I am working with a TIF to JPG conversion that will result in the JPG being printed from a web page. My issue is the final JPG image prints VERY blurry.

The TIF file that has the following settings,

*plat.tif*
Pixel Dimensions - 9600x7200
Document Size - 24x18 inches
Resolution - 400 px/in
File Size - 236 KB

When using the command
Code:
exec("convert plat.tif -density 300x300 -quality 100 plat.jpg");
the code takes 63 seconds to run. Is this normal?

Then i run
Code:
exec("convert plat.jpg -resize 792x612 -quality 100 plat_resize.jpg");
to reduce the JPG to the PX size i need. the code takes 73 seconds to run. Is this normal?

When plat_resize.jpg is viewed in Firefox using a standard <img src> tag the image looks not as good as the original TIF, but "OK". Though, my final output is to print the image and this is where my main problem is. The printed image looks blurry and unreadable. How can i get it to look as good or as close to the original TIF as possible?

Here are the files being used and generated.

http://www.zellco.com/imagemagick/plat.tif
http://www.zellco.com/imagemagick/plat.jpg
http://www.zellco.com/imagemagick/plat_resize.jpg
http://www.zellco.com/imagemagick/plat_resized.html (image in page ready to print.)

Thank much for all the replies to come.