Making the centroid of an image equal to 0

Hello:

I calculated the centroid of my input image. I am decomposing the image into zernike moments. As zernike moments lie on the unit circle, the centroid of the image has to be 0. How do I get an image that has a centroid of 0?

Thanks,

Urmila

[None None]

We are also using Zernike moments. But we are not getting the concept of mapping region into unit circle. Is it related to compressing an image or region in image or somethingelse. Pls help us. Thanks, Lalita

Answer 1

[Walter Roberson]

Find the centroid and subtract that off of all of your coordinates. Just don't try to index an array at the resulting values.

[Urmila]

What do you mean by not indexing an array at the resulting values?

[Walter Roberson]

Suppose your array is from 1 to 100, and the centroid shows up at (say) 35. You subtract that 35 from all of your coordinates, so your coordinate system now runs from -34 to 66. You can then do calculations based on that coordinate system. But do not try to index an array at location -34: array locations start at 1, always. Coordinates are not array indexes.

[None None]

Thanks. This will be really helpful for us for our project.