normalize images
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.
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.
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