Chapter 2 New Features in LabVIEW 5.1
LabVIEW 5.1 Addendum 2-58
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National Instruments Corporation
What URLs Can I Use with My Front Panel Images?With the Web Server, you can publish images of your VI front panels on
the World Wide Web. You do not need to modify the VIs to display their
front panels.
Front Panel Image Formats
The Web Server can generate images of VI front panels in the Joint
Photographic Experts Group (JPEG) and Portable Network Graphics
(PNG) image formats.
The JPEG image format is a public domain image format that all current
browsers support. It has been developed for the distribution of real-life
images and photographs and uses a lossy compression algorithm to reduce
the memory size of an image. When you use JPEG on images that contain
lines and text, such as front panels, the resulting image often displays
artifacts of the compression, such as fuzzy text or stray color pixels.
The PNG format is a recent public domain image format. The compression
algorithm in this format is lossless, which produces PNG images exactly
like the original images. PNG is designed to be the successor of the
Graphics Interchange Format (GIF), which also uses lossless compression.
PNG is an open standard that you also can use on true-color images.
Internet Explorer 4.0.1 and Netscape Navigator 4.0.4 support the PNG
format. Older browsers require a plug-in or an external application to view
PNG images.
Static Front Panel Image (.snap URL)
The .snap URL signals the server to return a static image of the front panel
of a VI currently in memory. The query parameters in the URL specify the
VI name and the attributes of the image.
You must open the front panel of the VI to take snapshots for static images
because closed front panels do not update the images of controls when the
value changes.