the gemstone with a laser beam for the processing of the gemstone.

7. The method as claimed in claim 1 comprising marking the rotary center using at least one of a laser light beam and ink.

8. A method comprising:
placing a rotatable member (102) on an actuator (104) such that a rotary center of the rotatable member (102) is at its reference position;
emitting a laser beam towards the rotatable member (102); and
focusing the laser beam towards the rotary center to mark the rotary center, wherein the marked rotary center is such that it has a pixel color value lesser than a threshold in an image.

9. A system (100) comprising:
a rotatable member (102) on which a gemstone is to be held for its machining, the rotatable member (102) comprising a rotary center about which the rotatable member (102) is rotatable, wherein the rotary center is marked such that it has a pixel color value lesser than a threshold in an image of the rotatable member (102);
an image capturing device (112) to capture the image of the rotatable member (102); and
a computing device (116) to process the image to determine a position of the rotary center relative to a reference position for the rotary center, wherein the position of the rotary center in the image is determined based on its pixel color value being lesser than the threshold, and wherein the reference position is a position of the rotary center in a reference image of the rotatable member (102).

10. The system (100) as claimed in claim 9 comprising a laser source (106) to mark the rotary center.

11. The system (100) as claimed in claim 10 comprising:
a first optical device (108) to direct the laser towards the rotatable member (102); and
a focusing optical device (110) to receive the laser and to focus it towards the rotary center of the rotatable member (102).

12. The system (100) as claimed in claim 9 comprising a second optical device (114) to direct light coming from the rotatable member (102) through a focusing optical device (110) towards the image capturing device (112).

13. The system (100) as claimed in claim 9 comprising an actuator (104) to rotate the rotatable member (102).

14. The system (100) as claimed in claim 9, wherein, to determine the position of the rotary center relative to the reference position for the rotary center, the computing device (116) is to:
overlay the image on the reference image; and
compare the position of the rotary center in the image and in the reference image.

15. The system (100) as claimed in claim 9, wherein the computing device (116) is to determine a displacement between the position of the rotary center in the image and the reference position of the rotary center based on a ratio of pixels to microns.

16. The system (100) as claimed in claim 15 comprising a second actuator to move the rotatable member (102) for the displacement such that the position of the rotary center coincides with the reference position of the rotary center.