PHP Gmagick extension

Is there a way to get all the colors of an image?

Example this image

The output should have the colors: yellow,black,blue.

It can also result in a Hex Value.

Can someone tell me any idea how to get that result? or maybe someone has already implemented this one, kindly show it to me.

Thanks. Any help would be greatly rewarded and appreciate开发者_高级运维d.

---

What about this thread: most colors used (color analysis)