Graphics Interchange Format Research Articles

RIP: Radiology Internet Protocol.

Radiology Internet Protocol (RIP) is an image transmission protocol designed to address the special needs of radiology World Wide Web (Web) servers. RIP preserves the ability to alter the window and level (W/L) settings of an image over the Internet from a remote location while maintaining short transmission times. RIP operates with a client-server paradigm and can be used for Web-based radiology teaching files or Internet-based teleradiology. The protocol itself is based on the concept of W/L partitioning, whereby the clinically most important W/L setting of an image is transmitted first. Supplementary data are appended to the initial transmitted image in the background while the user is reviewing the preliminary image. The time required to transmit the first image, or time-to-first-image, is comparable with that of graphics interchange format and Joint Photographic Expert Group (JPEG) files. The longer the user looks at an image, the more data are appended to it in the background. Ultimately, the user can view a received image at any W/L setting.

Adapting EcoCyc for use on the World Wide Web

The World Wide Web (WWW) offers the potential to deliver specialized information to an audience of unprecedented size. Along with this exciting new opportunity comes a challenge for software developers: instead of rewriting our software applications to operate over the WWW, how can we maximize software reuse by retrofitting existing applications? We have developed a Web server tool. written in Common Lisp, that allows existing graphical user interface applications written using the Common Lisp Interface Manager (CLIM) to hook easily into the WWW. This tool — CWEST (CLIM-WEb Server Tool, pronounced “quest”) — was developed to operate with EcoCyc, an electronic encylopedia of the genes and metabolism of the bacterium E. coli. EcoCyc consists of a database of objects relevant to E. coli biochemistry and a user interface, implemented in CLIM, that runs on the X-window system and generates graphical displays appropriate to biological objects. Each query to the EcoCyc WWW server is treated as a command to the EcoCyc program, which dynamically generates an appropriate CLIM drawing. CWEST translates that drawing, which can be a mixture of text and graphics, into the HyperText Markup Language (HTML) and/or the Graphics Interchange Format (GIF), which are returned to the client. Sensitive regions embedded in the CLIM drawing are converted to hyperlinks with Universal Resource Locators (URLs) that generate further EcoCyc queries. This tight coupling of CLIM output with Web output makes CLIM a powerful high-level programming tool for Web applications. The flexibility of Common Lisp and CLIM made implementation of the server tool surprisingly easy, requiring few changes to the existing EcoCyc program. The results can be seen at URL http://www.ai.sri.com/ecocyc/browser.html. We have made CWEST available to the CLIM community at large, with the hope that it will spur other software developers to make their CLIM applications available over the WWW.

Virtual frog dissection: interactive 3D graphics via the Web

We have developed a set of techniques for providing interactive 3D graphics via the World Wide Web (WWW) as part of the “Whole Frog” project 1 1 http://george.lbl.gov/ITG.hm.pg.docs/Whole.Frog/ Whole.Frog.html . We had three goals: 1. 1. to provide K-12 biology students with the ability to explore the anatomy of a frog with a virtual dissection tool; 2. 2. to show the feasibility of interactive visualization over the Web; and 3. 3. to show the possibility for the Web and its associated browsers to be an easily used and powerful front end for high-performance computing resources. We have developed techniques to utilize the Common Gateway Interface 2 2 http://hoohoo.ncsa.uiuc.edu/cgi/overview.html (CGI) capability of WWW servers to provide an interactive 3D visualization front end through Web clients. These techniques have been used to make a “Virtual Frog Dissection Kit” 3 3 http://www-itg.lbl.gov/vfrog . A student using this kit has the ability to view various parts of a frog from many different angles, and with the different anatomical structures visible or invisible. For example, the student can press “form” buttons that indicate that he or she wants to view the frog from above, with the exterior and skeleton removed. An advantage to this technique, as opposed to dissecting a real frog, is that undissection is as easy as dissection. The kit has a forms 4 4 http://hoohoo.ncsa.uiuc.edu/cgi/forms.html -based interface. Form submission results in a call to a CGI script, which in turn contacts a continuously running process on a more powerful machine to accomplish the graphics rendering of a large 3D data set representing the frog and its internal organs. The resulting image is converted to Graphics Interchange Format (GIF) encoding. When that process completes generation of the image, it passes the location of the image file and control back to the script which rewrites the image on the client. While this might sound awkward, the overall process is quite similar to how all rendering systems work, with the image being written into a local frame buffer, or sent across the network as an X-window image.

A Computer-based Atlas of Global Instrumental Climate Data

Color-shaded and contoured images of global gridded instrumental data have been produced as a computer-based atlas, available to the climate community through Internet. Each image simultaneously depicts anomaly maps of surface temperature, sea level pressure, 500-mb geopotential heights, and percentages of reference period precipitation. Monthly, seasonal, and annual composites are available, in either cylindrical equidistant or Northern and Southern Hemisphere polar projections. Temperature maps are available from 1854 to 1991, precipitation maps from 1851 to 1989, sea level pressure maps from 1899 to 1991, and 500-mb height maps from 1946 to 1991. All images exist as GIF (Graphics Interchange Format) files (1024×822 pixels, 256 color) and can be displayed on many different computer platforms. A Compact Disc Read-Only Memory version of the atlas is also available.