Zeros = emptyFour corners
01
Find the edge
It detects the valid data (tools like APP fill empty areas with zeros), traces the boundary and picks the four corners.
Products / MultiPointCrop
Don't crop.
Warp.
MultiPointCrop is a PixInsight module that turns the ragged edges of a mosaic into a clean rectangle by deforming the image instead of cutting it away. You keep the field you spent the nights collecting.
Free live preview
Geometry process
Automatic · Manual · Combined
Original stays untouched
Raw mosaic
Rectangle
Schematic, not a real result. Drag to turn a ragged mosaic edge into a rectangle. The dashed box is the largest area a plain crop would keep.
How it works
A mesh that follows the edge,
A mesh that follows the edge,
stars that stay round.
Instead of picking the biggest rectangle inside your data, MultiPointCrop stretches a deformation mesh so the edge of the data lands exactly on the edge of the frame.
Coons patchAs-similar-as-possible
02
Warp the mesh
A Coons patch gives a first guess, then a solver makes every mesh triangle as close to a pure rotation and scale as it can. Border points slide along the edge, so stars stay round.
Lanczos-3Multi-threaded
03
Render a new image
Resampling limits ringing so there are no dark halos around stars. The result opens in a new window, <id>_mpc. Your original is never changed.
Modes
Let it decide, or take over.
Three ways to work, all with a live preview of the result. You can find it under Process › Geometry › MultiPointCrop.
AutomaticDetect and go
Boundary and corners are detected when you execute. The fastest route for regular mosaics.
CombinedDetect, then fine-tune
Detect boundary turns the detected edge into points you can adjust by hand before running.
ManualDraw it yourself
Click the outline yourself. Exactly four points are corners. Hard mosaics, such as wide Milky Way fields, are what Manual and Combined are for.
Editing on the image
- ClickAdd a point on the nearest edge
- DragMove a point
- Ctrl + ClickToggle corner
- Shift + ClickPin: lock content in place
- Right-click or Alt + ClickDelete a point
Measured
More field, less distortion.
Numbers from the module's engine tests on a synthetic 2×2 mosaic (2600×1800, RGB float). After every run a quality report goes to the console.
Field of view
+10.9%
vs the largest plain crop
Empty pixels
0
and 0 folds in the mesh
Mean local stretch
1.03×
1.00 means no distortion
Render speed
55Mpx/s
Lanczos-3, multi-threaded
Solving takes about 1.4 s and the quarter-scale preview under 3 ms on this test. Example images from real data (IC 63) are coming soon.
Installation
Install, then activate.
A native module, so no scripts and no extra dependencies.
- Get the module
You'll receive
MultiPointCrop-pxm.dlland its signature fileMultiPointCrop-pxm.xsgn, plus your licence key. - Install it in PixInsight
Process › Modules › Install Modules, point it to the folder with both files and tick MultiPointCrop.
- Open the process
Find it under Process › Geometry › MultiPointCrop, then click an image to make it the target. The preview appears on the right.
- Activate
Enter the key in the Preferences tab. Without a licence the preview and point editing work, but Execute is locked.
Requirements
- OSWindows
- SoftwarePixInsight 1.9 (minimum version TBA)
- InputMosaic with empty areas as zeros, e.g. from APP
- OutputNew window
<id>_mpc - LicenceOnline activation, 2 computers
- InternetOnly to activate and re-check every 7 days; works 30 days offline
FAQ
Questions
Does it change my original image?
No. The result always opens in a new window named <id>_mpc, and the original is left as it was.
Can I try it without a licence?
The live preview and point editing work without a licence. Execute and Apply need an activated licence.
Why do stars stay round?
The solver asks every triangle of the mesh to be as close as possible to a rotation plus uniform scale, so local shapes are preserved. The quality report shows the stretch it measured, so distortion is reported instead of hidden.
Which mosaics are hard?
Very irregular mosaics, such as wide Milky Way fields, can wrinkle in Automatic mode. Use Combined or Manual and place the points yourself. Deep gaps between panels are detected in the metrics, not covered up.
Can I get a square image?
Yes, you can choose a square shape. Warping a non-square mosaic into a square stretches stars (about 1.4× at a 1.4:1 ratio). A “Square (crop)” variant that trims the long side first is planned.
Does it need internet?
Only to activate and to re-check the licence every 7 days. After a successful check it keeps working offline for 30 days. The module talks only to the licence server.
How many computers can I use?
Two. Deactivate this computer in the Preferences tab frees a slot you can use on another machine.
Pricing
One licence. Keep every edge.
Preview it for free, buy a licence when you want to export.
Early access
Personal licence
€XXone-time
VAT included where applicable
- MultiPointCrop module for PixInsight (Windows)
- Automatic, Manual and Combined modes
- Use on up to 2 of your own computers
- Free live preview, even without a licence
Payment link coming soon. Questions? [email protected]