# ImageMagick – MagickCore, C API: Compute a Message Digest for an Image
ImageMagick is a powerful, open-source software suite for creating, editing, converting, and manipulating images in over 200 formats. Ideal for web developers, graphic designers, and researchers, it offers versatile tools for image processing, including batch processing, format conversion, and complex image transformations.
Author: ImageMagick Studio LLC
Keywords: MagickCore, C API: Compute a Message Digest for an Image, Image Processing, Digital Image Editing, Image Conversion, Open-Source Software, Image Manipulation, Command-Line Image Tools

# Signature

## 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.