Darkgen is a dark frame library generator for ZWO cameras intended for use with allsky. It is derived from zwo-skycam, an abstration layer for Python zwoasi binding.
This tool was developed on x86_64 and should run on any posix-like platform for which the ZWO SDK is available, but your mileage may vary.
If you are using this with an allsky installation, simply point the tool at the library. Otherwise, fetch the SDK from ZWO.
Install dependencies from the package repositories:
sudo apt -y install python3 python3-pip python3-pil python3-numpy libusb-1.0-0
Install the ZWO ASI library binding
sudo -H pip3 install zwoasi
You can clone this repository by executing:
git clone https://github.com/ckuethe/zwo-darkgen
or download the code archive from GitHub
darkgen.py [-h] [-I] [-v] [-c CAMERA] [-l PATH] [-d PATH] [-f STR]
[-g MIN:MAX:STEP] [-x MIN:MAX:STEP] [--binning INT]
[--flip {n,h,v,hv,vh,b}] [--stack INT] [--quality INT]
[--offset INT] [--wbr INT] [--wbb INT]
| Short | Long | Description |
|---|---|---|
| -h | --help | show this help message and exit |
| -I | --info | Print info about selected camera and exit (False) |
| -c CAMERA | --camera CAMERA | Camera index (None) |
| -l PATH | --library PATH | path to SDK library (./libASICamera2.so) |
| -d PATH | --directory PATH | path to output darks (zwo_dark) |
| -f STR | --filename-format STR | filename pattern for darks. (dark_{expms}ms_{gain:03d}g_{temp:+03d}C.png) |
| -g MIN:MAX:STEP | --gain MIN:MAX:STEP | gain range to scan, specified as 3 integers. The value -1 for any of the fields signals that this field should be automatically chosen (-1:-1:-1) |
| -x MIN:MAX:STEP | --exposure MIN:MAX:STEP | exposure range to scan, in seconds, specified as 3 floating point values. (2.0:20.0:2.0) |
| -v | --verbose | Increase debug level |
| --flip {n,h,v,hv,vh,b} | whether the image is to be flipped on the horizonal or vertical axes, or both (none) |
|
| --binning INT | Pixel binning factor (1) |
|
| --stack INT | Number of exposures to stack to build dark frame (1) |
|
| --quality INT | image quality (100) |
|
| --offset INT | brightness offset (0) |
|
| --wbr INT | white balance:red (None) |
|
| --wbb INT | white balance:blue (None) |
When constructing the output filename, the following tokens are available to be interpolated as python formats.
{temp}- sensor temperature in C, rounded up (eg. 26.1°C -> 27°C){gain}- gain in arbitrary units{expms}- exposure time in milliseconds{model}- sanitized camera model (eg.ZWO ASI120MM Mini->zwo_asi120mm_mini){stack}- stacking factor
Because this tool uses PIL/Pillow for image output, file extension determines the file format. Any supported format can be produced, though formats with lossy image compression should not be used.