Now you know how to quickly resize a photograph and create images with alpha backgrounds. In order to keep the image with the background deleted, you must save it as a PNG or GIF file with the alpha check box selected. Press delete on your keyboard and the area will be removed. Drag until the space is covered and let go. The red overlay that appears represents the area that can be deleted.

Once you have the tool selected, click on part of the background you wish to delete and begin dragging. The Instant Alpha tool is located in Preview's tool bar, under the Select menu. If you need to take out a background on an image, you can use Preview's Instant Alpha feature to quickly and easily complete the task. Preview is also a great tool for doing all kinds of other simple adjustments on images. Also keep in mind that higher-resolution images are bigger files. If you need to print at a low fidelity or your image contains a lot of text, set the resolution to 150 or 300 pixels/inch. Adding pixels does not necessarily mean you will have a higher-resolution photograph, however, and some distortion can occur when resampling.įor images that will only be seen on a screen, make the resolution 72 pixels/inch. You can also adjust the resolution (pixels per inch) that your photo contains. Keep in mind that you will want to keep your image proportions locked so stretching does not occur. To adjust the dimensions of your image, you can set a custom height or width, or constrain your image to fit into common sizes. In the size adjustment box that appears, you will notice you have several options. If the image you want to open is associated with another program (like Photoshop), right-click the image file and mouse over 'Open With' and choose Preview from the list.įrom the Preview menu bar select Tools > Adjust Size. Preview handles nearly all popular image formats including JPEG, TIFF, PNG, and GIF. Photoshop can run as high as $199 for the latest version, and Elements still costs about $69. Though these applications are great solutions, they can also be costly and somewhat complicated for new users. Many tips floating around the Internet will suggest using Adobe's Photoshop or Photoshop Elements to accomplish tasks like resizing and adjusting image resolution. And best of all, it comes free on every Mac, bundled with OS X.

Using Preview, you can easily adjust your photos and get them ready for print, projects, and sharing.

One of the unsung heroes of Apple's Mac OS X is the simple, yet incredibly powerful, Preview application.

How to change a photo size on mac