You want to change PPI of your picture and you don’t know how? Continue reading and you are going to find the answer. It’s easy!
1.First open Photoshop, go to File > Open and select your image.
You can practise with this picture with dogs:
2. Go to Image > Image Size
3. An Image Size dialog box will appear like the one pictured below.
4. To change only the resolution, uncheck the Resample Image box.
5. In the Resolution field, type in your desired resolution.
6. Click OK to accept the changes.
Congratulations! You did it.