The halftone technique had been used before to create grayscale optical micrographs.
From the sciencedaily.com
In 1882 the German George Meisenbach patented a halftone process in England.
From the en.wikipedia.org
Halftone app turns them into spotty halftone images like those in a color comic magazine.
From the nytimes.com
The idea of halftone printing originates from William Fox Talbot.
From the en.wikipedia.org
At this point, the plate is said to carry about a 50% halftone.
From the en.wikipedia.org
In process color printing, the screened image, or halftone for each ink color is printed in succession.
From the en.wikipedia.org
The image shown on this page came from the upper-left hand lense and is known as the 1907 halftone.
From the en.wikipedia.org
Maximum printing halftone 90% in any one colour.
From the telegraph.co.uk
Minimum printing halftone 5% in any one colour.
From the telegraph.co.uk
More examples
A print obtained from photoengraving
An engraving used to reproduce an illustration
Halftone is the reprographic technique that simulates continuous tone imagery through the use of dots, varying either in size or in spacing, thus generating a gradient like effect. "Halftone" can also be used to refer specifically to the image that is produced by this process.
Half the interval between two notes on a scale; A picture made by using the process of half-toning; To reproduce a photograph or other continuous tone image by the use of dots of various sizes
(Halftones) Dot system of color photos to black and white. Hologram - A unique photographic printing that provides a three-dimensional effect on a flat surface. Holograms cannot be easily copied and are used for security and aesthetic purposes on cards.
(Halftones) Images that are converted into a pattern of precisely sized and positioned dots. The number of dots per inch determines clarity of image - more dots per inch produces a sharper image.
(Halftones) Line art and text require very clear edges and high contrast between areas where there is ink, and where there is not. However, photographs and drawings usually require varying degrees of ink density for accurate representation. ...
(Halftones) The traditional printing technology of converting the analog photo image to dots that can be etched onto the printing plate.
(Halftones) photographs or drawings with graduated tones. They can be single (spot) colour or black/white. They are produced with a high resolution dot pattern for printing.