Main Page Class Hierarchy Alphabetical List Compound List Compound Members Related Pages
vtkImageToPolyDataFilter Class Reference
generate linear primitives (vtkPolyData) from an image.
More...
#include <vtkImageToPolyDataFilter.h>
Inheritance diagram for vtkImageToPolyDataFilter:
[legend]Collaboration diagram for vtkImageToPolyDataFilter:
[legend]List of all members.
Public Methods |
virtual const char * | GetClassName () |
virtual int | IsA (const char *type) |
void | PrintSelf (ostream &os, vtkIndent indent) |
virtual void | SetOutputStyle (int) |
virtual int | GetOutputStyle () |
void | SetOutputStyleToPixelize () |
void | SetOutputStyleToPolygonalize () |
void | SetOutputStyleToRunLength () |
virtual void | SetColorMode (int) |
virtual int | GetColorMode () |
void | SetColorModeToLUT () |
void | SetColorModeToLinear256 () |
virtual void | SetLookupTable (vtkScalarsToColors *) |
virtual vtkScalarsToColors * | GetLookupTable () |
virtual void | SetSmoothing (int) |
virtual int | GetSmoothing () |
virtual void | SmoothingOn () |
virtual void | SmoothingOff () |
virtual void | SetNumberOfSmoothingIterations (int) |
virtual int | GetNumberOfSmoothingIterations () |
virtual void | SetDecimation (int) |
virtual int | GetDecimation () |
virtual void | DecimationOn () |
virtual void | DecimationOff () |
virtual void | SetDecimationError (float) |
virtual float | GetDecimationError () |
virtual void | SetError (int) |
virtual int | GetError () |
virtual void | SetSubImageSize (int) |
virtual int | GetSubImageSize () |
Static Public Methods |
int | IsTypeOf (const char *type) |
vtkImageToPolyDataFilter * | SafeDownCast (vtkObject *o) |
vtkImageToPolyDataFilter * | New () |
Protected Methods |
| vtkImageToPolyDataFilter () |
| ~vtkImageToPolyDataFilter () |
| vtkImageToPolyDataFilter (const vtkImageToPolyDataFilter &) |
void | operator= (const vtkImageToPolyDataFilter &) |
void | Execute () |
virtual void | PixelizeImage (vtkUnsignedCharArray *pixels, int dims[3], float origin[3], float spacing[3], vtkPolyData *output) |
virtual void | PolygonalizeImage (vtkUnsignedCharArray *pixels, int dims[3], float origin[3], float spacing[3], vtkPolyData *output) |
virtual void | RunLengthImage (vtkUnsignedCharArray *pixels, int dims[3], float origin[3], float spacing[3], vtkPolyData *output) |
Protected Attributes |
int | OutputStyle |
int | ColorMode |
int | Smoothing |
int | NumberOfSmoothingIterations |
int | Decimation |
float | DecimationError |
int | Error |
int | SubImageSize |
vtkScalarsToColors * | LookupTable |
Detailed Description
generate linear primitives (vtkPolyData) from an image.
-
Date:
-
2000/12/10 20:08:24
-
Revision:
-
1.4
vtkImageToPolyDataFilter converts raster data (i.e., an image) into polygonal data (i.e., quads or n-sided polygons), with each polygon assigned a constant color. This is useful for writers that generate vector formats (i.e., CGM or PostScript). To use this filter, you specify how to quantize the color (or whether to use an image with a lookup table), and what style the output should be. The output is always polygons, but the choice is n x m quads (where n and m define the input image dimensions) "Pixelize" option; arbitrary polygons "Polygonalize" option; or variable number of quads of constant color generated along scan lines "RunLength" option.
The algorithm quantizes color in order to create coherent regions that the polygons can represent with good compression. By default, the input image is quantized to 256 colors using a 3-3-2 bits for red-green-blue. However, you can also supply a single component image and a lookup table, with the single component assumed to be an index into the table. (Note: a quantized image can be generated with the filter vtkImageQuantizeRGBToIndex.) The number of colors on output is equal to the number of colors in the input lookup table (or 256 if the built in linear ramp is used).
The output of the filter is polygons with a single color per polygon cell. If the output style is set to "Polygonalize", the polygons may have an large number of points (bounded by something like 2*(n+m)); and the polygon may not be convex which may cause rendering problems on some systems (use vtkTriangleFilter). Otherwise, each polygon will have four vertices. The output also contains scalar data defining RGB color in unsigned char form.
-
Warning:
-
The input linear lookup table must be of the form of 3-component unsigned char.
-
Warning:
-
This filter defines constant cell colors. If you have a plotting device that supports Gouraud shading (linear interpolation of color), then superior algorithms are available for generating polygons from images.
-
Warning:
-
Note that many plotting devices/formats support only a limited number of colors.
-
See also:
-
vtkCGMWriter vtkImageQuantizeRGBToIndex vtkTriangleFilter
-
Examples:
-
vtkImageToPolyDataFilter (examples)
Member Function Documentation
virtual const char* vtkImageToPolyDataFilter::GetClassName |
( |
|
) |
[virtual] |
|
virtual int vtkImageToPolyDataFilter::IsA |
( |
const char * |
type |
) |
[virtual] |
|
|
Return 1 if this class is the same type of (or a subclass of) the named class. Returns 0 otherwise. This method works in combination with vtkTypeMacro found in vtkSetGet.h.
Reimplemented from vtkStructuredPointsToPolyDataFilter. |
int vtkImageToPolyDataFilter::IsTypeOf |
( |
const char * |
type |
) |
[static] |
|
|
Return 1 if this class type is the same type of (or a subclass of) the named class. Returns 0 otherwise. This method works in combination with vtkTypeMacro found in vtkSetGet.h.
Reimplemented from vtkStructuredPointsToPolyDataFilter. |
vtkImageToPolyDataFilter* vtkImageToPolyDataFilter::New |
( |
|
) |
[inline, static] |
|
|
Instantiate object with initial number of colors 256.
Reimplemented from vtkPolyDataSource. |
void vtkImageToPolyDataFilter::PrintSelf |
( |
ostream & |
os, |
|
|
vtkIndent |
indent |
|
) |
[virtual] |
|
|
Methods invoked by print to print information about the object including superclasses. Typically not called by the user (use Print() instead) but used in the hierarchical print process to combine the output of several classes.
Reimplemented from vtkSource. |
vtkImageToPolyDataFilter* vtkImageToPolyDataFilter::SafeDownCast |
( |
vtkObject * |
o |
) |
[static] |
|
|
Will cast the supplied object to vtkObject* is this is a safe operation (i.e., a safe downcast); otherwise NULL is returned. This method is defined in all subclasses of vtkObject with the vtkTypeMacro found in vtkSetGet.h.
Reimplemented from vtkStructuredPointsToPolyDataFilter. |
virtual void vtkImageToPolyDataFilter::SetColorMode |
( |
int |
|
) |
[virtual] |
|
|
Specify how to quantize color. |
virtual void vtkImageToPolyDataFilter::SetDecimation |
( |
int |
|
) |
[virtual] |
|
|
Turn on/off whether the final polygons should be decimated. whether to smooth boundaries. |
virtual void vtkImageToPolyDataFilter::SetDecimationError |
( |
float |
|
) |
[virtual] |
|
|
Specify the error to use for decimation (if decimation is on). |
virtual void vtkImageToPolyDataFilter::SetError |
( |
int |
|
) |
[virtual] |
|
|
Specify the error value between two colors where the colors are considered the same. Only use this if the color mode uses the default 256 table. |
|
Set/Get the vtkLookupTable to use. The lookup table is used when the color mode is set to LUT and a single component scalar is input. |
virtual void vtkImageToPolyDataFilter::SetNumberOfSmoothingIterations |
( |
int |
|
) |
[virtual] |
|
|
Specify the number of smoothing iterations to smooth polygons. (Only in effect if output style is Polygonalize and smoothing is on.) |
virtual void vtkImageToPolyDataFilter::SetOutputStyle |
( |
int |
|
) |
[virtual] |
|
|
Specify how to create the output. Pixelize means converting the image to quad polygons with a constant color per quad. Polygonalize means merging colors together into polygonal regions, and then smoothing the regions (if smoothing is turned on). RunLength means creating quad polygons that may encompass several pixels on a scan line. The default behavior is Polygonalize. |
virtual void vtkImageToPolyDataFilter::SetSmoothing |
( |
int |
|
) |
[virtual] |
|
|
If the output style is set to polygonalize, then you can control whether to smooth boundaries. |
virtual void vtkImageToPolyDataFilter::SetSubImageSize |
( |
int |
|
) |
[virtual] |
|
|
Specify the size (n by n pixels) of the largest region to polygonalize. When the OutputStyle is set to VTK_STYLE_POLYGONALIZE, large amounts of memory are used. In order to process large images, the image is broken into pieces that are at most Size pixels in width and height. |
The documentation for this class was generated from the following file:
- vtkImageToPolyDataFilter.h
Generated on Tue Mar 19 13:27:07 2002 for VTK by
1.2.14 written by Dimitri van Heesch,
© 1997-2002