How to Change PPI

Get a more detailed image by increasing PPI.

PPI (pixels per inch) is a measurement of an image's resolution. The higher the number, the more pixels per inch and the finer the detail. This setting can be easily changed in image-editing applications such as Adobe Photoshop. PPI is often confused with dots per inch, or DPI. PPI refers to the number of pixels on a screen, or in an image file. DPI refers to the maximum number of dots that can be printed, depending on the printing process that is used. Increasing the PPI of an image will generally yield a higher quality printed image as well.

Things You'll Need

• Adobe Photoshop or other image editor

Instructions

1. Click "Image" in Adobe Photoshop and select "Image Size."

2. Click the "Resolution" drop-down box on the right side of the screen and select "pixels/inch" if it is not already chosen.

3. Type a number into the "Resolution" box on the left side of the screen. The higher the number, the more detailed your image will be.

Tips & Warnings

• Images on the Web do not require a large pixel density to look good, unlike in print. Typically, a resolution of 72 ppi is adequate for online viewing.

• Increasing an image's PPI does not always produce a better, more clear or detailed image. Sometimes it can even make the image worse. If this happens, try to resolve the problem using the Unsharp Mask filter.

• Resizing is best done for images that are to be printed. You resize a document in the Image Size dialog box then change the "Document Size." Resampling is best done for images that are intended for the Web, because this option changes the number of pixels rather than the size of the image. This can be done by clicking on the "Resample Image" drop-down box.

References

• Adobe Photoshop CS5: About Pixel Dimensions and Printed Image Resolution
• Andrew Dacey Photography: DPI and PPI Explained

Resources

• "From Design Into Print: Preparing Graphics and Text for Professional Printing"; Sandee Cohen; 2009