% July 1992 %
% %
% %
-% Copyright 1999-2011 ImageMagick Studio LLC, a non-profit organization %
+% Copyright 1999-2012 ImageMagick Studio LLC, a non-profit organization %
% dedicated to making software imaging solutions freely available. %
% %
% You may not use this file except in compliance with the License. You may %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
-% The RotateImage, XShearImage, and YShearImage methods are based on the
-% paper "A Fast Algorithm for General Raster Rotatation" by Alan W. Paeth,
-% Graphics Interface '86 (Vancouver). RotateImage is adapted from a similar
+% The XShearImage() and YShearImage() methods are based on the paper "A Fast
+% Algorithm for General Raster Rotatation" by Alan W. Paeth, Graphics
+% Interface '86 (Vancouver). ShearRotateImage() is adapted from a similar
% method based on the Paeth paper written by Michael Halle of the Spatial
% Imaging Group, MIT Media Lab.
%
-%
*/
\f
/*
#include "MagickCore/list.h"
#include "MagickCore/monitor.h"
#include "MagickCore/monitor-private.h"
+#include "MagickCore/nt-base-private.h"
#include "MagickCore/pixel-accessor.h"
#include "MagickCore/quantum.h"
#include "MagickCore/resource_.h"
% %
% %
% %
-% A f f i n e T r a n s f o r m I m a g e %
-% %
-% %
-% %
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-%
-% AffineTransformImage() transforms an image as dictated by the affine matrix.
-% It allocates the memory necessary for the new Image structure and returns
-% a pointer to the new image.
-%
-% The format of the AffineTransformImage method is:
-%
-% Image *AffineTransformImage(const Image *image,
-% AffineMatrix *affine_matrix,ExceptionInfo *exception)
-%
-% A description of each parameter follows:
-%
-% o image: the image.
-%
-% o affine_matrix: the affine matrix.
-%
-% o exception: return any errors or warnings in this structure.
-%
-*/
-MagickExport Image *AffineTransformImage(const Image *image,
- const AffineMatrix *affine_matrix,ExceptionInfo *exception)
-{
- double
- distort[6];
-
- Image
- *deskew_image;
-
- /*
- Affine transform image.
- */
- assert(image->signature == MagickSignature);
- if (image->debug != MagickFalse)
- (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
- assert(affine_matrix != (AffineMatrix *) NULL);
- assert(exception != (ExceptionInfo *) NULL);
- assert(exception->signature == MagickSignature);
- distort[0]=affine_matrix->sx;
- distort[1]=affine_matrix->rx;
- distort[2]=affine_matrix->ry;
- distort[3]=affine_matrix->sy;
- distort[4]=affine_matrix->tx;
- distort[5]=affine_matrix->ty;
- deskew_image=DistortImage(image,AffineProjectionDistortion,6,distort,
- MagickTrue,exception);
- return(deskew_image);
-}
-\f
-/*
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-% %
-% %
-% %
+ C r o p T o F i t I m a g e %
% %
% %
q=swap;
}
#if defined(MAGICKCORE_OPENMP_SUPPORT)
- #pragma omp parallel for schedule(dynamic,4)
+ #pragma omp parallel for schedule(static,4)
#endif
for (x=0; x < (ssize_t) p->width; x++)
{
status=MagickTrue;
image_view=AcquireCacheView(image);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
- #pragma omp parallel for schedule(dynamic,4) shared(status)
+ #pragma omp parallel for schedule(static,4) shared(status)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
RadonProjection(source_cells,destination_cells,-1,projection);
(void) ResetRadonCells(source_cells);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
- #pragma omp parallel for schedule(dynamic,4) shared(status)
+ #pragma omp parallel for schedule(static,4) shared(status)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
clone_image=CloneImage(image,0,0,MagickTrue,exception);
if (clone_image == (Image *) NULL)
return((Image *) NULL);
- (void) SetImageVirtualPixelMethod(clone_image,BackgroundVirtualPixelMethod);
+ (void) SetImageVirtualPixelMethod(clone_image,BackgroundVirtualPixelMethod,
+ exception);
degrees=RadiansToDegrees(-atan((double) skew/width/8));
if (image->debug != MagickFalse)
(void) LogMagickEvent(TransformEvent,GetMagickModule(),
% %
% %
% %
-+ I n t e g r a l R o t a t e I m a g e %
+% I n t e g r a l R o t a t e I m a g e %
% %
% %
% %
% o rotations: Specifies the number of 90 degree rotations.
%
*/
-static Image *IntegralRotateImage(const Image *image,size_t rotations,
+MagickExport Image *IntegralRotateImage(const Image *image,size_t rotations,
ExceptionInfo *exception)
{
#define RotateImageTag "Rotate/Image"
Rotate 90 degrees.
*/
GetPixelCacheTileSize(image,&tile_width,&tile_height);
- tile_width=image->columns;
-#if defined(MAGICKCORE_OPENMP_SUPPORT)
- #pragma omp parallel for schedule(dynamic,4) shared(progress, status) omp_throttle(1)
+#if defined(MAGICKCORE_OPENMP_SUPPORT)
+ #pragma omp parallel for schedule(static,4) shared(progress,status)
#endif
for (tile_y=0; tile_y < (ssize_t) image->rows; tile_y+=(ssize_t) tile_height)
{
register ssize_t
i;
+ if (GetPixelMask(image,tile_pixels) != 0)
+ {
+ tile_pixels-=width*GetPixelChannels(image);
+ q+=GetPixelChannels(rotate_image);
+ continue;
+ }
for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
{
PixelChannel
rotate_traits,
traits;
- traits=GetPixelChannelMapTraits(image,(PixelChannel) i);
- channel=GetPixelChannelMapChannel(image,(PixelChannel) i);
+ channel=GetPixelChannelMapChannel(image,i);
+ traits=GetPixelChannelMapTraits(image,channel);
rotate_traits=GetPixelChannelMapTraits(rotate_image,channel);
if ((traits == UndefinedPixelTrait) ||
(rotate_traits == UndefinedPixelTrait))
/*
Rotate 180 degrees.
*/
-#if defined(MAGICKCORE_OPENMP_SUPPORT)
- #pragma omp parallel for schedule(dynamic,4) shared(progress,status) omp_throttle(1)
+#if defined(MAGICKCORE_OPENMP_SUPPORT)
+ #pragma omp parallel for schedule(static) shared(progress,status)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
i;
q-=GetPixelChannels(rotate_image);
+ if (GetPixelMask(image,p) != 0)
+ {
+ p+=GetPixelChannels(image);
+ continue;
+ }
for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
{
PixelChannel
rotate_traits,
traits;
- traits=GetPixelChannelMapTraits(image,(PixelChannel) i);
- channel=GetPixelChannelMapChannel(image,(PixelChannel) i);
+ channel=GetPixelChannelMapChannel(image,i);
+ traits=GetPixelChannelMapTraits(image,channel);
rotate_traits=GetPixelChannelMapTraits(rotate_image,channel);
if ((traits == UndefinedPixelTrait) ||
(rotate_traits == UndefinedPixelTrait))
Rotate 270 degrees.
*/
GetPixelCacheTileSize(image,&tile_width,&tile_height);
- tile_width=image->columns;
-#if defined(MAGICKCORE_OPENMP_SUPPORT)
- #pragma omp parallel for schedule(dynamic,4) shared(progress,status) omp_throttle(1)
+#if defined(MAGICKCORE_OPENMP_SUPPORT)
+ #pragma omp parallel for schedule(static,4) shared(progress,status)
#endif
for (tile_y=0; tile_y < (ssize_t) image->rows; tile_y+=(ssize_t) tile_height)
{
register ssize_t
i;
+ if (GetPixelMask(image,tile_pixels) != 0)
+ {
+ tile_pixels+=width*GetPixelChannels(image);
+ q+=GetPixelChannels(rotate_image);
+ continue;
+ }
for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
{
PixelChannel
rotate_traits,
traits;
- traits=GetPixelChannelMapTraits(image,(PixelChannel) i);
- channel=GetPixelChannelMapChannel(image,(PixelChannel) i);
+ channel=GetPixelChannelMapChannel(image,i);
+ traits=GetPixelChannelMapTraits(image,channel);
rotate_traits=GetPixelChannelMapTraits(rotate_image,channel);
if ((traits == UndefinedPixelTrait) ||
(rotate_traits == UndefinedPixelTrait))
ssize_t
y;
+ /*
+ X shear image.
+ */
assert(image != (Image *) NULL);
assert(image->signature == MagickSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
- GetPixelInfo(image,&background);
- SetPixelInfoPacket(image,&image->background_color,&background);
- if (image->colorspace == CMYKColorspace)
- ConvertRGBToCMYK(&background);
- /*
- X shear image.
- */
status=MagickTrue;
+ background=image->background_color;
progress=0;
image_view=AcquireCacheView(image);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
- #pragma omp parallel for schedule(dynamic,4) shared(progress, status)
+ #pragma omp parallel for schedule(static,4) shared(progress,status)
#endif
for (y=0; y < (ssize_t) height; y++)
{
if ((x_offset+i) < step)
{
p+=GetPixelChannels(image);
- SetPixelInfo(image,p,&pixel);
+ GetPixelInfoPixel(image,p,&pixel);
q+=GetPixelChannels(image);
continue;
}
- SetPixelInfo(image,p,&source);
+ GetPixelInfoPixel(image,p,&source);
CompositePixelInfoAreaBlend(&pixel,(MagickRealType) pixel.alpha,
&source,(MagickRealType) GetPixelAlpha(image,p),area,&destination);
- SetPixelPixelInfo(image,&destination,q);
- SetPixelInfo(image,p,&pixel);
+ SetPixelInfoPixel(image,&destination,q);
+ GetPixelInfoPixel(image,p,&pixel);
p+=GetPixelChannels(image);
q+=GetPixelChannels(image);
}
CompositePixelInfoAreaBlend(&pixel,(MagickRealType) pixel.alpha,
&background,(MagickRealType) background.alpha,area,&destination);
- SetPixelPixelInfo(image,&destination,q);
+ SetPixelInfoPixel(image,&destination,q);
q+=GetPixelChannels(image);
for (i=0; i < (step-1); i++)
{
- SetPixelPixelInfo(image,&background,q);
+ SetPixelInfoPixel(image,&background,q);
q+=GetPixelChannels(image);
}
break;
q-=GetPixelChannels(image);
if ((size_t) (x_offset+width+step-i) >= image->columns)
continue;
- SetPixelInfo(image,p,&source);
+ GetPixelInfoPixel(image,p,&source);
CompositePixelInfoAreaBlend(&pixel,(MagickRealType) pixel.alpha,
&source,(MagickRealType) GetPixelAlpha(image,p),area,&destination);
- SetPixelPixelInfo(image,&destination,q);
- SetPixelInfo(image,p,&pixel);
+ SetPixelInfoPixel(image,&destination,q);
+ GetPixelInfoPixel(image,p,&pixel);
}
CompositePixelInfoAreaBlend(&pixel,(MagickRealType) pixel.alpha,
&background,(MagickRealType) background.alpha,area,&destination);
q-=GetPixelChannels(image);
- SetPixelPixelInfo(image,&destination,q);
+ SetPixelInfoPixel(image,&destination,q);
for (i=0; i < (step-1); i++)
{
q-=GetPixelChannels(image);
- SetPixelPixelInfo(image,&background,q);
+ SetPixelInfoPixel(image,&background,q);
}
break;
}
ssize_t
x;
+ /*
+ Y Shear image.
+ */
assert(image != (Image *) NULL);
assert(image->signature == MagickSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
- GetPixelInfo(image,&background);
- SetPixelInfoPacket(image,&image->background_color,&background);
- if (image->colorspace == CMYKColorspace)
- ConvertRGBToCMYK(&background);
- /*
- Y Shear image.
- */
status=MagickTrue;
progress=0;
+ background=image->background_color;
image_view=AcquireCacheView(image);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
- #pragma omp parallel for schedule(dynamic,4) shared(progress, status)
+ #pragma omp parallel for schedule(static,4) shared(progress,status)
#endif
for (x=0; x < (ssize_t) width; x++)
{
if ((y_offset+i) < step)
{
p+=GetPixelChannels(image);
- SetPixelInfo(image,p,&pixel);
+ GetPixelInfoPixel(image,p,&pixel);
q+=GetPixelChannels(image);
continue;
}
- SetPixelInfo(image,p,&source);
+ GetPixelInfoPixel(image,p,&source);
CompositePixelInfoAreaBlend(&pixel,(MagickRealType) pixel.alpha,
&source,(MagickRealType) GetPixelAlpha(image,p),area,
&destination);
- SetPixelPixelInfo(image,&destination,q);
- SetPixelInfo(image,p,&pixel);
+ SetPixelInfoPixel(image,&destination,q);
+ GetPixelInfoPixel(image,p,&pixel);
p+=GetPixelChannels(image);
q+=GetPixelChannels(image);
}
CompositePixelInfoAreaBlend(&pixel,(MagickRealType) pixel.alpha,
&background,(MagickRealType) background.alpha,area,&destination);
- SetPixelPixelInfo(image,&destination,q);
+ SetPixelInfoPixel(image,&destination,q);
q+=GetPixelChannels(image);
for (i=0; i < (step-1); i++)
{
- SetPixelPixelInfo(image,&background,q);
+ SetPixelInfoPixel(image,&background,q);
q+=GetPixelChannels(image);
}
break;
q-=GetPixelChannels(image);
if ((size_t) (y_offset+height+step-i) >= image->rows)
continue;
- SetPixelInfo(image,p,&source);
+ GetPixelInfoPixel(image,p,&source);
CompositePixelInfoAreaBlend(&pixel,(MagickRealType) pixel.alpha,
&source,(MagickRealType) GetPixelAlpha(image,p),area,
&destination);
- SetPixelPixelInfo(image,&destination,q);
- SetPixelInfo(image,p,&pixel);
+ SetPixelInfoPixel(image,&destination,q);
+ GetPixelInfoPixel(image,p,&pixel);
}
CompositePixelInfoAreaBlend(&pixel,(MagickRealType) pixel.alpha,
&background,(MagickRealType) background.alpha,area,&destination);
q-=GetPixelChannels(image);
- SetPixelPixelInfo(image,&destination,q);
+ SetPixelInfoPixel(image,&destination,q);
for (i=0; i < (step-1); i++)
{
q-=GetPixelChannels(image);
- SetPixelPixelInfo(image,&background,q);
+ SetPixelInfoPixel(image,&background,q);
}
break;
}
% %
% %
% %
-% R o t a t e I m a g e %
+% S h e a r I m a g e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
-% RotateImage() creates a new image that is a rotated copy of an existing
-% one. Positive angles rotate counter-clockwise (right-hand rule), while
-% negative angles rotate clockwise. Rotated images are usually larger than
-% the originals and have 'empty' triangular corners. X axis. Empty
-% triangles left over from shearing the image are filled with the background
-% color defined by member 'background_color' of the image. RotateImage
-% allocates the memory necessary for the new Image structure and returns a
-% pointer to the new image.
+% ShearImage() creates a new image that is a shear_image copy of an existing
+% one. Shearing slides one edge of an image along the X or Y axis, creating
+% a parallelogram. An X direction shear slides an edge along the X axis,
+% while a Y direction shear slides an edge along the Y axis. The amount of
+% the shear is controlled by a shear angle. For X direction shears, x_shear
+% is measured relative to the Y axis, and similarly, for Y direction shears
+% y_shear is measured relative to the X axis. Empty triangles left over from
+% shearing the image are filled with the background color defined by member
+% 'background_color' of the image.. ShearImage() allocates the memory
+% necessary for the new Image structure and returns a pointer to the new image.
%
-% RotateImage() is based on the paper "A Fast Algorithm for General
-% Raster Rotatation" by Alan W. Paeth. RotateImage is adapted from a similar
-% method based on the Paeth paper written by Michael Halle of the Spatial
-% Imaging Group, MIT Media Lab.
+% ShearImage() is based on the paper "A Fast Algorithm for General Raster
+% Rotatation" by Alan W. Paeth.
%
-% The format of the RotateImage method is:
+% The format of the ShearImage method is:
%
-% Image *RotateImage(const Image *image,const double degrees,
-% ExceptionInfo *exception)
+% Image *ShearImage(const Image *image,const double x_shear,
+% const double y_shear,ExceptionInfo *exception)
%
% A description of each parameter follows.
%
% o image: the image.
%
-% o degrees: Specifies the number of degrees to rotate the image.
+% o x_shear, y_shear: Specifies the number of degrees to shear the image.
%
% o exception: return any errors or warnings in this structure.
%
*/
-MagickExport Image *RotateImage(const Image *image,const double degrees,
- ExceptionInfo *exception)
+MagickExport Image *ShearImage(const Image *image,const double x_shear,
+ const double y_shear,ExceptionInfo *exception)
{
Image
*integral_image,
- *rotate_image;
+ *shear_image;
+
+ ssize_t
+ x_offset,
+ y_offset;
MagickBooleanType
status;
- MagickRealType
- angle;
-
PointInfo
shear;
border_info;
size_t
- height,
- rotations,
- width,
y_width;
- ssize_t
- x_offset,
- y_offset;
-
- /*
- Adjust rotation angle.
- */
assert(image != (Image *) NULL);
assert(image->signature == MagickSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
assert(exception != (ExceptionInfo *) NULL);
assert(exception->signature == MagickSignature);
- angle=degrees;
- while (angle < -45.0)
- angle+=360.0;
- for (rotations=0; angle > 45.0; rotations++)
- angle-=90.0;
- rotations%=4;
+ if ((x_shear != 0.0) && (fmod(x_shear,90.0) == 0.0))
+ ThrowImageException(ImageError,"AngleIsDiscontinuous");
+ if ((y_shear != 0.0) && (fmod(y_shear,90.0) == 0.0))
+ ThrowImageException(ImageError,"AngleIsDiscontinuous");
/*
- Calculate shear equations.
+ Initialize shear angle.
*/
- integral_image=IntegralRotateImage(image,rotations,exception);
+ integral_image=CloneImage(image,0,0,MagickTrue,exception);
if (integral_image == (Image *) NULL)
ThrowImageException(ResourceLimitError,"MemoryAllocationFailed");
- shear.x=(-tan((double) DegreesToRadians(angle)/2.0));
- shear.y=sin((double) DegreesToRadians(angle));
+ shear.x=(-tan(DegreesToRadians(fmod(x_shear,360.0))));
+ shear.y=tan(DegreesToRadians(fmod(y_shear,360.0)));
if ((shear.x == 0.0) && (shear.y == 0.0))
return(integral_image);
if (SetImageStorageClass(integral_image,DirectClass,exception) == MagickFalse)
/*
Compute image size.
*/
- width=image->columns;
- height=image->rows;
- if ((rotations == 1) || (rotations == 3))
- {
- width=image->rows;
- height=image->columns;
- }
- y_width=width+(ssize_t) floor(fabs(shear.x)*height+0.5);
- x_offset=(ssize_t) ceil((double) width+((fabs(shear.y)*height)-width)/2.0-
- 0.5);
- y_offset=(ssize_t) ceil((double) height+((fabs(shear.y)*y_width)-height)/2.0-
- 0.5);
+ y_width=image->columns+(ssize_t) floor(fabs(shear.x)*image->rows+0.5);
+ x_offset=(ssize_t) ceil((double) image->columns+((fabs(shear.x)*image->rows)-
+ image->columns)/2.0-0.5);
+ y_offset=(ssize_t) ceil((double) image->rows+((fabs(shear.y)*y_width)-
+ image->rows)/2.0-0.5);
/*
- Surround image with a border.
+ Surround image with border.
*/
integral_image->border_color=integral_image->background_color;
integral_image->compose=CopyCompositeOp;
border_info.width=(size_t) x_offset;
border_info.height=(size_t) y_offset;
- rotate_image=BorderImage(integral_image,&border_info,image->compose,
- exception);
+ shear_image=BorderImage(integral_image,&border_info,image->compose,exception);
integral_image=DestroyImage(integral_image);
- if (rotate_image == (Image *) NULL)
+ if (shear_image == (Image *) NULL)
ThrowImageException(ResourceLimitError,"MemoryAllocationFailed");
/*
- Rotate the image.
+ Shear the image.
*/
- status=XShearImage(rotate_image,shear.x,width,height,x_offset,(ssize_t)
- (rotate_image->rows-height)/2,exception);
- if (status == MagickFalse)
- {
- rotate_image=DestroyImage(rotate_image);
- return((Image *) NULL);
- }
- status=YShearImage(rotate_image,shear.y,y_width,height,(ssize_t)
- (rotate_image->columns-y_width)/2,y_offset,exception);
+ if (shear_image->matte == MagickFalse)
+ (void) SetImageAlphaChannel(shear_image,OpaqueAlphaChannel,exception);
+ status=XShearImage(shear_image,shear.x,image->columns,image->rows,x_offset,
+ (ssize_t) (shear_image->rows-image->rows)/2,exception);
if (status == MagickFalse)
{
- rotate_image=DestroyImage(rotate_image);
+ shear_image=DestroyImage(shear_image);
return((Image *) NULL);
}
- status=XShearImage(rotate_image,shear.x,y_width,rotate_image->rows,(ssize_t)
- (rotate_image->columns-y_width)/2,0,exception);
+ status=YShearImage(shear_image,shear.y,y_width,image->rows,(ssize_t)
+ (shear_image->columns-y_width)/2,y_offset,exception);
if (status == MagickFalse)
{
- rotate_image=DestroyImage(rotate_image);
+ shear_image=DestroyImage(shear_image);
return((Image *) NULL);
}
- status=CropToFitImage(&rotate_image,shear.x,shear.y,(MagickRealType) width,
- (MagickRealType) height,MagickTrue,exception);
+ status=CropToFitImage(&shear_image,shear.x,shear.y,(MagickRealType)
+ image->columns,(MagickRealType) image->rows,MagickFalse,exception);
if (status == MagickFalse)
{
- rotate_image=DestroyImage(rotate_image);
+ shear_image=DestroyImage(shear_image);
return((Image *) NULL);
}
- rotate_image->compose=image->compose;
- rotate_image->page.width=0;
- rotate_image->page.height=0;
- return(rotate_image);
+ shear_image->compose=image->compose;
+ shear_image->page.width=0;
+ shear_image->page.height=0;
+ return(shear_image);
}
\f
/*
% %
% %
% %
-% S h e a r I m a g e %
+% S h e a r R o t a t e I m a g e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
-% ShearImage() creates a new image that is a shear_image copy of an existing
-% one. Shearing slides one edge of an image along the X or Y axis, creating
-% a parallelogram. An X direction shear slides an edge along the X axis,
-% while a Y direction shear slides an edge along the Y axis. The amount of
-% the shear is controlled by a shear angle. For X direction shears, x_shear
-% is measured relative to the Y axis, and similarly, for Y direction shears
-% y_shear is measured relative to the X axis. Empty triangles left over from
-% shearing the image are filled with the background color defined by member
-% 'background_color' of the image.. ShearImage() allocates the memory
-% necessary for the new Image structure and returns a pointer to the new image.
+% ShearRotateImage() creates a new image that is a rotated copy of an existing
+% one. Positive angles rotate counter-clockwise (right-hand rule), while
+% negative angles rotate clockwise. Rotated images are usually larger than
+% the originals and have 'empty' triangular corners. X axis. Empty
+% triangles left over from shearing the image are filled with the background
+% color defined by member 'background_color' of the image. ShearRotateImage
+% allocates the memory necessary for the new Image structure and returns a
+% pointer to the new image.
%
-% ShearImage() is based on the paper "A Fast Algorithm for General Raster
-% Rotatation" by Alan W. Paeth.
+% ShearRotateImage() is based on the paper "A Fast Algorithm for General
+% Raster Rotatation" by Alan W. Paeth. ShearRotateImage is adapted from a
+% similar method based on the Paeth paper written by Michael Halle of the
+% Spatial Imaging Group, MIT Media Lab.
%
-% The format of the ShearImage method is:
+% The format of the ShearRotateImage method is:
%
-% Image *ShearImage(const Image *image,const double x_shear,
-% const double y_shear,ExceptionInfo *exception)
+% Image *ShearRotateImage(const Image *image,const double degrees,
+% ExceptionInfo *exception)
%
% A description of each parameter follows.
%
% o image: the image.
%
-% o x_shear, y_shear: Specifies the number of degrees to shear the image.
+% o degrees: Specifies the number of degrees to rotate the image.
%
% o exception: return any errors or warnings in this structure.
%
*/
-MagickExport Image *ShearImage(const Image *image,const double x_shear,
- const double y_shear,ExceptionInfo *exception)
+MagickExport Image *ShearRotateImage(const Image *image,const double degrees,
+ ExceptionInfo *exception)
{
Image
*integral_image,
- *shear_image;
-
- ssize_t
- x_offset,
- y_offset;
+ *rotate_image;
MagickBooleanType
status;
+ MagickRealType
+ angle;
+
PointInfo
shear;
border_info;
size_t
+ height,
+ rotations,
+ width,
y_width;
+ ssize_t
+ x_offset,
+ y_offset;
+
+ /*
+ Adjust rotation angle.
+ */
assert(image != (Image *) NULL);
assert(image->signature == MagickSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
assert(exception != (ExceptionInfo *) NULL);
assert(exception->signature == MagickSignature);
- if ((x_shear != 0.0) && (fmod(x_shear,90.0) == 0.0))
- ThrowImageException(ImageError,"AngleIsDiscontinuous");
- if ((y_shear != 0.0) && (fmod(y_shear,90.0) == 0.0))
- ThrowImageException(ImageError,"AngleIsDiscontinuous");
+ angle=degrees;
+ while (angle < -45.0)
+ angle+=360.0;
+ for (rotations=0; angle > 45.0; rotations++)
+ angle-=90.0;
+ rotations%=4;
/*
- Initialize shear angle.
+ Calculate shear equations.
*/
- integral_image=CloneImage(image,0,0,MagickTrue,exception);
+ integral_image=IntegralRotateImage(image,rotations,exception);
if (integral_image == (Image *) NULL)
ThrowImageException(ResourceLimitError,"MemoryAllocationFailed");
- shear.x=(-tan(DegreesToRadians(fmod(x_shear,360.0))));
- shear.y=tan(DegreesToRadians(fmod(y_shear,360.0)));
+ shear.x=(-tan((double) DegreesToRadians(angle)/2.0));
+ shear.y=sin((double) DegreesToRadians(angle));
if ((shear.x == 0.0) && (shear.y == 0.0))
return(integral_image);
if (SetImageStorageClass(integral_image,DirectClass,exception) == MagickFalse)
/*
Compute image size.
*/
- y_width=image->columns+(ssize_t) floor(fabs(shear.x)*image->rows+0.5);
- x_offset=(ssize_t) ceil((double) image->columns+((fabs(shear.x)*image->rows)-
- image->columns)/2.0-0.5);
- y_offset=(ssize_t) ceil((double) image->rows+((fabs(shear.y)*y_width)-
- image->rows)/2.0-0.5);
+ width=image->columns;
+ height=image->rows;
+ if ((rotations == 1) || (rotations == 3))
+ {
+ width=image->rows;
+ height=image->columns;
+ }
+ y_width=width+(ssize_t) floor(fabs(shear.x)*height+0.5);
+ x_offset=(ssize_t) ceil((double) width+((fabs(shear.y)*height)-width)/2.0-
+ 0.5);
+ y_offset=(ssize_t) ceil((double) height+((fabs(shear.y)*y_width)-height)/2.0-
+ 0.5);
/*
- Surround image with border.
+ Surround image with a border.
*/
integral_image->border_color=integral_image->background_color;
integral_image->compose=CopyCompositeOp;
border_info.width=(size_t) x_offset;
border_info.height=(size_t) y_offset;
- shear_image=BorderImage(integral_image,&border_info,image->compose,exception);
+ rotate_image=BorderImage(integral_image,&border_info,image->compose,
+ exception);
integral_image=DestroyImage(integral_image);
- if (shear_image == (Image *) NULL)
+ if (rotate_image == (Image *) NULL)
ThrowImageException(ResourceLimitError,"MemoryAllocationFailed");
/*
- Shear the image.
+ Rotate the image.
*/
- if (shear_image->matte == MagickFalse)
- (void) SetImageAlphaChannel(shear_image,OpaqueAlphaChannel,exception);
- status=XShearImage(shear_image,shear.x,image->columns,image->rows,x_offset,
- (ssize_t) (shear_image->rows-image->rows)/2,exception);
+ status=XShearImage(rotate_image,shear.x,width,height,x_offset,(ssize_t)
+ (rotate_image->rows-height)/2,exception);
if (status == MagickFalse)
{
- shear_image=DestroyImage(shear_image);
+ rotate_image=DestroyImage(rotate_image);
return((Image *) NULL);
}
- status=YShearImage(shear_image,shear.y,y_width,image->rows,(ssize_t)
- (shear_image->columns-y_width)/2,y_offset,exception);
+ status=YShearImage(rotate_image,shear.y,y_width,height,(ssize_t)
+ (rotate_image->columns-y_width)/2,y_offset,exception);
if (status == MagickFalse)
{
- shear_image=DestroyImage(shear_image);
+ rotate_image=DestroyImage(rotate_image);
return((Image *) NULL);
}
- status=CropToFitImage(&shear_image,shear.x,shear.y,(MagickRealType)
- image->columns,(MagickRealType) image->rows,MagickFalse,exception);
+ status=XShearImage(rotate_image,shear.x,y_width,rotate_image->rows,(ssize_t)
+ (rotate_image->columns-y_width)/2,0,exception);
if (status == MagickFalse)
{
- shear_image=DestroyImage(shear_image);
+ rotate_image=DestroyImage(rotate_image);
return((Image *) NULL);
}
- shear_image->compose=image->compose;
- shear_image->page.width=0;
- shear_image->page.height=0;
- return(shear_image);
+ status=CropToFitImage(&rotate_image,shear.x,shear.y,(MagickRealType) width,
+ (MagickRealType) height,MagickTrue,exception);
+ if (status == MagickFalse)
+ {
+ rotate_image=DestroyImage(rotate_image);
+ return((Image *) NULL);
+ }
+ rotate_image->compose=image->compose;
+ rotate_image->page.width=0;
+ rotate_image->page.height=0;
+ return(rotate_image);
}
projects / imagemagick / blobdiff