GETCONVERTFACTOR
Description :
By recording two flat field images and two biases images from the CCD camera, the conversion factor (e-/Adu) and the readout noise (e-) can be computed accurately using this function.
Please have a look HERE to get important information about CCD testing functions.
Minimum version :1.6
Syntax :
GETCONVERTFACTOR ImgFlat1 ImgFlat2 ImgBias1 ImgBias2 X1 Y1 X2 Y2 AWindowsx Awindowsy FactConv RMSNoise [ErrorFactconv ErrorNoise]
Variables :
| Parameters | Inputs / Outputs | Type | Description |
| ImgFlat1 | Input | Image variable | First flat field image handle |
| ImgFlat2 | Input | Image variable | Second.flat field image handle |
| ImgBias1 | Input | Image variable | First bias image handle |
| ImgBias2 | Input | Image variable | Second bias image handle |
| 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 |
| AWindowsx | Input | Integer | Amount of windows in the horizontal direction of the image |
| AWindowsy | Input | Integer | Amount of windows in the vertical direction of the image, it shall lead to window that have a size of 20x20 pixels to 50x50pixels |
| FactConv | Output | Floating point | Conversion factor expressed in electrons per ADU |
| RMSNoise | Output | Floating point | Readout noise, computed from the two biases expressed in electrons RMS |
| ErrorFactconv | Output | Floating point | Optional : Error related to conversion factor (e-/ADU) |
| ErrorNoise | Output | Floating point | Optional : Error related to noise (e- rms) |
See also :
GETNOISE
GETLINEARITY
STAT
STATWINDOW
Example :
|
path$="C:\Prism\Images de test\ccd_test\CVF\" a$=path$+"flat1.cpa" a$=path$+"flat2.cpa" a$=path$+"bias1.cpa" a$=path$+"bias2.cpa" Width ImgBias2 Wt X1=1 GETCONVERTFACTOR ImgFlat1 ImgFlat2 ImgBias1 ImgBias2 X1 Y1 X2 Y2 NbWindowsx NbWindowsy FactConv RMSNoise ErrorMeasureStdDeviation ErrorMeasureRMSNoise print "FactConv=" FactConv " RMSNoise=" RMSNoise "
ErrCVF=" ErrorMeasureStdDeviation " ErrNoise="
ErrorMeasureRMSNoise Close ImgBias2 |