ImageMagick: MagickCore, C API for ImageMagick: Compute a Message Digest for an Image
Author: ImageMagick Studio LLC
Description: ImageMagick® is a software suite to create, edit, compose, or convert bitmap images. It can read and write images in a variety of formats (over 200) including PNG, JPEG, JPEG-2000, GIF, WebP, Postscript, PDF, and SVG. Use ImageMagick to resize, flip, mirror, rotate, distort, shear and transform images, adjust image colors, apply various special effects, or draw text, lines, polygons, ellipses and Bézier curves.
Keywords: magickcore, c, api, for, imagemagick:, compute, a, message, digest, for, an, image, ImageMagick, PerlMagick, image processing, image, photo, software, Magick++, OpenMP, convert

SignatureImage

## 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.