# ImageMagick: MagickCore, C API for ImageMagick: Compute a Message Digest for an Image
ImageMagick® is a software suite to create, edit, and compose bitmap images. It can read, convert and write images in a variety of formats (about 100) including GIF, JPEG, JPEG-2000, PNG, PDF, PhotoCD, TIFF, and DPX. Use ImageMagick to translate, flip, mirror, rotate, scale, shear and transform images, adjust image colors, apply various special effects, or draw text, lines, polygons, ellipses and Bézier curves. ImageMagick is free software delivered as a ready-to-run binary distribution or as source code that you can freely use, copy, modify, and distribute. Its license is compatible with the [cut: 1167 characters, first 599 kept]
Author: ImageMagick Studio LLC
Keywords: magickcore, c, api, for, imagemagick:, compute, a, message, digest, for, an, image, ImageMagick, ImageMagic, MagickCore, MagickWand, PerlMagick, Magick++, RMagick, PythonMagick, JMagick, TclMagick, Image, Magick, Magic, Wand

## SignatureImage

SignatureImage() computes a message digest from an image pixel stream with an implementation of the NIST SHA-256 Message Digest algorithm. This signature uniquely identifies the image and is convenient for determining if an image has been modified or whether two images are identical.

The format of the SignatureImage method is:

      MagickBooleanType SignatureImage(Image *image)

A description of each parameter follows:

##### image

The image.

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