Function draw_circle 

pub fn draw_circle(
    image: &mut Tensor,
    cx: i32,
    cy: i32,
    radius: usize,
    color: [f32; 3],
    thickness: usize,
) -> Result<(), ImgProcError>

Draw a circle on a u8 image. Draw a circle using the midpoint circle algorithm on a [H, W, 3] image tensor.

(cx, cy) is the center, radius is the radius in pixels. thickness == 0 fills the circle.