NetNews Usenet Archive 1992 #30/NN_1992_30.iso/spool/comp/sources/misc/4174

Text File | 1992-12-13 | 57.3 KB | 1,821 lines

Newsgroups: comp.sources.misc
Path: sparky!kent
From: [e-mail] (John Cristy)
Subject:  v34i037:  imagemagick - X11 image processing and display v2.2, Part09/26
Message-ID: <[e-mail]>
Followup-To: comp.sources.d
X-Md4-Signature: 90d00814723ce3528650c775e8603408
Sender: [e-mail] (Kent Landfield)
Organization: Sterling Software
References: <csm-v34i028=[e-mail]>
Date: Sun, 13 Dec 1992 20:28:11 GMT
Approved: [e-mail]
Lines: 1806

Submitted-by: [e-mail] (John Cristy)
Posting-number: Volume 34, Issue 37
Archive-name: imagemagick/part09
Environment: UNIX, VMS, X11, SGI, DEC, Cray, Sun, Vax

#!/bin/sh
# this is Part.09 (part 9 of a multipart archive)
# do not concatenate these parts, unpack them in order with /bin/sh
# file ImageMagick/quantize.c continued
#
if test ! -r _shar_seq_.tmp; then
    echo 'Please unpack part 1 first!'
    exit 1
fi
(read Scheck
 if test "$Scheck" != 9; then
    echo Please unpack part "$Scheck" next!
    exit 1
 else
    exit 0
 fi
) < _shar_seq_.tmp || exit 1
if test ! -f _shar_wnt_.tmp; then
    echo 'x - still skipping ImageMagick/quantize.c'
else
echo 'x - continuing file ImageMagick/quantize.c'
sed 's/^X//' << 'SHAR_EOF' >> 'ImageMagick/quantize.c' &&
X      q->length=0;
X      q+=step;
X      /*
X        Propagate the error in these proportions:
X                Q     7/16
X          3/16  5/16  1/16
X      */
X      cs+=step;
X      cs->red+=red_error-((red_error*9+8) >> 4);
X      cs->green+=green_error-((green_error*9+8) >> 4);
X      cs->blue+=blue_error-((blue_error*9+8) >> 4);
X      ns-=step;
X      ns->red+=(red_error*3+8) >> 4;
X      ns->green+=(green_error*3+8) >> 4;
X      ns->blue+=(blue_error*3+8) >> 4;
X      ns+=step;
X      ns->red+=(red_error*5+8) >> 4;
X      ns->green+=(green_error*5+8) >> 4;
X      ns->blue+=(blue_error*5+8) >> 4;
X      ns+=step;
X      ns->red+=(red_error+8) >> 4;
X      ns->green+=(green_error+8) >> 4;
X      ns->blue+=(blue_error+8) >> 4;
X    }
X    odd_scanline=!odd_scanline;
X  }
X  /*
X    Free up memory.
X  */
X  (void) free((char *) scanline);
X  (void) free((char *) range_table);
X  (void) free((char *) cache);
X  (void) free((char *) image->pixels);
X  image->packets=dithered_image->packets;
X  image->pixels=dithered_image->pixels;
X  dithered_image->file=(FILE *) NULL;
X  dithered_image->pixels=(RunlengthPacket *) NULL;
X  DestroyImage(dithered_image);
X  return(False);
}
X
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%  I n i t i a l i z e C u b e                                                %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Function InitializeCube initialize the Cube data structure.
%
%  The format of the InitializeCube routine is:
%
%      InitializeCube(number_colors,tree_depth,number_pixels,optimal)
%
%  A description of each parameter follows.
%
%    o number_colors: This integer value indicates the maximum number of
%      colors in the quantized image or colormap.  Here we use this value
%      to determine the depth of the color description tree.
%
%    o tree_depth: Normally, this integer value is zero or one.  A zero or
%      one tells Quantize to choose a optimal tree depth of Log4(number_colors).
%      A tree of this depth generally allows the best representation of the
%      reference image with the least amount of memory and the fastest
%      computational speed.  In some cases, such as an image with low color
%      dispersion (a few number of colors), a value other than
%      Log4(number_colors) is required.  To expand the color tree completely,
%      use a value of 8.
%
%    o number_pixels: Specifies the number of individual pixels in the image.
%
%    o optimal: An unsigned integer value greater than zero indicates that
%      the optimal representation of the reference image should be returned.
%
*/
static void InitializeCube(number_colors,tree_depth,number_pixels,optimal)
unsigned int
X  number_colors,
X  tree_depth,
X  number_pixels,
X  optimal;
{
X  register int
X    i;
X
X  static int
X    log4[6] = {4, 16, 64, 256, 1024, ~0};
X
X  unsigned int
X    level;
X
X  unsigned long int
X    max_shift;
X
X  /*
X    Initialize tree to describe color cube.  Depth is: Log4(colormap size)+2;
X  */
X  cube.node_queue=(Nodes *) NULL;
X  cube.nodes=0;
X  cube.free_nodes=0;
X  if (tree_depth > 1)
X    cube.depth=Min(tree_depth,8);
X  else
X    {
X      for (i=0; i < 6; i++)
X        if (number_colors <= log4[i])
X          break;
X      cube.depth=i+3;
X      if (!optimal)
X        cube.depth--;
X    }
X  /*
X    Initialize the shift values.
X  */
X  for (max_shift=0; number_pixels > 0; max_shift++)
X    number_pixels<<=1;
X  for (level=0; level < cube.depth; level++)
X  {
X    cube.shift[level]=(cube.depth-level-1) << 1;
X    if (cube.shift[level] > max_shift)
X      cube.shift[level]=max_shift;
X  }
X  /*
X    Initialize the square values.
X  */
X  for (i=(-MaxRGB); i <= MaxRGB; i++)
X    cube.squares[i+MaxRGB]=i*i;
X  /*
X    Initialize root node.
X  */
X  cube.root=
X    InitializeNode(0,0,(Node *) NULL,MaxRGB >> 1,MaxRGB >> 1,MaxRGB >> 1);
X  if (cube.root == (Node *) NULL)
X    {
X      Warning("unable to quantize image","memory allocation failed");
X      exit(1);
X    }
X  cube.root->parent=cube.root;
X  cube.root->number_colors=(~0);
X  cube.colors=0;
}
X
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%  I n i t i a l i z e N o d e                                                %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Function InitializeNode allocates memory for a new node in the color cube
%  tree and presets all fields to zero.
%
%  The format of the InitializeNode routine is:
%
%      node=InitializeNode(node,id,level,mid_red,mid_green,mid_blue)
%
%  A description of each parameter follows.
%
%    o node: The InitializeNode routine returns this integer address.
%
%    o id: Specifies the child number of the node.
%
%    o level: Specifies the level in the classification the node resides.
%
%    o mid_red: Specifies the mid point of the red axis for this node.
%
%    o mid_green: Specifies the mid point of the green axis for this node.
%
%    o mid_blue: Specifies the mid point of the blue axis for this node.
%
%
*/
static Node *InitializeNode(id,level,parent,mid_red,mid_green,mid_blue)
unsigned int
X  id,
X  level;
X
Node
X  *parent;
X
unsigned int
X  mid_red,
X  mid_green,
X  mid_blue;
{
X  register int
X    i;
X
X  register Node
X    *node;
X
X  if (cube.free_nodes == 0)
X    {
X      register Nodes
X        *nodes;
X
X      /*
X        Allocate a new nodes of nodes.
X      */
X      nodes=(Nodes *) malloc(sizeof(Nodes));
X      if (nodes == (Nodes *) NULL)
X        return((Node *) NULL);
X      nodes->next=cube.node_queue;
X      cube.node_queue=nodes;
X      cube.next_node=nodes->nodes;
X      cube.free_nodes=NodesInAList;
X    }
X  cube.nodes++;
X  cube.free_nodes--;
X  node=cube.next_node++;
X  node->parent=parent;
X  for (i=0; i < 8; i++)
X    node->child[i]=(Node *) NULL;
X  node->id=id;
X  node->level=level;
X  node->children=0;
X  node->mid_red=mid_red;
X  node->mid_green=mid_green;
X  node->mid_blue=mid_blue;
X  node->number_colors=0;
X  node->number_unique=0;
X  node->total_red=0;
X  node->total_green=0;
X  node->total_blue=0;
X  return(node);
}
X
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%  P r u n e C h i l d                                                        %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Function PruneChild deletes the given node and merges its statistics into
%  its parent.
%
%  The format of the PruneSubtree routine is:
%
%      PruneChild(node)
%
%  A description of each parameter follows.
%
%    o node: pointer to node in color cube tree that is to be pruned.
%
%
*/
static void PruneChild(node)
register Node
X  *node;
{
X  register Node
X    *parent;
X
X  /*
X    Merge color statistics into parent.
X  */
X  parent=node->parent;
X  parent->children&=~(1 << node->id);
X  parent->number_unique+=node->number_unique;
X  parent->total_red+=node->total_red;
X  parent->total_green+=node->total_green;
X  parent->total_blue+=node->total_blue;
X  cube.nodes--;
}
X
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%  P r u n e L e v e l                                                        %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Procedure PruneLevel deletes all nodes at the bottom level of the color
%  tree merging their color statistics into their parent node.
%
%  The format of the PruneLevel routine is:
%
%      PruneLevel(node)
%
%  A description of each parameter follows.
%
%    o node: pointer to node in color cube tree that is to be pruned.
%
%
*/
static void PruneLevel(node)
register Node
X  *node;
{
X  register int
X    id;
X
X  /*
X    Traverse any children.
X  */
X  if (node->children > 0)
X    for (id=0; id < 8; id++)
X      if (node->children & (1 << id))
X        PruneLevel(node->child[id]);
X  if (node->level == (cube.depth-1))
X    PruneChild(node);
}
X
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%  R e d u c e                                                                %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Function Reduce traverses the color cube tree and prunes any node whose
%  number of colors fall below a particular threshold.
%
%  The format of the Reduce routine is:
%
%      Reduce(node)
%
%  A description of each parameter follows.
%
%    o node: pointer to node in color cube tree that is to be pruned.
%
%
*/
static void Reduce(node)
register Node
X  *node;
{
X  register unsigned int
X    id;
X
X  /*
X    Traverse any children.
X  */
X  if (node->children > 0)
X    for (id=0; id < 8; id++)
X      if (node->children & (1 << id))
X        Reduce(node->child[id]);
X  if (node->number_colors <= cube.pruning_threshold)
X    {
X      /*
X        Node has a sub-threshold color count so prune it.  Node is an colormap
X        entry if parent does not have any unique colors.
X      */
X      if (node->parent->number_unique == 0)
X        cube.colors++;
X      PruneChild(node);
X      if (node->parent->number_colors < cube.next_pruning_threshold)
X        cube.next_pruning_threshold=node->parent->number_colors;
X    }
X  else
X    {
X      /*
X        Find minimum pruning threshold.  Node is a colormap entry if it has
X        unique colors.
X      */
X      if (node->number_unique > 0)
X        cube.colors++;
X      if (node->number_colors < cube.next_pruning_threshold)
X        cube.next_pruning_threshold=node->number_colors;
X    }
}
X
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%  R e d u c t i o n                                                          %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Function Reduction repeatedly prunes the tree until the number of nodes
%  with n2 > 0 is less than or equal to the maximum number of colors allowed
%  in the output image.  On any given iteration over the tree, it selects
%  those nodes whose n1  count is minimal for pruning and merges their
%  color statistics upward. It uses a pruning threshold, ns, to govern
%  node selection as follows:
%
%    ns = 0
%    while number of nodes with (n2 > 0) > required maximum number of colors
%      prune all nodes such that n1 <= ns
%      Set ns to minimum n1 in remaining nodes
%
%  When a node to be pruned has offspring, the pruning procedure invokes
%  itself recursively in order to prune the tree from the leaves upward.
%  n2,  Sr, Sg,  and  Sb in a node being pruned are always added to the
%  corresponding data in that node's parent.  This retains the pruned
%  node's color characteristics for later averaging.
%
%  For each node, n2 pixels exist for which that node represents the
%  smallest volume in RGB space containing those pixel's colors.  When n2
%  > 0 the node will uniquely define a color in the output image. At the
%  beginning of reduction,  n2 = 0  for all nodes except a the leaves of
%  the tree which represent colors present in the input image.
%
%  The other pixel count, n1, indicates the total number of colors
%  within the cubic volume which the node represents.  This includes n1 -
%  n2  pixels whose colors should be defined by nodes at a lower level in
%  the tree.
%
%  The format of the Reduction routine is:
%
%      Reduction(number_colors)
%
%  A description of each parameter follows.
%
%    o number_colors: This integer value indicates the maximum number of
%      colors in the quantized image or colormap.  The actual number of
%      colors allocated to the colormap may be less than this value, but
%      never more.  Note, the number of colors is restricted to a value
%      less than or equal to 65536 if the continuous_tone parameter has a
%      value of zero.
%
%
*/
static void Reduction(number_colors)
register unsigned int
X  number_colors;
{
X  cube.next_pruning_threshold=1;
X  while (cube.colors > number_colors)
X  {
X    cube.pruning_threshold=cube.next_pruning_threshold;
X    cube.next_pruning_threshold=cube.root->number_colors-1;
X    cube.colors=0;
X    Reduce(cube.root);
X  }
}
X
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%  Q u a n t i z a t i o n E r r o r                                          %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Function QuantizationError measures the difference between the original
%  and quantized images.  This difference is the total quantization error.
%  The error is computed by summing over all pixels in an image the distance
%  squared in RGB space between each reference pixel value and its quantized
%  value.
%
%  The format of the QuantizationError routine is:
%
%      QuantizationError(image,mean_error_per_pixel,
%        normalized_mean_square_error,normalized_maximum_square_error)
%
%  A description of each parameter follows.
%
%    o image: The address of a byte (8 bits) array of run-length
%      encoded pixel data of your reference image.  The sum of the
%      run-length counts in the reference image must be equal to or exceed
%      the number of pixels.
%
%    o mean_error_per_pixel: The address of an integer value.  The value
%      returned is the mean error for any single pixel in the image.
%
%    o normalized_mean_square_error: The address of a real value.  The value
%      returned is 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 your image.
%
%    o normalized_maximum_square_error: The address of a real value.  The value
%      returned is 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.
%
%
*/
void QuantizationError(image,mean_error_per_pixel,normalized_mean_square_error,
X  normalized_maximum_square_error)
Image
X  *image;
X
unsigned int
X  *mean_error_per_pixel;
X
double
X  *normalized_mean_square_error,
X  *normalized_maximum_square_error;
{
X  register int
X    i;
X
X  register RunlengthPacket
X    *p;
X
X  register unsigned int
X    blue_distance,
X    green_distance,
X    red_distance;
X
X  unsigned long int
X    distance,
X    maximum_error_per_pixel,
X    total_error;
X
X  /*
X    For each pixel, collect error statistics.
X  */
X  for (i=(-MaxRGB); i <= MaxRGB; i++)
X    cube.squares[i+MaxRGB]=i*i;
X  maximum_error_per_pixel=0;
X  total_error=0;
X  p=image->pixels;
X  for (i=0; i < image->packets; i++)
X  {
X    red_distance=(int) p->red-(int) image->colormap[p->index].red+MaxRGB;
X    green_distance=(int) p->green-(int) image->colormap[p->index].green+MaxRGB;
X    blue_distance=(int) p->blue-(int) image->colormap[p->index].blue+MaxRGB;
X    distance=cube.squares[red_distance]+cube.squares[green_distance]+
X      cube.squares[blue_distance];
X    total_error+=(distance*(p->length+1));
X    if (distance > maximum_error_per_pixel)
X      maximum_error_per_pixel=distance;
X    p++;
X  }
X  /*
X    Compute final error statistics.
X  */
X  *mean_error_per_pixel=(unsigned int) total_error/(image->columns*image->rows);
X  *normalized_mean_square_error=((double) *mean_error_per_pixel)/
X    (3.0*MaxRGB*MaxRGB);
X  *normalized_maximum_square_error=((double) maximum_error_per_pixel)/
X    (3.0*MaxRGB*MaxRGB);
}
X
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%  Q u a n t i z e I m a g e                                                  %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Function QuantizeImage analyzes the colors within a reference image and
%  chooses a fixed number of colors to represent the image.  The goal of the
%  algorithm is to minimize the difference between the input and output image
%  while minimizing the processing time.
%
%  The format of the Quantize routine is:
%
%      colors=QuantizeImage(image,number_colors,tree_depth,dither,optimal)
%
%  A description of each parameter follows.
%
%    o colors: The QuantizeImage function returns this integer
%      value.  It is the actual number of colors allocated in the
%      colormap.  Note, the actual number of colors allocated may be less
%      than the number of colors requested, but never more.
%
%    o image: Specifies a pointer to an Image structure;  returned from
%      ReadImage.
%
%    o number_colors: This integer value indicates the maximum number of
%      colors in the quantized image or colormap.  The actual number of
%      colors allocated to the colormap may be less than this value, but
%      never more.  Note, the number of colors is restricted to a value
%      less than or equal to 65536 if the continuous_tone parameter has a
%      value of zero.
%
%    o tree_depth: Normally, this integer value is zero or one.  A zero or
%      one tells Quantize to choose a optimal tree depth of Log4(number_colors).
%      A tree of this depth generally allows the best representation of the
%      reference image with the least amount of memory and the fastest
%      computational speed.  In some cases, such as an image with low color
%      dispersion (a few number of colors), a value other than
%      Log4(number_colors) is required.  To expand the color tree completely,
%      use a value of 8.
%
%    o dither: Set this integer value to something other than zero to
%      dither the quantized image.  The basic strategy of dithering is to
%      trade intensity resolution for spatial resolution by averaging the
%      intensities of several neighboring pixels.  Images which suffer
%      from severe contouring when quantized can be improved with the
%      technique of dithering.  Severe contouring generally occurs when
%      quantizing to very few colors, or to a poorly-chosen colormap.
%      Note, dithering is a computationally expensive process and will
%      increase processing time significantly.
%
%    o colorspace: An unsigned integer value that indicates the colorspace.
%      Empirical evidence suggests that distances in YUV or YIQ correspond to
%      perceptual color differences more closely than do distances in RGB
%      space.  The image is then returned to RGB colorspace after color
%      reduction.
%
%    o optimal: An unsigned integer value greater than zero indicates that
%      the optimal representation of the reference image should be returned.
%
%
*/
void QuantizeImage(image,number_colors,tree_depth,dither,colorspace,optimal)
Image
X  *image;
X
unsigned int
X  number_colors,
X  tree_depth,
X  dither,
X  colorspace,
X  optimal;
{
X  Nodes
X    *nodes;
X
X  /*
X    Reduce the number of colors in the continuous tone image.
X  */
X  if (number_colors > MaxColormapSize)
X    number_colors=MaxColormapSize;
X  InitializeCube(number_colors,tree_depth,image->columns*image->rows,optimal);
X  if ((image->compression == RunlengthEncodedCompression) &&
X      (image->packets == (image->columns*image->rows)))
X    CompressImage(image);
X  if (colorspace != RGBColorspace)
X    RGBTransformImage(image,colorspace);
X  Classification(image);
X  if (!optimal)
X    dither|=cube.colors > (1 << (cube.depth-1));
X  Reduction(number_colors);
X  Assignment(image,dither,optimal);
X  if (colorspace != RGBColorspace)
X    TransformRGBImage(image,colorspace);
X  /*
X    Release color cube tree storage.
X  */
X  do
X  {
X    nodes=cube.node_queue->next;
X    (void) free((char *) cube.node_queue);
X    cube.node_queue=nodes;
X  }
X  while (cube.node_queue != (Nodes *) NULL);
}
X
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   Q u a n t i z e I m a g e s                                               %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  QuantizeImages analyzes the colors within a set of reference images and
%  chooses a fixed number of colors to represent the set.  The goal of the
%  algorithm is to minimize the difference between the input and output images
%  while minimizing the processing time.
%
%  The format of the QuantizeImages routine is:
%
%      QuantizeImages(images,number_images,number_colors,tree_depth,dither,
%        optimal)
%
%  A description of each parameter follows:
%
%    o images: Specifies a pointer to a set of Image structures.
%
%    o number_images:  Specifies an unsigned integer representing the number
%      images in the image set.
%
%    o colormap_image: Specifies a pointer to a Image structure.  Reduce
%      images to a set of colors represented by this image.
%
%    o number_colors: This integer value indicates the maximum number of
%      colors in the quantized image or colormap.  The actual number of colors
%      allocated to the colormap may be less than this value, but never more.
%      Note, the number of colors is restricted to a value less than or equal
%      to 65536 if the quantized image is not DirectClass.
%
%    o tree_depth: Normally, this integer value is zero or one.  A zero or
%      one tells QUANTIZE to choose a optimal tree depth.  An optimal depth
%      generally allows the best representation of the reference image with the
%      fastest computational speed and the least amount of memory.  However,
%      the default depth is inappropriate for some images.  To assure the best
%      representation, try values between 2 and 8 for this parameter.
%
%    o dither: Set this integer value to something other than zero to
%      dither the quantized image.  The basic strategy of dithering is to
%      trade intensity resolution for spatial resolution by averaging the
%      intensities of several neighboring pixels.  Images which suffer
%      from severe contouring when quantized can be improved with the
%      technique of dithering.  Severe contouring generally occurs when
%      quantizing to very few colors, or to a poorly-chosen colormap.
%      Note, dithering is a computationally expensive process and will
%      increase processing time significantly.
%
%    o colorspace: An unsigned integer value that indicates the colorspace.
%      Empirical evidence suggests that distances in YUV or YIQ correspond to
%      perceptual color differences more closely than do distances in RGB
%      space.  The image is then returned to RGB colorspace after color
%      reduction.
%
%    o optimal: An unsigned integer value greater than zero indicates that
%      the optimal representation of the reference image should be returned.
%
%
*/
void QuantizeImages(images,number_images,colormap_image,number_colors,
X  tree_depth,dither,colorspace,optimal)
Image
X  **images;
X
unsigned int
X  number_images;
X
Image
X  *colormap_image;
X
unsigned int
X  number_colors,
X  tree_depth,
X  dither,
X  colorspace,
X  optimal;
{
X  Nodes
X    *nodes;
X
X  register unsigned int
X    i;
X
X  /*
X    Reduce the number of colors in the continuous tone image sequence.
X  */
X  InitializeCube(number_colors,tree_depth,~0,optimal);
X  if (colormap_image != (Image *) NULL)
X    {
X      /*
X        Reduce images to a set of colors represented by the colormap image.
X      */
X      if ((colormap_image->compression == RunlengthEncodedCompression) &&
X          (colormap_image->packets ==
X           (colormap_image->columns*colormap_image->rows)))
X        CompressImage(colormap_image);
X      if (colorspace != RGBColorspace)
X        RGBTransformImage(colormap_image,colorspace);
X      Classification(colormap_image);
X      if (colorspace != RGBColorspace)
X        TransformRGBImage(colormap_image,colorspace);
X      optimal=True;
X    }
X  for (i=0; i < number_images; i++)
X  {
X    if ((images[i]->compression == RunlengthEncodedCompression) &&
X        (images[i]->packets == (images[i]->columns*images[i]->rows)))
X      CompressImage(images[i]);
X    if (colorspace != RGBColorspace)
X      RGBTransformImage(images[i],colorspace);
X    if (colormap_image == (Image *) NULL)
X      Classification(images[i]);
X  }
X  if (!optimal)
X    dither|=cube.colors > (1 << (cube.depth-1));
X  Reduction(number_colors);
X  for (i=0; i < number_images; i++)
X  {
X    Assignment(images[i],dither,optimal);
X    if (colorspace != RGBColorspace)
X      TransformRGBImage(images[i],colorspace);
X  }
X  /*
X    Release color cube tree storage.
X  */
X  do
X  {
X    nodes=cube.node_queue->next;
X    (void) free((char *) cube.node_queue);
X    cube.node_queue=nodes;
X  }
X  while (cube.node_queue != (Nodes *) NULL);
}
SHAR_EOF
echo 'File ImageMagick/quantize.c is complete' &&
chmod 0644 ImageMagick/quantize.c ||
echo 'restore of ImageMagick/quantize.c failed'
Wc_c="`wc -c < 'ImageMagick/quantize.c'`"
test 60634 -eq "$Wc_c" ||
    echo 'ImageMagick/quantize.c: original size 60634, current size' "$Wc_c"
rm -f _shar_wnt_.tmp
fi
# ============= ImageMagick/rotate.c ==============
if test -f 'ImageMagick/rotate.c' -a X"$1" != X"-c"; then
    echo 'x - skipping ImageMagick/rotate.c (File already exists)'
    rm -f _shar_wnt_.tmp
else
> _shar_wnt_.tmp
echo 'x - extracting ImageMagick/rotate.c (Text)'
sed 's/^X//' << 'SHAR_EOF' > 'ImageMagick/rotate.c' &&
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%                 RRRR    OOO   TTTTT   AAA   TTTTT   EEEEE                   %
%                 R   R  O   O    T    A   A    T     E                       %
%                 RRRR   O   O    T    AAAAA    T     EEE                     %
%                 R R    O   O    T    A   A    T     E                       %
%                 R  R    OOO     T    A   A    T     EEEEE                   %
%                                                                             %
%                                                                             %
%                Rotate a raster image by an arbitrary angle.                 %
%                                                                             %
%                                                                             %
%                                                                             %
%                           Software Design                                   %
%                             John Cristy                                     %
%                              July 1992                                      %
%                                                                             %
%                                                                             %
%  Copyright 1992 E. I. du Pont de Nemours & Company                          %
%                                                                             %
%  Permission to use, copy, modify, distribute, and sell this software and    %
%  its documentation for any purpose is hereby granted without fee,           %
%  provided that the above Copyright notice appear in all copies and that     %
%  both that Copyright notice and this permission notice appear in            %
%  supporting documentation, and that the name of E. I. du Pont de Nemours    %
%  & Company not be used in advertising or publicity pertaining to            %
%  distribution of the software without specific, written prior               %
%  permission.  E. I. du Pont de Nemours & Company makes no representations   %
%  about the suitability of this software for any purpose.  It is provided    %
%  "as is" without express or implied warranty.                               %
%                                                                             %
%  E. I. du Pont de Nemours & Company disclaims all warranties with regard    %
%  to this software, including all implied warranties of merchantability      %
%  and fitness, in no event shall E. I. du Pont de Nemours & Company be       %
%  liable for any special, indirect or consequential damages or any           %
%  damages whatsoever resulting from loss of use, data or profits, whether    %
%  in an action of contract, negligence or other tortious action, arising     %
%  out of or in connection with the use or performance of this software.      %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Function RotateImage is based on the paper "A Fast Algorithm for General
%  Raster Rotatation" by Alan W. Paeth.  RotateImage is adapted from a similiar
%  routine based on the Paeth paper written by Michael Halle of the Spatial
%  Imaging Group, MIT Media Lab.
%
*/
X
/*
X  Include declarations.
*/
#include "display.h"
#include "image.h"
X
/*
X  External declarations.
*/
extern char
X  *application_name;
X
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   C o l u m n S h e a r                                                     %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Procedure ColumnShear displaces a subcolumn of pixels a specified number of
%  pixels.
%
%  The format of the ColumnShear routine is:
%
%      ColumnShear(source_image,source_columns,column,y,length,displacement,
%        background)
%
%  A description of each parameter follows.
%
%    o source_image: A pointer to a ColorPacket structure which contains the
%      source image.
%
%    o source_columns: Specifies the number of columns in the source image.
%
%    o column: Specifies which column in the image to move.
%
%    o y: Specifies the offset in the source image.
%
%    o length: Specifies the number of pixels to move.
%
%    o displacement: Specifies the number of pixels to displace the column of
%      pixels.
%
%    o background: Specifies the background color.
%
%
*/
static void ColumnShear(source_image,source_columns,column,y,length,
X  displacement,background,range_limit)
ColorPacket
X  *source_image;
X
register unsigned int
X  source_columns;
X
unsigned int
X  column,
X  y,
X  length;
X
double
X  displacement;
X
ColorPacket
X  background;
X
register unsigned char
X  *range_limit;
{
X  ColorPacket
X    last_pixel;
X
X  enum {UP,DOWN}
X    direction;
X
X  int
X    blue,
X    green,
X    red,
X    step;
X
X  long int
X    fractional_step;
X
X  register ColorPacket
X    *p,
X    *q;
X
X  register int
X    i;
X
X  if (displacement == 0.0)
X    return;
X  else
X    if (displacement > 0.0)
X      direction=DOWN;
X    else
X      {
X        displacement*=(-1.0);
X        direction=UP;
X      }
X  step=(int) floor(displacement);
X  fractional_step=UpShifted(displacement-(double) step);
X  if (fractional_step == 0)
X    {
X      /*
X        No fractional displacement-- just copy the pixels.
X      */
X      switch (direction)
X      {
X        case UP:
X        {
X          p=source_image+y*source_columns+column;
X          q=p-step*source_columns;
X          for (i=0; i < length; i++)
X          {
X            *q=(*p);
X            q+=source_columns;
X            p+=source_columns;
X          }
X          /*
X            Set old column to background color.
X          */
X          for (i=0; i < step; i++)
X          {
X            *q=background;
X            q+=source_columns;
X          }
X          break;
X        }
X        case DOWN:
X        {
X          p=source_image+(y+length)*source_columns+column;
X          q=p+step*source_columns;
X          for (i=0; i < length; i++)
X          {
X            q-=source_columns;
X            p-=source_columns;
X            *q=(*p);
X          }
X          /*
X            Set old column to background color.
X          */
X          for (i=0; i < step; i++)
X          {
X            q-=source_columns;
X            *q=background;
X          }
X          break;
X        }
X      }
X      return;
X    }
X  /*
X    Fractional displacment.
X  */
X  step++;
X  last_pixel=background;
X  switch (direction)
X  {
X    case UP:
X    {
X      p=source_image+y*source_columns+column;
X      q=p-step*source_columns;
X      for (i=0; i < length; i++)
X      {
X        red=DownShift(last_pixel.red*(UpShift(1)-fractional_step)+p->red*
X          fractional_step);
X        green=DownShift(last_pixel.green*(UpShift(1)-fractional_step)+p->green*
X          fractional_step);
X        blue=DownShift(last_pixel.blue*(UpShift(1)-fractional_step)+p->blue*
X          fractional_step);
X        last_pixel=(*p);
X        p+=source_columns;
X        q->red=range_limit[red];
X        q->green=range_limit[green];
X        q->blue=range_limit[blue];
X        q+=source_columns;
X      }
X      /*
X        Set old column to background color.
X      */
X      red=DownShift(last_pixel.red*(UpShift(1)-fractional_step)+
X        background.red*fractional_step);
X      green=DownShift(last_pixel.green*(UpShift(1)-fractional_step)+
X        background.green*fractional_step);
X      blue=DownShift(last_pixel.blue*(UpShift(1)-fractional_step)+
X        background.blue*fractional_step);
X      q->red=range_limit[red];
X      q->green=range_limit[green];
X      q->blue=range_limit[blue];
X      q+=source_columns;
X      for (i=0; i < step-1; i++)
X      {
X        *q=background;
X        q+=source_columns;
X      }
X      break;
X    }
X    case DOWN:
X    {
X      p=source_image+(y+length)*source_columns+column;
X      q=p+step*source_columns;
X      for (i=0; i < length; i++)
X      {
X        p-=source_columns;
X        red=DownShift(last_pixel.red*(UpShift(1)-fractional_step)+p->red*
X          fractional_step);
X        green=DownShift(last_pixel.green*(UpShift(1)-fractional_step)+p->green*
X          fractional_step);
X        blue=DownShift(last_pixel.blue*(UpShift(1)-fractional_step)+p->blue*
X          fractional_step);
X        last_pixel=(*p);
X        q-=source_columns;
X        q->red=range_limit[red];
X        q->green=range_limit[green];
X        q->blue=range_limit[blue];
X      }
X      /*
X        Set old column to background color.
X      */
X      red=DownShift(last_pixel.red*(UpShift(1)-fractional_step)+
X        background.red*fractional_step);
X      green=DownShift(last_pixel.green*(UpShift(1)-fractional_step)+
X        background.green*fractional_step);
X      blue=DownShift(last_pixel.blue*(UpShift(1)-fractional_step)+
X        background.blue*fractional_step);
X      q-=source_columns;
X      q->red=range_limit[red];
X      q->green=range_limit[green];
X      q->blue=range_limit[blue];
X      for (i=0; i < step-1; i++)
X      {
X        q-=source_columns;
X        *q=background;
X      }
X      break;
X    }
X  }
X  return;
}
X
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   I n t e g r a l R o t a t i o n                                           %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Function IntegralRotation rotates the source image starting at location
%  (x,y) an integral of 90 degrees and copies the result to the rotated image
%  buffer.
%
%  The format of the IntegralRotation routine is:
%
%      IntegralRotation(image,source_columns,source_rows,rotated_image,
%        rotated_columns,x,y,rotations)
%
%  A description of each parameter follows.
%
%    o source_image: A pointer to a Image structure containing the source
%      image.
%
%    o source_columns: Specifies the number of columns of pixels in the
%      source image.
%
%    o source_rows: Specifies the number of rows of pixels in the source
%      image.
%
%    o rotated_image: A pointer to a ColorPacket structure containing the
%      rotated image.
%
%    o rotated_columns: Specifies the number of columns of pixels in the
%      rotated image.
%
%    o x: Specifies the x offset in the source image.
%
%    o y: Specifies the y offset in the source image.
%
%    o rotations: Specifies the number of 90 degree rotations.
%
%
*/
static void IntegralRotation(image,source_columns,source_rows,rotated_image,
X  rotated_columns,x,y,rotations)
Image
X  *image;
X
unsigned int
X  source_columns,
X  source_rows;
X
ColorPacket
X  *rotated_image;
X
unsigned int
X  rotated_columns,
X  x,
X  y,
X  rotations;
{
X  ColorPacket
X    *q;
X
X  register RunlengthPacket
X    *p;
X
X  register int
X    i,
X    j;
X
X  /*
X    Expand runlength packets into a rectangular array of pixels.
X  */
X  p=image->pixels;
X  image->runlength=p->length+1;
X  switch (rotations)
X  {
X    case 0:
X    {
X      /*
X        Rotate 0 degrees.
X      */
X      for (j=0; j < source_rows; j++)
X      {
X        q=rotated_image+rotated_columns*(y+j)+x;
X        for (i=0; i < source_columns; i++)
X        {
X          if (image->runlength > 0)
X            image->runlength--;
X          else
X            {
X              p++;
X              image->runlength=p->length;
X            }
X          q->red=p->red;
X          q->green=p->green;
X          q->blue=p->blue;
X          q->index=p->index;
X          q++;
X        }
X      }
X      break;
X    }
X    case 1:
X    {
X      /*
X        Rotate 90 degrees.
X      */
X      for (j=source_columns-1; j >= 0; j--)
X      {
X        q=rotated_image+rotated_columns*y+x+j;
X        for (i=0; i < source_rows; i++)
X        {
X          if (image->runlength > 0)
X            image->runlength--;
X          else
X            {
X              p++;
X              image->runlength=p->length;
X            }
X          q->red=p->red;
X          q->green=p->green;
X          q->blue=p->blue;
X          q->index=p->index;
X          q+=rotated_columns;
X        }
X      }
X      break;
X    }
X    case 2:
X    {
X      /*
X        Rotate 180 degrees.
X      */
X      q=rotated_image;
X      for (j=source_rows-1; j >= 0; j--)
X      {
X        q=rotated_image+rotated_columns*(y+j)+x+source_columns;
X        for (i=0; i < source_columns; i++)
X        {
X          if (image->runlength > 0)
X            image->runlength--;
X          else
X            {
X              p++;
X              image->runlength=p->length;
X            }
X          q--;
X          q->red=p->red;
X          q->green=p->green;
X          q->blue=p->blue;
X          q->index=p->index;
X        }
X      }
X      break;
X    }
X    case 3:
X    {
X      /*
X        Rotate 270 degrees.
X      */
X      for (j=0; j < source_columns; j++)
X      {
X        q=rotated_image+rotated_columns*(y+source_rows)+x+j-rotated_columns;
X        for (i=0; i < source_rows; i++)
X        {
X          if (image->runlength > 0)
X            image->runlength--;
X          else
X            {
X              p++;
X              image->runlength=p->length;
X            }
X          q->red=p->red;
X          q->green=p->green;
X          q->blue=p->blue;
X          q->index=p->index;
X          q-=rotated_columns;
X        }
X      }
X      break;
X    }
X    default:
X      break;
X  }
}
X
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   R o w S h e a r                                                           %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Procedure RowShear displaces a subrow of pixels a specified number of
%  pixels.
%
%  The format of the RowShear routine is:
%
%      RowShear(source_image,source_columns,row,y,length,displacement,
%        background)
%
%  A description of each parameter follows.
%
%    o source_image: A pointer to a ColorPacket structure.
%
%    o source_columns: Specifies the number of columns in the source image.
%
%    o row: Specifies which row in the image to move.
%
%    o y: Specifies the offset in the source image.
%
%    o length: Specifies the number of pixels to move.
%
%    o displacement: Specifies the number of pixels to displace the row of
%      pixels.
%
%    o background: Specifies the background color.
%
%
*/
static void RowShear(source_image,source_columns,row,x,length,displacement,
X  background,range_limit)
ColorPacket
X  *source_image;
X
unsigned int
X  source_columns,
X  row,
X  x,
X  length;
X
double
X  displacement;
X
ColorPacket
X  background;
X
register unsigned char
X  *range_limit;
{
X  ColorPacket
X    last_pixel;
X
X  enum {LEFT,RIGHT}
X    direction;
X
X  int
X    blue,
X    green,
X    red,
X    step;
X
X  long int
X    fractional_step;
X
X  register ColorPacket
X    *p,
X    *q;
X
X  register int
X    i;
X
X  if (displacement == 0.0)
X    return;
X  else
X    if (displacement > 0.0)
X      direction=RIGHT;
X    else
X      {
X        displacement*=(-1.0);
X        direction=LEFT;
X      }
X  step=(int) floor(displacement);
X  fractional_step=UpShifted(displacement-(double) step);
X  if (fractional_step == 0)
X    {
X      /*
X        No fractional displacement-- just copy.
X      */
X      switch (direction)
X      {
X        case LEFT:
X        {
X          p=source_image+row*source_columns+x;
X          q=p-step;
X          for (i=0; i < length; i++)
X          {
X            *q=(*p);
X            q++;
X            p++;
X          }
X          /*
X            Set old row to background color.
X          */
X          for (i=0; i < step; i++)
X          {
X            *q=background;
X            q++;
X          }
X          break;
X        }
X        case RIGHT:
X        {
X          /*
X            Right is the same as left except data is transferred backwards
X            to prevent deleting data we need later.
X          */
X          p=source_image+row*source_columns+x+length;
X          q=p+step;
X          for (i=0; i < length; i++)
X          {
X            p--;
X            q--;
X            *q=(*p);
X          }
X          /*
X            Set old row to background color.
X          */
X          for (i=0; i < step; i++)
X          {
X            q--;
X            *q=background;
X          }
X          break;
X        }
X      }
X      return;
X    }
X  /*
X    Fractional displacement.
X  */
X  step++;
X  last_pixel=background;
X  switch (direction)
X  {
X    case LEFT:
X    {
X      p=source_image+row*source_columns+x;
X      q=p-step;
X      for (i=0; i < length; i++)
X      {
X        red=DownShift(last_pixel.red*(UpShift(1)-fractional_step)+p->red*
X          fractional_step);
X        green=DownShift(last_pixel.green*(UpShift(1)-fractional_step)+p->green*
X          fractional_step);
X        blue=DownShift(last_pixel.blue*(UpShift(1)-fractional_step)+p->blue*
X          fractional_step);
X        last_pixel=(*p);
X        p++;
X        q->red=range_limit[red];
X        q->green=range_limit[green];
X        q->blue=range_limit[blue];
X        q++;
X      }
X      /*
X        Set old row to background color.
X      */
X      red=DownShift(last_pixel.red*(UpShift(1)-fractional_step)+
X        background.red*fractional_step);
X      green=DownShift(last_pixel.green*(UpShift(1)-fractional_step)+
X        background.green*fractional_step);
X      blue=DownShift(last_pixel.blue*(UpShift(1)-fractional_step)+
X        background.blue*fractional_step);
X      q->red=range_limit[red];
X      q->green=range_limit[green];
X      q->blue=range_limit[blue];
X      q++;
X      for (i=0; i < step-1; i++)
X      {
X        *q=background;
X        q++;
X      }
X      break;
X    }
X    case RIGHT:
X    {
X      p=source_image+row*source_columns+x+length;
X      q=p+step;
X      for (i=0; i < length; i++)
X      {
X        p--;
X        red=DownShift(last_pixel.red*(UpShift(1)-fractional_step)+p->red*
X          fractional_step);
X        green=DownShift(last_pixel.green*(UpShift(1)-fractional_step)+p->green*
X          fractional_step);
X        blue=DownShift(last_pixel.blue*(UpShift(1)-fractional_step)+p->blue*
X          fractional_step);
X        last_pixel=(*p);
X        q--;
X        q->red=range_limit[red];
X        q->green=range_limit[green];
X        q->blue=range_limit[blue];
X      }
X      /*
X        Set old row to background color.
X      */
X      red=DownShift(last_pixel.red*(UpShift(1)-fractional_step)+
X        background.red*fractional_step);
X      green=DownShift(last_pixel.green*(UpShift(1)-fractional_step)+
X        background.green*fractional_step);
X      blue=DownShift(last_pixel.blue*(UpShift(1)-fractional_step)+
X        background.blue*fractional_step);
X      q--;
X      q->red=range_limit[red];
X      q->green=range_limit[green];
X      q->blue=range_limit[blue];
X      for (i=0; i < step-1; i++)
X      {
X        q--;
X        *q=background;
X      }
X      break;
X    }
X  }
X  return;
}
X
/*
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%   R o t a t e I m a g e                                                     %
%                                                                             %
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%
%  Function RotateImage creates a new image that is a rotated copy of an
%  existing one.  It allocates the memory necessary for the new Image structure %  and returns a pointer to the new image.
%
%  Function RotateImage is based on the paper "A Fast Algorithm for General
%  Raster Rotatation" by Alan W. Paeth.  RotateImage is adapted from a similiar
%  routine based on the Paeth paper written by Michael Halle of the Spatial
%  Imaging Group, MIT Media Lab.
%
%  The format of the RotateImage routine is:
%
%      RotateImage(image,degrees,clip)
%
%  A description of each parameter follows.
%
%    o status: Function RotateImage returns a pointer to the image after
%      rotating.  A null image is returned if there is a memory shortage.
%
%    o image: The address of a structure of type Image;  returned from
%      ReadImage.
%
%    o degrees: Specifies the number of degrees to rotate the image.
%
%    o clip: A value other than zero clips the corners of the rotated
%      image and retains the original image size.
%
%
*/
Image *RotateImage(image,degrees,clip)
Image
X  *image;
X
double
X  degrees;
X
int
X  clip;
{
#define DegreesToRadians(x) ((x)*3.14159265358979323846/180.0)
X
X  ColorPacket
X    background,
X    *rotated_pixels;
X
X  double
X    x_shear,
X    y_shear;
X
X  Image
X    *rotated_image;
X
X  register ColorPacket
X    *p;
X
X  register int
X    i,
X    x,
X    y;
X
X  register RunlengthPacket
X    *q;
X
X  unsigned int
X    number_rows,
X    number_columns,
X    rotations,
X    x_offset,
X    y_offset,
X    y_width;
X
X  /*
X    Adjust rotation angle.
X  */
X  while (degrees < -45.0)
X    degrees+=360.0;
X  rotations=0;
X  while (degrees > 45.0)
X  {
X    degrees-=90.0;
X    rotations++;
X  }
X  rotations%=4;
X  /*
X    Calculate shear equations.
X  */
X  x_shear=(-tan(DegreesToRadians(degrees)/2.0));
X  y_shear=sin(DegreesToRadians(degrees));
X  if ((rotations == 1) || (rotations == 3))
X    {
X      /*
X        Invert image size.
X      */
X      y_width=image->rows+
X        (int) ceil(fabs(x_shear)*(double) (image->columns-1));
X      number_columns=image->rows+2*
X        (int) ceil(fabs(x_shear)*(double) (image->columns-1));
X      number_rows=image->columns+
X        (int) ceil(fabs(y_shear)*(double) (y_width-1));
X      rotated_image=CopyImage(image,number_columns,number_rows,False);
X      if (rotated_image == (Image *) NULL)
X        {
X          Warning("unable to rotate image","memory allocation failed");
X          return((Image *) NULL);
X        }
X      rotated_image->columns=image->rows;
X      rotated_image->rows=image->columns;
X    }
X  else
X    {
X      y_width=image->columns+
X        (int) ceil(fabs(x_shear)*(double) (image->rows-1));
X      number_columns=image->columns+2*
X        (int) ceil(fabs(x_shear)*(double) (image->rows-1));
X      number_rows=image->rows+
X        (int) ceil(fabs(y_shear)*(double) (y_width-1));
X      rotated_image=CopyImage(image,number_columns,number_rows,False);
X      if (rotated_image == (Image *) NULL)
X        {
X          Warning("unable to rotate image","memory allocation failed");
X          return((Image *) NULL);
X        }
X      rotated_image->columns=image->columns;
X      rotated_image->rows=image->rows;
X    }
X  /*
X    Initialize rotated image attributes.
X  */
X  rotated_pixels=(ColorPacket *)
X    malloc(number_columns*(number_rows+2)*sizeof(ColorPacket));
X  if (rotated_pixels == (ColorPacket *) NULL)
X    {
X      Warning("unable to rotate image","memory allocation failed");
X      return((Image *) NULL);
X    }
X  if ((x_shear == 0.0) || (y_shear == 0.0))
X    {
X      /*
X        No shearing required; do integral rotation.
X      */
X      x_offset=0;
X      y_offset=0;
X      IntegralRotation(image,rotated_image->columns,rotated_image->rows,
X        rotated_pixels+number_columns,number_columns,x_offset,y_offset,
X        rotations);
X    }
X  else
X    {
X      typedef struct Point
X      {
X        double
X          x,
X          y;
X      } Point;
X
X      double
X        x_max,
X        x_min,
X        y_max,
X        y_min;
X
X      Point
X        corners[4];
X
X      unsigned char
X        *range_limit,
X        *range_table;
X
X      unsigned int
X        column,
X        row;
X
X      /*
X        Initialize rotated image buffer to background color.
X      */
X      rotated_image->class=DirectClass;
X      background.red=image->pixels[0].red;
X      background.green=image->pixels[0].green;
X      background.blue=image->pixels[0].blue;
X      p=rotated_pixels;
X      for (i=0; i < (number_columns*(number_rows+2)); i++)
X      {
X        *p=background;
X        p++;
X      }
X      /*
X        Perform an initial integral 90 degree rotation.
X      */
X      x_offset=(number_columns-rotated_image->columns)/2;
X      y_offset=(number_rows-rotated_image->rows)/2;
X      IntegralRotation(image,rotated_image->columns,rotated_image->rows,
X        rotated_pixels+number_columns,number_columns,x_offset,y_offset,
X        rotations);
X      /*
X        Initialize range table.
X      */
X      range_table=(unsigned char *) malloc(3*(MaxRGB+1)*sizeof(unsigned char));
X      if (range_table == (unsigned char *) NULL)
X        {
X          DestroyImage(rotated_image);
X          Warning("unable to rotate image","memory allocation failed");
X          return((Image *) NULL);
X        }
X      for (i=0; i <= MaxRGB; i++)
X      {
X        range_table[i]=0;
X        range_table[i+(MaxRGB+1)]=(unsigned char) i;
X        range_table[i+(MaxRGB+1)*2]=MaxRGB;
X      }
X      range_limit=range_table+(MaxRGB+1);
X      /*
X        Perform a fractional rotation.  First, shear the image rows.
X      */
X      row=(number_rows-rotated_image->rows)/2;
X      for (i=0; i < rotated_image->rows; i++)
X      {
X        RowShear(rotated_pixels+number_columns,number_columns,row,x_offset,
SHAR_EOF
true || echo 'restore of ImageMagick/rotate.c failed'
fi
echo 'End of  part 9'
echo 'File ImageMagick/rotate.c is continued in part 10'
echo 10 > _shar_seq_.tmp
exit 0
exit 0 # Just in case...