Convert an image to Bitmap mode

If your image is in color, select Image > Mode > Grayscale, then select Image > Mode > Bitmap. If your image is already in grayscale, select Image > Mode > Bitmap.

In the Bitmap dialog box, enter a value for Output resolution and select a unit of measurement. By default, the current resolution is applied.

Select a conversion method from the Use menu:

• 50% Threshold: Converts pixels brighter than middle gray to white and darker pixels to black.
• Pattern Dither: Arranges gray values into geometric dot patterns.
• Diffusion Dither: Spreads tonal variation across pixels using error diffusion, creating a grainy, film-like look.
• Halftone Screen: Simulates the appearance of halftone dots in the converted image. Printing with a halftone printer may produce moiré patterns.
  • Frequency: Lines per inch (lpi) or centimeters, depending on the paper and press.
  • Angle: Orientation of the halftone screen in degrees. A 45° angle is common for black-and-white prints.
  • Shape: Dot shape to use for the halftone.
• Custom Pattern: Simulates the appearance of a custom halftone screen in the converted image. Choose a custom pattern, typically one with a variety of gray shades. To use this option, you first need to define a pattern and then screen the grayscale image to apply the texture. To cover the entire image, the pattern must be as large as the image. Otherwise, the pattern is tiled. Photoshop comes with several self-tiling patterns that can be used as halftone screen patterns.