Halftone Photographs Research Articles

Maarten A.T.M. Broekmans and Herbert Pöllmann. Applied Mineralogy of Cement and Concrete. Reviews in Mineralogy & Geochemistry, Volume 74. Mineralogical Society of America & The Geochemical Society, Chantilly, Virginia, USA, 2012, x + 364 pp. ISBN 978-0-939950-88-1, ISSN 1529-6466. List Price $40.

Maarten A.T. M. Broekmans and Herbert Pollmann. Applied Mineralogy of Cement and Concrete . Reviews in Mineralogy & Geochemistry, Volume 74. Mineralogical Society of America & The Geochemical Society, Chantilly, Virginia, USA, 2012, x + 364 pp. ISBN 978-0-939950-88-1, ISSN 1529-6466. List Price $40. The book series Reviews in Mineralogy and Geochemistry has, for almost forty years, produced some of the most authoritative reviews in the mineral sciences. This latest edition concerning the mineralogy of cement and concrete maintains this high standard and is a very welcome addition to the series, bridging a gap in the literature which will ensure its position as a standard reference work. The editors are both well respected mineral scientists, who have contributed significantly to the study and understanding of cements. Their complementary interests put them in a strong position to lead the development of this work and together with their eleven co-authors they have produced a volume of considerable merit. As with other works in the series, this book is densely printed on high quality paper, very well illustrated with line drawings and half-tone photographs, and is thoroughly referenced. In the hands of other publishers, the physical format of the book might have expanded considerably, but in keeping with its predecessors, this review remains both compact and a pleasure to read. Herbert Pollmann's opening chapter on Calcium Aluminate Cement (CAC) reflects his great enthusiasm for the subject and his characteristic attention to detail. He clearly and succinctly describes the technology of CAC production, the phase relationships of the clinker minerals and their crystallographic structures. Their hydration is illustrated through the use of dynamic (‘stacked’) diffraction patterns and excellent micrographs, which combine to lead …

H.-R. Wenk and A. Bulakh, Minerals: Their Constitution and Origin. Cambridge University Press, 2004, xxii + 646 pp. Price £95 (US $ 130) (hardback) ISBN 0 52182238 6, £35 (US $ 70) (paperback) ISBN 0 52152958 1.

This comprehensive book by Hans-Rudolf Wenk from Berkeley and Andrei Bulakh from St. Petersburg aims (according to the Preface) to be “an introduction to mineralogy for undergraduate students and graduate students in all fields of geology, materials science, and environmental sciences...”. It enters a field with stiff competition. The authors comment on the pressures worldwide to shorten the time available to teach mineralogy and their aim was a book that “provides an alternative to existing texts by focussing more tightly on concepts, at the expense of completeness, and by integrating geological processes and applications more closely with the discussions of systematic mineralogy”. Later in the Preface the authors suggest that the content of the whole book should be the minimum a ‘mineralogy graduate student’ (a species I fear long extinct in the UK, except perhaps in Cambridge) should know. The book is modular and for one-semester courses the authors suggest sections and chapters that might be dropped. I read the book with these objectives in mind and tried to put myself in the place of an average student, a state of which I have personal experience. My first impression was that one would have to talk mighty fast to fit even a fraction into a single semester. The book is a comprehensive treatment not only of mineralogy, but also includes, in the later sections, some igneous, metamorphic and sedimentary petrology, and discussions of soil formation and mineral deposits. It is therefore broader in scope than most conventional mineralogy books. Copiously illustrated with drawings and half-tone photographs in the text, and with a nice 16 page central section in colour with pictures of interference figures, thin sections and museum-style mineral specimens, the general appearance is impressive. The text includes three types of box: ‘technical boxes’, which give detail, sometimes mathematical, which …

Bahamian Landscapes: An Introduction to the Geography of the Bahamas (review)

Southeastern Geographer Vol. XXXVI, No. 1, May 1996, pp. 87-89 REVIEW Bahamian Landscapes: An Introduction to the Geography of the Bahamas. Neil E. Sealey, Media Publishing, Nassau, 1994. 129 p., maps, photos, figs., tables, bibliography, and index. $11.95 paper (ISBN 0-9643786-0-4). George A. Brook The first edition oíBahamian Landscapes was published in 1985 and went out of print in 1993. When Longman Caribbean indicated that they did not want to continue with the title, Media Enterprises Ltd., in association with the author, published the second edition locally. One reason for this move was that the Bahamas Ministry of Education had made the study of Bahamian geography compulsory for their General Certificate of Secondary Education (GCSE). The author updated the first edition and added a chapter on climate, so that the book now contains six chapters that cover portions ofthe GSCE and college preparatory syllabuses in geography. Bahamian Landscapes is not, however, a geography of the Bahamas, for there is little comment on human activities. Nor is it a physical geography of the Bahamas, as there is no section on plants and animals. The first edition was an introduction to the geology of the Bahamas; the second edition is an introduction to the geology of the islands with a chapter on climate appended. This said, the book is inexpensive, well written, well illustrated with 143 figures (including 71 half-tone photographs) and 29 tables, and provides the reader with a good account of the geological history of the Bahamas, the origins of the various landforms, and the physical resources. It is the kind of book any geographer should read before going to the Bahamas because it explains why the islands look the way they do. The book has nine chapters: 1-4 dealing with the ancient and recent geological history of the islands, including their origin; 5-7 with the ridgeland, rockland, wetland, and coastal landscapes; 8 with natural resources; and 9 with climate. Sealey, a Senior Lecturer at the College of The Bahamas, sets the scene in a two-page " Introduction" before chapter 1 . Here we find out that there are 5,000 square miles ofland in the Bahamas, all below 200 ft. elevation, and 50,000 square miles of shallow-water banks adjacent to ocean 20,000 feet deep. In chapter 1, "The Origin and Structure of the Bahamas Platform," we learn that the platform on which the islands sit originated as North America and Africa Dr. Brook is Professor and Head of the Department of Geography at the University ofGeorgia, Athens, GA 30602-2502. Southeastern Geographer separated about 200 million years ago. Chapter 2, "The Banks—A Story of Sedimentation," is one ofthe most interesting in the book. Here Sealey describes the Bahamas as " a vast carbonate factory, a bucket in which the level is always overflowing into the canyons and oceans around it" (p. 28). The bucket, he says, has coral reef walls inside of which lie extensive plains of oolitic sands. He cautions, however, that "probably the greatest mistake that can be made is to believe that the Bahamian islands are coral islands" (p. 18), pointing out that "if any single thing can be called the builder of the Bahamas, it must truly be the calcareous green algae" (p. 21), which take up calcium carbonate from ocean water far faster than do corals. In this chapter mention also is made ofthe exciting discovery in 1986 of giant living stromatolites in the waters of Exuma Cays. In chapter 3, "The Canyons," we learn that the submarine canyons of the Bahamas, which are up to three miles deep, are some of the deepest in the world and dwarfthe Grand Canyon ofArizona (one mile deep). Chapter 4, "The Islands and Their Recent Geological History," also is essential reading for an understanding of the landscapes and seascapes of the Bahamas. It presents evidence for higher and lower sea levels (including raised beaches and sea caves and submerged peats and cave stalagmites), and stresses that the islands themselves exist because, during the last interglacial, sea level was 20 ft. higher than now and because on numerous other occasions sea level was slightly lower than at...

Nach Dem Holocaust: Juden in Deutschland 1945-1950; The Jews in Germany, 1945-1993: The Building of a Minority; Speaking out: Jewish Voices from United GermanyBrennerMichael Nach Dem Holocaust: Juden in Deutschland 1945-1950 Beck'sche Reihe 1139BeckMünchen, 1995, 256, DM 24.00CohnMichael The Jews in Germany, 1945-1993: The Building of a Minority PraegerWestport, Conn./London, 1994, xiv, 128, £39.95/$45.00SternSusan Speaking out: Jewish Voices from United

Nach Dem Holocaust: Juden in Deutschland 1945-1950; The Jews in Germany, 1945-1993: The Building of a Minority; Speaking out: Jewish Voices from United GermanyBrennerMichael <i>Nach Dem Holocaust: Juden in Deutschland 1945-1950</i> Beck'sche Reihe 1139BeckMünchen, 1995, 256, DM 24.00CohnMichael <i>The Jews in Germany, 1945-1993: The Building of a Minority</i> PraegerWestport, Conn./London, 1994, xiv, 128, £39.95/$45.00SternSusan <i>Speaking out: Jewish Voices from United

A differential-processing extraction approach to text and image segmentation

To efficiently store the information found in paper documents, text and non-text regions need to be separated. Non-text regions include half-tone photographs and line diagrams. The text regions can be converted (via an optical character reader) to a computer-searchable form, and the non-text regions can be extracted and preserved in compressed form using image-compression algorithms. In this paper, an effective system for automatically segmenting a document image into regions of text and non-text is proposed. The system first performs an adaptive thresholding to obtain a binarized image. Subsequently the binarized image is smeared using a run-length differential algorithm. The smeared image is then subjected to a text characteristic filter to remove error smearing of non-text regions. Next, baseline cumulative blocking is used to rectangularize the smeared region. Finally, a text block growing algorithm is used to block out a text sentence. The recognition of text is carried out on a text sentence basis.

The Simple Stage, Its Origins in the Modern American Theatre. By Arthur Feinsod. New York: Greenwood Press, 1992; pp. 245, 50 half-tone photographs. $45.00 hardcover.

An abstract is not available for this content so a preview has been provided. Please use the Get access link above for information on how to access this content.

Brian Juan O'Neill, Social inequality in a Portuguese hamlet: land, late marriage and bastardy 1870–1978, Cambridge studies in social anthropology (Cambridge: Cambridge University Press, 1987). Pages 430, 25 figures and 24 half-tone photographs. £30.

Brian Juan O'Neill, Social inequality in a Portuguese hamlet: land, late marriage and bastardy 1870–1978, Cambridge studies in social anthropology (Cambridge: Cambridge University Press, 1987). Pages 430, 25 figures and 24 half-tone photographs. £30.

Classification of newspaper image blocks using texture analysis

An important step in the analysis of images of printed documents is the classification of segmented blocks into categories such as half-tone photographs, text with large letters, text with small letters, line drawings, etc. In this paper, a method to classify blocks segmented from newspaper images is described. It is assumed that homogeneous rectangular blocks are first segmented out of the image using methods such as run-length smoothing and recursive horizontal/vertical cuts. The classification approach is based on statistical textural features and feature space decision techniques. Two matrices, whose elements are frequency counts of black-white pair run lengths and black-white-black combination run lengths, are used to derive texture information. Three features are extracted from the matrices to determine a feature space in which block classification is accomplished using linear discriminant functions. Experimental results using different block segmentation results, different newspapers, and different image resolutions are given. Performance and speed with different image resolutions are indicated.

Quantitative optical image subtraction by means of pulse-width modulation through one-dimensional contact screens

A quantitative optical image-subtraction method based on the principle of spatial pulse-width modulation through a one-dimensional contact-screen process and superposition of positive and negative halftone photographs is described. The difference in intensity transmittance of two images A and B can be measured by either superposing the halftone positive of A onto the halftone negative of B or vice versa. Not only subtle differences between the two photographs but also the polarity of such differences can be found.

Laser Line Art

The military as well as some commercial users of technical manuals are moving toward a universal requirement of microfilmability for these documents. The halftone photographic process presently utilized for illustration purposes is not suitable for microfilming. The employed solution to this problem is the production of a line-art illustration by manually tracing the various objects of interest in the photographs. This technique results in substantially increased costs for technical manual development meeting the microfilmability requirements. An approach to simplifying the conversion of continuous-tone or halftone photographs to line art has been developed utilizing optical processing techniques. This paper describes the approach, including development of an optimal enhancement filter, the implementation and results of a cost/benefit study.

New publication policies

As an experiment to improve communications, the council has instituted an alternative form of publication: summaries of papers, with the full article available in microfiche. The summaries will include abstracts and may include figures, tables, and references. Since halftone photographs do not reproduce well in microfiche, authors are advised to include such photographs in their summaries.The full text of the summary plus the manuscript can be ordered on microfiche from AGU by interested individuals. Authors can order the fiche at a special rate as [reprints.] The full manuscript will be included in the microfilm and microfiche editions of the journals and will therefore be part of the archived literature. Libraries that subscribe to AGU journals and are not already subscribing to the microform editions will be offered the fiche editions at a special rate.

A Blind Approach to the Removal of a Fresco

A fresco painted on a wall in the U.S. Capitol, Washington, in 1857 was covered over with a new wall in a redecoration scheme of 1950. In the process the fresco was faced with a protective layer and a gap was left between this and the wall. Blueprints were left of the construction, but much important detail was missing. The painting had now to be removed to another part of the Capitol. The article describes how this was done from behind and how the fresco was mounted on a new support, strong but light. As the bricks were removed, the plaster had to be reinforced until the fresco could safely be taken out downwards and backwards and fixed to a new frame constructed of aluminium and wire mesh. The panel could now be transported by trolley and crane to its new position. Here it was bolted to a prepared frame in the wall, the facing was removed, and the paint surface retouched The article is illustrated with 23 half-tone photographs and detailed diagrams.

Commercial Flower Production

THE Ministry of Agriculture and Fisheries has recently reprinted three booklets on the production of ornamental plants for market. Bulletin No. 109 (London : H.M. Stationery Office. Is. 6d. net) deals with summer flowers ; Bulletin No. 110 (1s. net) describes the horticulture of plants with decorative foliage ; and Bulletin No. 112 (2s. net) considers the treatment of pot plants. All three bulletins have been written by Dr. H. V. Taylor and Dr. Katharine H. Johnstone. A general section on the raising of seedlings appears in each number, and descriptions of the varieties, cultivation and any special technique are given for each species. Length of text for a particular species is in proportion to its market value, and though the bulletins have no pretence to the encyclopædic, the grower will find that commercial factors have all been dealt with adequately. A number of drawings by L. N. Staniland illustrate the bulletin on foliage ; the others have a smaller number of half-tone photographs. Part 1 of the series dealt with spring flowers and flowers grown under glass ; it appeared first in 1936. The three booklets now reprinted should provide a modern compendium for growers who may b3 attempting to restore pre-war floral glories.