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Sphere dithered with HalftoneThe same sphere before ditheringSourceDithered

16Halftone screen

Halftone

Round, square or diamond dots on an angled grid, growing with the shadows like newspaper and offset print. Set the screen size and angle.

Author
Frederic Ives
Year
1880s
Complexity
medium
Processing cost
2 / 5

How it works

A grid of dots or lines, turned to an angle like a print screen, grows with the tone. Screen size, angle and dot shape are adjustable.

Threshold ranks of one 8×8 dot cell at 0°
3112339372191
71531474529135
1927515957492517
3543556361534133
3240526062544234
1624485658502618
41228444630146
0820363822102
  • The image is covered by a grid of 8×8 pixel cells, each holding one dot that grows from its center as the image gets darker. The round dot becomes a checkerboard at 50% gray, then round holes.
  • A pixel turns white when its brightness exceeds the threshold at its position; the thresholds rank pixels by their distance to the dot center. Ranking pixels as they actually fall on the grid keeps every gray level exact.
  • In the editor, set the screen size (4–64 px) and the angle, and pick round, square or diamond dots. With dots lighter than the background, the dots mark the light areas instead.