I found that Bicubic resampling , especially downsizing my 3008x2000 images to 640x480 results in very soft images with loss of detail. I'm not sure if there is a better way of downsizing images, even the stepped manner didnt seem to work too well. I tried the rest of the available options in PS CS, and found that Bilinear downsizing seem to provide very crisp images with less detail loss. If you know more about this issue, please contribute.