2026-10-09 APP 2.0.0-beta48 has been released !
This is mainly a bug fix release for the reported bugs in beta47. In addition it has a significant User Interface performance improvement noticable when you need to process 1000s of images in APP.
2026-10-03 APP 2.0.0-beta47 has been released !
This is a very big release... many code optimizations/rewrites, many parts of APP are much faster and more precise, especially star analysis and registration are much faster ! Big mosaics will go much faster 🙂
And we introduce a new preview filter, which includes the new Adaptive Deep Sky Stretch and a General Levels Stretch, this has been long over due. The old preview filter (the panel on the right side to stretch and preview your data) has not been updated for a couple of years and it is a critical part of any APP session.
Adaptive Deep Sky Stretch or ADSS is a much more intuitive stretch algorithm. It is also color preserving (which is a great new addition in itself ! ) which means that the highlights are no longer bleached, color is maintained from the linear data while stretching. You can simply stretch your data using the sky background level and signal width sliders which work much easier and more intuitive. You no longer need to fiddle with the old complicated sliders with zoom buttons. All the zoom buttons for the sliders are made redundant. And you can enter slider values in the slider value fields yourself. I will make a youtube video in the coming days to explain and fully introduce ADSS. Once the video is ready, it will be highlighted on the forum.
RGB Combine upgrade !. The RGB Combine Tool has been rewritten mostly. The tool is faster and easier to use and most importantly, the Luminance slider to inject a luminance channel or channels into the RGB composite is now working correctly. It no longer bleaches the RGB colors. Combined with the new ADSS preview, you will get much better and easier great composites with great color! I will also explain this in a new youtube video.
Hi,
What is the recommended way to non-destructively save a linear APP-image to continue image processing in another tool, like eg. PhotoShop or Affinity Photo?
Or put in another way, does saving a stretched image in APP always mean losing some of the original image information, and thereby limiting what can be achieved with further processing in other tools?
Currently in my workflow, I do the bulk of the processing in APP, (eg. Integrations, RGB combine and LPC) and after a light stretch, I save the image in a 32-bit TIFF format and continue tweeking the tiff-image in Affinity photo. Even though TIFF is a lossless format, I just want to verify if there is something to be gained from saving a non-streched image in tiff-format or even just use the the linear fits-file from APP directly as input to Affinity (which is an option). This certainly would require more work and your recommendations here would be very helpful.
Thanks,
Anders
Hi Anders,
Good question, I think stretching will remove data as the preferred way in APP is always to use the linear data. I asked Mabula for a double check on that. I'd say that if you can process linear in another package, I'd probably do that. But I'll see what Mabula has to say as well.
I’m still learning Affinity, but thus far I have gotten much better results when importing stretched tiff versus linear tiff.
I would be interested to hear your experience with linear files.
Yes, so you indeed do limit your data with stretching. However, it is a good starting point, usually, for touch-ups in another package as the stretching APP does may be somewhat better. But, if the other package is able to stretch, you can always compare both and try to make them produce the same result. If that works, I'd likely do that and then save the result in the other package to a stretched one.
Thanks Vincent and Jeff for your input.
After some further tests and comparisons, I tend to agree with you. Loading a linear fits-file and stretching it in Affinity, I have found it difficult to even come close to the result I’m able to achieve quite easily in APP.
So revising my thinking, it may be a good idea to make the most of APP stretching facilities that applies to the whole image before exporting to a tiff format. Importing it into Affinity is still very useful to be able to take advantage of powerful generic image processing features like layering and masking for further enhancements.
I do not use APP for any post processing. I create the stacks in APP and then combine and process the .FIT files in another piece of software.
