Preferred method for moderate image enlargement?

[mikedavid]

For moderate increases in image size, what has everyone found to yield the better printed image:

1) Resampling the image to a lower dpi (say from 300 to 240)

or

2) Using a Lanzcos / Bicubic / S-Spline routine to enlarge the image, thereby maintaining the 300 dpi resolution

Thanks!

[drisley]

I use Q-Image. It automatically resizes the image to the proper dpi for print without user input. You have a choice of different methods of interpolation. Lanczos was the best method available, but now they have included vector interpolation which they say is the best.

If you dont want to buy Qimage, get Irfanview which is free and resamples the image to the larger dpi using Lanczos.

If you don't and you just reduce the dpi, your printer will have to do the interpolation. The results just aren't as good (although the diff might be minor).

Also, many say you should add some extra final sharpening to the image just before printing on an inkjet. QImage also does that automatically.

A great photoshop plugin for extra sharpening without extra noise is Sharp-N-Smart ;)

http://threedee1.tripod.com/sharpnsmart/sharpnsmart.html