vstarstack 0.3.7.10

Stacking astrophotos

Installation

From PyPa

python3 -m pip install vstarstack

From sources

python -m pip install .

OR

python -m build --wheel .
python -m pip install dist/vstarstack-<CURRENT_BUILD_PARAMETERS>.whl

Modes of image presentation

• sphere mode
• flat mode

Sphere mode

In this mode we use knowledge about celestial sphere and the fact, that out images are some projections of celestial sphere. So when we need to perform some movements of image for alignment, we have to use rotations of celestial sphere.

This mode should be used when perspective distorsions are valueable.

Projections

• perspective projection - use perspective projection with specified focal length and pixel size

Flat mode

In this mode we don't know anything about celestial sphere and consider images as just flat images. We use standart movements of flat surface (rotation + shift) for alignment.

Modes of image aligning

• stars mode - images contains stars and should be aligned by stars
• compact_objects - images contains some small object, much less than image size, and this object should be cutted out and images should be aligned to center object

Stars mode

Command for work with stars beginning with vstarstack stars.

detect

vstarstack stars detect - detect stars on image

lonlat

vstarstack stars lonlat

If we use sphere mode, we transform (y,x) coordinates of detected stars into (lat,lon) coordinates, with (0,0) at center of image.

describe

vstarstack stars describe

We build descriptors for N most brightest stars. Each descriptor is invariant to rotations of image - it contains only information about distances to other stars, their relative brightness and angles between pairs of other stars. So we can use this descriptor for identifying stars.

match

vstarstack stars match

We match the same stars on different images using descriptors

net

vstarstack stars net

Build net.json - file with info about star matching. This is intermidiate format.

cluster

vstarstack stars cluster

Build clusters.json - file with clusters of stars. It contains info about stars coordinates on each frame.

process

vstarstack stars process - do all steps above in a single run

License

GNU GPLv3