vcm

Circles

the script call for Circles is

vcm.Circles(clip[, int xo = frame width / 2][,int yo = frame height / 2][, int fdia = greater of xo and yo][,float dim = 0.75][, int dots = 2][, int cint = 50][, int rgb=[255,255,255])

clip: input clip RGB, YUV or GRAY constant format.
xo:X coordinate of fish eye image. Can be reasonably outside input frame.
yo:Y coordinate of fish eye image. Can be reasonably outside input frame.
fdia: Diameter to be specially marked
dim: factor of dimming. 0 is fully blackened and 1.0 is input is not dimmed. This is to ensure the white dots are visible clearly on image.
dots: 1 to 5. Density of dots per some arbitrary square area.
cint: Interval between circles. 10 to higher fitting circle
rgb: color of dots as 8bit red, green, blue array.

concentric circles are drawn on image. Specified diameter is highlighted.