The original image was a jpeg. The HTML was from the example posted in the Illustrations thread:
Code:
<p><IMG style="WIDTH: 375px; HEIGHT: 500px" hspace=0
src="BdIm__1.jpg" align=baseline border=0></p>
The 375x500 size is only honored by MobiPocket (according to their documentation) if it reduces the size of the image. In this case it was originally 510x680, and so far as I can tell it is still 510x680 in the -jpeg case. Either this particular size syntax isn't recognized, or the Desktop Reader does not reduce image sizes.
I used the command
Code:
mobigen.exe file.html -c1 -s0 -jpeg
to produce the attached .prc files (one without -jpeg).