Many are disappointed after taking a photo, but the result looks blurry or pixelated after zooming. They are pretty sure that the resolution (megapixel) is fine but it’s actually just one part of the equation. Another part of it is called DPI.
This DPI thing is closely related to photo resolution. You may have seen the term used when trying to print something. The printing program will ask you for the DPI setting. Normally, the higher the DPI, the sharper the printing result would be. So, what is a DPI, and how to check the DPI of an image?
What is a DPI?
DPI stands for “dots per inch” which measures how many dots of ink can be printed in one square inch of paper. This term is exclusively being used in the printing world. So, asking for DPI info from a photo is a bit misleading.
Instead, if you want to see the density of a picture, the term you should be using is PPI or “pixels per inch” which represents the number of pixels that appear on an inch of a screen.
Generally speaking, DPI and PPI are similar. The only difference is the medium, one is on a sheet of paper while another strives on a digital screen. All in all, it’s okay to sometimes use these terms interchangeably.
How to check the DPI (PPI) of an image on Windows
Here’s the guide on how to check the DPI (more accurately PPI) on Windows 10.
1. Locate the image file on the File Explorer.
2. Right-click on it and select Properties.
3. Go to the Details tab.
4. The DPI/PPI can be found under Horizontal resolution and Vertical resolution. Both numbers are normally the same.
5. Alternatively, you may launch the image with Windows Photos and then navigate to See more > File info > Size info to get the DPI data.
How to change DPI with Photoshop
But if you have Photoshop, here’s the guide.
1. Open the image you want to change its DPI in Photoshop.
2. Navigate to Image > Image Size…
3. Enter the DPI number in the Resolution row. In this example, I’m increasing the DPI to 150.
4. Be sure to tick the Resample box. Then, select the profile and noise level. If you are not sure, just set it to Automatic.
5. Finally, click OK to apply the modifications.
6. You can Save the modified image. Ideally, you want to save it as a new file to preserve the vanilla image.
If you are increasing the DPI like I did on the example above, Photoshop will create new pixels based on the existing pixels. This is basically an upscaling process that may or may not give you a satisfactory result. As a suggestion, try some dedicated tools for upscaling images here.