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Graphics Pitfalls

Large file sizes

• Saved in the wrong format
• The picture dimensions are too large and need to be cropped

Quality Degradation

• Can often see pixelation when a picture is stretched to be bigger than it was originally
• Can see banding of colour when saving images that have a lot of gradiations in colour as a GIF instead of a JPG
• Image resized, but the original aspect ratio (the height to width ratio of an image)

Manage Your File Size

Graphics take up bandwidth and server space. This is a considerable concern for Blackboard since we don’t want students to wait too long for their files to download.

Remember to:

1. Choice the appropriate format, given the type of graphic. GIF’s file sizes are smaller than JPEGS. However, GIFs should not be used for photographs or graphics with a lot of colour gradiation.
2. Minimize the number of graphics that you use per page in Blackboard.
3. Scan pictures to a Screen Resolution of 72 dpi.  If you know that you will only use pictures for screen display only, scan them to 72 dpi (dots per inch). Monitors can not display more than 72 dpi. Therefore, scanning at a higher resolution will give you more information than needed. However, if you want to print the same image in the future, scan at a higher resolution. You can then decrease the dpi to 72 when using for the web, if your image editing program allows you to.  Keep in mind that reducing a picture from, for example, 300 dpi to 72 dpi will make the picture larger. This is because the 72 dpi picture will have less information per inch, thus spreading the picture data over more surface area.