How to resize digital images for print

How is the quality of digital cameras, so does the volume of pixels that are able to capture. These days, shooting in the highest quality of the camera can produce an image larger than actually can print the printer. While most image editing programs are happy resize your photos for you in their respective dialog boxes, Printing, knowing how to do it yourself gives you more control.

In this article you will learn how to resize large images from your digital camera, for print using Adobe Photoshop and Photoshop Elements. Fortunately, the steps are exactly the same in both programs.

Document size and resolution

To begin, you need two numbers: the document (or rather, print) size and resolution. When you print a photo per page, the size of the document are most often the same as the size of the paper.

The next number refers to the size of the pixel and, as discussed in our primer of image resolution, the resolution is a measure that controls it. The goal in the press is to make the pixels too small to be seen individually (otherwise the print will look blocky). This is higher resolution than that to which the camera was set (usually 72 or 150 ppi, depending on the manufacturer and model). If you are printing on an inkjet printer at home, the resolution should fall somewhere between 240 and 480 ppi if you're using matte or glossy paper or 180 and 240 ppi for regular or textured paper.

Resize the image size dialogue box

If the image does not need to be cropped, you can use the image size dialogue box for scaling. This dialog is also useful to learn how large can I print the image with a resolution Date. (For example, if you used a lower quality setting on your camera, the image may not contain enough pixels to print a photo 8-by-10 inch high resolution.)

You can call this dialog box in Adobe Photoshop (any version) by opening a photo and choosing image > image size-(in Photoshop Elements, choose Image > Resize >--the size of the picture, or press command-option-I in both programs). In the dialog reveals all sorts of information about your photo as file size (the amount of space it occupies on the hard disk), the pixel dimensions, and more important for printing-the size of the document section that tells you how great the photo would be if you printed the current resolution.

First, you need to lock the size in pixels of your photos if you disable the resample image checkbox at the bottom of the dialog box. This allows you to experiment with resolution and size of the document without affecting the number of pixels that contains photos (which preserves the quality of the photos).

Next, enter the size of the document you want in the width field; both the height and resolution will change automatically to maintain the aspect ratio (the ratio between width and height). If the resulting resolution falls within the guidelines mentioned above, press OK and the picture will be scaled accordingly. If the resolution is too low, then enter the size of the document. Alternatively, you can enter the desired resolution and Photoshop will recalculate the size of the document for you.

Resizing with the cropping tool

If the picture needs cropping-or if you cannot get exactly the right dimensions using the image size dialogue box-you can use the cropping tool and settle the width, height and resolution right in the options bar.

In Photoshop or Photoshop Elements, open the photo and press c on your keyboard to activate the crop tool. Trotting up to the options bar at the top of the screen and enter "10" to "8" width and height (you must include the unit of measure, even if you do not need to use quotation marks). In the resolution field, enter 240.

Tip: If you want to crop a photo, while preserving the original aspect ratio, draw a crop box around the entire photo and then hold down SHIFT while you drag a corner handle inward diagonally. You can also use the arrow keys on your keyboard to move the crop box in place.

When you've just to the right of the crop box, press enter or double click inside the box to accept it. If the image is displayed to enlarge once accepted the crop, have entered too big of physical dimensions and/or too high of a resolution for the number of pixels that contains the image. In this case, pressing Command-Z to undo the crop and enter a smaller print size or lower resolution or both.

Lesa Snider, author of Photoshop CS5: The Missing Manual (Pogue Press/O'Reilly) and coauthor of iPhoto imminent 11: The Missing Manual or ' (Pogue Press/Reilly), recordings training videos for KelbyTraining.com and Lynda.com, is Chief Evangelist for iStockphoto.com, a long-time member of the Photoshop World Dream Team instructor and founder of GraphicReporter.com.

For other Macintosh computing news, visit Macworld. Story copyright © 2010 Mac Publishing LLC. All rights reserved.