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Normalize whiting thumbnails #6

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veronika
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The image normalization process modifies the image histogram so that the range of grey tones goes from black to white. It is a lossless process so no information is lost. The end result is that the images are more similar in tone range, i.e., none look too dark or to faded. Images with deep shadows in pin holes may still look a bit faded compared to the rest but in general the images look like they were photographed under the same lighting conditions. Normalization makes it easier to compare the tonal values of different grounds.

The image normalization process modifies the image histogram so that the range of grey tones goes from black to white.  It is a lossless process so no information is lost.  The end result is that the images are more similar in tone range, i.e., none look too dark or to faded.  Images with deep shadows in pin holes may still look a bit faded compared to the rest but in general the images look like they were photographed under the same lighting conditions.  Normalization makes it easier to compare the tonal values of different grounds.
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@jo-pol
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jo-pol commented Aug 26, 2020

Some got a much blacker background than others. Not sure that is what you want but maybe I don't understand this tonal effect. Some thumbnails don't show a full repeat so you might want larger sections from the original PDF: https://archive.org/details/laceguideformak00whit/page/234/mode/2up

afbeelding

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jo-pol commented Aug 26, 2020

Perhaps the poster at the end of the book is a better source: https://archive.org/details/laceguideformak00whit/page/423/mode/2up

It just has the rows and columns exchanged, or rather, Jo Edkins did and I reused her work.

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jo-pol commented Nov 3, 2023

image

Ideally we should implement a toggle between two tables. One with colse-ups of the stitches, one with normalized tonal versions clipped from the poster.

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