combine

Output lines that are in both specified files

$ combine [path/to/file1] and [path/to/file2]

$ combine [path/to/file1] not [path/to/file2]

$ combine [path/to/file1] or [path/to/file2]

$ combine [path/to/file1] xor [path/to/file2]

combine [options] input_image... output_image

Note: This synopsis represents the common usage of the `combine` utility found in ImageMagick versions prior to v7, or as a symlink to the main `magick` command in newer versions for specific legacy operations. For more general image composition, refer to `magick composite` or `magick convert`.

-channel value
    Specifies which image channels (e.g., Red, Green, Blue, Alpha) are processed for the operation.

-compress type
    Defines the image compression type for the output file (e.g., JPEG, Zip, LZW).

-quality value
    Sets the image compression quality for formats like JPEG, MIFF, or PNG (0-100).

-strip
    Removes any profiles, comments, or metadata from the output image.

-verbose
    Displays detailed information about the image processing progress, including image attributes.

-monochrome
    Transforms the output image to black and white, effectively creating a bilevel image.

The combine command is a utility from the ImageMagick suite, a powerful open-source software collection for image manipulation. Unlike general-purpose file utilities, combine is specifically designed for working with raster images. Its primary functions include joining multiple individual images into a single multi-image file (e.g., creating a GIF animation from a sequence of JPEGs, or a multi-page TIFF document).

Additionally, combine can be used to extract or combine specific color channels (like red, green, blue) from one or more images into a new image. This makes it valuable for specialized image processing tasks, such as creating grayscale images from a single channel, or merging channels from different sources. While it's part of a larger suite, combine offers a focused set of functionalities for complex image assembly and channel-level operations, particularly in scripting and automated workflows.

• Domain Specific: The combine command is part of the ImageMagick suite and is exclusively for image processing, not for general text or file manipulation.
• Version Dependency: Its specific behavior and availability as a standalone executable can vary between ImageMagick versions. In ImageMagick 7 and newer, many of its functionalities are integrated into the unified magick command.
• Distinction from composite: Often confused with composite, which overlays images. combine typically merges images into a multi-frame file or performs channel-specific operations.

One of combine's key uses is to take a series of individual images and merge them into a single file format that supports multiple frames or pages, such as multi-page TIFFs, animated GIFs, or multi-layer MIFF files. This is crucial for applications requiring image sequences or grouped visual content.

Beyond simple merging, combine excels at working with individual color channels (Red, Green, Blue, Alpha). Users can extract a single channel from an image as a new grayscale image, or combine channels from different input images to create a new composite image. This is particularly useful for advanced image analysis or specialized visual effects.

The combine command is one of the original utilities within the ImageMagick software suite, which was first released in 1987. Over decades, ImageMagick has evolved significantly. While combine has maintained its core purpose of merging images into multi-frame files or processing color channels, its role has somewhat shifted with the introduction of ImageMagick 7. In this newer version, a unified `magick` command largely encompasses the functionalities previously found in separate utilities like `combine`, `convert`, and `mogrify`, though `combine` might still exist as a backward-compatible symlink or for specific legacy scripts.

magick(1), composite(1), convert(1), mogrify(1)