# distance between images, pixel by pixel

I'm need to calculate the euclidean distance between two `cv::Mat`

images in a pixel by pixel manner. Is there a function that does this?
Specifically, I need the result to be of the form

```
diff[i] = sqrt( (r1-r2)^2 + (g1-g2)^2 + (b1-b2)^2 )
```

where `diff`

is a `Mat`

. If there is no function, is there a simple way to calculate this?

Thanks!

just saying:

`^`

is the 'binary or' operator in c++, not pow !you can use cv::norm for the L2 distance:

How can I store the result in a

`Mat`

? Sorry - I justed started using opencv yesterday.don't ever feel sorry for asking ;)

why do you want to do that ? (and there's no easy way)

I'm implemented painterly rendering for a project. One of the steps is the calculate the distance between the source and a blurred image in a pixel by pixel manner, then sum square regions of the distance map to make decisions. I found the sum of the regions in a Mat using

`operator()`

and`sum`

-- I'm hoping that the distance map can be found as a Mat then.