) so pure image quality shouldn't be too important.
I think this is an excellent solution and the ' Save for Web' feature will tell you the projected filesize as well as give a preview of how your file will appear including the jpeg compression artifacts.
I thought I'd pull some comparison shots out to show the sort of reduction you're going to be looking at.
Though, of course, the effectiveness of this technique will depend on the specific image you're working with, this example should give you an idea on what you're looking at.
At 157 kb, the image is: This comes from Photoshop CS 5.5's "Save For Web" resizing from a RAW, on Medium Quality at about 20% of the pixel size.
At a shade over 10 kb, this becomes: This is about 10% of the original picture size, and on the Low Quality setting.
Both of these suffer from compression, but this should give you a rough idea of what you're sacrificing for image size.
I don't quite understand what "5L x 3.6w" means, but the obvious thing to do here is to just to scale the photo down.
I'm presuming that this will be used as a thumbnail or similar (if you're trying to do anything else with a 10 k B JPEG, give up now!
From PDFArea Software: Image to PDF Converter Free is a quick and easy-to-use PDF utility that is designed to batch convert image files to PDF document.
To achieve a 15x reduction in file size, you're going to be losing a lot of detail -- I'd expect an unreasonable amount.
Of course, it depends on the specific image how well the JPEG routines can work -- since it's not just based on pixel dimensions.10kb is very small, and it will be hard to get adequate detail for a 5"x3.6" print at that size. I would recommend all of these as good primers: Reduce file size without losing quality, What are jpeg artifacts...?