Scanning for Presentations and More

There are many questions to ask when preparing for a presentation. The first one is what type of presentation will this be. Slides, desktop (Keynote, PowerPoint), authoring (HyperCard, Director, Authorware). The second question is how will the finished product be presented? CD, laptop, handouts, overheads, the Web, distributed on a disk?

Another important question is about your audience: to whom are you presenting? If you are presenting to non-westerners, there are a few extra things to take into consideration. For example how graphics and color is used. Will scanned images be included?


When scanning an image for presentations keep in mind how it will be used. Will it be a background image, or an illustration, a graphic element used like a bullet or pointer, or maybe a logo.

How you plan to use your graphics will be a factor in how they should be scanned. Keeping your scanned image to the size and pixel depth of their usage will keep file sizes in check and your presentations from slowing to a crawl.

Elsewhere in this cookbook are instructions for Using the Scanners, and a Scanning FAQ.

Plan your presentation in advance. Sketch a few layouts on graph paper. Move your repeating elements around, work with boxes that represent your images in different sizes. Experiment until you get the look your seeking. Then, scan your images according to those specifications.

How you plan on displaying your presentation is also a factor.

Stand-alone and Desktop Presentations
Most presentation software packages give you the option to save your presentation as a stand alone-document. This means you or your viewer will not need to have the program on their computer to view the presentation.
Many of these programs will convert your images to a lower resolution in the saving process.
If you're planning on using the stand-alone feature, you may choose to index, convert (to 256 colors), and save the color image as a PICT (for Mac TIF for Windows) file before placing it into your presentation. This process gives you more control over how the final image will appear in your presentation.
If you are running your presentation from presentation software running on your computer, your graphics options will be limited by your internal RAM, hard drive space, and the computer's processor speed.
Know how your image will be used and scan the image according to your image size requirements. Don't scan an image at 5 inches high if you only need a 3-inch high image. If your projection device can only display 256 colors (web color space), scan your image at 24 bit color and index the color to reduce it to the best 256 colors for that image. For more information about the indexing conversion process see the how to make a JPEG and GIF pages. Follow the indexing directions on that page, but instead of saving as a GIF or JPEG, save as a PICT (for Mac) or TIF (Windows).
Many presentation packages will now out put your presentation files in HTML format for the Web.
Consult your software manual for all your out put options. Research the effects the out put options will have on your graphics before you begin constructing your presentation.
Converting to Slides
If you are planning to out put your presentation to slide film you will want to scan your images for a higher-quality output. This process will use more memory for image processing and storage. You should plan ahead and know how your graphics will be used before scanning them. Scan your images to the size for their planned usage, with dpi set to 300 and color at 24 bit (16 million). For more information about converting your presentation to slides see the How to Use t he LFR pages.
Color Overheads If you are planning on printing color overheads know the line screen resolution of you printer and scan your images with that line screen in mind. When printing your overheads in the Smith Hall Computing Site, your images should be scanned in 24 bit color and 150-200 dpi. Remember to scan your images to the proportions you will be using them, anything more is a wast of memory resources and your time. For more information about printing in the Smith Hall Computing Site, see the Printing Information pages.
A Few Numbers
Here are some proportions for scanning background images for your presentations. Knowing these proportions will help you to keep from over scanning and using up memory and space. They can also be used as a guide when trying to work out the proportions for other scanned images to be included in your presentation.
Proportions for making background images:
Keynote PowerPoint
Overhead 14.222" x 10.667"
11.11" x 8.333"
10" x 7.5"
Slides 10.4" x 6.75" 11.25" x 7.5"
On Screen 8.89" x 6.67" 10" x 7.5"

Use of Color

Here are a few things to take into consideration when working with color in your presentations.
Color Blindness
Eight percent of males and five percent of females have the most common variety of color blindness. They have dificulty distinguishing reds and greens, yellows and greens (some look brown); purples and megentas can look blue. Shades of the simular colors placed together may not be noticed (lime green and orange side by side). To give you some idea of what a color blind person would (or would not) see: I have heard a color blind person describe a pink Rhododendron as the most beautiful flower blue flower he had ever seen.
Place light colors of orchid, lavender, and off-white together, and many who are color blind would not see the difference. Traffic lights are recognized only by the placement of the lights. Top light=stop, bottom=go. Most color blind people don't tell others of their situation.
Psychological and Social Effects of Color
People have known for a long time that color has an effect on people. Some color combinations can make people active and edgy. Some can put you into such a relaxed state that we will fall asleep.
Colors are Symbolic
Different cultures apply very different meanings to color. Here, we often use red to symbolize danger. In some places, red symbolizes prosperity and joy. In our culture, black is the color of death and mourning; white, symbolic of purity. In other cultures, white is symbolic of death and mourning.

Colors are often highly political and religious. Here green is symbolic of nature, fertility, growth, and poison. In Moslem countries it is a holy color and its use should probably be avoided. The same holds true for orange and green in Northern Ireland. They are the colors used by its divided parties and would best be avoided.

Some Things to Keep in Mind

The Graphics Technology Cookbook text links
Digital cameras
desktop video
and sound
Web pages Class handouts and
PDF instructions
and printing
Slides and
and Authoring
User Web Site