## NAME

normalize -- Normalize images

## USAGE

normalize images

## PARAMETERS

- images
- Images to be normalized.

- norm = INDEF
- Normalization factor to be used if not INDEF. If INDEF the normalization factor is determined by sampling the images.

- sample_section = "[]"
- Section of the image to be sampled in determining the image mean.

- lower = INDEF
- Lower limit of pixel values for calculating the normalization. INDEF corresponds to the minimum possible pixel value.

- upper = INDEF
- Upper limit of pixel values for calculating the normalization. INDEF corresponds to the maximum possible pixel value.

## DESCRIPTION

Each of the images is normalized. The normalization is specified by the
parameter *norm*
. If the value of *norm*
is INDEF then a normalization
is determined by sampling the image. The normalization is then the mean
of the pixels in the sample section with values in the range *lower*
to *upper*
. The default sample section selects all pixels in the image.
The normalized images are of datatype "real" and replace the original images.

## EXAMPLES

To normalize a set of two dimensional images excluding deviant pixels below 1000 and above 5000 and subsampling every fifth pixel in each dimension:

cl> normalize frame* sample=[*:5,*:5] low=1000 up=5000