issue with stacking 32 bit floating point tif files

[andrea]

Hello Han,
I am using the 2024-08-01 version of the program and I have tried upload 32-bit floating point tif files for stacking; however I have got an error message saying "error accessing the file" and a "no fits" tag in the result column of the stack menu.

is that normal? I remember older versions of the program would be able to stack without problem, but I have found that, at least for tif files, the program become increasingly slower compared to 1-year older versions, and in the current version failed to open the image at all

not sure if that is related to my processing though, which is different from the traditional astro-workflow:

• I open raw files from the camera in DXO photolab to go under lens correction and noise ruduction steps, then I save to linear DNG.
• I then open the DNG in rawtherapee to align the black point of each image and save to tif 32 bit floating point before I import to a raw converter-

I am attaching a tif file for reference.
https://drive.google.com/file/d/1fq5fFP4CECn1h6cBBSTaUdtcV8akM6bj/view?usp=drive_link

thank you!

[han.k]

Hi Andrea,

Nice image.

Unfortunately ASTAP can not read 32 bit TIF files. It can only export uncompressed 32 bit TIF files but no re-import.

For camera images 16 bit (48 bit colour) should be more efficient since the camera images are 12, 14 or 16 bit maximum. That would also speed up loading the files. Only after stacking a 32 bit foramt would be useful because bitness increases.

Here a table of the input and out put formats available:
http://hnsky.org/astap.htm#file_formats

I hope the program has becomes faster since last year. That is one of the objectives.

Cheers, Han

[han.k]

Correct link:
http://hnsky.org/astap.htm#file_formats

[andrea]

Thank you Han,
I used 16 bit floating point tiffs and it worked fast and well!