School of Information Technology
Illinois State University

One way to speed the display of documents is to specify the WIDTH and HEIGHT of an image. This allows the browser to set up the space for the image and then to continue retrieving text as the image is displayed. Notice that in displaying the following images the browser creates an outlined block and then fills in the image.

This example also demonstrates how to define an image so that the content of the image becomes recognizable before the full resolution image has been displayed.

For JPEG files, two copies are actually displayed -- one low resolution copy and then a higher resolution copy directly over the first one. In this example a 20% resolution image is displayed and then a 90% version.

For GIF files, an interlaced version of the image is displayed. The image is stored in a format that causes it to be displayed in sections producing a "venetian blind" effect when it is displayed.

To study these examples, click on the RELOAD button and watch the display closely.

        LoRes/HiRes JPG (6+27K)                Interlaced GIF (48K)

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Contact us at School of Information Technology(ITK), Part of the College of Applied Science and Technology(CAST)
Illinois State University, Campus Box 5150
Normal, IL 61790-5150
(309) 438-8338