UCGIS Virtual Seminar - Fall 1998 [Back][Refresh][Options][Search] Taiwan [Edit*][Delete*] [Image] interactive Taiwan Dawn Wright 10/18/98 [Image] Nice map. It seems a good start to allow Jay Raiford 10/19/98 people that do not... [Image] How was "Taiwan map" constructed? Vinh Nguyen 10/20/98 [Image] [Image] re: how the map was made Erik Shepard 10/21/98 [Image] [Image] Clickable area of irregular Vinh Nguyen 10/21/98 shape. [Image] [Image] imagemaps Erik Shepard 10/22/98 [Image] Re: Interactive Taiwan Map Byong-Woon Jun 10/20/98 [Image] Comments Erik Shepard 10/21/98 [Image] comments Guangxiang Cheng 10/23/98 [Image] Post new message in this thread ------------------------------------------------------------------------ [Top][Previous][Next][Print][Reply][Edit*][Move*][Delete*] Date: October 18, 1998 09:08 PM Author: Dawn Wright (dawn@dusk.geo.orst.edu) Subject: interactive Taiwan Discuss Interactive Taiwan http://peacock.tnjc.edu.tw/ADD/maps/taiwanmap.html (http://forums.library.orst.edu/forums/Index.cfm?CFApp=7&Message_ID=2088) ------------------------------------------------------------------------ [Top][Previous][Next][Print][Reply][Edit*][Move*][Delete*] Date: October 19, 1998 07:18 PM Author: Jay Raiford (jraifor@lsu.edu) Nice map. It seems a good start to allow people that do not know the country, like myself, to see it without digging out the atlas. Scale seems to be a problem with the country map. Guess there was a need to fit it all on the first page but made it difficult to see the place names. (http://forums.library.orst.edu/forums/Index.cfm?CFApp=7&Message_ID=2130) ------------------------------------------------------------------------ [Top][Previous][Next][Print][Reply][Edit*][Move*][Delete*] Date: October 20, 1998 12:55 AM Author: Vinh Nguyen (vnguyen@oce.orst.edu) Subject: How was "Taiwan map" constructed? When checking this site, I learned that the hyperlink between the map of Taiwan in the main page and zoomed-in maps of sub-areas in Taiwan map (jpg images) is written by the AREA element of HTML. To view the HTML source file for the current page, on the View menu of the browser, click "Source" (browsers such as Netscape, IE). You could see the source file for the main page in the attachment. I excerpt a linking line in the source file as follow: AREA SHAPE="RECT" COORDS="174, 6, 258, 63" HREF="./taipei.html" The AREA element specifies a single area (COORDS=174, 6, 258, 63) of an image which, if selected, will link to the hyperlink identified by HREF (link to Taipei map). COORDS describes the position of an area (in pixels) of the image in comma-separated x, y coordinates where the upper-left corner is "0,0". Like Jay, I think maps at this site are nice for people that want to have a first look at the country of Taiwan. But I could not find the metadata for these maps such as map resolution, projection. In distributed computing, lack of metadata will result in difficulty for some end-users to process and interpret data; even they may find the maps useless. Vinh. Attachments:

Taiwan Map

This is an interactive map.

Click on any box to ZOOM IN.

Go back home TNJC page !

(http://forums.library.orst.edu/forums/Index.cfm?CFApp=7&Message_ID=2134) ----------------------------------------------------------------------- [Top][Previous][Next][Print][Reply][Edit*][Move*][Delete*] Date: October 21, 1998 07:00 AM Author: Erik Shepard (shepard@uga.edu) Subject: re: how the map was made Vinh, This is an imagemap in HTML. Essentially what they have done is to create an overview map (the complete country) and several zoomed in maps. Clicking on the original image generates a location clicked which is then compared against the imagemap (these are the individual AREA elements). It then links you to the corresponding new image or page. Imagemaps are not hard to create if the area that you are working with is fairly simple or general (in this case, the areas are delimited by rectangles) but are quite a bit more complicated when the area is irregular (such as state or county boundaries, etc). (http://forums.library.orst.edu/forums/Index.cfm?CFApp=7&Message_ID=2188) ------------------------------------------------------------------ [Top][Previous][Next][Print][Reply][Edit*][Move*][Delete*] Date: October 21, 1998 06:16 PM Author: Vinh Nguyen (vnguyen@oce.orst.edu) Subject: Clickable area of irregular shape. Erik, You are right. It is more complicated if zoom-in area is of irregular shape. In this case the AREA element of HTML is still workable. Attribute SHAPE = "POLYGON" and COORDS = " successive x,y vertices of the polygon" (referred to the coordinate of the upper-left corner pixel which is "0,0"). Vinh (http://forums.library.orst.edu/forums/Index.cfm?CFApp=7&Message_ID=2199) ------------------------------------------------------------- [Top][Previous][Next][Print][Reply][Edit*][Move*][Delete*] Date: October 22, 1998 06:23 AM Author: Erik Shepard (shepard@uga.edu) Subject: imagemaps Vinh, You are correct. It is still possible with an irregular polygon. Just a *huge* pain to define each of possibly hundreds of vertices. But you can write scripts which will take a coverage or shapefile and automatically generate the coordinate lists to make it a little easier. Erik (http://forums.library.orst.edu/forums/Index.cfm?CFApp=7&Message_ID=2206) ------------------------------------------------------------------------ [Top][Previous][Next][Print][Reply][Edit*][Move*][Delete*] Date: October 20, 1998 08:08 AM Author: Byong-Woon Jun (bwjun@arches.uga.edu) Subject: Re: Interactive Taiwan Map Interactive Taiwan Map. Click it to see. I agree with you all. I think it seems to provide a good starting point to allow strangers to see the country as Jay indicated. However, it has several problems: lack of scale, orientation, and metadata. It is difficult to see the place names on the first page because of scale problem. Lack of orientation seems to be another problem with the first page. We have no idea of where is north or south. The last, but bigger problem, is lack of metadata as Vinh mentioned. We have no idea of map projection and accuracy, etc so that it is difficult to interpret map. I think the map was constructed by using image map function in HTTP server (hypertext transfer protocol). The Web server usually provides us with two maps: static and dynamic maps. The image map function allow us to make clickable or dynamic hyperlink map like the given example. MapEdit software by Netscap Inc. is a good example to make a clickable map. The problems with preparing it is that the well scanned base map is required and it's very time-consuming. Jun (http://forums.library.orst.edu/forums/Index.cfm?CFApp=7&Message_ID=2154) ------------------------------------------------------------------------ [Top][Previous][Next][Print][Reply][Edit*][Move*][Delete*] Date: October 21, 1998 07:05 AM Author: Erik Shepard (shepard@uga.edu) Subject: Comments From a technical viewpoint, imagemaps were one of the first ways to display map information in a browser, but are notoriously difficult to work with for irregular boundaried polygons. They also suffer from the problem that scale is fixed and predetermined (in the new page) and are essentially just ways to get from one static map to another. Newer products from ESRI, MapInfo, and others enable more dynamic maps in a web page but also require some understanding of web applications design. However, they are more flexible in that you can control for user chosen scales, symbolization, etc. (http://forums.library.orst.edu/forums/Index.cfm?CFApp=7&Message_ID=2189) ------------------------------------------------------------------------ [Top][Previous][Next][Print][Reply][Edit*][Move*][Delete*] Date: October 23, 1998 01:53 PM Author: Guangxiang Cheng (gcheng1@tiger.lsu.edu) Subject: comments While it is a nice site to review the geographic feature of taiwan, I would think there is a long way to go toward a ideal web-based GIS or GIS-distributed computing. It does give me imagination of what the future of web-based GIS. First, the speed should be much faster. Second, the data model may be in vector or raster model instead of jpg or gif file. Third, much more information should be available to surfers. For instance, if you want to know the population of Taibei city, you can have choice to get what you want. This is what GIS can provide - geography plus information. (http://forums.library.orst.edu/forums/Index.cfm?CFApp=7&Message_ID=2234)