Saving a very large file that is not PSB

[GBacon2010]

Adobe states that PSD is for files that are up to 30k x 30k and PSB files are files up to 330k x 300k in resolution.  I have a file that is 168960 px by 39492 px.  So, I saved it at PSB.  Now that I'm done with layering, etc., I flattened the image and again saved it to PSB.  What I want to do now is save to another format.  Photoshop gives me several options that do not work; PNG and TIFF (4GB limit).  I was successful in saving a PNG, but after it was done, I was unable to view the file in another application. I wasn't even able to open it in Photoshop.  The file is 8-bit, no layers.  How does one save (or export) to another file format?

[Stephen Marsh]

You may need to reduce the resolution.

What is the final intended use of this image?

If it is for print, what is the required physical print size in inches or CM and what resolution PPI is ideally required?

[GBacon2010]

Others in the astronomy community want the full size image.  I don't know what they want to use it for.

[D Fosse]

I have a file that is 168960 px by 39492 px.

By GBacon2010

That is, to be frank, an absolutely outrageous size. No practical scenario will ever need that - unless you work for NASA.

[GBacon2010]

Well, I do work for NASA and it's astronomical image that others want to use... and they want it at full resolution.  They don't use Photoshop and they want it in another format.  

[rayek.elfin]

Have you considered BMP yet? I can save a million pixel wide file in PhotoLine as a BMP. 

BMP ought to work.

Scratch that, Photoshop doesn't support BMP for larger files. Sigh. I should've known. Tiresome.

I'd just switch to an alternative at this point, to be honest. Download the fully functional trial version of PhotoLine at pl32.com, import the psb, export as BMP.  Or even as a RAW image. Share with the others.

Done.

If the tool is found wanting, find another tool.

(Unlike Photoshop, PhotoLine doesn't impose arbitrary limits on its image dimensions - it's memory limited. That said, saving a 1,000,000 by 500,000 monochrome image as a 62.5GB BMP file did take a while on my 128GB machine 😄

Another advantage of PhotoLine over Photoshop is that layers have their own individual dimensions, bitdepth and resolution. That allows for a much more efficient resource management compared to Photoshop. A small edit in a huge file only has to take place in that one particular spot.

Yes, it loads fits files too.

)

[LAMY2017]

So, it IS rocket science, GB! 😉

This search --

adobe.com:converting psb to jpg

resulted in only one webpage on the Adobe site -- to convert psD to JPG. So no help from the creators.

This search --

converting psb to jpg

found dozens of free and paid converters for PSB to JPG. I cannot recommend any of them, as I haven't used them. Buyer beware. I also did not check their limitations.

[rayek.elfin]

JPEG/JFIF supports a maximum image size of 65,535×65,535 pixels. So not an option for the OP's file which has much larger dimensions.