,, / I I ~ ' ,f ( \ \. \ • I / \ I -.;..;,r • ...- /} bulletin of the (I , -\•· ''"'\. 8 \ ~...J.. a tographic InJOrmatioll So ~yJ "' I ~ I i. ~ ·,· Number 23, Wintet 1996 ,. ~ ' -r- , J • I '--.,t ~ ! -...) r ~....... ~·· ') '-........_ ·""--. -· . ,..,... ...... ...... .. · ~~ .._;.~ , , sk~Jets - ·, I I \ 4 4'..': 9~'-v . I 4.__J~ •• ... ' ", •; , I \ '~' , ........_ , in this issue messages MESSAGES 1 FEATURED ARTICLES MESSAGE FROM THE Edge pixels: the effect of scanning resolution 3 NACIS PRESIDENT on color reproduction Living in Wisconsin always affords P. Andrew Ray one the opportunity to experience The production of smooth scale changes in an 12 and appreciate the change in animated map project climatic seasons. The progression Martin i>o11 Wyss is natural and symbolic of the cycles that we all encounter during CARTOGRAPHY BULLETIN BOARD 21 our lifetime. An organization GIS, image processi11g, and microcomputer laboratories must also experience cycles of The cartographic section at the University of Western 011tario growth and change, and this year Are yo11 compatible with yo11r printing service bureau? NACIS members will witness several. MAP LIBRARY BULLETIN BOARD 24 First, we will bid adieu to Sona Pe1111 State U11iv. IARL GIS literacy project Andrews as our editor of Carto- graphic Perspectives. Over the last REVIEWS several years she has provided Map projections: a reference manual 25 meritorious service to our organi- reviewed by C. Peter Keller zation that will be very difficult to replace. Her imagination, tireless The AGI source book for GIS 26 devotion, and intense desire to reviewed by feff Torguso11 improve our journal will be sorely A new social atlas of Britain 28 missed by all cartographic profes- reviewed by He11ry W. Castner sionals. At the NACIS Annual Banquet last October Sona was CARTOGRAPHIC EVENTS 29 presented with a plague signifying her achievements as Editor. ESSAY Given Sona's impending Geography and cartography in the twenty-first century 30 editorship retirement, the Carto- by Mark Mo11111011ier graphic Perspectives Editorial Board is now currently searching for a ANNOUNCEMENTS 32 new editor. By this Spring a selection will be made and we NACIS NEWS 33 hope to have a smooth transition between editors before the end of we should increase the annual At our Wilmington Meeting I dues. A short report will then be also sensed an air of electricity that sent to members about the dues signified how exciting a time it is increase and members will be for cartographers. We are witness­ asked to vote (i.e. yes/no) on the ing vast changes in the way we recommended increase at the create and present maps and Annual Meeting this Fall in San spatial information, and we are Antonio. I don't believe any presented with more challenges President relishes the idea of being than ever before. Cartographers remembered for a dues increase, are a hearty breed and we tend to but both the Board and I agreed thrive in the opportunities that are that it is necessary if we want to presented to us. We are a robust maintain our journal's quality and and enthusiastic group and that is breadth. why NACIS is such a strong Third, I would like all NACIS organization. members to help sign up a new Best wishes for the year, and I member this year. Whether it is be hope to see many of you in San a student or a twenty-year profes­ Antonio this Fall. sional, NACIS has much to offer and even with a dues increase will Keith Rice still be very inexpensive to join. NACIS President We have a body of great members right now, but it is always healthy for an organization to get a trans­ fusion of new ideas and perspec­ ~ aboutthe cover tives. Lastly, I would like everyone to consider attending our 1996 Annual Meeting this Fall in San Antonio, Texas. It will be held The<ov~\cp downtown at the Menger Hotel was designed and pro- Summer. Whoever the new editor during the first week of October. duced by Laurence T. Mandelin, a is I hope all members will give am always amazed at the success graduate of the Geography Department of the University of their support and best wishes to of NACIS meetings. The work­ Wisconsin-Milwaukee. The map this intrepid cartographer. shops, field trips, papers, and was taken from "The Heart of the Second, it is likely that the discussion forums are always of Grand Canyon, Grand Canyon NACIS annual dues will be the highest caliber, and there is National Park, Arizona" pub­ increased this year. This can be terrific interaction among the lished in 1978 by the National attributed mostly to the rising conference participants. Geographic Society. A portion of costs of printing Cartographic The candor and esprit de corps the map that shows the area Perspectives and its increase in between conference attendees was around Phantom Ranch and the pages per issue. Both past and once again exemplified at the Colorado River was scarmed in OFOTO in the MAC Format. It present NACIS Board Members Wilmington, North Carolina was cropped and saved as a TIFF extensively discussed this issue Meeting. Where else could you File and exported to the MS-DOS and considered manv alternatives, have cartographers from the Format and imported into Corel such as limiting the ~umber of widest array of professions and Photo Paint! In Corel Photo Paint! pages per issue. In the end, backgrounds imaginable discuss­ it was and lighted in contrast and however, everyone agree that ing their craft? Students, profes­ brightness. That TIFF was Cnrtograpliic Perspectives should be sors, librarians, federal govern­ imported into Corel Draw! where strongly supported since it pro­ ment employees, and cartographic the CP logo and text were added. vides a timely and innovative entrepreneurs all felt welcome at We would like to extend a special publication that has also elevated Wilmington. A NACIS meeting is thanks to the National Geographic the status of NACIS as an organi­ also a perfect opportunity to Society for granting us permission zation. During the begirming of energize your cartographic psyche to use their map for the cover. this year, several Board Members and indulge in cartographic and I will be analyzing how much repartee. Number 23, Winter 1996 cartographic perspectives 3 Edge Pixels: the Effect of Scanning Resolution on Color Reproduction As a result of the digital revolution, many journal articles have been P. Andrew Ray written on the technical aspects of digitization. One of the most docu­ Depart111en t of Geography mented facts is that increased scanning resolution means greater legibil­ Social Scien ce Centre ity of the text and fine details of the digital file. However, little has University oJWestem Ontario been written about the fact that increasing the resolution also results in Lo11don, 011tario better color reproduction, and it is this issue that this paper will ad­ N6A 5C2 dress. While the differences in color reproduction between high resolu­ tion scans and lower resolution scans are subtle, they can be quantified and illustrated graphically using the histogram feature of Adobe Photoshop (an image processing software package). This article begins by reviewing the principles of scanning after which several color images, both color and black and white, scanned at increasing resolu­ tions, will be presented to support the author's thesis. he digital revolution has unleashed a barrage of journal articles that INTRODUCTION T have dealt with many of the technical aspects of digitizing paper­ based images and text. For instance, in a major study, Cornell University, Xerox Corporation and the Commission on Preservation and Access (CPA) undertook a collaborative effort to test a prototype system for recording the text of deteriorating books as digital images (Cloonan 1993, Cohen 1993). Among other things, the study concluded that 600 dots per inch (dpi) scanning and printing results in a high quality paper replace­ ment for brittle textual materials (CPA 1992). Yale University has also undertaken a study to digitize fragile materi­ The digital revolu tion has als. This project is being carried out in three phases. The goals of the unleashed a barrage of journal second phase are to assemble, test, and evaluate the basic operating elements of imaging architecture (Conway and Weaver 1994). As a result articles that have dealt with of this research, it was determined that the optimal scanning resolution for many of the technical aspects of capturing full legibility of microfilm and photographs is 600 dpi (Conway digitizing paper-based images and Weaver 1994). and text. The Bodleian Library at Oxford University is currently working on two separate projects to scan photographs. Gartner (1994) briefly describes the process of digitization and the impact of scanning resolution on text legibility. In another article, Kenney and Conway (1994) discuss four issues related to digitization: 1) system functionality, 2) storage media deterioration, 3) digital image data quality, and 4) integrity of sources. Their treatment of scanning resolution is in terms of black and whi te text, that is, the ability of the scanner to capture the fineness of detail and the legibility of print. Furthermore, Cohen (1993) also touches upon scanning resolution as it relates to the legibility of text. Tilton (1994), on the other hand, discusses scanning resolution in terms of the display size of the digital image. That is, he comments upon the relationship between screen resolution and magnification ratio in order to determine the proper scanning resolution for a digital image. Cartolano, Gertz and Klimley (1995) determined that full legibility of 1 mm text can be achieved if the original image is scanned at 200 dpi in 24 bit color. They stated that "once the full information is captured at the 4 cartogmplzic perspectives Number 23, Winter 1996 highest resolution required for full capture, it should not be necessary to re-scan in the future, since no information would be added by scanning at a higher resolution" (Cartolano et al.
Details
-
File Typepdf
-
Upload Time-
-
Content LanguagesEnglish
-
Upload UserAnonymous/Not logged-in
-
File Pages41 Page
-
File Size-