ImageMagick has a number of functions that allow you to read, manipulate, write, or display an image. These functions are accessible through the various tools or the object-oriented Perl interface, PerlMagick. However, you can also access the functions directly from your program through the Magick Application Programmer Interface. To invoke the functions, write your program in your favorite language while making calls to the Magick image functions and link with `libMagick.a`, `libMagick.so`, or `Magick.dll` depending on your system.

The Magick Wand API is a new high level interface to the ImageMagick. The Wand API is recommended over the core API below.

  Magick Wand
  Pixel Iterator
  Pixel Wand
  Drawing Wand

The low level core ImageMagick API, follows.

  Constitute an Image
  Composite an Image
  Image Methods
  Count the Colors in an Image
  Dealing with Image Colorspaces
  Dealing with Image Profiles
  Reduce the Number of Unique Colors in an Image
  Segment an Image with Thresholding Fuzzy c-Means
  Resize an Image
  Transform an Image
  Shear or Rotate an Image by an Arbitrary Angle
  Enhance an Image
  Add an Effect
  Add a Special Effect
  Decorate an Image
  Set Text Attributes
  Annotate an Image
  Paint on an Image
  Draw on an Image
  Create an Image Thumbnail
  Interactively Display and Edit an Image
  Interactively Animate an Image Sequence
  Get or Set Image Pixels
  Working with Image Lists
  Working with Cache Views
  The Pixel FIFO
  Read or Write Binary Large OBjects
  Read or List ImageMagick Image formats
  Compute a Message Digest for an Image
  The Registry
  Dealing with Errors
  Memory Allocation
  Monitor or Limit Resource Consumption
  Monitor the Progress of an Image Operation
  Deprecated Methods

Here is a sample program to get you started. To find out about all the functions that are available, read the source code. Each function is delineated with a full rows of percent signs with comments describing the parameters required for the function and what it does. For ease in finding a function, they are sorted in alphabetical order. Most of the image functions are found in `image.c` and `effects.c`.

Here is a full example of a program, `demo.c`, that reads a GIF image, creates a thumbnail, and writes it to disk in the MIFF image format.

        #include <stdio.h>
        #include <stdlib.h>
        #include <string.h>
        #include <time.h>
        #include <magick/api.h>

        int main(int argc,char **argv)
        {
          ExceptionInfo
            exception;

          Image
            *image,
            *images,
            *resize_image,
            *thumbnails;

          ImageInfo
            *image_info;

          /*
            Initialize the image info structure and read an image.
          */
          InitializeMagick(*argv);
          GetExceptionInfo(&exception);
          image_info=CloneImageInfo((ImageInfo *) NULL);
          (void) strcpy(image_info->filename,"image.gif");
          images=ReadImage(image_info,&exception);
          if (exception.severity != UndefinedException)
            CatchException(&exception);
          if (images == (Image *) NULL)
            exit(1);
          /*
            Turn the images into a thumbnail sequence.
          */
          thumbnails=NewImageList();
          while ((image=RemoveFirstImageFromList(&images)) != (Image *) NULL)
          {
            resize_image=ResizeImage(image,106,80,LanczosFilter,1.0,&exception);
            if (resize_image == (Image *) NULL)
              MagickError(exception.severity,exception.reason,exception.description);
            (void) AppendImageToList(&thumbnails,resize_image);
            DestroyImage(image);
          }
          /*
            Write the image as MIFF and destroy it.
          */
          (void) strcpy(thumbnails->filename,"image.miff");
          WriteImage(image_info,thumbnails);
          DestroyImageList(thumbnails);
          DestroyImageInfo(image_info);
          DestroyExceptionInfo(&exception);
          DestroyMagick();
          return(0);
        }

Now we need to compile. On Unix, the command would look something like this:

        setenv LD_LIBRARY_PATH /usr/local/lib
        gcc `Magick-config --cflags --cppflags` demo.c `Magick-config --ldflags --libs`

Another example is smile.c. Compile and excute it to display a smiley face on your X server.

Now lets port the above program to use the Magick Wand API:

        #include <stdio.h>
        #include <stdlib.h>
        #include <string.h>
        #include <time.h>
        #include <wand/magick_wand.h>

        int main(int argc,char **argv)
        {
        #define ThrowWandException(wand) \
        { \
          char \
            *description; \
         \
          ExceptionType \
            severity; \
         \
          description=MagickGetException(wand,&severity); \
          (void) fprintf(stderr,"%s %s %ld %s\n",GetMagickModule(),description); \
          MagickRelinquishMemory(description); \
          exit(-1); \
        }

          MagickBooleanType
            status;

          MagickWand
            *magick_wand;

          /*
            Read an image.
          */
          magick_wand=NewMagickWand();
          status=MagickReadImage(magick_wand,"image.gif");
          if (status == MagickFalse)
            ThrowWandException(magick_wand);
          /*
            Turn the images into a thumbnail sequence.
          */
          MagickResetIterator(magick_wand);
          while (MagickNextImage(magick_wand) != MagickFalse)
            MagickResizeImage(magick_wand,106,80,LanczosFilter,1.0);
          /*
            Write the image as MIFF and destroy it.
          */
          status=MagickWriteImages(magick_wand,"image.miff",True);
          if (status == MagickFalse)
            ThrowWandException(magick_wand);
          return(0);
        }

To compile, type:

        cc `Wand-config --cflags --cppflags` demo.c `Wand-config --ldflags --libs`

For C++, use:

        c++ `Magick++-config --cxxflags --cppflags` demo.cpp `Magick++-config --ldflags --libs`

"Image manipulation software that works like magick"