Source: http://stackoverflow.com/questions/123838/get-the-resolution-of-a-jpeg-image-using-c-and-the-net-environment
Using System.Drawing.Image;
It depends what you are looking for... if you want the DPI of the image then you are looking for the HorizontalResolution which is the DPI of the image.
Image i = Image.FromFile(@"fileName.jpg");
i.HorizontalResolution;
If you want to figure out how large the image is then you need to calculate the measurements of the image which is:
int docHeight = (i.Height / i.VerticalResolution);
int docWidth = (i.Width / i.HorizontalResolution);
This will give you the document height and width in inches which you could then compare to the min size needed.
