[lewisa]

Im not sure how Picasa handles resizing of images. It might just have three set default sizes if I remember correctly.

In an ideal world, you would use image editing software, such as Photoshop, Paint Shop Pro or The Gimp to resize the image to 800x 600 or whatever size was required.

Then you might want to do some mild sharpening, as reducing the size of the image can soften it.

Then you want to save the image as a jpeg controlling the amount of compression.

On Photoshop 7 for example(an old version by todays standards, its expensive software to upgrade though!), this is a 12 step scale ranging form 12(least compression-best quality-biggest file size), to 1 (most compression-worst quality-smallest file size).

Then if you required the file to be under 500K for example, you would set the compression to the highest value upto 12 (ie least amount of compresion possible) that resulted in a file less than 500K.


The last point about the amount of compression is the main issue probably, ideally you want software where you have control of this value.

Photoshop is expensive, but the industry standard.
The Gimp is open source and therefore free.
Paint Shop Pro is a lot cheaper than Photoshop, but will still cost a bit.

HTH.