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include "ccdred.h"
.help cor Feb87 noao.imred.ccdred
.nf ----------------------------------------------------------------------------
cor -- Process CCD image lines
These procedures are the heart of the CCD processing. They do the desired
set of processing operations on the image line data as efficiently as
possible. They are called by the PROC procedures. There are four procedures
one for each readout axis and one for short and real image data.
Some sets of operations are coded as single compound operations for efficiency.
To keep the number of combinations managable only the most common
combinations are coded as compound operations. The combinations
consist of any set of line overscan, column overscan, zero level, dark
count, and flat field and any set of illumination and fringe
correction. The corrections are applied in place to the output vector.
The column readout procedure is more complicated in order to handle
zero level and flat field corrections specified as one dimensional
readout corrections instead of two dimensional calibration images.
Column readout format is probably extremely rare and the 1D readout
corrections are used only for special types of data.
.ih
SEE ALSO
proc, ccdred.h
.endhelp -----------------------------------------------------------------------
$for (sr)
# COR1 -- Correct image lines with readout axis 1 (lines).
procedure cor1$t (cors, out, overscan, zero, dark, flat, illum,
fringe, n, darkscale, flatscale, illumscale, frgscale)
int cors[ARB] # Correction flags
PIXEL out[n] # Output data
real overscan # Overscan value
PIXEL zero[n] # Zero level correction
PIXEL dark[n] # Dark count correction
PIXEL flat[n] # Flat field correction
PIXEL illum[n] # Illumination correction
PIXEL fringe[n] # Fringe correction
int n # Number of pixels
real darkscale # Dark count scale factor
real flatscale # Flat field scale factor
real illumscale # Illumination scale factor
real frgscale # Fringe scale factor
int i, op
begin
op = cors[OVERSCAN] + cors[ZEROCOR] + cors[DARKCOR] + cors[FLATCOR]
switch (op) {
case O: # overscan
do i = 1, n
out[i] = out[i] - overscan
case Z: # zero level
do i = 1, n
out[i] = out[i] - zero[i]
case ZO: # zero level + overscan
do i = 1, n
out[i] = out[i] - overscan - zero[i]
case D: # dark count
do i = 1, n
out[i] = out[i] - darkscale * dark[i]
case DO: # dark count + overscan
do i = 1, n
out[i] = out[i] - overscan - darkscale * dark[i]
case DZ: # dark count + zero level
do i = 1, n
out[i] = out[i] - zero[i] - darkscale * dark[i]
case DZO: # dark count + zero level + overscan
do i = 1, n
out[i] = out[i] - overscan - zero[i] - darkscale * dark[i]
case F: # flat field
do i = 1, n
out[i] = out[i] * flatscale / flat[i]
case FO: # flat field + overscan
do i = 1, n
out[i] = (out[i] - overscan) * flatscale / flat[i]
case FZ: # flat field + zero level
do i = 1, n
out[i] = (out[i] - zero[i]) * flatscale / flat[i]
case FZO: # flat field + zero level + overscan
do i = 1, n
out[i] = (out[i] - overscan - zero[i]) * flatscale /
flat[i]
case FD: # flat field + dark count
do i = 1, n
out[i] = (out[i] - darkscale * dark[i]) * flatscale / flat[i]
case FDO: # flat field + dark count + overscan
do i = 1, n
out[i] = (out[i] - overscan - darkscale * dark[i]) *
flatscale / flat[i]
case FDZ: # flat field + dark count + zero level
do i = 1, n
out[i] = (out[i] - zero[i] - darkscale * dark[i]) *
flatscale / flat[i]
case FDZO: # flat field + dark count + zero level + overscan
do i = 1, n
out[i] = (out[i] - overscan - zero[i] -
darkscale * dark[i]) * flatscale / flat[i]
}
# Often these operations will not be performed so test for no
# correction rather than go through the switch.
op = cors[ILLUMCOR] + cors[FRINGECOR]
if (op != 0) {
switch (op) {
case I: # illumination
do i = 1, n
out[i] = out[i] * illumscale / illum[i]
case Q: # fringe
do i = 1, n
out[i] = out[i] - frgscale * fringe[i]
case QI: # fringe + illumination
do i = 1, n
out[i] = out[i]*illumscale/illum[i] - frgscale*fringe[i]
}
}
end
# COR2 -- Correct lines for readout axis 2 (columns). This procedure is
# more complex than when the readout is along the image lines because the
# zero level and/or flat field corrections may be single readout column
# vectors.
procedure cor2$t (line, cors, out, overscan, zero, dark, flat, illum,
fringe, n, zeroim, flatim, darkscale, flatscale, illumscale, frgscale)
int line # Line to be corrected
int cors[ARB] # Correction flags
PIXEL out[n] # Output data
real overscan[n] # Overscan value
PIXEL zero[n] # Zero level correction
PIXEL dark[n] # Dark count correction
PIXEL flat[n] # Flat field correction
PIXEL illum[n] # Illumination correction
PIXEL fringe[n] # Fringe correction
int n # Number of pixels
pointer zeroim # Zero level IMIO pointer (NULL if 1D vector)
pointer flatim # Flat field IMIO pointer (NULL if 1D vector)
real darkscale # Dark count scale factor
real flatscale # Flat field scale factor
real illumscale # Illumination scale factor
real frgscale # Fringe scale factor
PIXEL zeroval
real flatval
int i, op
begin
op = cors[OVERSCAN] + cors[ZEROCOR] + cors[DARKCOR] + cors[FLATCOR]
switch (op) {
case O: # overscan
do i = 1, n
out[i] = out[i] - overscan[i]
case Z: # zero level
if (zeroim != NULL)
do i = 1, n
out[i] = out[i] - zero[i]
else {
zeroval = zero[line]
do i = 1, n
out[i] = out[i] - zeroval
}
case ZO: # zero level + overscan
if (zeroim != NULL)
do i = 1, n
out[i] = out[i] - overscan[i] - zero[i]
else {
zeroval = zero[line]
do i = 1, n
out[i] = out[i] - overscan[i] - zeroval
}
case D: # dark count
do i = 1, n
out[i] = out[i] - darkscale * dark[i]
case DO: # dark count + overscan
do i = 1, n
out[i] = out[i] - overscan[i] - darkscale * dark[i]
case DZ: # dark count + zero level
if (zeroim != NULL)
do i = 1, n
out[i] = out[i] - zero[i] - darkscale * dark[i]
else {
zeroval = zero[line]
do i = 1, n
out[i] = out[i] - zeroval - darkscale * dark[i]
}
case DZO: # dark count + zero level + overscan
if (zeroim != NULL)
do i = 1, n
out[i] = out[i] - overscan[i] - zero[i] -
darkscale * dark[i]
else {
zeroval = zero[line]
do i = 1, n
out[i] = out[i] - overscan[i] - zeroval -
darkscale * dark[i]
}
case F: # flat field
if (flatim != NULL) {
do i = 1, n
out[i] = out[i] * flatscale / flat[i]
} else {
flatval = flatscale / flat[line]
do i = 1, n
out[i] = out[i] * flatval
}
case FO: # flat field + overscan
if (flatim != NULL) {
do i = 1, n
out[i] = (out[i] - overscan[i]) * flatscale / flat[i]
} else {
flatval = flatscale / flat[line]
do i = 1, n
out[i] = (out[i] - overscan[i]) * flatval
}
case FZ: # flat field + zero level
if (flatim != NULL) {
if (zeroim != NULL) {
do i = 1, n
out[i] = (out[i] - zero[i]) * flatscale / flat[i]
} else {
zeroval = zero[line]
do i = 1, n
out[i] = (out[i] - zeroval) * flatscale / flat[i]
}
} else {
flatval = flatscale / flat[line]
if (zeroim != NULL) {
do i = 1, n
out[i] = (out[i] - zero[i]) * flatval
} else {
zeroval = zero[line]
do i = 1, n
out[i] = (out[i] - zeroval) * flatval
}
}
case FZO: # flat field + zero level + overscan
if (flatim != NULL) {
if (zeroim != NULL) {
do i = 1, n
out[i] = (out[i] - overscan[i] - zero[i]) *
flatscale / flat[i]
} else {
zeroval = zero[line]
do i = 1, n
out[i] = (out[i] - overscan[i] - zeroval) *
flatscale / flat[i]
}
} else {
flatval = flatscale / flat[line]
if (zeroim != NULL) {
do i = 1, n
out[i] = (out[i] - overscan[i] - zero[i]) * flatval
} else {
zeroval = zero[line]
do i = 1, n
out[i] = (out[i] - overscan[i] - zeroval) * flatval
}
}
case FD: # flat field + dark count
if (flatim != NULL) {
do i = 1, n
out[i] = (out[i] - darkscale * dark[i]) * flatscale/flat[i]
} else {
flatval = flatscale / flat[line]
do i = 1, n
out[i] = (out[i] - darkscale * dark[i]) * flatval
}
case FDO: # flat field + dark count + overscan
if (flatim != NULL) {
do i = 1, n
out[i] = (out[i] - overscan[i] - darkscale * dark[i]) *
flatscale / flat[i]
} else {
flatval = flatscale / flat[line]
do i = 1, n
out[i] = (out[i] - overscan[i] - darkscale * dark[i]) *
flatval
}
case FDZ: # flat field + dark count + zero level
if (flatim != NULL) {
if (zeroim != NULL) {
do i = 1, n
out[i] = (out[i] - zero[i] - darkscale * dark[i]) *
flatscale / flat[i]
} else {
zeroval = zero[line]
do i = 1, n
out[i] = (out[i] - zeroval - darkscale * dark[i]) *
flatscale / flat[i]
}
} else {
flatval = flatscale / flat[line]
if (zeroim != NULL) {
do i = 1, n
out[i] = (out[i] - zero[i] - darkscale * dark[i]) *
flatval
} else {
zeroval = zero[line]
do i = 1, n
out[i] = (out[i] - zeroval - darkscale * dark[i]) *
flatval
}
}
case FDZO: # flat field + dark count + zero level + overscan
if (flatim != NULL) {
if (zeroim != NULL) {
do i = 1, n
out[i] = (out[i] - overscan[i] - zero[i] -
darkscale * dark[i]) * flatscale / flat[i]
} else {
zeroval = zero[line]
do i = 1, n
out[i] = (out[i] - overscan[i] - zeroval -
darkscale * dark[i]) * flatscale / flat[i]
}
} else {
flatval = flatscale / flat[line]
if (zeroim != NULL) {
do i = 1, n
out[i] = (out[i] - overscan[i] - zero[i] -
darkscale * dark[i]) * flatval
} else {
zeroval = zero[line]
do i = 1, n
out[i] = (out[i] - overscan[i] - zeroval -
darkscale * dark[i]) * flatval
}
}
}
# Often these operations will not be performed so test for no
# correction rather than go through the switch.
op = cors[ILLUMCOR] + cors[FRINGECOR]
if (op != 0) {
switch (op) {
case I: # illumination
do i = 1, n
out[i] = out[i] * illumscale / illum[i]
case Q: # fringe
do i = 1, n
out[i] = out[i] - frgscale * fringe[i]
case QI: # fringe + illumination
do i = 1, n
out[i] = out[i]*illumscale/illum[i] - frgscale*fringe[i]
}
}
end
$endfor
|
