如何使用C从ImageMagick棒中提取PPM图像属性？

Question

In order to convert almost any type of image into a PPM I'm using ImageMagick's wand API. From the wand how do I extract the PPM properties of width, height, modval and raw RGB data? Here is some skeleton code.

Many thanks in advance for reading the question.

  /* Read an image. */
  MagickWandGenesis();
  magick_wand = NewMagickWand();
  status = MagickReadImage(magick_wand, argv[1]);
  if (status == MagickFalse)
    ThrowWandException(magick_wand);

  /* TODO convert to P6 PPM */

  /* TODO get PPM properties */
  ppm->width = ...
  ppm->height = ...
  ppm->modval = 3 * ppm->width;
  ppm->data = malloc(ppm->width * ppm->height * 3);
  /* TODO fill ppm->data */

Answer 1

From ImageMagick Forum

width = MagickGetImageWidth(magick_wand);
height = MagickGetImageHeight(magick_wand);
ppm->width = width;
ppm->height = height;
ppm->modval = 3 * width;
ppm->data = malloc (3 * width * height);
status = MagickExportImagePixels(magick_wand, 0, 0, width, height, "RGB",
            CharPixel, ppm->data);