StarStaX - Version 0.60
02) Photo Gallery
04) Change Log
05) Known Bugs
06) Blending Modes
07) Usage & Tutorials
08) System Requirements
09) Download and Installation
10) Frequently Asked Questions
StarStaX is a fast multi-platform image stacking and blending software, which allows to merge a series of photos into a single image using different blending modes. It is developed primarily for Star Trail Photography where the relative motion of the stars in consecutive images creates structures looking like star trails. Besides star trails, it can be of great use in more general image blending tasks, such as noise reduction or synthetic exposure enlargement.
StarStaX has advanced features such as interactive gap-filling and can create an image sequence of the blending process which can easily be converted into great looking time-lapse videos.
StarStaX is currently under development. The current (development) version 0.60 was released on July 15th, 2013. StarStaX is available as a free download for Mac OS X, Windows and Linux.
Please send feedback, bugs, results and suggestions via e-mail to:
Check out the StarStaX Flickr group for some great photos created using StarStaX!
Did you get some nice photos using StarStaX ? Let me know!
Features - Version 0.60
Blending/stacking modes: Lighten, Darken, Average, Addition, Subtraction, Multiplication
Interactive gap filling mode to automatically close small gaps in star trails (see the gap filling tutorial)
Comet mode blending to create comet-like star trails
Interactive help browser with documentation, tutorials and web resources
Supports a multitude of image formats (JPG, TIFF up to 16-bit/channel, PNG, etc.), Raw images cannot (yet) be developed using StarStaX - there are many better tools for that. For Raw images, use your favorite Raw converter, make your adjustments and export the images as TIFF.
Cumulative mode: A stacked image can be saved after each frame is processed (to create a cumulative stacking video)
Averaging and subtraction of dark frames to remove hot pixels and noise
Smooth zoom, 100% view, different view interpolation modes (anti-aliasing)
GPU support for fast navigation within images
Multi-touch / mouse wheel support for scrolling
Multi-CPU / multi-core and SSE optimized for processing speed
Multi-language (currently: English, German and Spanish)
Version 0.41 (bugfix release)
Version 0.31 (bugfix release)
Known Bugs - Version 0.60
Mac OS X version
Lighten: Compares the images and chooses the brightest pixel at each location. Use this to create star trails. If your camera pauses between consecutive exposures, there might be small gaps in the resulting star trails. In that case, the "Gap Filling" mode should be used, see below.
Gap Filling: Optimized 'Lighten' blending mode which tries to eliminate small gaps in star trails. The user can choose a threshold to limit processing to certain regions of the image (e.g. only the star trails) and control the amount of gap filling to be applied. See the corresponding gap filling tutorial.
Comet Mode: In 'Lighten' and 'Gap Filling' modes, StarStaX offers a 'comet mode' which adds a fading effect to the end of the star trails, simulating the look of comet trails. The length of the trails can be varied, of course.
Darken: Compares the images and chooses the darker pixel at each location. Use this to remove star trails.
Average: Averages the individual images. This can be used to reduce random noise from a set of photos of the same scene, thereby creating smoother images, particularly in image regions with low brightness and color variation.
Addition / Subtraction / Multiplication: Adds, subtracts or multiplies the images. Adding is particularly useful to synthetically generate longer exposed images from a set of individual images of the same scene. Here, the exposure of the stacked image is equal to the sum of the exposures of the individual input images.
Dark frame subtraction: When dark frames, i.e. photos taken with closed shutter or lens cap on, are available, they are averaged and automatically subtracted from each input image. This can reduce sensor noise and remove sensor pixel errors (hot-pixels) in the final image.
Usage & Tutorials
StarStaX has been designed to be easy-to-use without a steep learning curve. To get started quickly, take a look at this tutorial and the help browser included in StarStaX. There are tooltips available for most of the options and features of StarStaX. Just hover the mouse pointer over user interface elements of StarStaX to get a quick explanation of the underlying features and options.
Here is a quick overview of general usage:
Load input images (menu bar or icon), optionally: load dark frames
Select blending mode in preferences
Save output image
Zooming / Scrolling
Plus ("+") and minus ("-") keys for smooth zooming
Click and hold left mouse button to drag the image
Horizontal and vertical scrolling with mouse wheel or two-finger multi-touch gesture
Double-click to center view on an image area (this area becomes the new "focus" for smooth zooming)
"F" key to fit zoom to window size
"Z" key for the all important 100% view
Select cumulative saving in "Blending" preferences tab
An image will be saved to the specified location after each image is processed
Mac OS X version
StarStaX requires Mac OS X 10.7 Lion or higher and a 64-bit capable Intel processor (Intel Core 2 Duo or better). To find out if your Intel Mac has a 64-bit CPU, please refer to: http://support.apple.com/kb/HT3696
StarStaX requires Windows XP or higher.
StarStaX has been tested on Ubuntu 12.04, 12.10 and 13.04. It may or may not work on other distributions.
Requirements for the Ubuntu 12.04, 12.10 and 13.04 versions:
glibc >= 2.15, libjpeg62, freeglut3
Download and Installation
StarStaX is available as a free download for Mac OS X, Windows and Linux.
If you like StarStaX please consider making a contribution to support further development.
Please let me know on which OS you are running StarStaX. Thanks!
Installation instructions are given below:
Mac OS X 10.9 (OS X Mavericks)
A build of StarStaX for Mac OS X Mavericks (10.9) is available as a .dmg file from here: StarStaX-0.60-experimental_Mac_10.9.dmg or StarStaX-0.60-experimental_Mac_10.9.dmg
Mac OS X 10.7 (OS X Snow Leopard) - 10.8 (OS X Mountain Lion)
StarStaX is available as a .dmg file from here: StarStaX-0.60_Mac.dmg
Download and mount the disk image and drag StarStaX to your Applications folder.
In case of problems opening StarStaX, please see this FAQ entry!
Windows version (stable)
StarStaX is available as a .zip file from here: StarStaX-0.60_Windows.zip or StarStaX-0.60_Windows.zip
Extract the .zip archive and double-click on "StarStaX.exe" in the folder StarStaX-0.60. There is no installer. You can manually copy the StarStaX folder to any folder you like and create a link to StarStaX.exe, e.g. on the desktop or in the program menu. To uninstall just remove the StarStaX folder from your harddisk.
Linux version (stable)
StarStaX is available as a .tgz file from here:
Ubuntu 12.04 and 12.10 (x86, 32bit)
Ubuntu 12.04 and 12.10 (amd64, 64bit)
Ubuntu 13.04 (x86, 32bit)
Ubuntu 13.04 (amd64, 64bit)
Download and extract the .tgz file. Execute the start script 'startStarStaX.sh' .
See the system requirements above.
Frequently Asked Questions
Q: Can I host a copy of StarStaX on my server ?
A: No. Please refrain from doing so. Use a link to www.starstax.net instead.
Q: Will there be a version for Mac OS X 10.4, 10.5 or 10.6 ?
A: On the Mac, OS X 10.7 Lion is the absolute minimum requirement.
Q: Does StarStaX run on my PowerPC (G4 / G5) or Intel Core Solo / Duo Mac ?
A: On the Mac, at least an Intel Core 2 Duo processor (64-bit) is required. There is no PowerPC support.
Q: Can you implement feature XXX ?
A: StarStaX is developed in (valuable and scarce) spare time, so feature requests cannot be handled immediately. I am constantly developing my own ideas on how StarStaX could be further developed. If you have a good idea, let me know.
Q: Why can't StarStaX read my Canon/Nikon/Sony etc. raw camera files ?
A: Raw development is a highly non-trivial problem. While a simple raw plug-in could be included rather easily into StarStaX, it's quality would certainly not be on par with available commercial and open-source products (Aperture, Lightroom, RawTherapee, etc.). That's why there won't be any raw support in StarStaX in the near future.
Q: On my Mac, I get the message “StarStaX cannot be opened because it is from an unidentified developer”. What can I do ?
A: This message comes from the “Gatekeeper” of Mac OS X. To open StarStaX, right-click on StarStaX.app, select open and confirm the following dialog. From then, StarStaX.app can be started as usual. Another alternative - although not recommended - is to disable Gatekeeper completely. See this Apple support document for further details.
Q: How can I choose the image format to save my stacked image in ?
A: StarStaX guesses the format from the file name. Simply add your favorite image extension to the filename in the save dialog, e.g. myGreatStackedImage.jpg.
Q: Cmd+A does not work on Mac OS X to select all my images !?
A: This is a known bug. As a workaround, you can select the first and last image while holding down the Shift key.
Q: Is StarStaX available in my favorite language ?
A: StarStaX is localized to English, German and Spanish. If you want to help in translating it to your native language, let me know!
Q: I think I have found a bug in StarStaX !
A: Let me know and tell me how to reproduce it.
Q: Where can I get some help / tips on using StarStaX ?
A: You might wanna take a look at the StarStaX Flickr Group.
Q: StarStaX ? What does that mean ?
A: StarStaX is a Star Trails Image Stacker for Mac OS X.
Q: Is StarStaX open-source / Do I have do pay for it ?
A: StarStaX remains closed-source for now and is available as freeware. It uses (and dynamically links) to the Qt framework which is used under the LGPL Version 2.1 license.
Q: I want to credit StarStaX !
A: Please use a link to www.starstax.net.
Christian Enzweiler for design and graphics work
Alfonso Pereira Castro for the Spanish translation of StarStaX
All the StarStaX users for lots of feedback and suggestions
The girls and guys behind the amazing Qt framework