Saving Large PI Files as Small JPGs

[Oscar in Bin (John)]

PI can produce some very large files after processing. My latest is just over 300,000KB!!!!
Attachments to the Imaging Forum on Ice in Space want images of 200KB.
When I use PI to save to this size you get junk.

What is the secret to getting such a large reduction and maintaining reasonable image quality?

[AstroViking (Steve)]

Hi John,

The best option is to export your finished image from PI as a JPG or PNG, then use a program to then scale down that image to a smaller resolution and lower quality factor.

I use either 'Preview' (built in to macOS) or the excellent 'GraphicConvertor' (about $65, shareware) to then scale down and watermark my images.

If you're using Windows, unfortunately I don't know what pre-installed program you can use - you could always try installing GIMP and see if that works for you. On a Linux machine, you have GIMP, as well as the command-line driven 'ImageMagick' tools, and I'm certain there are many others.

Once you get them to about 400kB, the forum software can take over and chop them down to it's 200kB limit.

Cheers,
V.

[joshman (Josh)]

I owuld highly recommend saving out your finished image at full resolution and as high a quality as you can, this is your master copy, then use a freeware program like IrfanView64 to save a copy at a reduced scale. Irfan view is great because you can set the finished image size (in kB) and it will compress as required to meet that requirement. It will also do batch conversions if you have a lot of images that need the treatment.

[Leo.G (Leo)]

As others have recommended save as a large full size file for future use.
I believe windows 10 and 11 both have resize options available standard.
I don't have win 10 or 11, I have win 7 and use a free program called Moo0 image resizer. It works like many of the others mentioned with adjustable parameters depending on what you want for the output.

[RAJAH235]

Hi,
I can thoroughly recommend this free program.
Been using it for years.

Has heaps of features as well.
Go to > https://www.faststone.org/
& down the bottom is > "FastStone Photo Resizer 4.4 Freeware"

Easy to use too & works on WIN7, WIN10 & WIN11.

[Ryderscope (Rodney)]

Originally Posted by Oscar in Bin

PI can produce some very large files after processing. My latest is just over 300,000KB!!!!
Attachments to the Imaging Forum on Ice in Space want images of 200KB.
When I use PI to save to this size you get junk.

What is the secret to getting such a large reduction and maintaining reasonable image quality?

Hi John, it is actually quite easy in PI and I do it all the time for attaching images to a post in IIS. In PI I simply use the Resample tool to set the image width to 1000 pixels and then save it as a JPEG. It then attaches fine to the post. Whilst the image size does come out at more than 200k I find that it still uploads to the post ok.

If you are interested in a critical review of the image, I do still recommend uploading the image to a cloud file sharing service or other such as Flickr or Astrobin as this provides the opportunity for a proper look at the final result.

[AdamJL]

+1 to Rodney’s suggestion. PI can export as a small jpeg as well