File Shrinking Techniques, or
Help! My files are too big!
If your scanned photographs are too big, it may be because they were scanned at an unnecessarily high resolution. Many scanners are set at default to scan at 300 dots per inch, which looks great when printed 8" x 10" onto paper. However, 300 dpi is much higher than necessary for simple screen viewing. Screen graphics can be scanned at 72 dots per inch without any significant change in naked-eye resolution.
Two solutions for overly-large graphics:
Option 1: Reset scanner to 100 dpi and rescan the images
Option 2: Resize the scanned picture by changing the width and height in a graphics editing program such as Paintshop Pro, Photoshop, VuePro, iPhoto or any of a variety of others. Open the picture in the graphics application, search for the resize menu option (different programs put their resize option in different places), and and save it again. You can always stretch the picture's viewing size bigger in your digital story.
I don't have a graphics editor
Microsoft's built-in Paint graphics program does not do resize. You will need 3rd-party software. If you do not have a graphics program installed, look for a free version or shareware version on the Internet. PC Users could visit www.download.com or www.hotfiles.com Search for free Paintshop Pro version or JPEG-Resizer. Macintosh people with the latest OS can use the free built-in iPhoto, or search www.download.com or www.versiontracker.com for "picture editors."
If you are unable to resize pictures for any reason and your digital story is still over five megabytes, you will need to delete pictures until you get the size down.
Using a graphics editor
In the resize feature, select a Width and Height that is approximately one-half the original picture size and you should see no difference in the image quality, yet the files will shrink by far more than 50-percent. The example files below were resized by selecting 640 for the width and clicking on "preserve aspect ratio" which automatically calculates the correct Height so as not to distort the pictures. Changing the Dpi (dots per inch) makes no difference in file size once the picture is scanned.
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| Before resizing, each 300-dpi sample picture above was over a megabyte. The original width was approximately 1400 | ||
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Each picture was resized by selecting Width of 640 and letting "preserve aspect ratio" determine the appropriate Height
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The resized picture files are approximately
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You be the judge
Can you see any difference in quality in the two pictures below?
©
2002 Curious Moments Hendrick Neubauer
Lion's Mouth at 1,038 kb (screen shot)
©
2002 Curious Moments Hendrick Neubauer
Lion's Mouth at 125 kb
(12-percent of its original file size)
It is beyond the scope of this Sidebar lesson, but sound and video files can be resized in similar ways.
End