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1943 Radio Manual - free PDF download!

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This has some very interesting information. Thank you and thank you to the website providers for this.


One interesting note on the pictures in the document. They were originally halftone photos printed as black dots of various sizes on the white page and they don't reproduce perfectly well when scanned. When you looked at in the original document with your  "out of focus" they make the picture as good as could be reproduced in a 1940's book.


I have found that if you scan such pictures on a very high dots per inch setting, as high as your scanner will work (like 2400 dots per inch), you can restore a much better picture with some hidden detail that is often difficult to see in the original. You need to use something like Corel Photo Paint or a similar image processing program, and the files will be huge at first. Apply the Gaussian smoothing filter and preview the picture with different sizes (diameters) of the filter until you see the dots turn into almost smooth variations of grey. (It won't be perfect, but will be much better than just dots). You can then cut the resolution by re-sampling the picture to a smaller dots per inch (maybe 300 dots per inch), but still preserve that information in a much more visible picture with a much smaller memory size. I have seen much more detail with this trick than you see at first look at the old halftone pictures. This works on more modern books that have similar resolution, but it gives some amazing results on the older books.



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