# OpenCV4Android mathematical operations on Mat objects

Hello. I am new to OpenCV4Android. I want to rewrite code from C++ to OpenCV4Android:

```
{
double meanI = 0.0;
{
Mat tmp;
pow(abs(I), alpha, tmp);
meanI = mean(tmp).val[0];
}
I = I / pow(meanI, 1.0/alpha);
```

}

```
{
double meanI = 0.0;
{
Mat tmp;
pow(min(abs(I), tau), alpha, tmp);
meanI = mean(tmp).val[0];
}
I = I / pow(meanI, 1.0/alpha);
```

}

So I have a problem, because I dont know how to make:

1. abs of mat object -> abs(I)

2. how to divide matrix by DOUBLE -> I = I / pow(meanI, 1.0/alpha)

Can anyone help me with that?

Ad.1 I have no clue how to do it by function

Ad.2 I tried sth like that: Core.divide( Math.pow(meanI, 1.0/alpha), I, I) is that correct?