Digital Imagery Michael Nieckoski Technology Learning Services January 2009

Agenda What are digital images? File formats and sizes Sources for Images Use and Copyright Working with images in MSWord Modifying images in Editing programs Hints and Tips Digital Fakery Disclaimers : This will NOT be a serious Photoshop workshop.

What are digital images? Digital images are electronic representations of analog photographs and graphics Photos are reduced to individual bits called “pixels” and each pixel is coded so that it can be saved electronically The digitizing process shows how analog information is made into a digital image…

Digitizing * During the scanning process, each pixel in the photo is assigned codes for: Color, brightness, contrast, location, etc. The digital codes are placed in a table and saved as a file. When you display the image, the software decodes the File, reads the coded values, and paints it to the screen.

Why Why would you use digital images?

How How would you use digital images?

Programs Photoshop –Photoshop Elements –Free Photoshop Express on the web Gimp – Free! Windows Paint, PaintShop Pro

File Formats For Print.tif (or.tiff) For the Web.png.gif.jpg (or jpeg) Proprietary formats.psd.psp Others –.BMP Bitmap (B&W) –.PICT Macintosh –.EPS publishing

Which one,.gif or.jpg?.gif format is used for images with large areas of color – graphical images, clipart – with 256 colors only!.jpg format is for photographs – handles millions of colors, is compressed. Saved as.gif

File size Determined by several factors: Resolution –set this when scanning or shooting. –In dpi or “dots per inch” –The more dots per inch, the more information captured, therefore the larger the file. –The web can handle 72 dpi Compression Color palate These two are also related To the file format used.

About saving images in Photoshop Usually you’ll want to save an image that you are editing in the Photoshop (PSD) format to ensure that all the image data is preserved. Photoshop format doesn’t compress your image data. Your digital camera may save photos in JPEG format, but it’s better to use the Photoshop format rather than resave a photo in JPEG format unless you are ready to share it or use it on a web page. Each time you save in JPEG format, the image data is compressed, potentially causing some data to be lost. You may start to notice reduced image quality after 2-3 saves. *A disadvantage of saving in Photoshop PSD format is that the file size will increase significantly because the file is not compressed. *Another disadvantage: because PSD is a proprietary format, images can’t be inserted into Word, the Web, etc.

Sources for Images Your own – camera, scanning Government sites: ex. LOC, NASALOCNASA Social sites the web: Flickr, Photobucket, Creative Commons licensingFlickr Web pages should be your last location –because of the use issues associated with using someone else’s material Google images Ditto images

Use and Copyright BEWARE!! Changing one format to another Use of logos and trademarks – Just don’t! Attribute your use – include URL Stock Photography (visible and invisible watermarks)

A couple of Legal sources Creative Commons Wikimedia Commons

Modifying Images in MSWord Insert menu>PICTURE>insert “Picture from File” You can also copy and paste Click on the image to work with it –Use the “handlebars” to resize Use the Image Toolbar to make changes Placement of image –Behind text, wrap style –In a text box –In a table

Working in your Image Editing Program: Manipulating Images Most commonly used: –Crop –Adjust brightness and contrast –Red-eye –Re-size (use 72 dpi for the web) –Text on top for titles or captions –Transparency –Layers

Hints and tips I To take a “screen shot” press the Prt Scr key –Loads the clipboard Paste this into your graphics program to crop, edit, and save. Some commercial products: Snag-It

Hints and tips II: Hints and tips II: Printing a single window To take a shot of a single window: press Alt + Prt Scr Paste this directly into PowerPoint, Word, etc. (this is excellent for creating training materials!)

Images can be large, so be aware of your storage capacities (network drive, flash drive, scratch drive in Photoshop) Create an images folder in your workspace(s) and keep them together Chose a naming scheme and stick to it! Name files consistently with short and descriptive names. (phot_flower_rose.jpg) Hints and tips III: Hints and tips III: Saving and storing images

More Hints and Tips Make the image as close to the useable size as possible to avoid distortion (stretching or scrunching) When saving, use the “Save for Web” feature in Photoshop – it gives you many options to optimize your images.

Can we believe what we see?

Digital Fakery Current events: The case of Kristen Roovers – – – “Our trip to China” photo Articles:

Michael Nieckoski EAB 101 Ext