I have a
700Kb JPEG file (white cardboard texture) that I'm using as a background on a website.
A file this large takes too long to load for snappy page hits. I don't need the full resolution, a reduction in image quality is fine, but I do need to keep the JPEG the same size (to fill the entire screen).
What would be a good free PC or web utility that would allow me to modify a JPEG as described? I'd rather not use Photoshop or other professional software.