Setting the DPI for images-is it possible


#1

Hi… Graphic artists have reviewed some of my work and they ask if the dpi can be increased.
Is the DPI set or can it be changed. For commerciall use, higher dpi is preferable.


#2

DPI/PPI has no meaning in digital images. It only means something if the image is printed, scanned or displayed.

Some art creation programs try to deal with this somewhat mis-leading statistic, an image is so many pixels wide and so many pixels high.

DPI (Dots Per Inch) is a term used in printing / scanning, e.g. This Laser Printer can print 300 DPI means that the printer makes up the printed image out of dots of which it is capable of printing 300 x 300 (not always square) dots per inch so the best it can do is when printing a 1920x1080 image will be 6.4 by 3.6 inches on the paper. Scanning is same, give it the image just printed and it’ll give you a 1920 x 1080 image (probably slanted - always happens with scanners)

PPI is the same thing for screens and varies wildly. A modern mobile phone, iPhone 12 - Wiki says its screen is 2532 x 1170 pixels which is 460 ppi while a cheap laptop may have a 15 inch screen that displays 1376 x 720 pixels which would typically be about 100 ppi

You can add ExIf metadata - that’s the stuff that records things like the location an image was taken. If you right click on an image in Windows, select Properties then Details you may find a PPI number (my 17 inch laptop says a 1920x1080 is 96 PPI) - the PPI numbers monitors report tend to be very dodgy at best (the Windows numbers are calculated based who-knows what).

So, if you’re printing something (the most likely reason to be asked for anything related to DPI) then as mentioned above a 1920x1080 image if printed at 6.4 x 3.6 will have 300 dpi, to make this 1200 dpi you’d just give them an image that was 7680 x 4320.

DAE’s Intelligent Resize is about the only option to magically create non-existent pixels.