/*
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% %
% %
% %
% I s G r a y I m a g e %
% %
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%
% IsGrayImage() returns MagickTrue if all the pixels in the image have the
% same red, green, and blue intensities.
%
% The format of the IsGrayImage method is:
%
% MagickBooleanType IsGrayImage(const Image *image,
% ExceptionInfo *exception)
%
% A description of each parameter follows:
%
% o image: the image.
%
% o exception: return any errors or warnings in this structure.
%
*/
MagickExport MagickBooleanType IsGrayImage(const Image *image,
ExceptionInfo *exception)
{
CacheView
*image_view;
ImageType
type;
long
y;
register const PixelPacket
*p;
register long
x;
assert(image != (Image *) NULL);
assert(image->signature == MagickSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
if ((image->type == BilevelType) || (image->type == GrayscaleType) ||
(image->type == GrayscaleMatteType))
return(MagickTrue);
if (image->colorspace == CMYKColorspace)
return(MagickFalse);
type=BilevelType;
image_view=AcquireCacheView(image);
for (y=0; y < (long) image->rows; y++)
{
p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
if (p == (const PixelPacket *) NULL)
break;
for (x=0; x < (long) image->columns; x++)
{
if (IsGrayPixel(p) == MagickFalse)
{
type=UndefinedType;
break;
}
if ((type == BilevelType) && (IsMonochromePixel(p) == MagickFalse))
type=GrayscaleType;
p++;
}
if (type == UndefinedType)
break;
}
image_view=DestroyCacheView(image_view);
if (type == UndefinedType)
return(MagickFalse);
((Image *) image)->type=type;
if ((type == GrayscaleType) && (image->matte != MagickFalse))
((Image *) image)->type=GrayscaleMatteType;
return(MagickTrue);
}
MagickExport MagickBooleanType GradientImage(Image *image,
const GradientType type,const SpreadMethod method,
const PixelPacket *start_color,const PixelPacket *stop_color)
{
DrawInfo
*draw_info;
GradientInfo
*gradient;
MagickBooleanType
status;
register ssize_t
i;
/*
Set gradient start-stop end points.
*/
assert(image != (const Image *) NULL);
assert(image->signature == MagickSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
assert(start_color != (const PixelPacket *) NULL);
assert(stop_color != (const PixelPacket *) NULL);
draw_info=AcquireDrawInfo();
gradient=(&draw_info->gradient);
gradient->type=type;
gradient->bounding_box.width=image->columns;
gradient->bounding_box.height=image->rows;
gradient->gradient_vector.x2=(double) image->columns-1.0;
gradient->gradient_vector.y2=(double) image->rows-1.0;
if ((type == LinearGradient) && (gradient->gradient_vector.y2 != 0.0))
gradient->gradient_vector.x2=0.0;
gradient->center.x=(double) gradient->gradient_vector.x2/2.0;
gradient->center.y=(double) gradient->gradient_vector.y2/2.0;
gradient->radius=MagickMax(gradient->center.x,gradient->center.y);
gradient->spread=method;
/*
Define the gradient to fill between the stops.
*/
gradient->number_stops=2;
gradient->stops=(StopInfo *) AcquireQuantumMemory(gradient->number_stops,
sizeof(*gradient->stops));
if (gradient->stops == (StopInfo *) NULL)
ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
image->filename);
(void) ResetMagickMemory(gradient->stops,0,gradient->number_stops*
sizeof(*gradient->stops));
for (i=0; i < (ssize_t) gradient->number_stops; i++)
GetMagickPixelPacket(image,&gradient->stops[i].color);
SetMagickPixelPacket(image,start_color,(IndexPacket *) NULL,
&gradient->stops[0].color);
gradient->stops[0].offset=0.0;
SetMagickPixelPacket(image,stop_color,(IndexPacket *) NULL,
&gradient->stops[1].color);
gradient->stops[1].offset=1.0;
/*
Draw a gradient on the image.
*/
status=DrawGradientImage(image,draw_info);
draw_info=DestroyDrawInfo(draw_info);
if ((start_color->opacity == OpaqueOpacity) &&
(stop_color->opacity == OpaqueOpacity))
image->matte=MagickFalse;
if ((IsGrayPixel(start_color) != MagickFalse) &&
(IsGrayPixel(stop_color) != MagickFalse))
image->type=GrayscaleType;
return(status);
}
