PixInsight FAQ

Updated 2024 January 2

This is a categorized list of frequently asked questions about PixInsight. Please select a category to find your question.

Briefly, PixInsight is an advanced image processing software platform. It has been designed specifically for astrophotography and other technical imaging fields. PixInsight is a modular, open-architecture system where the entire processing and file handling capabilities are implemented as external installable modules.

PixInsight has been ported as a native 64-bit application to Linux, macOS and Windows operating systems. PixInsight is a strongly multithreaded environment able to exploit all processors and processor cores available on modern hardware.

PixInsight is both an image processing environment and a software development framework. The core PixInsight application integrates three user interfaces: a graphical interface, a command-line interface, and a scripting interface based on the JavaScript language. As a development platform, PixInsight provides the PixInsight Class Library (PCL), an ISO C++ framework for development of PixInsight modules, and the PixInsight JavaScript Runtime (PJSR), an ECMA 262-5 compliant environment readily available in the core PixInsight application.

The PixInsight project originates from the inside of astrophotography: PixInsight is a software platform made by astrophotographers, for astrophotographers.

Because we feel that we can make a significant contribution to the world of image processing software, especially in astrophotography and other technical imaging fields. Our software is based on novel paradigms and provides innovative and elegant solutions of unparalleled efficiency and versatility, not available elsewhere.

As noted in the preceding answer, PixInsight is based on design principles and paradigms that are quite different from what is customary in most imaging applications. More specifically, these are some partial answers to your question:

  • PixInsight is an object-oriented software platform. In PixInsight, object orientation pervades the whole system from its inner core to the most visible elements of the user interface. This has very important implications; see FAQ 1.6 for a more elaborate description.
  • PixInsight provides rigorous implementations of efficient, modern algorithms and tools. For example, there are techniques and tools that other applications regard as "advanced" but we consider as obsolete.
  • PixInsight supports five numeric types to represent and store pixel data: 8, 16 and 32-bit integers, plus 32 and 64-bit IEEE 754 floating real numbers. The five data types are supported transparently by all processing tools. In addition, PixInsight supports 32 and 64-bit floating point complex pixel data to store images represented in the frequency domain. Complex pixel data are supported by the PCL and PJSR development frameworks.
  • In PixInsight, each tool has been designed to maximize your control over the underlying processes and algorithms. Within reasonable limits of usability, there are no concessions to simplification, or approximate/simplified implementations.
  • In PixInsight, versatility, accuracy and efficiency always prevail over ease of use.

Because PixInsight has to be an always innovative, ever-evolving project. Image processing is a vast discipline, where a reduced group of developers cannot have expertise in all fields necessary to provide a sufficiently complete solution.

We, the creators of PixInsight, have our own limitations in knowledge, time and resources. We are conscious that we can't go beyond certain limits, especially as is needed to follow the constant evolution of technology. So the only way we can ensure an evolving future for PixInsight is to open it to the contributions and collaborations of other developers.

This is why we make big efforts to create and maintain development frameworks for PixInsight: the PixInsight Class Library (PCL), an ISO C++ development framework to write PixInsight modules, and the PixInsight JavaScript Runtime (PJSR), a script development environment available in the core PixInsight application.

Not more steep than other technical, highly-specialized applications, and actually not very steep, considering the complexity of our platform. From our experience, most users become quite proficient with PixInsight after a couple weeks—or less, depending on how intensely they use our software.

If you are accustomed to other document-oriented, linear-workflow applications, then our object-oriented interface and nonlinear workflow usually requires an initial adaptation period (we call it disintoxication period). Once our users discover the power and flexibility of PixInsight, they can't think of returning to other degraded working environments anymore.

PixInsight is an object-oriented software platform. In PixInsight, object orientation pervades the whole system from its inner core to the outermost visible elements of the user interface. One of the most important consequences of this object-oriented architecture is that images and processes are independent in PixInsight. A process can be defined in absence of any image. In other words, a process does not know anything about any particular image until it is executed. Process instances are living, self-sufficient and self-contained objects. This allows for nonlinear workflows and confers a great versatility and adaptability to the PixInsight platform.

For example, in other applications, you must follow a select image, open tool, apply tool sequence each time you want to modify an image in some way. This is a linear workflow and a document-oriented environment.

In PixInsight, you define an arbitrary set of process instances independently of images. If necessary, a process can acquire some properties from one or more existing images—or even from theoretical, virtual images—as a pattern to define its parameters, just for convenience. However, the process itself does not depend on any particular image. You define a set of process instances that you can store, organize, modify and reuse arbitrarily as self-sufficient, live objects. Eventually, one or more of these process instances can be executed on one or more objects such as images, disk files, elements of the graphical interface, or special control objects that can change the behavior of the whole PixInsight platform globally—processes are not necessarily tied to images in PixInsight. This is a nonlinear workflow and an object-oriented environment.

PixInsight is a closed-source, commercial software project.

However, as a development platform PixInsight can be used to create open-source image processing tools. Developers on the PixInsight platform are free to release their PixInsight modules and scripts under the conditions and licenses that they decide: either as commercial, shareware, freeware, or open-source products. In this sense, PixInsight acts just as an operating system: open-source projects can be developed under PixInsight just as they can be developed under commercial OSs such as Windows and macOS.

We at Pleiades Astrophoto are already releasing many standard PixInsight modules and scripts as open-source products under the PCL license, which is a liberal BSD-like license. Our intention is to continue publishing a growing number of open-source tools in the future.

We need to sell PixInsight licenses in order to support ourselves economically, as well as to get the necessary resources to continue our research and development work on PixInsight.

PixInsight is neither a game nor a hobby for us. We work on it full time (in fact, we work on it almost 24/7). PixInsight is our main professional project, and we want to be able to continue working on it for many years to come. Nobody helps us economically—in fact, with the exception of our users and a few good friends (extremely nice people), nobody helps us at all. We have no sponsors, and we don't want any sponsors because we want to stay independent. We are a small emerging company that depends exclusively on its own means.

PixInsight is an independent image processing platform. It will never be implemented—neither as a whole nor partially—as a plug-in for another application.

So if you are a user of that application, then sorry, you're out of luck ;)

PixInsight is not difficult at all: it is just quite different—and we think it is much better, too. However, PixInsight does not offer fast-food solutions, but only rigorous, flexible and efficient solutions.

Some fixed ideas exist in the astrophotography community. We think some of them are due to limitations in the software tools commonly used. A good example of this problem is data linearity. If an ubiquitous imaging application is unable to handle linear data, then it imposes severe restrictions that in turn cause a lack of perspective in its users, who get accustomed to work in a degraded environment. With the passing time, the degraded environment tends to be seen as the only valid way, and the people that have grown with it tend to develop a strong resistance to changes.

Then it comes into scene a new software: PixInsight. It comes from Spain, a small country in Europe. The PixInsight guys start speaking of things such as wavelets, multiscale processing, RGB working spaces, object-oriented interfaces, and a plethora of new and strange things that are quite different from layers, hand-painted masks, and the like. Unfortunately, our work has been seen as a threat, not as a way to improve things. However, this situation has changed largely during the last years. It has been a long way since we released the first versions of our software, and we are now just at the beginning.

We really enjoy our work on PixInsight, and we are sure you can enjoy it as well, provided you try it without prejudices, and forget all fixed ideas.

PixInsight and Photoshop® are two very different applications. They are in fact so different in their goals, in the way they have been conceived, and in how they are being developed, that we actually think that PixInsight and Photoshop® represent, in many aspects, two opposite ways of understanding image processing. So if you are using Photoshop®, or a similar application, then PixInsight cannot be a replacement: it can only be a change.

PixInsight pursues a scientific, highly technical approach to image processing. Most of our tools have been designed to solve the problems specific to astrophotography and other technical imaging fields through rigorous and flexible implementations, where the user has full control on every relevant parameter of each applied process. While we try to design and implement our tools to facilitate the user's work as much as possible, ease of use is not one of our main goals. In general, we make no concessions to simplification: there are no fast-food solutions in PixInsight. Versatility, efficiency, powerful tools, rigorous implementations and the development of astrophotography through image processing culture are the main elements of our vision and our mission as the developers of PixInsight.

Photoshop® has not been conceived or designed to solve the kind of problems that arise in highly technical imaging fields, of which astrophotography is one of the most demanding ones. Photoshop® is a general-purpose image edition application. It is excellent for image edition and retouching but it doesn't qualify for astrophotography because it lacks the necessary algorithms and tools; it is simply not based on the correct principles to provide the required solutions. Photoshop® pursues a simplified approach to image manipulation, where the user has little or no control over the applied processes. Due to its lack of resources and to the inadequacy of its implementations, Photoshop® is being applied to astrophotography through tricky procedures, including arbitrary manual manipulations and retouching practices without documentary and algorithmic basis that we consider unacceptable in astrophotography.

Hand-painted masks, arbitrary manual selections, retouching, unrigorous layering techniques and other 'magical recipes' are just the opposite of what we understand by astrophotography. Contrarily to what it may seem at first sight, these procedures tend to block your creativity: they teach you nothing about your data and don't require you to understand your images and the actual problems you have to face and solve to build them.

PixInsight provides you with a completely different platform where you can develop your astrophotography with solid foundations. With PixInsight we want to grow your image processing knowledge, as the best way to materialize your creativity and your pursuit of excellence.

The PixInsight project originates from the inside of astrophotography. It is a software platform made by astrophotographers for astrophotographers. PixInsight is not a general-purpose product made by a large multinational company with mass-market interests. It is a highly specialized platform in constant evolution, for which astrophotography is its natural ecosystem. PixInsight is available as native 64-bit applications on Linux, macOS and Windows, and a single commercial license allows you to install and run PixInsight on any machine you own, on all supported platforms, with unlimited free updates and support. The development of PixInsight is open to the community through an integrated scripting environment (PJSR, the PixInsight JavaScript Runtime) and a comprehensive, cross-platform C++ module development framework (PCL, the PixInsight Class Library). PixInsight is our personal project and we back it with hard work every day. We are close to you and easy to reach. We are different.

During the second half of 2012 we were working on a layers tool for PixInsight 1.8. You can see a screenshot of the new Layers tool here. However, early in 2013 I decided to abort this line of development. The rationale of this decision is that trying to compete with image retouching applications is a strategic error for PixInsight. Let me explain this statement.

As of writing this FAQ entry (August 2013), we have many priorities before a layers tool. They include new image processing tools, new scripts, new documentation, and the official 1.8.0 release of PixInsight, which we want to have ready in October.

Three good examples of our recent development work are the new TGVDenoise tool and the new versions of ImageIntegration and StarAlignment, which we have released in June and July. TGVDenoise, created by PTeam member Carlos Milovic after one year of R+D work, is a noise reduction tool based on total generalized variation, a novel signal processing concept with important applications to image regularization and restoration. The new StarAlignment supports image registration under arbitrary distortions. IMHO our current ImageIntegration and StarAlignment tools represent the state of the art in image preprocessing, and TGVDenoise is leading edge image processing technology. Some of our short and medium term projects include:

  • A new tool for drizzle integration of images.
  • New tools based on total generalized variation, including a spatially-adaptive version of TGVDenoise and an image restoration (deconvolution) tool.
  • A tool version of the MaskedStretch script, including real-time preview.
  • An improved version of PixelMath with a large set of new language features.
  • A new deconvolution tool based on multiscale maximum entropy.

As you can see, we work hard with our scarce resources. So, why not to include a Layers tool in the above list? Wouldn't layers make us more competitive? Actually, we think it's just the opposite.

Unfortunately, we not only have to compete with other applications specialized in astrophotography, but also with general-purpose image retouching and manipulation applications. This includes not just Adobe® Photoshop®, but also a number of open-source applications that act like free (gratis) clones or substitutes of Photoshop®.

For example, future versions of GIMP will support 32-bit images. This will erode our potential market. We will never be able to compete with free software products supported by lots of developers that don't need to sell licenses to live. So trying to mimic what these applications do is just the best way to waste our little resources to get nothing at all in return. Basically, nobody will use our layers if they are available for free in a clone of Photoshop®. The best sign of this is that professional astronomers are currently supporting GIMP as an alternative to Photoshop®. The same is starting to happen in the astrophotography community.

So our only choice is to make PixInsight the best possible image processing platform. We can only survive in the niche of highly specialized, highly technical, innovative applications. Definitely, PixInsight is not like Photoshop®—including clones of it—, and the differences between them can only tend to grow.

That said, we don't exclude the possibility of a Layers tool in PixInsight. Definitely not now, and it's unlikely to happen in the near future, but perhaps in the long term. Or maybe it will be written by other PixInsight/PCL developers...

Not at all. Layers represent a long standing paradigm in document-oriented applications. For example, a layered document organization has important advantages in editing software such as CAD, vector/bitmap drawing and desktop publishing applications. However, layers give you no value at all in terms of image processing. Powerful image processing resources, such as PixelMath and previews in PixInsight, can do everything you can achieve with layers and much more, with much more accuracy, control and flexibility.

However, if you want to paint your images, you certainly may need layers. For painting, drawing and arbitrary retouching, a layers tool is probably the best option. In such case, however, you should ask yourself if trying to do astrophotography that way is really worth the effort. After all, if at the end of the process you are going to paint your images, why acquire them with a telescope? Why not just download them from the Internet, or even paint them completely?

The answer is yes if you want to paint, manipulate or retouch your images arbitrarily using some tricks, plugins, actions and other magical recipes with fancy names. The answer is definitely no if you want to do image processing. See FAQ 1.11, FAQ 1.13 and FAQ 1.14 above.

The PixInsight core application and all process and file format support modules have been written entirely in the C++ programming language. A few small, critical sections of our code base have been written in assembly language.

All PixInsight scripts authored by our team and other users and developers, as well as many maintenance and testing tools that we use internally, have been written in the JavaScript language using the PixInsight JavaScript Runtime (PJSR) framework.

We currently offer two software licenses:

Yes, you can read it here.

The price of a commercial PixInsight license is 300.00 euros for users from non-EU countries. Users from EU member countries must pay their respective VAT rates, that is, the final price for an EU user is 300.00 EUR plus the VAT rate applicable in his or her country. See this page for detailed information on the European legislation that forces us to apply VAT rates this way.

If you want to know the price of a commercial PixInsight license in other currencies (e.g., USD), you can use a real-time universal currency converter such as xe.com. As of updating this FAQ entry (January 2024), the price of a commercial PixInsight license is 329 USD approximately.

Not at all. The commercial PixInsight application only requires an active connection to carry out the online license activation procedure, a one-time procedure that takes place the first time you run the PixInsight core application on a new machine. Once activated, the commercial application does not need an active Internet connection.

Our automatic update system requires an active Internet connection to download information and data for available update packages. However, you can disable the update system via preferences. When the update system fails to connect to our server, this does not prevent the application from continuing to work normally.

Absolutely not. The commercial license lets you use PixInsight on all supported platforms and operating systems. This currently includes Linux, macOS, and Windows.

Absolutely not. Our commercial users have the right to install and use PixInsight on any computer they own, on any supported operating system, and even simultaneously on all of them. The only limit is that only our licensed users have the right to use their copies of PixInsight. Other than the fact that a commercial licensee cannot share his/her copy of our software, we impose no practical restrictions.

When you run PixInsight on a machine where you don't have a valid license file, the Software Activation window is shown. You can request new activation codes for your license from this window easily (the instructions to do so are available on the same window). The online license activation procedure is safe, fast and straightforward, and allows you to activate your license in a few minutes.

However, if you prefer to avoid an online license activation (for example, because you want to use PixInsight on a machine without Internet access), you can copy your license file from one computer where you already have activated your license.

Your license file is a small plain text file named PixInsightLicense. It is located on a specific folder on each supported platform:

On Linux:

On macOS:

On Windows:

where $HOME or %UserProfile% represent your home folder, that is, your personal folder, where you usually have your documents, images, music, etc., on each operating system.

Note: On macOS, the $HOME/Library folder is hidden by default. To show it with Finder you must show hidden files by pressing Command + Shift + . (full stop/period). See this MacWorld article for more information.

If you copy your license file to the same folder of another machine you own (you can create the folder if it doesn't exist), the commercial PixInsight application will run on that machine without asking for an online license activation.

However, as we have said before, the online license activation procedure is simple, fast and safe, and will allow you to use PixInsight in just a few minutes on any machine you have.

Alternatively, you can request new license activation codes from our website using our software distribution system. See FAQ 2.10 for details if you prefer doing it this way.

If you lose your license file, then yes, you'll have to reactivate your license. The procedures available in this case are the same that you must apply to use PixInsight on a new computer. See FAQ 2.7 for complete information.

You'll have to reactivate your license. The procedures available in this case are the same that you must apply to use PixInsight on a new computer. See FAQ 2.7 for complete information.

To use PixInsight on a machine where you don't have a valid license file—for example, on a new machine, after a system reinstall, or if your license file has been deleted or damaged—you need to reactivate your license. You can also use a license reactivation to move a trial license to a different machine.

The easiest and fastest way to reactivate your license is to run PixInsight on the machine in question. The Software Activation window will be shown. You can request new activation codes for your license from this window easily (the instructions to do so are available on the same window). You'll receive an email with new activation codes for your license in a few minutes.

If you prefer, you can also request new activation codes from our corporate website:

  • Visit our software distribution system and log in with your credentials: user name and password. You'll find your username in the instructions email you received when you purchased your license, or when your trial license was approved. If you have changed your password or can't remember it, you can request a new one.
  • On the software distribution main page, click the License Reactivation link.
  • Read the information given and click the Request License Reactivation link.
  • Our system will send you an email with a verification link. The email will be sent to the address you have associated with your license. Read the email and click the verification link to reactivate your license. If you change your mind, just do nothing: the verification link will expire automatically after one hour.
  • You will receive a second email with new activation codes for your license. Run PixInsight and copy and paste your user identifier and the activation code for your platform (Linux, macOS, or Windows) on the corresponding fields of the Software Activation window.
  • Please wait a few seconds while your license is validated on our server and your new license file is generated. Then PixInsight will be launched normally.

No. Juridic entities, such as associations, clubs, observatories, universities, schools, companies, etc., cannot be users of our software. We only sell PixInsight licenses to physical persons, that is, to individuals with verifiable identities.

No. Since version 1.8.4 of PixInsight, we no longer provide special licenses to universities. FAQ 2.11 applies to all entities, including universities.

We currently don't offer educational licenses at a reduced cost, or educational discounts.

Commercial users have access to all software updates for PixInsight version 1.x at no charge. This includes all bugfix, maintenance and improvement releases of the PixInsight core application and all standard modules we release for this version. Of course, we refer only to modules released officially as part of the standard PixInsight distribution (these are what we call standard modules); we cannot speak for modules authored and distributed by third-party developers, which may be subject to different conditions.

We use PayPal to process all our online payments. Paypal allows secure credit card payments (Visa, Mastercard, AmEx, Discover, etc.), among other payment methods.

We also support manual bank transfers for licenses purchased from European Union member countries. You must transfer the funds to our bank account if you prefer this payment method. When the money lands in our bank account, your license is processed in the usual way (you receive an email with license activation codes, etc.). Please contact us first if you want to pay for your commercial PixInsight license using a bank transfer.

Online payments through PayPal have the advantage that the licenses are processed in a completely automatic way by our system. Typically, after purchasing a license online, the user receives an email with download/installation instructions and license activation codes within a few minutes. Licenses paid by bank transfers require our manual intervention, and the banks involved and we can delay for several days.

Because we really need to be sure that we grant trial licenses to actual potential users of our software. This is the only way we can protect our system from continued abuse and hacking attempts.

Piracy is a serious problem for us and, if you are interested in PixInsight, then it is also your problem. If our software is pirated, that hurts both you and us, because if we are unable to sell software licenses, the PixInsight project may be hurt to the point that it may become inviable.

When we grant you a fully functional, full-featured trial version of our software, you must take your responsibility. We take ours by backing our product. We only ask you to let us know that you are an actual person willing to test our software. There are thousands of hard work hours and many dreams behind PixInsight. We think that sending us your actual name and address is a very small price for the opportunity to try out our software.

We are not going to sell your data or send you spam; we are not that kind of person. If you think that about us, then don't request a trial PixInsight license.

The trial PixInsight application is a fully functional, full-featured version with only three limitations:

  • The trial version of PixInsight requires an active Internet connection to run. This happens because the trial version requires an online license validation process with our server each time the core application is executed.

  • A trial PixInsight license can only be used on a single machine and operating system (currently we support Linux, macOS and Windows).

  • The trial PixInsight application cannot be used after the corresponding trial license has expired. Currently our trial licenses have a standard duration of 45 days.

Other than these three limitations, the trial PixInsight application is identical to the commercial version. There are no watermarks on saved images, size limits, disabled features, etc. What you try is exactly what you can purchase. Of course, the commercial version does not have any of the above limitations. For more details, visit our trial license request page.

Not simultaneously. A trial license allows you to install and run PixInsight on a single machine, on any supported operating system (currently Linux, macOS and Windows) at a given time. For security reasons, we have limited the trial license to one machine and platform. The commercial license does not impose this restriction (see FAQs FAQ 2.5 and FAQ 2.6).

You can reactivate your trial license to move it to a different machine and/or operating system. See FAQ 2.7 for detailed information. After reactivating your trial license, it won't work on the previous machine.

Note that a license reactivation does not extend your trial period. Your trial license will expire after 45 days since the date of approval, irrespective of the machine your are using it on.

Not at all. A PixInsight license is strictly personal and non-transferable. Hence it cannot be sold or transferred. Section 4 of our End User License Agreement states the following:

4. This End User License will be strictly personal, non-transferable and non-exclusive, and does not under any circumstance confer ownership thereof. You may not rent, lease, lend, redistribute, transfer or sublicense the Software or its use.

Unlike other commercial software products, which associate their licenses to one or more physical machines, PixInsight's licensing system is based solely on the user's identity. The licensed user is entirely responsible for the use he or she makes of our software. For this reason we can impose no restrictions on the number of installations.

When we release version 2.0, the price of a commercial 2.x license for existing users will be directly proportional to the time of use of their 1.x licenses.

For example, a user who purchased his or her license a few months before the 2.0 release date will have access to the new version at no cost. A user who purchased a license a few years before the 2.0 release will have to pay the full 2.x license price. These examples should not be taken literally; the exact terms of our upgrade policy will be determined when appropriate, but you get the idea.

We cannot say anything precise about that. A version 2.0 of PixInsight is not in our mind at present; we still have a lot of work to do with the current version.

That happens because you still have the license file corresponding to your previous (and expired) trial license on your machine. You have to remove that file manually before activating your new trial license. The license file is a small plain text file named PixInsightLicense on the following folders:

On Linux:

On macOS:

On Windows:

where $HOME or %UserProfile% represent your home folder, that is, your personal folder where you usually have your documents, images, music, etc., on each operating system.

Note: On macOS, the $HOME/Library folder is hidden by default. To show it with Finder you must show hidden files by pressing Command + Shift + . (full stop/period). See this MacWorld article for more information.

Once you have removed your expired trial license file, you can run the PixInsight core application to activate your new trial license with the new activation codes you have received.

This usually happens because your trial license file has been damaged or has lost synchronization with our server for some reason. Network errors and some antivirus and file management applications cause these problems, especially on Windows.

To solve this problem, you must manually remove your license file and perform a license reactivation. The license file is a small plain text file named PixInsightLicense on the following folders:

On Linux:

On macOS:

On Windows:

where $HOME or %UserProfile% represent your home folder, that is, your personal folder where you usually have your documents, images, music, etc., on each operating system.

Note: On macOS, the $HOME/Library folder is hidden by default. To show it with Finder you must show hidden files by pressing Command + Shift + . (full stop/period). See this MacWorld article for more information.

If your license file exists, remove it since it is invalid or has been damaged. Otherwise don't care.

Once you have removed your damaged trial license file, in case it still exists, you can run the PixInsight core application to reactivate your trial license with new activation codes, which you can request very easily. See FAQ 2.10 for complete information.

PixInsight installation packages for Linux are compressed tar archives (.tar.gz or .tar.xz). To install one of these archives, just extract its full contents on any directory, preferably on one located under your home directory. Then become root and run the installer program from a terminal. Normally you should just type "yes" and press Enter to accept the default settings. Say './installer --help' for detailed information on command line arguments.

If you have a previous version of PixInsight already installed, you must uninstall it by moving the /Applications/PixInsight folder to trash. Just run the .pkg installation package and follow the instructions.

Just run the installer package and follow the instructions. There is no need to uninstall a previous version because the installer removes it automatically.

Reboot your machine before installing a new version of PixInsight. Also check your computer thoroughly for viruses, Trojans, spyware and other malwares with a good, up-to-date virus protection software. This should not happen on a clean Windows installation.

Your Windows machine has a problem with secure connections (SSL/TLS). Please note that PixInsight is not causing this problem. First of all, make sure that you are using the latest version of PixInsight available for Windows. Second, check your computer thoroughly for viruses and other malwares with a good, up-to-date virus protection software. If you still experience this problem, take a look at this page where Microsoft describes a hotfix that may solve this issue for you:


If nothing else works, a workaround is using non-secure update repositories. Follow these steps:

  • From the main menu, select RESOURCES > Updates > Manage Repositories
  • On the Manage Update Repositories dialog, click the Edit button.
  • Change the URL to "http://pixinsight.com/update/1.8.6" (without quotes) instead of "https://pixinsight.com/update/1.8.6"
  • Click the OK button to confirm the new repository, and OK again to accept the dialog.

This should allow you to download updates (modules, scripts, etc.), but please realize that you will be using an insecure connection to identify and download update packages. Instead of using this workaround, we strongly encourage you to fix the SSL/TLS connection problem on your machine.

See FAQ 3.5.

This cannot happen with current 1.8.5 and 1.8.6 versions of PixInsight. Our Windows installer packages, as well as all executable files in our software distribution, are digitally signed with an Extended Validation (EV) certificate.

This is not possible, mainly because each version uses a different set of configuration settings stored in the same configuration file. Always install and use the latest version of PixInsight available for your platform.

This problem is reported with relative frequency to our support team by Windows users. If this happens, then something is wrong and potentially dangerous in your Windows installation. Based on our support experience, the most probable causes are:

  • An antivirus, firewall or file analysis application running as a background process has blocked access to an installed module (for example, to scan it for viruses), which has prevented the PixInsight core application from installing it upon startup. When the PixInsight core application fails to install a module, it removes the corresponding dynamic link library (.dll file) from its internal list of installed modules for security.
  • Your computer is infected with a malware program.
  • Your computer has or has had a hardware or software problem that causes sporadic disk access errors.

To reinstall a lost module, follow these steps:

  • From the main menu, select PROCESS > Modules > Install Modules.
  • On the Install Modules dialog, click the Search button.
  • The missing module or modules should be detected and identified automatically.
  • Click the Install button.

Please understand that we have no control or responsibility on the behavior of other applications, such as virus protection or malware programs. If you experience this problem, use a different virus protection software and check your computer thoroughly for viruses, Trojans, spyware and other malwares with a good, up-to-date virus protection software.

No. PixInsight is available exclusively as an electronic download from our software distribution system.

No we can't. You have to download them from our software distribution system.

  • Email-based support. Our support email address is support (at) pixinsight (dot) com. You can also use our Contact Form.
  • PixInsight Forum, the official community of PixInsight users. This is definitely our best support resource.

Nothing. Our user support services are free for all our licensed users (both commercial and trial licenses).

No we can't.

No we can't. See the Resources section of our website for information on tutorials, examples, videos and workshops. We encourage you to register on PixInsight Forum, where a vibrant community of PixInsight users will be more than happy to help you.

PixInsight can save 32-bit and 64-bit floating point and integer images in TIFF format. However, most (all?) other applications don't support these numeric formats.

If you want to open TIFF files with image retouching applications and generic viewers, save them in 8-bit format. Some applications are also able to read 16-bit images, but the 8-bit format is the best option for the sake of compatibility. Be careful to prevent losing your original image; always keep it in its original numeric format (typically 32-bit floating point), preferably in PixInsight's native XISF format.

FITS is an obsolete, inefficient and poorly defined format. It is a source of endless interoperability problems. In our opinion, the blind adoption of the FITS format may be the worst mistake made by the astronomy community.

We have created the XISF format because we need a contemporary, really extensible, efficient, interoperable and well defined file format. For more information, see the XISF resources page on our website and the XISF Version 1.0 Specification document.

As of version 1.8.3, PixInsight has been ported as a native 64-bit application to Linux, macOS, and Windows. See also the System Requirements section for information on minimum supported versions and platform-specific requirements.

Our primary development platform is 64-bit Linux. All the development work for the PixInsight core application and all core modules is done on Linux. Currently we use Red Hat Enterprise Linux Workstation 7.4 on all of our development workstations.

The macOS and Windows versions of PixInsight are ports of the main development trunk on Linux. All versions of PixInsight are native applications in their respective platforms.

You can expect the same quality standards from PixInsight on all supported platforms.

Since Linux is our primary development platform, the Linux version of PixInsight is the most stable and feature-rich version, where you'll in general get the maximum performance.

Take a look at our PixInsight Benchmark project for more information about PixInsight's performance on different operating systems and hardware. See also the System Requirements section.

As of updating this document (December 2018), PixInsight 1.8.6 has been fully tested on the following Linux distributions:

Red Hat Enterprise Linux Workstation 7.5.

Fedora 29 Workstation.

Ubuntu 18.04.1 LTS Desktop.

For the latest 1.8.6 version of PixInsight, we recommend the KDE Plasma desktop environment. KDE 4.10 or later and GNOME 3 also work fine.

Of course, other Linux distributions, such as CentOS, Debian, Arch, Slackware, Gentoo, OpenSUSE, Mandriva, etc., also should work fine.

PixInsight is a platform-agnostic application. Besides minimal adaptations to some platform-specific idiosyncrasies (for example, window control icons are placed on the left side of the title bar by default on macOS), our graphical user interface does not follow the conventions or visual style guidelines of any particular operating system or desktop manager.

The macOS version of PixInsight is not a typical macOS application, and the same happens on Windows and Linux. By adjusting a few preferences settings, you can configure PixInsight's graphical interface to look and behave virtually identically on all supported operating systems.

We are currently writing complete reference documentation for most standard PixInsight tools. The available documentation is integrated with the PixInsight core application, and is also available online. To give you an idea of the quality and extension of our documentation, take a look at the documentation for the StarAlignment and ImageIntegration tools. Writing PixInsight reference documentation is an extremely complex and time consuming task. We are generating new documentation as fast as we can, given our limited resources.

Besides the reference documentation, we have processing examples and tutorials. Currently our strongest bet is in producing video tutorials as the best learning resources on our software.

The PixInsight Resources website by Alejandro Tombolini and Enzo De Bernardini provides a large number of excellent documents, written tutorials and video tutorials about our user interface and much more essential topics.

Yes! Take a look at the video tutorials section on this website. We favor video tutorials as the best learning resources on PixInsight. On the same page you'll find links to other online resources providing video tutorials.

If you are interested in PixInsight, the PixInsight Resources website by Alejandro Tombolini and Enzo De Bernardini is an absolute must-know.

The answers are yes and not yet, respectively. We already have a quite complete reference documentation for the PixInsight Class Library (PCL). However, we still don't have the necessary reference documentation on the PixInsight JavaScript Runtime (PJSR). Again, this is an important pending task that we must carry out as soon as possible.

Always feel free to post any questions and doubts about PCL and PJSR programming on PixInsight Forum, where we'll be glad to do our best to help you.

PixInsight is a complex research and development project with an international scope and audience by nature. As a small software development company, our resources are very limited, and we must invest all of them in our development and maintenance tasks. Making localized versions of PixInsight is something that we simply cannot afford at present. Bear in mind that PixInsight is a commercial software product, so we can only depend on our own resources.

To understand the complexity of our work, consider that we must perform, among others, the following tasks on a daily basis:

  • Design and development of new image processing tools.
  • Continued development of the PixInsight core application on three platforms: Linux, macOS and Windows.
  • Design and development of better and stronger software protections to fight piracy.
  • Fixing bugs and implementing new features and improvements in the core application and all standard modules.
  • Fixing bugs and implementing new features and improvements in our development tools and frameworks (PCL and PJSR).
  • Testing the whole PixInsight platform.
  • Planning and producing new video tutorials.
  • Authoring new processing examples and tutorials.
  • Authoring development documentation (currently an important pending task).
  • Authoring user interface documentation (currently an important pending task).
  • Maintenance of our file servers and licensing system.
  • Maintenance of our corporate website.
  • Provide email-based and forum-based user support.
  • Carry out bureaucratic tasks related to our company.
  • Live our lives!

Adding the extra complexity involved with localized versions of our software is just too much for us. We have chosen the English language as the best communication vehicle to cover the widest possible audience worldwide. We currently have no plans to publish localized versions of PixInsight; we actually prefer to invest our scarce time in producing new and improved tools and tutorials, instead of making translations.

This is a copy of the official announcement we published on PixInsight Forum on October 5th 2009:

The PixInsight LE freeware application was first published in 2004. The free LE (Limited Edition) application has represented the initial development stages of the PixInsight project, as well as the first public release of PixInsight.

After nearly five years since the last update (LE version, today we have made the decision to discontinue PixInsight LE. We know this may be a controversial decision, but we have at least three strong reasons to take it:

  • PixInsight LE is a completely obsolete application. It does not provide a minimally accurate idea of PixInsight's current state of development.

  • PixInsight LE is only available on Windows, which is contrary to what we want to achieve with PixInsight. Within the goals and general philosophy behind PixInsight, it is unfair to continue maintenance of a freeware product for a single platform.

  • For a long time, PixInsight LE has been counterproductive to the aspirations of the PixInsight project. PixInsight LE is very often seen as a tool which is only valid to solve a very specific problem (gradient removal with the DynamicBackgroundExtraction tool, a.k.a. DBE), and nearly nothing more. Actually, PixInsight LE, even being obsolete, provides a reasonably complete, 32-bit post-processing solution, which is able to achieve better results than other commercial products. It always amazes us when we read descriptions of how PixInsight LE is used for DBE, then the image is downgraded to 16-bit, as a necessary step to open it with other application, with the purpose to apply levels, curves, etc. That is quite disappointing because PixInsight LE offers far better histogram and curves transformations, not to mention advanced color saturation adjustments, morphological transformations, wavelet transforms, noise reduction tools, pixel math, an efficient masking system, and an accurate color management system, among other tools and features. Unfortunately, we feel that today PixInsight LE has become an obstacle to understand what PixInsight actually is, what it can do, and how it evolves.

Based on these considerations, from now on the old PixInsight LE application will no longer be available for download from our servers.

Definitely yes! The fact that we have discontinued it doesn't mean that you can't use it. We are glad to know that our software can still be useful, even if it has become obsolete.

The old PixInsight LE is a freeware application. As long as you don't allow public access to your copy, you can share it privately.

Disclaimer— Pleiades Astrophoto S.L. assumes no responsibility or liability for copies of our software that have not been downloaded directly from our official website or file servers (www.pixinsight.com and its subdomains). When you share your copy of the old PixInsight LE application, you are the sole responsible for any damage caused directly or indirectly as a result of viruses or other malwares that might be infecting your copy.

Sorry, no. Doing so is illegal because it violates the terms of PixInsight LE's End User Agreement. The agreement is included in PixInsight LE's documentation, under the "Legal Matters" section.

If we detect copies of the old PixInsight LE archives publicly available on the Internet, we'll do everything we can to force their removal, including, when necessary, all legal actions available to fight piracy.

Disclaimer— Pleiades Astrophoto S.L. is not responsible or liable for any problems caused by illegal copies of our software. In particular, we are not responsible or liable for any damage caused by viruses or other malwares infecting illegal copies of PixInsight LE. We are only responsible for software that has been directly downloaded from our official website and file servers (www.pixinsight.com and its subdomains).

Yes, in the medium-long term. The new PixInsight LE will be a subset of the tools available on the PixInsight platform. It will be a closed system because it won't allow installation of additional modules, and it will include no scripting system. It will be approximately equivalent to the old PixInsight LE application in terms of functionality and features, but it will share the technology of the current PixInsight platform, and it will be available for all operating systems supported by PixInsight (currently Linux, macOS and Windows).

The new PixInsight LE won't be a freeware product, but its price will be very reasonable, considering its processing power.

We currently have no planned release dates for PixInsight LE. Right now we have too many ongoing projects and development priorities.

Of course. We don't know other way to work but by doing what we love.

The word PixInsight mixes two concepts: pixel and insight. It is something like "an insight into the pixel", or "an insightful look at the pixels". My intention was probably to show you that I take your pixels very seriously :D

No, no and NO!!! It is PixInsight. Exactly PixInsight.