ImageMagick: MagickCore, C API for ImageMagick: Compare an Image to a Reconstructed Image
Author: ImageMagick Studio LLC
Description: 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 GPL. It runs on all major operating systems. The functionality of ImageMagick is typically utilized from the command line or you can use the features from programs written in your favorite programming language. Choose from these interfaces: MagickCore (C), MagickWand (C), ChMagick (Ch), Magick++ (C++), JMagick (Java), L-Magick (Lisp), PascalMagick (Pascal), PerlMagick (Perl), MagickWand for PHP (P [cell cut: 1167 characters, first 1000 kept]
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## CompareImageChannels CompareImageChannels() compares one or more image channels of an image to a reconstructed image and returns the difference image. The format of the CompareImageChannels method is:
      Image *CompareImageChannels(const Image *image,
        const Image *reconstruct_image,const ChannelType channel,
        const MetricType metric,double *distortion,ExceptionInfo *exception)
A description of each parameter follows: ##### image The image. ##### reconstruct_image The reconstruct image. ##### channel The channel. ##### metric The metric. ##### distortion The computed distortion between the images. ##### exception Return any errors or warnings in this structure. ## GetImageChannelDistrortion GetImageChannelDistrortion() compares one or more image channels of an image to a reconstructed image and returns the specified distortion metric. The format of the CompareImageChannels method is:
      MagickBooleanType GetImageChhannelDistortion(const Image *image,
        const Image *reconstruct_image,const ChannelType channel,
        const MetricType metric,double *distortion,ExceptionInfo *exception)
A description of each parameter follows: ##### image The image. ##### reconstruct_image The reconstruct image. ##### channel The channel. ##### metric The metric. ##### distortion The computed distortion between the images. ##### exception Return any errors or warnings in this structure. ## IsImagesEqual IsImagesEqual() measures the difference between colors at each pixel location of two images. A value other than 0 means the colors match exactly. Otherwise an error measure is computed by summing over all pixels in an image the distance squared in RGB space between each image pixel and its corresponding pixel in the reconstruct image. The error measure is assigned to these image members:
          o mean_error_per_pixel:  The mean error for any single pixel in
      the image.
##### normalized_mean_error The normalized mean quantization error for any single pixel in the image. This distance measure is normalized to a range between 0 and 1. It is independent of the range of red, green, and blue values in the image. ##### normalized_maximum_error The normalized maximum quantization error for any single pixel in the image. This distance measure is normalized to a range between 0 and 1. It is independent of the range of red, green, and blue values in your image. A small normalized mean square error, accessed as image->normalized_mean_error, suggests the images are very similar in spatial layout and color. The format of the IsImagesEqual method is:
      MagickBooleanType IsImagesEqual(Image *image,
        const Image *reconstruct_image)
A description of each parameter follows. ##### image The image. ##### reconstruct_image The reconstruct image.

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