Scanning

“ A common problem with scanning an opened book is "guttering", which happens when the spine of the book is not pressed flat enough, and the inside of each page, where it meets the spine, is curved against the glass. There's more about this, and an example, scan3, in the FAQ [S.17] "Why am I getting a lot of mistakes in my OCRed text?". To avoid guttering, make sure that the spine is held down throughout the scan. (Some people put a weight on the spine to hold the spine down on each scan; others just press their hand against it.) ”

“ Planetary scanners are a different breed to all the others. They are really not scanners at all, but a very high-end digital camera on a stand. You place the book face-up with the pages open, with the camera looking straight down on it. It takes a picture, and passes it on to the connected computer. Planetary scanners are ideal for old, fragile, valuable books that can't be exposed to the stress of normal scanning. They typically come supplied with specialized software, sometimes even their own dedicated computer, and they are very, very expensive—$20,000+.
S.3. Which scanner should I get? ”

“ Tidy is also embedded in some Windows GUI tools, like Tidy-GUI,
HTML-Kit and NoteTab.
Scanning FAQ
S.1. What is a scanner?
A scanner is a machine that makes an image, a picture of the page that is fed to it, and sends that image to your computer. It only makes an image, like a camera does; it doesn't turn that image into text.
S.2. What types of scanners are there?
The most common type of scanner, the kind you're likely to find in your local computer store, is a flatbed scanner. ”

“ Close on the heels of the magnetic ink readers came those that use the principle of optical scanning, analogous to the method man uses in reading. This breakthrough came in 1961, and was effected by several different firms, such as Farrington Electronics, National Cash Register, Philco, and others, including firms in Canada and England. We read a page of printed or written material with such ease that we do not realize the complex way our brains perform this miracle, and the optical scanner that “reads” for the computer requires a fantastically advanced technology. ”

“ NATDP is scanning at 300 dots per inch, a standard scanning resolution. Though adequate for capturing text that is all of a standard size, 300 dpi is unsuitable for any kind of photographic material or for very small text. Many scanners allow for different image formats, TIFF, of course, being a de facto standard. But if one intends to exchange images with other people, the ability to scan other image formats, even if they are less common, becomes highly desirable. ”

“ If you are using a scanner to copy a book for the first time, be patient with yourself. Some people start off with too high expectations of what they can achieve. Believe it or not, scanning does work effectively ”

“ Some very productive volunteers manage to turn out an e-text a week; some books can take a year or more.
Scanning itself doesn't take too long. Even if it takes you as much as two minutes per page to scan, you will still complete a 300 page book in 10 hours, and you will probably be scanning much faster than that [S.9] . The problem is that the text generated by the scanner and your OCR package is usually faulty. There are many cute scanner errors, mistaking b for h, or e for c, so that "heard" is scanned as "beard" or "ear" as "car". Makes the story more interesting sometimes! ”

“ In the future, researchers working from their own workstations in their offices, or their networks, will have access—wherever they might be—through a request server being built into the new digital library. A second assumption is that the preferred means of finding the material will be by looking through a catalogue. PERSONIUS described the scanning process, which uses a prototype scanner being developed by Xerox and which scans a very high resolution image at great speed. ”

“ Drum scanners are mostly used by publishers for professional, high-quality artwork. The paper is placed on the surface of a drum that rotates past a fixed scanning head. The drum can be very large. Because the sensors don't have to move, the electronics and optics can be of higher quality, and produce very accurate, high-definition images. ”

“ Carl FLEISCHHAUER, coordinator, American Memory, Library of Congress, reported AM's experience with scanning bound materials, which he likened to the problems involved in using photocopying machines. Very few devices in the industry offer book-edge scanning, let alone book cradles. The problem may be unsolvable, FLEISCHHAUER said, because a large enough market does not exist for a preservation-quality scanner. AM is using a Kurzweil scanner, which is a book-edge scanner now sold by Xerox. ”

“ Peter nodded. "The big problem," he said slowly, "was the development of a scanning device. In order to reconstruct any object faithfully, the reformed atom must reassemble in exactly the same relative position. No one could ever do it mechanically. But a magnetic field can bend the radiation if the field is strong and localized. ”

“ These scanners, which are still in operation, are faster. They also tend to produce an image that is properly aligned, versus the skewing that sometimes occurs with flatbed scanners. An important difference is the printed books are damaged: prior to scanning, the spines of the books are cut off, in order for the individual pages to be ingested by the scanner.
Figure 3: Image from the Doré illustrations of Dante’s Inferno
It has been Project Gutenberg’s intention to make all the original images from the scanners available, alongside the finished eBook. ”

“ Scanning parameters were 100 kV source voltage, 160 μA source current, 0.2 mm copper filter, 750 ms exposure time, 1440 angular steps over 360° with 2 averaged images per rotation position, 2304×2304 pixel detector size, and about 1 h 20 min scan time. ”

“ CLSM: confocal laser scanning microscopy; μCT: micro-computed tomography; FOV: field of view; MRI: magnetic resonance imaging; NHM: Natural History Museum, London, UK; NMR: nuclear magnetic resonance; USNM: National Museum of Natural History, Washington DC, USA; ZMB: Systematische Zoologie am Museum für Naturkunde, Berlin, Germany.
Authors' contributions
AZ designed and coordinated the experiments, carried out the dissections, prepared specimens and carried out scanning and 3D modelling. CF and SM prepared and scanned specimens. TB supervised the experiments. ”

“ They left the blister, Wes closed the airtight, and cracked the valve that let the air out of the blister. He snapped the switch on the outside panel and then leaned back in his chair while the cathode heated.
"With electrical scanning, you'll have curvature of field with this gadget. That isn't too bad, I suppose, because the restorer will have the same curvature. But you're going to scan three ways, which means correction for the linear distance from the tube as well as the other side deflections and their aberrations. ”

“ Use a diffraction peak of high intensity that can be rapidly but reproducibly (S r <0.01) measured. b. Mount the sam ple, work ing standard, or blank filter. Measure the diffraction peak area for each silica po lymo rph. Scan times m ust be long, e.g., 15 min (longer scan times will lower the limit of detection) . c. Mea sure the background on each side of the peak for one-half the time used for peak scanning. The sum of these two counts is the average background. Determine the position of the background for each sample. ”

“ I use a free program call IrfanView for my image viewing, and it loads DjVu format just fine. I haven't looked much into conversion, but there are a few web-based conversion tools (to convert images to DjVu) and a few command-line programs to convert them from DjVu to other formats (TIFF, JPEG, and a few others) . I think if we clearly point out where a decent browser plugin is, we should use the DjVu plugin, especially if we are going to do a lot of book scanning (harddrive space on WM servers unfortunately isn't infinite) . ”

“ For a given book, scanner, PC and OCR software, there must be some "ideal" scanner settings, but if you change any of these components, the ideal scanner settings will change with them. Some OCR packages recognize greyscale better than black and white; some don't like greyscale at all. Some books have small print needing higher resolution; some are speckled so that higher resolution leads to more errors. ”

“ The two mistakes that people inexperienced with scanners most commonly make are not holding the spine down firmly enough to get a flat image of the paper, and not setting the brightness correctly, or letting too much light get in. ”

“ As the material to be read comes into the field of the scanner, it is illuminated so that its image is distinct enough for the optical system to pick up and project onto a disc spinning at 10,000 revolutions per minute. ”

“ Certainly; we opened every package and parcel; we not only opened every book, but we turned over every leaf in each volume, not contenting ourselves with a mere shake, according to the fashion of some of our police officers. We also measured the thickness of every book-cover with the most accurate measurement, and applied to each the most jealous scrutiny of the microscope. ”

“ Scan1 is as near to a perfect scan as you can expect in PG work. It comes from "The Founder of New France" by Charles W. Colby. It is only a 300 dpi image, but given the quality of the print and of the scan, 300dpi is all we need. Ironically, it comes from Gardner Buchanan, who complains about the age and infirmity of his scanner in his description of how he produces a text. ”

“ He wrote on it, using the pointed fingernail of his right forefinger—the Talking Nail of a Scanner—in quick cleancut script: "Pls, drlng, whrs Crnching Wire?"
She pulled the long gold-sheathed wire out of the pocket of her apron. She let its field sphere fall to the carpeted floor. Swiftly, dutifully, with the deft obedience of a Scanner's wife, she wound the Cranching Wire around his head, spirally around his neck and chest. She avoided the instruments set in his chest. She even avoided the radiating scars around the instruments, the stigmata of men who had gone Up and into the Out. ”

“ In bidding my young readers adieu I shall not lose entire thought of them, but often when I am engaged in looking through the microscope, I shall think and ask myself, "Are they, too, absorbed in this pleasant work, and how many will become true workers and original investigators in this great field?" We shall all know in due time, for no earnest worker in any branch of science can long remain unknown. He will be found out sooner or later. A devoted student in microscopy will become so happy over the marvellous creatures and their curious ways that he cannot keep his pleasure to himself. ”

“ Do you think I wanted you to marry a Scanner? Didn't I tell you we're almost as low as the habermans? We're dead, I tell you. We've got to be dead to do our work. How can anybody go to the Up-and-Out? Can you dream what raw Space is? ”

“ Chestboxes went up to Overload and dropped to Dead all around him as he had moved from man to man, shoving the drifting corpses out of his way as he fought to scan each man in turn, to clamp vises on unnoticed broken legs, to snap the Sleeping Valve on men whose instruments showed they were hopelessly near overload. With men trying to work and cursing him for a Scanner while he, professional zeal aroused, fought to do his job and keep them alive in the Great Pain of Space, he had smelled that smell. ”

“ The first is that if the light upon the paper be stronger than that in the apparent field of the microscope, the image will not be well seen, or if the paper be too feebly lighted, it will be difficult to keep the point of the pencil in view. The light from the microscope is thrown into the eye, and the view of the image upon the paper is the effect of a mental act, the eye looking out in the direction from which the rays appear to come. ”

“ Briefly, the polariscope consists of two parts—the analyser, placed in the barrel of the microscope above the objective, and the polariser, arranged underneath the revolving stage. The analyser is so fitted that it may be shot in and out of the barrel in order that the polariser alone may be used, or the latter may be removed, leaving only the analyser in position, or both may be removed to enable the object to be examined in ordinary light, either reflected or transmitted. ”

“ Bore a hole through the cork, just large enough to allow the upright rod to slip through it, and there is the “stand” of your microscope. Now take your pocket-lens, and get an optician to bore a hole through one end of it, just large enough to receive the upturned end of the wire; slip the lens on the wire, and the microscope is complete.
The cork, though grasping the upright stem with tolerable firmness, can be slid up and down so as to insure the correct focus, and can be pushed aside whenever the object has to be viewed with the naked eye, and must not be removed from its place. ”

“ We must darken the room in which we make the experiment and, having lighted the candle, we may proceed to make a compound microscope, for that is really what we are about to do. Taking the lens which gives the greatest magnification, we look through it till we can see a clearly defined image of the lighted candle, then we fix the lens at that spot, so that, during the rest of our experiment, the candle and lens remain at the same distance from one another. ”