composite

composite [options] base-image composite-image [mask-image] output-image

-compose operator
    Composition operator (e.g., Over, In, Out, Atop, Multiply, Screen). Default: Over.

-dissolve percent
    Dissolve composite image into base by percentage (0-100).

-geometry geometry
    Position and size of composite image (e.g., 100x100+10+20).

-gravity type
    Gravity direction (NorthWest, Center, SouthEast, etc.).

-blend percent-geometry
    Blend using grayscale alpha channel.

-watermark brightnessx-saturation
    Watermark brightness and saturation adjustment.

-displace geometry
    Displacement map for pixel shifting.

-matte
    Enable matte (transparency) preservation.

-quality value
    JPEG/MIFF/PNG compression quality (1-100).

-compress type
    Compression type (None, BZip, LZW, etc.).

-density geometry
    Horizontal/vertical resolution.

-channel type
    Apply to specific channels (R, G, B, A, etc.).

-page geometry
    Preferred page size and location.

-limit type value
    Pixel cache resource limit (memory, map, etc.).

-verbose
    Print detailed processing info.

-version
    Print ImageMagick version.

-help
    Print usage summary.

The composite command from ImageMagick overlays a composite image onto a base image, supporting transparency, masks, and various blending modes. It enables precise positioning via geometry, gravity, and displacement maps.

Key features include Porter-Duff composition operators (e.g., Over, In, Out, Atop), dissolve effects for transparency gradients, and channel-specific operations. Users specify the base image first, then the overlay image, followed by the output file. An optional mask controls transparency.

Ideal for watermarking photos, adding logos, creating thumbnails with badges, or compositing graphics. It handles multiple formats via ImageMagick's support for 200+ image types. Options like -gravity simplify alignment (NorthWest, Center, SouthEast), while -compose defines how pixels blend. Advanced uses involve displacement for warping or morphology for effects.

Performance scales with image size; use -limit for memory control. Deprecated in ImageMagick 7 in favor of magick composite, but widely used in IM6.

Deprecated in ImageMagick 7+; use magick composite. Large images may consume high memory; specify -limit. Requires ImageMagick installation.

composite -gravity center -dissolve 50 logo.png photo.jpg output.jpg
Overlays logo at center with 50% dissolve.

Over (default), In, Out, Atop, Xor, Plus, Minus, Add, Subtract, Difference, Multiply, Divide, Screen, Darken, Lighten, ColorBurn, LinearBurn, etc. See man composite.

Introduced in ImageMagick 5.x (early 2000s), evolved from original 1990 toolkit by John Cristy. Supports Porter-Duff compositing since v6. Key updates in v6.3+ added advanced operators; IM7 (2017) unified under magick. Widely used in scripting, automation, and batch processing.

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