H5DARKFRAMES (beta)

H5Darkframes is a python library for generating and using darkframes library. For now, it supports only asi zwo cameras (see https://github.com/MPI-IS/camera_zwo_asi).

This is beta, and need some more testing

Installation

from source:

git clone https://github.com/MPI-IS/h5darkframes.git
cd h5darkframes
pip install .

from pypi:

pip install h5darkframes

Usage

Assuming that camera-zwo-asi is installed and a camera is plugged:

creating a darkframe library

First, a configuration file must be created. In a terminal:

darkframes-zwoasi-config

This will create in the current directory a file darkframes.toml with a content similar to:

[darkframes]
average_over = 5

[camera.controllables]
AutoExpMaxExpMS = 30000
AutoExpMaxGain = 285
AutoExpTargetBrightness = 100
BandWidth = "auto"
CoolerOn = 0
Exposure = 300
Flip = 0
Gain = 400
HighSpeedMode = 0
MonoBin = 0
Offset = 8
TargetTemp = 26
WB_B = 95
WB_R = 52

[camera.roi]
start_x = 0
start_y = 0
width = 4144
height = 2822
bins = 1
type = "raw8"

[darkframes.controllables.TargetTemp]
min = -15
max = 15
step = 3
threshold = 1
timeout = 600

[darkframes.controllables.Exposure]
min = 1000000
max = 30000000
step = 5000000
threshold = 1
timeout = 0.1

[darkframes.controllables.Gain]
min = 200
max = 400
step = 100
threshold = 1
timeout = 0.1

You may edit this file to setup:

• your desired camera configuration

• the controllables over which darkframes will be created, and over which range

• the number of pictures that will be averaged per darkframes

For example:

[darkframes.controllables.TargetTemp]
min = -15
max = 15
step = 3
threshold = 1
timeout = 600

implies that darkframes will be taken for values of temperature -15, -12, -9, ... up to +15.

creating the darkframes library

Call in a terminal:

# change "mylibraryname" to a name of your choice
darkframes-zwoasi-library --name mylibraryname

You may get stats regarding the library (requires a file 'darkframes.hdf5' in the current directory):

darkframes-info

using the library

import h5darkframes as dark
import camera_zwo_asi as zwo
from pathlib import Path

# path to the library
path = Path("/path/to/darkframes.hdf5")

# handle over the library
library = dark.ImageLibrary(path)

# handle over the camera
camera = zwo.Camera(0)

# taking a picture. Image is an instance of zwo.Image
image = camera.capture()

# getting the current camera configuration
controls = camera.get_controls()

# "Temperature", "Exposure" and "Gain" must be the
# controllables that have been iterated over
# during the creation of the library
darkframe_target = {
       "Temperature": controls["Temperature"].value,
       "Exposure": controls["Exposure"].value,
       "Gain": controls["Gain"].value
}

# getting the darkframe that is the closest to the target
# darkframe: a numpy array
# darkframe_config: the config of the camera when the darkframe was taken
darkframe, darkframe_config= library.get(darkframe_target)

# optional sanity checks
assert image.get_data().shape == darkframe.shape
assert image.get_data().dtype = darkframe.dtype

# substracting the darkframe
substracted_image = image.get_data()-darkframe