Messages

1

Bug Reports / Re: 1.8.8-2 iMac drizzle weight issue?

« on: 2019 December 09 12:52:00 »

This bug is now fixed:

https://gitlab.com/pixinsight/PCL/commit/a1e5997d57e2feff61d98645e4edf732c6f6a711

The fixed version of the ImageIntegration module will be included in version 1.8.8-3, which I am preparing now as a cumulative update/bugfix release for all platforms.

1) Notice that the satellite trail shows in the difference image as a subtle level change along the trail. Does this indicate a small normalization issue related to rejection in drizzle?

Not at all. With a drop shrink value of 1.0, the satellite trail has pixel values close to 0.9474 on the drizzle weights image. This is approximately equal to 1 - 1/19, which corresponds to the expected weight when only one image of the set of 19 integrated images has been rejected.

2) Note that in this example ImageIntegration uses bilinear interpolation. As a test, please change it to Nearest Neighbor and retry the entire process. You will see that the satellite trail is now much more prominent in the drizzle integrated result. I think this is an issue also. Note, I recall several years ago NN being an issue with drizzle, maybe it is just not supported by drizzle?

Nearest neighbor interpolation should not be used for drizzle integration. This is because NN does not provide subpixel interpolation accuracy, which is crucial for the drizzle algorithm, even for a drizzle scale of 1. Ideally we should issue at least a warning message when this happens in drizzle, but this would require storing additional metadata in .xdrz files.

2

General / Re: alignment method

« on: 2019 December 09 12:09:30 »

Three important reasons:

- JPEG images have compression artifacts that prevent any useful analysis.

- JPEG images are 8-bit integer images. Severely truncated star profiles are far from ideal to diagnose image registration issues.

- Our image registration algorithms, and very especially our distortion correction algorithms, have been conceived and designed to work with linear data. Anyway, if you really want to work with already stretched data (which is strongly discouraged), please upload the TIFF files in 16-bit integer format at least.

3

General / Re: Question regarding image rendering

« on: 2019 December 09 05:57:17 »

Hi Mike,

By default PixInsight uses a fast interpolation algorithm to render images on the screen at zoom factors smaller than 1:2. This algorithm is very fast but somewhat less accurate than other standard interpolation methods, which can lead to dimmed faint stars and other small-scale features. Compare the images at zoom ratios of 1:2 or larger. You can also disable fast screen renditions with Preferences:

- From the main menu, select Edit > Global Preferences.

- On the Preferences interface, select the Miscellaneous Image Window Settings section.

- Uncheck the Use fast screen renditions option.

- Click Apply Global, or press F6.

Also take into account that other applications may be applying sharpening filters to screen renditions to make them look 'better'. PixInsight does not do that.

4

General / Re: alignment method

« on: 2019 December 08 10:58:26 »

You have uploaded JPEG images. We can't help you with these. We need the unstretched frames in XISF or FITS format.

5

General / Re: MURE Denoise with ASI1600MM

« on: 2019 December 08 10:56:43 »

Indeed those repositories are correct for version 1.8.8-2 of PixInsight. You should have received the MureDenoiseDetectorSettings script as a regular update. Otherwise something strange is happening with your PixInsight installation. A virus protection application messing with application files, maybe?

6

General / Re: alignment method

« on: 2019 December 08 02:37:04 »

Hi Carmine,

Just the contrary, the new distortion correction algorithm implemented in recent versions of the StarAlignment tool is much more capable and accurate than previous versions. The local distortion correction algorithm aims at achieving centipixel registration accuracy. However, it is also more demanding of good star shapes to perform precise PSF measurements, and this may cause problems under less than ideal focusing conditions.

"2-D surface spline" and "thin plate spline" are more or less equivalent terms to describe the registration device used by StarAlignment when distortion correction is enabled (thin plate splines is used more frequently).

If you upload the images that are giving you problems, I'd be glad to take a look to try to help you.

7

General / Re: How to enable TRACK VIEW as default

« on: 2019 December 08 01:56:37 »

mmmh, maybe it should go in the “Wish List”

The track view option cannot be enabled by default, nor can it be enabled through process icons.

OK. Any possibility of this being available in the future ?

No, the Track View option cannot be enabled by default for several reasons.

Processes, process instances and images are completely independent and self-sufficient objects. This is a consequence of PixInsight's object-oriented design. The track view functionality is borderline in this context. It has been designed as a special working mode, available on some process interfaces as a convenience feature. It is not intended to be part of these processes, nor the way these processes work normally, and should only be used in special cases where an increased level of interaction with several images can be useful temporarily. On the other hand, the track view feature can have a non-negligible cost in terms of resource consumption, which would affect negatively the performance of the whole platform if it were enabled systematically.

8

Bug Reports / Re: PI throws error does not start

« on: 2019 December 08 01:29:38 »

This problem has not been caused by PixInsight. Check the following article on Autodesk Knowledge Network for a similar problem and possible solutions:

https://knowledge.autodesk.com/support/autocad/troubleshooting/caas/sfdcarticles/sfdcarticles/AutoCAD-startup-error-load-liabrary-failed-with-error-87.html

9

Bug Reports / Re: 1.8.8-2 iMac drizzle weight issue?

« on: 2019 December 06 09:02:24 »

Hi Mike,

Bug confirmed. I have reproduced it with other data sets that I have just checked. At first glance this looks like a 'simple' coordinate roundoff error, but I have to investigate it in depth. I've probably caused this bug with the latest improvements I've made to my drizzle implementation (in core version 1.8.7), where I have made slight changes to the way drizzle applies coordinate systems internally, in order to make it fully compatible with regular image integration.

Workaround: set drop shrink to 0.99. This fixes the problem completely, and is a good hint that this is just a numeric roundoff issue.

Thank you for discovering this bug. I'll work to fix it as soon as possible.

By the way, this image looks terrific with drizzle x2

10

General / Re: Nvidia Geforce 2080 adjustment

« on: 2019 December 06 07:52:19 »

I am right now working on an update to the PixInsight core application, where I hope to fix these problems with deficient OpenGL implementations on Windows. An update with core version 1.8.8-3 for Windows should be available in a few days. I just ask for some patience, I am doing all I can do to solve this situation.

11

General / Re: How to enable TRACK VIEW as default

« on: 2019 December 06 07:46:43 »

Hi Mick,

The track view option cannot be enabled by default, nor can it be enabled through process icons. You can save a project, where the state of track view options for open tool windows is serialized and restored when you open the project.

12

General / Re: Thread count and Amdahl's law

« on: 2019 December 06 07:43:02 »

Does it make senses to run pixinsight with a 64 ot 128 multithread architecture ? (AMD 3970 or 3990)

Definitely yes! Many processes in PixInsight implement embarrassingly parallel tasks, which benefit maximally from an increase in the number of available processor cores. Other processes that we have implemented using high-level parallelism also have the potential to run much faster on the new generation of AMD Ryzen Threadripper processors, especially when used in combination with fast NVMe storage devices. Along with this, we are working on new improvements to our multithreading support for the next 1.8.9 and 1.8.10 releases.

Budget permitting, if I were to build a new workstation I'd wait for the 3990WX with Linux and not less than 128 GB of RAM.

13

General / Re: Mouse cursor problem with latest PixInsight release (1.8.7 Ripley) on 2009 iMac

« on: 2019 December 03 09:18:25 »

Since core version 1.8.7, PixInsight requires a processor with SSE4.2 instruction support on FreeBSD, Linux and macOS. This Core 2 Duo machine is no longer compatible with recent versions of PixInsight.

14

Bug Reports / Re: Blink Window size error on MacBookPro

« on: 2019 December 03 09:16:51 »

We cannot reproduce this problem on any of our macOS machines, including several MacBook Pro laptops.

Can you confirm that this happens with the latest version 1.8.8-2 of PixInsight?

15

Bug Reports / Re: Weighed Batch Processing Script fails to complete - invalid drizzle path

« on: 2019 December 03 09:04:42 »

We cannot reproduce this problem with the WBPP script. It always generates drizzle files correctly in all of our tests.

Can you provide a data set where this problem can be reproduced?