AIPS HELP file for LAYER in 31DEC20
As of Sun Jul 5 20:03:53 2020
LAYER: Task to create an RGB image from multiple images
OUTNAME Output name(name).
OUTCLASS Output name(class).
OUTSEQ -1.0 9999.0 Output name(seq. #).
0 => highest unique
OUTDISK 0.0 9.0 Output image disk drive #
0 => highest with space
BLC Bottom left corner of input
TRC Top right corner of input
APARM 0.0 Disk numbers for <= 10 images
BPARM 0.0 Catalog #'s for <= 10 images
CPARM 0.0 Absorption optical depth
factor for images
DPARM 0.0 Emission optical depth factor
ARRAY1 0.0 Scale factor for emission
PLCOLORS 0.0 1.0 Colors of <= 10 images
DOCOLOR -1.0 1.0 > 0 => absorption colored
DOWEIGHT -1.0 1.0 Emission scaled by brightness
Use: LAYER will create a new cube with 3 planes from the weighted
planes of up to 10 images. The images are assumed to be fully
aligned. They will often be the output of SCLIM which may be
used to clip and scale, linearly or non-linearly, the original
images. The 3 planes can then be used to display the 3rd
dimension as color on the TV or with display tasks such as
GREYS, PCNTR, and KNTR.
LAYER assigns a basic optical depth to each input pixel and then
scales that optical depth to "absorb" the current RGB sums and
separately scales the optical depth to add to the absorbed. The
basic optical depth tau of a pixel in image i is
tau = (Bi(x,y) - MINi) / (MAXi - MINi)
where Bi(x,y) is the input image brightness at pixel (x,y), MAXi
is the max(Bi) over all (x,y) and MINi is the min(Bi). The
emission due to this pixel in color c is
Ii(c,x,y) = ARRAY1(i)*F*[1 - exp (DPARM(i)*PLCOLORS(c,i)*tau)]
where F is either 1.0 or tau depending on DOWEIGHT (<= or > 0,
resp). The absorption optical depth of this pixel is
TAUabs(all c) = CPARM(i) * tau
if DOCOLOR <= 0, or
TAUabs(c) = CPARM(i) * tau * PLCOLORS(c,i)
if DOCOLR > 0.
Clearly this is an experimental task which will take a lot of
fiddling to get the good results that are possible, As
experience is gained, suggestions will be added.
OUTNAME.....Output name of image(name). No good default.
OUTCLASS....Output name of image(class). Standard defaults.
OUTSEQ......Output name of image(seq. #). 0 => highest unique
OUTDISK.....Disk drive # of Output image. 0 => highest with
BLC.........The bottom left-hand pixel of the input image
which becomes the bottom left corner of the
new image. The value (0,0) means (1,1).
TRC.........The top right-hand pixel of the input image
which becomes the top right corner of the
new image. The value (0,0) means take the top
right hand corner of the image.
APARM.......Disk number for image i, i = 1 to 10. No default,
0 => no image i.
BPARM.......Catalog number for image i, no default:
0 => no image i.
CPARM.......Absorption optical depth factor for image i. No
default; 0 => no absorption by image i.
DPARM.......Emission optical depth factor for image i. No default.
0 => no emission by image i.
ARRAY1......Scale emission of image i by ARRAY1(i). <= 0 -> 1.
PLCOLORS....RGB Colors of image i as array (3,10). No default.
PLCOLORS(c,i) = 0 => no contribution of image i to color
DOCOLOR.....> 0 => absorption is colored by PLCOLORS; <= 0 =>
absorption is equal in all colors.
DOWEIGHT....> 0 => emission is weighted by brightness at pixel as
well as the (1 - exp(t)) function. <= 0 => weight = 1.