PDFTron pdfnet-node

Class: MonoImageSettings

PDFNet.Optimizer. MonoImageSettings

new MonoImageSettings()

An object that stores downsampling/recompression settings for monochrome images.

Members

<static> CompressionMode

Type:
  • number
Properties:
Name Type Description
e_jbig2 number
e_flate number
e_none number

<static> DownsampleMode

Type:
  • number
Properties:
Name Type Description
e_off number
e_default number

Methods

forceChanges(force)

Sets whether image changes that grow the PDF file should be kept. This is off by default.
Parameters:
Name Type Description
force boolean if true all image changes will be kept.
Returns:
this object, for call chaining
Type
PDFNet.Optimizer.MonoImageSettings

forceRecompression(force)

Sets whether recompression to the specified compression method, should be forced when the image is not downsampled. By default the compression method for these images will not be changed.
Parameters:
Name Type Description
force boolean if true the compression method for all
Returns:
this object, for call chaining
Type
PDFNet.Optimizer.MonoImageSettings

setCompressionMode(mode)

Sets the output compression mode for monochrome images The default value is e_jbig2
Parameters:
Name Type Description
mode number the compression mode to set 
PDFNet.Optimizer.MonoImageSettings.CompressionMode = {
	e_jbig2 : 0,
	e_flate : 1,
	e_none : 2,
	e_ccitt: 3
}
Returns:
this object, for call chaining
Type
PDFNet.Optimizer.MonoImageSettings

setDownsampleMode(mode)

Sets the downsample mode for monochrome images The default value is e_default
Parameters:
Name Type Description
mode number the compression mode to set 
PDFNet.Optimizer.MonoImageSettings.DownsampleMode = {
 e_off : 0,
	e_default : 1
}
Returns:
this object, for call chaining
Type
PDFNet.Optimizer.MonoImageSettings

setImageDPI(maximum, resampling)

Sets the maximum and resampling dpi for monochrome images. By default these are set to 450 and 300 respectively.
Parameters:
Name Type Description
maximum number the highest dpi of an image before it will be resampled
resampling number the image dpi to resample to if an image is encountered over the maximum dpi
Returns:
this object, for call chaining
Type
PDFNet.Optimizer.MonoImageSettings

setJBIG2Threshold(jbig2_threshold)

Sets the quality for lossy JBIG2Decode compression mode. The threshold is a floating point number in the range from 4 to 9 The default value for JBIG2 is 8.5. The setting is ignored for FLATE.
Parameters:
Name Type Description
jbig2_threshold number the quality for lossy compression modes.
Returns:
this object, for call chaining
Type
PDFNet.Optimizer.MonoImageSettings