We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
theoretically be as good as black and white, and any falling off from this standard is not due to inherent conditions but to insufficient experience and perhaps to some extent to the difficulty in getting sufficient exposure. With the additive processes, it should be possible to get quality exactly corresponding to that obtained in black-and-white photography, but in the subtractive processes the color process does not necessarily reproduce exactly the scale of rendering the negative, and in the development of a new process, a careful investigation of the accuracy with which the process reproduces the scale is necessary.
3. Production of the Positive. The practical making of the positives for projection in the additive processes presents little more difficulty than black-and-white work. More attention to detail is required, and a rather higher standard of regularity of quality must be maintained, but the process does not involve any special difficulty. When we turn to the subtractive processes, the handling is, of course, the key to the whole matter. From every other point of view, these processes are the most satisfactory, and the only thing that has kept them back is the intrinsic difficulty of making the positives. A detailed discussion of the difficulties of the subtractive processes and of the methods by which they are overcome would occupy too much space to be possible here.
4. Projection Machine. The additive processes require, of course, their own special projector, the Kinemacolor machine having rotary filters which can be thrown out of the way, thus making the machine convertible to a black-and-white projector, while the Gaumont process requires a triple projection machine with registering arrangement which cannot easily be converted into a black-andwhite machine. These special projecting machines are the great disadvantage of the additive processes and will probably always restrict their use.
5. Light Required for Projection. Both the Gaumont and the Kinemacolor processes involve a considerable loss of light, so that more current has to be used in projection. The absorption of the Kinemacolor filters, which are as light as possible, is such that only two-thirds of the incident light reaches the screen, and for equal brightnesses two and a half times as much current must be used. With the Gaumont process, the matter is somewhat worse, the filters being not only slightly darker than the Kinemacolor filters, but the blue representing the entire loss of one-third of the light, since, while the blue filter contributes to the color of the scene, it adds very little, indeed, to the total brightness.
The subtractive processes, having their highlights represented by clear film, do not require any increase of current whatever, the brightness being the same as for black and white. This is one of the great advantages of the subtractive processes.
6. Definition. There seems to be no intrinsic reason why the definition in the additive processes should not be as good as in black and white. In the Kinemacolor process, at any rate, the definition is as good, but in the Gaumont process the definition may be affected to some extent by slight imperfections in register. The high aperture
154