composite

Overlay one image on top of another

$ composite [overlay.png] [background.png] [output.png]

$ composite -geometry +[100]+[50] [overlay.png] [background.png] [output.png]

$ composite -blend [50]% [image1.png] [image2.png] [output.png]

$ composite [overlay.png] [background.png] [mask.png] [output.png]

$ composite -compose multiply [overlay.png] [background.png] [output.png]

$ composite -dissolve [75]% [overlay.png] [background.png] [output.png]

$ composite -gravity center [overlay.png] [background.png] [output.png]

composite [options] overlay background [mask] output

composite is the ImageMagick tool for combining two or more images into a single image. It provides extensive compositing operations similar to layer blending in graphics editors, enabling complex image manipulation from the command line.
The overlay image is placed over the background image according to the specified compose method and positioning. An optional mask image can control which parts of the overlay affect the final result. Common operations include watermarking, creating image collages, and applying visual effects.
The gravity option provides convenient positioning (center, corners, edges) while geometry allows pixel-precise placement. Blend modes like multiply, screen, and overlay follow standard graphics compositing mathematics.

-compose METHOD

Compositing operator: over, multiply, screen, overlay, darken, lighten, etc.

Position offset for overlay (+X+Y format).

Anchor point: center, north, south, east, west, northeast, etc.

Blend percentages for source and destination.

Dissolve overlay into background at specified percentage.

Apply overlay as watermark with given brightness.

Tile the overlay image across the background.

Hide the overlay within the background image (steganography).

Create a stereo anaglyph image.

Set image resolution.

Output compression quality (0-100).

Image order matters: overlay comes before background in the command. The output inherits dimensions from the background image by default. Alpha channels affect compositing; use -alpha options for explicit control. For batch operations, consider mogrify or magick for better performance.

composite is part of ImageMagick, originally created by John Cristy in 1990. It has evolved to support dozens of compositing operators, matching capabilities found in professional image editing software. The tool remains essential for scriptable image manipulation.

convert(1), montage(1), mogrify(1), magick(1)