I did not have time last night to do a sample, but did this morning. Rather than use a high quality image, I have used a poorer quality, to demonstrate the possibilities.

 

I took a 99 x 94 x 133 ppi sample of China Straits, a compressed JPG from my gallery. The original compression was about 80 % progressive. 

 

In Photoshop CS2, a 200% Bicubic Smoother resize was applied to the sample cut. This resized image was further resize to 400% for a total of 800% over the original image. 

 

The two images side by side are a comparison, one to the left is 94 x 99 x 133 ppi, and the image to the right is 752 x 792 x 133 dpi.  

 

You could also make a comparison of the original, in the reverse order, to see how the pixels were resized and anti-aliased, but I believe this image comparison speaks for itself.

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