How to calculate mean and standard deviation in from the image sample

Hello guys,

I have calculated the height of every rectangle, which are present in the image through the Pixel to micron conversion. But, i have to calculate following thing by automated loading the height previously

1) mean of height, μ = Formula (h1+h2+h3+h4)/4

2) standard deaviation for that height, σ= formula attached in the image

can you please tell me an code for that? so i can run that code to find out in my PC.

Additionally,if user only want to take 3 or 2 sample of height then can we put that condition so it can only calculate for 3 or 2 or according to user reuirements? I appreciate if you mention code for this option too.

Image attached in the comment

Thanks a lot in advance.

Esila

[Esila Darci]

@Matt J @Image Analyst @Oleg Komarov @Stuart Layton @Star Strider @Walter Roberson

[KALYAN ACHARJYA]

Can you more specific please?

You have the input image as attached?

You wish to calculate those h1,h2,... values? right?

[Esila Darci]

@KALYAN ACHARJYA

Yes this is input image , I have already calculated h1, h2 , h3 and h4 by pixel to micron factor. Now i want to calculate the following two values

1) mean of height, μ = Formula (h1+h2+h3+h4)/4

2) standard deaviation for that height

[Esila Darci]

I mean matlab can load the values which i have calculated previously of h1, 2,3 and 4 and calculate the following two values

1) mean of height, μ = Formula (h1+h2+h3+h4)/4

2) standard deaviation for that height

[Esila Darci]

@Matt J @Image Analyst @Oleg Komarov @Stuart Layton @Star Strider @Walter Roberson

[Esila Darci]

@Matt J @Image Analyst @Oleg Komarov @Stuart Layton @Star Strider @Walter Roberson

[Stuart Layton]

@Esila Darci please stop @ mentioning people

[Esila Darci]

I thought you are having expertise to answer my question. Sorry.

Answer 1

[KALYAN ACHARJYA]

As you mentioned, you have the h1,h2,h3...(Already computed or known data)

mu=(h1+h2+h3+h4)/4;

And standard deaviation as per attached formula

N=4;
h=[h1,h2,h3,h4];
std_d=sqrt((1/N)*sum((h-mu)^2));

[Esila Darci]

Hi @KALYAN ACHARJYA

how to load the data automatically from my previous values. can you please tell me the code for that?

Thanks

Esila

[KALYAN ACHARJYA]

"how to load the data automatically from my previous values"

Are you asking using the previous data, like calculate B(i) using B(i-1)??

[Esila Darci]

Kalyan you don't undestand the my question. I have calculated h1,h2,h3 and h4 for the current matlab program. In addition to this matlab code, i would like to recall this h1,h2,h3,h4 value so i can use it for the mean and standard deviation calculation.