Here's a little contribution to the discussion....
I decided to run a simple test. I took a photo fresh from my Camera. The photo was done at the 6.1MP setting with Standard jpeg compression on my Kodak Easyshare Z760. Note, my camera also has a Fine setting which decreases compression (larger file size for same shot). The Auctiva/Aurigma uploaded the photo and it was stored at 167.42KB.
Here's the photo at 400x300 px as stored at Auctiva.
I then displayed the photo in a browser window by copy and paste of the link, and saved the photo to my desktop.
Here are some stats on before and after, after being the saved photo back to my desktop.
Before: Size 1,257,942 bytes, WxH 2856x2142 px, Res 96x96 dots per inch
After: Size 171439 bytes, WxH 1024x768 px, Res. 230x230 dots per inch
It was the dots per inch that caught my attention. I checked the photo before and after with MS Paint, which does give a DPI attribute for Properties.
That increase in DPI might account for the dithering effects seen on photos and the size increase.
When I get a chance, I'll try a similar test with a scanned image at high scan res (high DPI).
The Fine setting on my camera does not affect the DPI, only the compression (tested).
Danno
Edit: I took the same original photo and resized it using Paint to 1019x767 (just under the 1024x768 limit) and used the Basic HTML uploader for a test. Here's the results.
Before: Size 131,700 bytes, WxH 1019x765 px, Res 96x96 dots per inch
After: Size 124,097 bytes, WxH 1019x765 px, Res. 96x96 dots per inch
Note the DPI did not change and only a small decrease in file size was observed.
Here's that second test with pre-sized photo at Auctiva 400x300.
The second test suggests that presizing a photo that requires best resolution (precludes dithering) and using the old HTML uploader is possibly a better choice when extremely fine details are required, i.e. it appears to upload and store as processed at the desktop.
Sophie's photo when displayed at the full size, as stored by Aurigma, might be a whisker better (pun intended).
