Changing the Resolution and Print Size of Photos
You can reduce the size of your image and change its resolution to prevent someone from printing and using it as a high-quality photo. Resolution refers to the number of dots or pixels that are in one inch.
- Dots per inch (dpi)
- Measures the print quality and needs to be around 200-300 or higher for an image to look good as a print. A lower resolution will make the printed image appear grainy.
- Pixels per inch (ppi)
- Measures the quality of an image on your monitor. To look good displayed on a monitor an image only needs to be about 72 pixels per inch (ppi). Therefore, if you only need an image to look good on a monitor, you can lower the resolution to distort the print quality.
You can change the resolution by resampling your image and adjusting the number of pixels. When you resample your image, you increase or decrease the number of pixels used and distort the printed image.
Resampling down reduces the pixels and results in good viewing on a monitor, but a smaller print size. Resampling up increases the number of pixels and results in a larger image for the monitor and print, but poor overall quality. Adobe® Photoshop®, Corel® Paint Shop Pro®, and The Gimp are several photo-editing applications that you can use to resample your photos.
NOTE: Resampling down cannot be undone without loss of quality. We recommend that you save a copy of the original image before resampling.
To Change the Resolution and Resize Your Image in Adobe Photoshop
- Open the image file in Adobe Photoshop.
- From the Image menu, select Image size.
- In the dialog box, deselect Resample Image.
- In the Document Size Resolution field, enter the reduced number of pixels.
- Select Resample Image.
- In the Pixel Dimensions field, enter a new width.
- Click OK.
- From the File menu, select Save for Web.
- Click Save.