Best way to find HSV values

Question

I am going to apply a HSV threshold to the image below in order to extract the tennis ball. But I could not figure out the best way to find the correct HSV values of the ball. Which method/software do you suggest to me? (I am using Ubuntu) Also according to your experiences which min/max values do you prefer to me? (±10? ±5?)

Regards

Answer 1

You can use Gimp to get needed color. The tool is called Color Picker. It also shows HSV values. Here's screenshot of your image:

Answer 2

Have you considered to use Hough Circle^Doc ?

I think in this case it would be much more indicted, because the colors in your image aren't so clear