GetDark

Description :

This function allows to analyze a set of images based on a window statistic to perform dark current analysis and returns two plots, two images and datas.
This function needs a window definition, a master Bias frame (a median stack of 11 bias frames at least).
The computed data is returned into a window, such as drak current rate and cosmic hit rates. One returned image is the median stack of the darks, the bias frame being subtracted on each image. the second image shows the defects from the dark frame. The two plots are collapsed row/collumn in order to spot dark non uniformity.

Please have a look HERE to get important information about CCD testing functions.

Minimum version : 1.61

Syntax :

GETDARK ImagesArray AmtImage ImgBias X1 Y1 X2 Y2 XpixelSize YpixelSize Exposuretime

Variables :

Parameters Inputs / Outputs Type Description
ImagesArray Input Array of image handler An array of images handles (that points the the pixel datas) that needs to be previously loaded.
AmtImage Input Integer Amount of images to analyze
ImgBias Input Image variable Master Bias frame, made of at least 11 elementary bias frame using 0s exposure time
X1 Input Integer Left bottom X image coordinates where the statistic will be computed
Y1 Input Integer Left bottom Y image coordinates where the statistic will be computed
X2 Input Integer Top right X image coordinates where the statistic will be computed
Y2 Input Integer Top right Y image coordinates where the statistic will be computed
XpixelSize Input Floating point X pixel size, overriden if figure found into the image file header
YpixelSize Input Floating point Y pixel size, overriden if figure found into the image file header
Exposuretime Input Floating point Exposure time expressed in sec, overriden if figure found into the image file header

See also :
GETNOISE
GETLINEARITY
STAT
STATWINDOW
GETCONVERFACTOR

Example :

path$="C:\Prism\Images de test\ccd_test\dark\"

// Loads dark files with the same exposure time ...

AmtImage=5
for i=1 AmtImage
str i i$
a$="Dark-"+i$+".cpa"
a$=path$+a$
print a$
open ImagesArray[i-1] a$
next i

// Loads bias file
a$=path$+"Bias.cpa"
open ImgBias a$

X1=200
Y1=200
X2=500
Y2=500

// Overriden if found into the header
XpixelSize=6.4
YpixelSize=6.4
// as seconds
Exposuretime=60

GETDARK ImagesArray AmtImage ImgBias X1 Y1 X2 Y2 XpixelSize YpixelSize Exposuretime

// Close images
for i=1 AmtImage
close ImagesArray[i-1]
next i