flatten images flatfield
images
Images to be flattened.
flatfield
Flat field image to be divided into the images.
minflat = INDEF
All flat field pixels less than or equal to this value are replaced by
unit response. If INDEF all the flat field pixels are used.
pixtype = real
The pixel datatype of the flattened image. The null string ("") defaults
the pixel datatype to that of the original image before flattening.
The other choices are "short", "integer", "long", and "real".
Each of the images is flatten by dividing by the flatfield flat field image. The flattened images replace the original images. The pixel datatype of the flattened images is specified by the pixtype. The null string ("") leaves the datatype of the images unchanged. Low values in the flat field may be replaced by unit response by specifying a minflat value. All pixels in the flat field less than or equal to minflat are given unit response.
To flatten a set of two dimensional images excluding pixels below .2 in the flat field:
cl> flatten frame* flat minflat=0.2