Blowup is probably the best resize app, primarily because of the additional effects, and Genuine Fractals perhaps second. However, I find that due to the requirements and the algorithms used it really depends more on what you are trying to resize and how large you want to resize the image. Remember, CS typically has a max of 32,000 x 32,000 ppi for some versions.

 

Some resize CS plug-ins, can resize as a stand alone, and also in conjunction with CS, some do not.  How that works for GF, is you resize the image and apply any modifications and effects to the image using CS. Say you want to resize an image to 200% using CS. You then use the plug-in to resize the image another 200 to 500%, using a fractal algorithm.  This is how you get the up to 1000% increase in resize over the original. 

 

I have to recommend that the best ppi for image resize is approximately 300 to 400 ppi.   

 

There are several stand alone resize apps that will do large images, as large as your computer can handle, but I have tried them, and do not feel they are the quality of GF.

 

Another point I would like to add. If you are a good photographer and have used Photoshop for many years, you are usually able to add many additional personal refinements to any finished image without using these plug-ins, but these plug-ins could save time.

 

There is always some degradation for any resize, in the form of pixilation, tessellation, or blurred anti-aliasing. In most cases it is minimal enough the human eye does not notice, sometimes a number 4 loop is required to see the difference. However, that is the reason for rendering an image in high resolution 300 to 600 ppi, so that you could resize to lower resolutions or larger sizes with no or minimal loss. 

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