Class: PDFRasterizer

PDFNet. PDFRasterizer


new PDFRasterizer()

PDFRasterizer is a low-level PDF rasterizer.

The main purpose of this class is to convert PDF pages to raster images (or bitmaps).

Methods


<static> create(type)

PdFRasterizer constructor and destructor

Parameters:
Name Type Description
type number/enum
PDFNet.PDFRasterizer.Type = {
	e_BuiltIn : 0
	e_GDIPlus : 1
}
Returns:

A promise that resolves to an object of type: "PDFRasterizer"

Type
PDFNet.PDFRasterizer

destroy()

Frees the native memory of the object.


enableDisplayListCaching(enabled)

Parameters:
Name Type Description
enabled boolean

getChunkRendererPath(page, file_path, width, height, demult, device_mtx, clip, scrl_clp_regions, cancel)

Parameters:
Name Type Description
page PDFNet.Page
file_path string
width number
height number
demult boolean
device_mtx PDFNet.Matrix2D
clip PDFNet.Rect
scrl_clp_regions PDFNet.Rect
cancel boolean
Returns:

A promise that resolves to an object of type: "ChunkRenderer"

Type
PDFNet.ChunkRenderer

getColorPostProcessMode()

Returns:

A promise that resolves to the current color post processing mode.

Type
number
Example
Return value enum:
<pre>
PDFNet.PDFRasterizer.ColorPostProcessMode = {
	e_postprocess_none : 0
	e_postprocess_invert : 1
}
</pre>

getRasterizerType()

Returns:

A promise that resolves to the type of current rasterizer.

Type
number
Example
Return value enum:
<pre>
PDFNet.PDFRasterizer.Type = {
	e_BuiltIn : 0
	e_GDIPlus : 1
}
</pre>

rasterizeAnnot(annot, page, device_mtx, demult, cancel)

Parameters:
Name Type Description
annot PDFNet.Annot
page PDFNet.Page
device_mtx PDFNet.Matrix2D
demult boolean
cancel boolean
Returns:

A promise that resolves to an object of type: "OwnedBitmap"

Type
PDFNet.OwnedBitmap

setAnnotationState(annot, new_view_state)

Parameters:
Name Type Description
annot PDFNet.Annot
new_view_state number/enum
PDFNet.Annot.State = {
	e_normal : 0
	e_rollover : 1
	e_down : 2
}

setAntiAliasing(enable_aa)

Parameters:
Name Type Description
enable_aa boolean

setCaching(enabled)

enables or disables caching. Caching can improve the rendering performance in cases where the same page will be drawn multiple times.

Parameters:
Name Type Description
enabled boolean

if true PDFRasterizer will cache frequently used graphics objects.


setColorPostProcessMode(mode)

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.

Parameters:
Name Type Description
mode number/enum
PDFNet.PDFRasterizer.ColorPostProcessMode = {
	e_postprocess_none : 0
	e_postprocess_invert : 1
}

is the specific transform to be applied


setDrawAnnotations(render_annots)

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

Parameters:
Name Type Description
render_annots boolean

True to draw annotations, false otherwise.


setGamma(expgamma)

sets the gamma factor used for anti-aliased rendering.

Parameters:
Name Type Description
expgamma number

is the exponent value of gamma function. Typical values are in the range from 0.1 to 3.

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).


setHighlightFields(highlight)

Enable or disable highlighting form fields. Default is disabled.

Parameters:
Name Type Description
highlight boolean

true to highlight, false otherwise.


setImageSmoothing(smoothing_enabled, hq_image_resampling)

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.

Parameters:
Name Type Description
smoothing_enabled boolean

True to enable image smoothing, false otherwise.

hq_image_resampling boolean

True to use a higher quality (but slower) smoothing algorithm

Default Value:
  • image smoothing is enabled and hq_image_resampling is false.

setOCGContext(ctx)

sets the Optional Content Group (OCG) context that should be used when rendering the page. This function can be used to selectively render optional content (such as PDF layers) based on the states of optional content groups in the given context.

Parameters:
Name Type Description
ctx PDFNet.OCGContext

Optional Content Group (OCG) context, or NULL if the rasterizer should render all content on the page.


setOverprint(op)

enable or disable support for overprint and overprint simulation. 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).

Parameters:
Name Type Description
op number/enum
PDFNet.PDFRasterizer.OverprintPreviewMode = {
	e_op_off : 0
	e_op_on : 1
	e_op_pdfx_on : 2
}

e_op_on: always enabled; e_op_off: always disabled; e_op_pdfx_on: enabled for PDF/X files only.

Default Value:
  • By default overprint is only enabled for PDF/X files.

setPathHinting(enable_hinting)

Enable or disable path hinting.

Parameters:
Name Type Description
enable_hinting boolean

if true path hinting is enabled. 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.


setPrintMode(is_printing)

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.

Parameters:
Name Type Description
is_printing boolean

set to true is the page should be rendered in print mode.

Default Value:
  • 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, PDFNet uses a built-in, high-quality, and platform independent rasterizer.

Parameters:
Name Type Description
type number/enum
PDFNet.PDFRasterizer.Type = {
	e_BuiltIn : 0
	e_GDIPlus : 1
}

Rasterizer type.


setThinLineAdjustment(grid_fit, stroke_adjust)

Set thin line adjustment parameters.

Parameters:
Name Type Description
grid_fit boolean

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.

stroke_adjust boolean

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.


updateBuffer()

this function is typically called for progressive rendering, in which we don't want to stop the main rendering thread. Since the rendering thread may modify separation channels, we don't consider separations in progressive rendering.