June
2006
Tidbits - Digital Images Special Edition
Many libraries own digital cameras to take pictures at special events and programs. Once you take the pictures, however, do you know what to do with them next? How you want to use the images will dictate your next step. This issue of Tidbits will focus on some tips to consider.
How will your images be used?
Will you be printing the images? Emailing them? Posting them on a web page? Each of these actions requires a different process to prepare them for their output.
Printing
Most digital cameras are set to take pictures at a fairly high resolution. This keeps the print quality of the image at its best. If you're simply going to print the images or include them in a document to be printed, you shouldn't have to tweak them unless you want to crop or fix the lighting effect.
How can you tell if the resolution is high enough for printing? In Photoshop Elements, for example, you can go to IMAGE > RESIZE > IMAGE SIZE. The Image Size window will tell you the resolution and the document size when printed.
Example:
If you're sending something to a professional printer or a newspaper rather than printing on a desktop printer, you may need to save your image with a higher resolution. At least 300 pixels/inch is generally recommended, but your printing service should be able to tell you what they require. Simply change the number in the resolution box to change the resolution of your image. Sometimes this will affect the quality of your image, but you'll just have to use some trial and error until you accomplish a good result.
Emailing
If you need to email your images, it is best if you save them at a lower resolution and size so that you don't fill up your friends' and/or colleagues' inboxes. A quick and easy way to do this is to use Windows to resize automatically for you. For info on how to do this, see the October 2003 issue of Tidbits.
Posting on the web
To prepare your images for posting on the web, you'll need to resize your images in Photoshop Elements. Here's how:
- Open the image to be resized.
- Select FILE > SAVE FOR WEB.
- Under NEW SIZE, change the pixel width or height (it should retain proportions if you change one or the other). 350-400 pixels is a pretty good width for a landscape oriented image.
- Click OK.
- Name your image and save it in the images directory for your web site.
Example of Save for Web window:
Using the SAVE FOR WEB option will automatically save your images at a resolution of 72 or 75, which is the optimal resolution for images being viewed online. All you have to do from here is to remember to upload your newly resized images to your web server!
Be aware of file size
If you're emailing or posting images on the web, you need to be aware of the size of the images you are trying to share. If they're too big, you can clog up someone's inbox or make them wait a long time for the image to download in a browser.
Generally, if you follow the steps above, you shouldn't have to worry about file size. However, if you'd like to know how to check your images to make sure they're not too big, here's how:
- Right click on the START button and select EXPLORE from the shortcut menu.
- You are now in Windows Explorer. Click on your MY DOCUMENTS icon in the lefthand menu.
- Navigate to where your images are saved in the list of folders on the right.
- Right click on the image you want to check.
- Select PROPERTIES from the shortcut menu.
- The size of the file will display.
Example:
If the file's size is in KB, you're in good shape. If it is in MB, you'll need to resize it using the steps above. For an easy-to-understand guide to file size, go to Family Internet at About.com's File Sizes Explained.
JPGs, GIFs, and PNGs, oh my!
There are three main graphic formats in use on the web these days. How do you know which to use when? Some simple tips follow.
JPGs
If your image has a lot of color information, like this photograph
you'll want to save it as a JPG. Most digital cameras automatically save pictures in JPG format.
GIFs
If your image is more like clip art or doesn't have much color info, like the images below
you should save it as a GIF.
PNGs
The PNG format is relatively new. PNG is slowly replacing GIF as a format of choice for line art, text, screenshots, and general web graphics as the support across browsers becomes more stable. The PNG format is becoming preferred because it is lossless (it doesn't distort the original image), so the quality will be higher than that of a GIF. Photoshop Elements offers the ability to save in this format, so give it a try and see what you think.
Adieu
Farewell until next time from the library system where all the computers are fast, all the books are worth reading, and all the librarians are above average!
This issue of Tidbits was written by Beth Carpenter, Web Services Manager for the Outagamie Waupaca Library System. Please send any comments or questions about this issue to Beth.
Supporting public libraries in Outagamie and Waupaca counties