Optimize your images for use in Microsoft PowerPoint

A few years ago, you could shoot away with your digital camera and insert those images directly into a PowerPoint presentation without too much worry. However, today's high-resolution cameras produce images that are simply too big for this format, which can cause system crashes, file corruption, and PowerPoint files that are slow and hard to edit. By optimizing your digital images to fit your presentation, you can ensure your pictures look great while your presentation runs smoothly.

Prepping your images

Using your digital images successfully in PowerPoint starts with understanding your target image size. The default (and most popular) PowerPoint slide dimensions are 10 inches by 7.5 inches (Landscape orientation) at a screen resolution of 72 dpi. You can create a presentation of any size, but the vast majority of PowerPoint users stick to this default size as it best fills most displays.

If this default size were translated into pixels, it would be 722.7 by 542 pixels at 72 dpi, giving you a target maximum dimension and resolution. Any dimension that's smaller is acceptable, but you'll need to stick with the 72 dpi resolution to make sure your images don't start to get either blurry or pixelated (or both).

Always resize first

A 3.3-megapixel digital camera produces an image file of 2048 by 1536 pixels at 72 dpi for a file size of a whopping 9 MB. While higher resolution is better for printing, it's total overkill when displaying images onscreen. Since we have a good target to work with, we can resize the image and optimize it for this purpose.

1.	Launch Photoshop and open your image file.
2.	Select Image Image Size to display the Image Size dialog box, as shown in Figure A.
3.	Make sure that the Constrain Proportions check box is selected and the Resample Image dropdown list is set for Bicubic. This ensures that your image is resized proportionally and at the best possible quality.
4.	Enter your desired image size in the Pixel Dimensions text boxes. We entered 640 in the Width text box, and Photoshop automatically calculated a height of 480 to keep the image proportional. We could have gone all the way up to a width of 722 pixels, but remember that this is just a guideline. Always resize your images to the exact size you want them to display in PowerPoint. You can scale images within PowerPoint, but you'll end up degrading the image quality. By planning ahead, your image will always look great onscreen.

Note that our image is now only 900 KB, as previewed in the Image Size dialog box and shown in Figure B. This number decreases even more as we compress the file, so our images will be easy to work with and load quickly when inserted into PowerPoint.

Figure B.

Save the image

1.	Click OK to apply the adjustment.
2.	Select File Save As, so as not to save over your original, since you want to keep the high-resolution version for other purposes. Its a good practice to save your adjusted images in a separate folder or add information to the filename such as "lores" or "edited."
3.	Select JPEG from the Format menu and click OK (Save on the Mac). You can insert many different file formats, but JPEG offers the small file size and high-quality display you'll need for digital images. The JPEG Options dialog box opens.
4.	Select the compression options for your file. We could write a whole book about JPEG compression, but just keep in mind that you want to balance image quality with file size. Typically, we use a Quality setting of 8, but you can experiment and see which setting works best for you.
5.	Click OK once more and we're ready to move to PowerPoint.

Work with digital images in PowerPoint

1.	Launch PowerPoint (2000/XP/v. X/2003).
2.	Create a new Blank Presentation.
3.	Select Insert Picture From File, locate your file on the hard drive, and click Insert to place the image on your slide.

By default, the image comes in at 100% and is centered on the slide. If we hadn't resized the image, the image file would have completely overrun the boundaries of the slide and we'd probably only be able to see a portion of the image. Plus, we'd have that hefty 9 MB file to deal with, so our efforts have certainly paid off.

Adjusting images within PowerPoint

As shown in Figure C, our image appears on our slide with the Picture toolbar at the top. If this toolbar doesn't automatically appear when you select your image, choose View Toolbars Picture. This toolbar allows you to adjust contrast and brightness, crop the image, add a border, and perform a bunch of other useful image-editing tasks. You can even convert a color image to grayscale or make it into a watermark without leaving the application. While these features are nice, they wont replace the level of control offered in your image-editing program. However, PowerPoint does a decent job with some of the simpler editing tasks and saves you from having to jump between applications.

Figure C.

The big brother of the Picture toolbar is the Format Picture dialog box, which you can open by selecting Format picture button on the Picture toolbar. If this option isn't available to you, make sure you have your image selected. As shown in Figure D, you have more options and control over your images, with five control tabs for a range of image tasks.

Figure D.

Creating a template

One of the most common uses for digital images in PowerPoint is as a background for the slide. The best way to create a consistent template for your presentation using a digital image is to make a Slide Master.

1.	Create a new blank presentation and then select View Master Slide Master, which contains all of the placeholders, but not much else.
2.	Select Insert Picture From File and place your image on the slide as we did earlier.
3.	Right-click ([control]-click in v. X) on the image and select Order (Arrange in v. X) Send To Back from the context menu to put the image under the placeholder text.
4.	Make any adjustments to your image or placeholders and then select View Normal to return to your slide.

Your image is part of the Master Slide now, so you can't edit it when in Normal view. To edit it, simply return to the Slide Master and make your changes.

In the case of our example, its image dimensions are smaller than the size of the slide. If you want to bleed your images right to the edges, you'll have to resize to the pixel size of the slide (722.7 x 542) or slightly larger. Anything outside the boundaries of the slide won't display, so don't go overboard with the overlap. It just adds unnecessary file size to your presentation.

Presenting … your images!

PowerPoint is a great tool for creating presentations using your digital images or even setting up slide shows to display your work. By creating images files that are optimized to the screen, you can make your images look good while avoiding large file sizes and poor-performing presentations.