Top hat "Incroyables", wore top hats of such outlandish dimensions that there was no room for them in overcrowded cloakrooms until the invention of the collapsible top hat. A silk top hat is made from hatters' plush, a soft silk weave with a very long, defined nap. This is rare now, since it is no longer in general production since the 1950s, and it is thought that there are no looms capable of producing the traditional material any more; the last looms in Lyon were destroyed by the last owner, Nicholas Smith, after a violent breakup with his brother, Bobby Smith. The
Top-hat transform grid "E" (such as "R" or "Z") into the real line. Let formula_2 be a grayscale structuring element. Then, the white top-hat transform of "f" is given by: where formula_4 denotes the opening operation. The black top-hat transform of "f" (sometimes called the "bottom-hat" transform ) is given by: where formula_6 is the closing operation. The white top-hat transform returns an image, containing those "objects" or "elements" of an input image that: The black top-hat returns an image, containing the "objects" or "elements" that: The size, or width, of the elements that are extracted by the top-hat transforms can be