Class PDFDraw

PDFDraw contains methods for converting PDF pages to images and to Bitmap objects. Utility methods are provided to export PDF pages to various raster formats as well as to convert pages to GDI+ bitmaps for further manipulation or drawing.

Inheritance

object

PDFDraw

Implements

IDisposable

Inherited Members

object.ToString()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

Namespace: pdftron.PDF

Assembly: PDFNet.dll

Syntax

public class PDFDraw : IDisposable

Remarks

This class is available on all platforms supported by PDFNet.

Constructors

PDFDraw()

PDFDraw constructor and destructor.

Declaration

public PDFDraw()

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

PDFDraw(double)

Instantiates a new pDF draw.

Declaration

public PDFDraw(double dpi)

Parameters

Type	Name	Description
double	dpi	the dpi

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

Methods

Dispose()

Releases all resources used by the PDFDraw

Declaration

public override sealed void Dispose()

Dispose(bool)

Declaration

[HandleProcessCorruptedStateExceptions]
protected virtual void Dispose(bool A_0)

Parameters

Type	Name	Description
bool	A_0

DrawInRect(Page, Graphics, Rect)

Draws the contents of the page to a given Graphics object.

Declaration

public void DrawInRect(Page page, Graphics gr, Rect rect)

Parameters

Type	Name	Description
Page	page	The source PDF page.
Graphics	gr	Device context
Rect	rect	The rectangle in the device context inside of which the page will be drawn.

Remarks

this method is only supported on Windows platforms. If your application is running on a Windows platform, you can select GDI+ rasterizer with SetRasterizerType() and e_GDIPlus type.

DrawInRect(Page, IntPtr, Rect)

Draws the contents of the page to a given Graphics object.

Declaration

public void DrawInRect(Page page, IntPtr dc, Rect rect)

Parameters

Type	Name	Description
Page	page	The source PDF page.
IntPtr	dc	Device context (i.e. HDC structure).
Rect	rect	The rectangle in the device context inside of which the page will be drawn.

Remarks

this method is only supported on Windows platforms. If your application is running on a Windows platform, you can select GDI+ rasterizer with SetRasterizerType() and e_GDIPlus type.

Export(Page, string)

A utility method to export the given PDF page to an image file.

Declaration

public void Export(Page page, string filename)

Parameters

Type	Name	Description
Page	page	The source PDF page.
string	filename	The name of the output image file. The filename should include the extension suffix (e.g. 'c:/output/myimage.png').

Remarks

By default, the function exports to PNG.. The file format of the output image. Currently supported formats are:

• RAW format. There are four possibilities: e_rgba - if transparent and color page; e_gray_alpha - if transparent and gray page; e_rgb - if opaque and color page; e_gray - if opaque and gray page.
• Bitmap image format (BMP)
• Joint Photographic Experts Group (JPEG) image format
• 24-bit W3C Portable Network Graphics (PNG) image format
• 8-bit, palettized PNG format. The exported file size should be smaller than the one generated using "PNG", possibly at the expense of some image quality.
• Tag Image File Format (TIFF) image format.
• Tag Image File Format (TIFF) image format (with 8-bit pallete).

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

Export(Page, string, string)

Export.

Declaration

public void Export(Page page, string filename, string format)

Parameters

Type	Name	Description
Page	page	the page
string	filename	the filename
string	format	the format

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

Export(Page, string, string, Obj)

Export.

Declaration

public void Export(Page page, string filename, string format, Obj encoder_hints)

Parameters

Type	Name	Description
Page	page	the page
string	filename	the filename
string	format	the format
Obj	encoder_hints	the encoder_params

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

~PDFDraw()

Declaration

protected ~PDFDraw()

GetBitmap(byte*, int, int, int, double, PixelFormat)

Gets the bitmap.

Declaration

public static Bitmap GetBitmap(byte* buf, int width, int height, int stride, double dpi, PixelFormat pixfmt)

Parameters

Type	Name	Description
byte*	buf	An unmanaged buffer of image data
int	width	Width of buf
int	height	Height of buf
int	stride	Stride of buf
double	dpi	Resolution of buf
PixelFormat	pixfmt	Pixel format of buf

Returns

Type	Description
Bitmap	the bitmap

GetBitmap(Page)

Gets the bitmap.

Declaration

public Bitmap GetBitmap(Page page)

Parameters

Type	Name	Description
Page	page	the page

Returns

Type	Description
Bitmap	the bitmap

GetBitmapSource(Page)

Gets the bitmap. (WPF BitmapSource)

Declaration

public BitmapSource GetBitmapSource(Page page)

Parameters

Type	Name	Description
Page	page	the page

Returns

Type	Description
BitmapSource	the bitmap (WPF BitmapSource)

GetSeparationBitmaps(Page)

Gets the Separations from the page

Declaration

public Separation[] GetSeparationBitmaps(Page page)

Parameters

Type	Name	Description
Page	page	the page

Returns

Type	Description
Separation[]	Separations array

SetAntiAliasing(bool)

Enable or disable anti-aliasing. Anti-Aliasing is a technique used to improve the visual quality of images when displaying them on low resolution devices (for example, low DPI computer monitors). Anti-aliasing is enabled by default.

Declaration

public void SetAntiAliasing(bool enable_aa)

Parameters

Type	Name	Description
bool	enable_aa	whether to enable anti-aliasing

SetCaching(bool)

Sets the caching.

Declaration

public void SetCaching(bool enabled)

Parameters

Type	Name	Description
bool	enabled	the new caching

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

SetClipRect(Rect)

Clip the render region to the provided rect (in page space)

Declaration

public void SetClipRect(Rect clip_rect)

Parameters

Type	Name	Description
Rect	clip_rect	Clipping rect. By default, PDFDraw will rasterize the entire page box.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

SetColorPostProcessMode(ColorPostProcessMode)

Draws the page into a given memory buffer. Set the color post processing transformation. This transform is applied to the rasterized bitmap as the final step in the rasterization process, and is applied directly to the resulting bitmap (disregarding any color space information). Color post processing only supported for RGBA output.

Declaration

public void SetColorPostProcessMode(PDFRasterizer.ColorPostProcessMode mode)

Parameters

Type	Name	Description
PDFRasterizer.ColorPostProcessMode	mode	mode is the specific transform to be applied.

SetDPI(double)

Sets the output image resolution.

DPI stands for Dots Per Inch. This parameter is used to specify the output image size and quality. A typical screen resolution for monitors these days is 92 DPI, but printers could use 200 DPI or more.

Declaration

public void SetDPI(double dpi)

Parameters

Type	Name	Description
double	dpi	the new dPI

Remarks

            <p>The size of resulting image is a function of DPI and the dimensions of 

the source PDF page. For example, is DPI is 92 and page is 8 inches wide, the output bitmap will have 92*8 = 736 pixels per line. If you know the dimensions of the destination bitmap, but don't care about DPI of the image you can use pdfdraw.SetImageSize() instead.

if you would like to rasterize extremely large bitmaps (e.g. with resolutions of 2000 DPI or more) it is not practical to use PDFDraw directly because of the memory required to store the entire image. In this case, you can use PDFRasterizer directly to generate the rasterized image in stripes or tiles.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

SetDefaultPageColor(Color)

Sets the default color of the page backdrop.

Declaration

public void SetDefaultPageColor(Color c)

Parameters

Type	Name	Description
Color	c	The color (RGB) to set.

SetDrawAnnotations(bool)

Enable or disable annotation and forms rendering. By default, all annotations and form fields are rendered.

Declaration

public void SetDrawAnnotations(bool render_annots)

Parameters

Type	Name	Description
bool	render_annots	True to draw annotations, false otherwise.

SetFlipYAxis(bool)

Flips the vertical (i.e. Y) axis of the image.

Declaration

public void SetFlipYAxis(bool flip_y)

Parameters

Type	Name	Description
bool	flip_y	true to flip the Y axis, false otherwise. For compatibility with most raster formats 'flip_y' is true by default.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

SetGamma(double)

Sets the gamma factor used for anti-aliased rendering.

Declaration

public void SetGamma(double exp)

Parameters

Type	Name	Description
double	exp	exponent value of gamma function. Typical values are in the range from 0.1 to 3.

Remarks

Gamma correction can be used to improve the quality of anti-aliased image output and can (to some extent) decrease the appearance common anti-aliasing artifacts (such as pixel width lines between polygons). Gamma correction is used only in the built-in rasterizer.

SetHighlightFields(bool)

Enable or disable highlighting form fields. Default is disabled.

Declaration

public void SetHighlightFields(bool highlight_fields)

Parameters

Type	Name	Description
bool	highlight_fields	true to highlight, false otherwise.

SetImageSize(int, int)

SetImageSize can be used instead of SetDPI() to adjust page scaling so that image fits into a buffer of given dimensions.

If this function is used, DPI will be calculated dynamically for each page so that every page fits into the buffer of given dimensions.

Declaration

public void SetImageSize(int width, int height)

Parameters

Type	Name	Description
int	width	The width of the image, in pixels/samples.
int	height	The height of the image, in pixels/samples.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

SetImageSize(int, int, bool)

Sets the image size.

Declaration

public void SetImageSize(int width, int height, bool preserve_aspect_ratio)

Parameters

Type	Name	Description
int	width	the width
int	height	the height
bool	preserve_aspect_ratio	the preserve_aspect_ratio

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

SetImageSmoothing(bool, bool)

Enable or disable image smoothing. The rasterizer allows a tradeoff between rendering quality and rendering speed. This function can be used to indicate the preference between rendering speed and quality. image smoothing is enabled by default.

Declaration

public void SetImageSmoothing(bool smoothing_enabled, bool hq_image_resampling)

Parameters

Type	Name	Description
bool	smoothing_enabled	whether to enable image smoothing
bool	hq_image_resampling	whether to use a higher quality (but slower) smoothing algorithm

Remarks

image smoothing option has effect only if the source image has higher resolution that the output resolution of the image on the rasterized page. PDFNet automatically controls at what resolution/zoom factor, 'image smoothing' needs to take effect.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

SetOCGContext(Context)

Declaration

public void SetOCGContext(Context ctx)

Parameters

Type	Name	Description
Context	ctx

SetOverprint(OverprintPreviewMode)

Enable or disable support for overprint. Overprint is a device dependent feature and the results will vary depending on the output color space and supported colorants (i.e. CMYK, CMYK+spot, RGB, etc). By default overprint is enabled for only PDF/X files.

Declaration

public void SetOverprint(PDFRasterizer.OverprintPreviewMode op)

Parameters

Type	Name	Description
PDFRasterizer.OverprintPreviewMode	op	e_op_on: always enabled; e_op_off: always disabled; e_op_pdfx_on: enabled for PDF/X files only.

SetPageBox(Box)

Selects the page box/region to rasterize.

Declaration

public void SetPageBox(Page.Box region)

Parameters

Type	Name	Description
Page.Box	region	Page box to rasterize. By default, PDFDraw will rasterize page crop box.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

SetPageTransparent(bool)

Sets the page color to transparent. By default, PDFDraw assumes that the page is imposed directly on an opaque white surface. Some applications may need to impose the page on a different backdrop. In this case any pixels that are not covered during rendering will be transparent.

Declaration

public void SetPageTransparent(bool is_transp)

Parameters

Type	Name	Description
bool	is_transp	If true, page's backdrop color will be transparent. If false, the page's backdrop will be a opaque white.

Remarks

If true, page's backdrop color will be transparent. If false, the page's backdrop will be a opaque white.

SetPathHinting(bool)

Enable or disable path hinting. Path hinting is used to slightly adjust paths in order to avoid or alleviate artifacts of hair line cracks between certain graphical elements. This option is turned on by default.

Declaration

public void SetPathHinting(bool enable_ph)

Parameters

Type	Name	Description
bool	enable_ph	whether to enable path hinting.

SetPrintMode(bool)

Tells the rasterizer to render the page 'print' mode. Certain page elements (such as annotations or OCG-s) are meant to be visible either on the screen or on the printed paper but not both. A common example, is the "Submit" button on electronic forms.

Declaration

public void SetPrintMode(bool is_printing)

Parameters

Type	Name	Description
bool	is_printing	set to true if the page should be rendered in print mode. By default, print mode flag is set to false.

SetRasterizerType(Type)

Sets the core graphics library used for rasterization and rendering. Using this method it is possible to quickly switch between different implementations. By default, PDFDraw uses the built-in, platform independent rasterizer.

Declaration

public void SetRasterizerType(PDFRasterizer.Type type)

Parameters

Type	Name	Description
PDFRasterizer.Type	type	Rasterizer type.

Remarks

This method is deprecated, since the GDI+ rasterizer itself is deprecated and will be removed in a future version of PDFNet. It is strongly recommended to use the default built-in rasterizer and to use the XPS print path where vector conversion is needed.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

SetRotate(Rotate)

Sets the rotation value for this page.

Declaration

public void SetRotate(Page.Rotate r)

Parameters

Type	Name	Description
Page.Rotate	r	the new rotate

Remarks

This method is used only for drawing purposes and it does not modify the document (unlike Page::SetRotate()).

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

SetThinLineAdjustment(bool, bool)

Set thin line adjustment parameters.

Declaration

public void SetThinLineAdjustment(bool pixel_grid_fit, bool stroke_adjust)

Parameters

Type	Name	Description
bool	pixel_grid_fit	if true (horizontal/vertical) thin lines will be snapped to integer pixel positions. This helps make thin lines look sharper and clearer. This option is turned off by default and it only works if path hinting is enabled.
bool	stroke_adjust	if true auto stroke adjustment is enabled. Currently, this would make lines with sub-pixel width to be one-pixel wide. This option is turned on by default.

Implements

IDisposable