Optimizing File Sizes for ANGEL

Uploading very large files to ANGEL-or elsewhere on the Web-can cause several issues. Large files take longer for students to download and they strain the performance of the ANGEL system. Some types of files that tend to be large are videos, high-resolution photos, PowerPoint presentations, and PDFs.

In many cases, some preparation of the files ahead of time can reduce their size and optimize them for use in ANGEL. In addition, Penn State offers several options for storing large files outside ANGEL. For details, see the Media Storage Options at Penn State help topic. Following are some tips to help you avoid "large file syndrome" in ANGEL.

Videos

Videos may be the number one cause of problems in ANGEL. Videos should never be directly uploaded into ANGEL. The file sizes are just too large. Instead, consider using the ITS Streaming Server to deliver videos and provide a link to them in ANGEL. An ITS Streaming Server account is free to any faculty member. To obtain an account, go to http://streaming.psu.edu/ and select the Log in link. If you are an instructor of record according to the Registrar, you will automatically get an account by logging on. Others can request an account by e-mailing accounts@psu.edu. Access to videos delivered on the streaming server can be limited, if desired, so that only your class can view them, thus making them compliant with TEACH Act requirements. As an alternative to the ITS Streaming Server, you can store video files in your personal Penn State Access Account Storage Space (PASS).

Note: The QuickTime Streaming Service is scheduled to be discontinued on November 1, 2015. Please see http://video.psu.edu for more information regarding this replacement. 

Photographs and PowerPoint

Uploading an 8"x10" photograph at high resolution is in most cases overkill, and in many cases will be a disadvantage. If a student's computer monitor does not support higher resolutions, he or she will need to scroll to see all parts of the photograph. A good rule of thumb is to size the photo to the size that you want it to be viewed. A 5"x7" photo is normally adequately large enough to view on the Web. If you are thoughtful about how you crop your photo, you can actually add visual interest while saving space.

In most cases, the JPEG format will provide optimum file size for photos, and the GIF format works better for graphics that have less color. Saving a JPEG as full quality (Quality setting such as 10 or 12 in Photoshop) is normally too high. Try setting the quality to 6 or 8 and see whether your photo still looks good. Medium quality looks good for most photos.

Screen Capture. JPEG Opyions Screen.
JPEG Quality setting within Photoshop

You also do not need to make a photo high-resolution; 72 dpi is all a computer monitor can display anyway, so anything over that is just wasted bandwidth. That goes for PowerPoint presentations as well. It is pointless to import large, high-resolution images into PowerPoint and then scale them down. Scaling them down in PowerPoint does not make the file size any smaller and will create longer downloads. Optimize your images first before importing. If you save your PowerPoint slides as JPEGs, choose the Least (Mac)/Low (PC) quality setting from the options, and consider reducing the image height and width. The "Least" setting in most cases will be quite adequate for viewing.

PDF Files

The main factors that determine small PDF file sizes are image resolution, image type (bitmaps take up more space than vector graphics), the number of fonts used (limit your fonts to common ones such as Arial or Times Roman), and the level of compression. Newer versions of Adobe Acrobat will generally produce smaller file sizes due to better compression techniques. If color is not required, you can convert your file to grayscale by selecting Advanced > Print Production > Convert Colors, then selecting Device Gray: Convert. Selecting Advanced > PDF Optimizer opens a dialogue box that will help you to create the smallest file size to fit your quality needs. It contains settings for images, fonts, transparency, objects, and other settings that control file size. You can also perform a "space audit" by using the Audit space usage... button to tell you the parts of the file that are using the most space.

Screen Capture. PDF Optimizer Window.
Audit space usage button in the Adobe Acrobat PDF Optimizer

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