Hi,

Background Description:

I'm trying to implement a program using C++ that returns the most common angle in a picture using chaining.
My program chains around objects recording the direction of the lines as numbers 0 - 7. 0 being North going clockwise round to 7 as North-West.
In order to smooth this result for each point I add the 10 neighbouring points and then divide the result by 10 to give an average/smoothed direction for that point.

Problem:

The problem comes when averaging a corner or line which has points that include values such as 0 and 7 returning the wrong results.

Does anyone know a way I can get around this?

Any help would be greatly appreciated. Thank you

If I understand you well, you can start with the statement that each point already has an uncertainty of +/- nx8.
So, if you add val1 +/- n1x8 + val2 +/- n2x8
+ ..... / 10, then you get a basic value plus
an offset which is a function of all the integers n divided by 10.
If I do this for 2 points : 1 and 7 I get
as result 4 + 4x(n1 + n2). So possible values are 4, 0, 8 etc.
This approach helps you ?

Regards.

The above is true, but gives no easy solution.
I think a better approach is to consider every
value as a vector. Decompose every vector in a X and a Y part. For instance :
0 : rY
1 : (r/V2)X + (r/V2)Y
2 : rX
3 : (r/V2)X - (r/V2)Y
etcetera.
If you assume that these are unit vectors the r's vanishes.
Sum all 10 X and all 10 Y values.
The average angle can be found by
arctan(Y/X). The signs of Y and X gives the
final quadrant.

I hope this will help you