Good question. I am not familiar with pixels per inch but how do I check or alter the image size based on it? I guess it really gets confusing using that as a resizing definition, similar I have tried to resize the image by percent instead of an actual size. It results in resizing the image, but it is always a guess as to what percentage change will result in the size I am looking for.
Simplier if I could just input the size requested and the program returned an altered image in the size as requested. (I use to use a graphics program that came with my digital camera that was easier to use for resizing than paint.net).
Microsoft Paint has the same problem. If you want to resize an image, you have to resize it by a percentage, there is no way to resize based on an actual measurement (ie from 3 inches to 2 inches).
Jeff