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pdftron::PDF::Image Class Reference

#include <Image.h>

Public Types

enum  InputFilter {
  e_none, e_jpeg, e_jp2, e_flate,
  e_g3, e_g4, e_ascii_hex
}
 

Public Member Functions

 Image (SDF::Obj image_xobject=0)
 
 Image (const Image &)
 
Imageoperator= (const Image &)
 
SDF::Obj GetSDFObj () const
 
bool IsValid () const
 
Filters::Filter GetImageData () const
 
int GetImageDataSize () const
 
ColorSpace GetImageColorSpace () const
 
int GetImageWidth () const
 
int GetImageHeight () const
 
SDF::Obj GetDecodeArray () const
 
int GetBitsPerComponent () const
 
int GetComponentNum () const
 
bool IsImageMask () const
 
bool IsImageInterpolate () const
 
SDF::Obj GetMask () const
 
void SetMask (Image &image_mask)
 
void SetMask (SDF::Obj mask)
 
SDF::Obj GetSoftMask ()
 
void SetSoftMask (Image &soft_mask)
 
GState::RenderingIntent GetImageRenderingIntent () const
 
int Export (const UString &filename)
 
int Export (Filters::FilterWriter &writer)
 
void ExportAsTiff (const UString &filename)
 
void ExportAsTiff (Filters::FilterWriter &writer)
 
void ExportAsPng (const UString &filename)
 
void ExportAsPng (Filters::FilterWriter &writer)
 

Static Public Member Functions

static Image Create (SDF::SDFDoc &doc, const UString &filename, SDF::Obj encoder_hints=0)
 
static Image Create (SDF::SDFDoc &doc, const unsigned char *buf, size_t buf_size, int width, int height, int bpc, ColorSpace color_space, SDF::Obj encoder_hints=0)
 
static Image Create (SDF::SDFDoc &doc, Filters::FilterReader &image_data, int width, int height, int bpc, ColorSpace color_space, SDF::Obj encoder_hints=0)
 
static Image Create (SDF::SDFDoc &doc, const unsigned char *buf, size_t buf_size, SDF::Obj encoder_hints=0)
 
static Image Create (SDF::SDFDoc &doc, Filters::Filter image_data, SDF::Obj encoder_hints=0)
 
static Image CreateImageMask (SDF::SDFDoc &doc, const char *buf, size_t buf_size, int width, int height, SDF::Obj encoder_hints=0)
 
static Image CreateImageMask (SDF::SDFDoc &doc, Filters::FilterReader &image_data, int width, int height, SDF::Obj encoder_hints=0)
 
static Image CreateSoftMask (SDF::SDFDoc &doc, const char *buf, size_t buf_size, int width, int height, int bpc, SDF::Obj encoder_hints=0)
 
static Image CreateSoftMask (SDF::SDFDoc &doc, Filters::FilterReader &image_data, int width, int height, int bpc, SDF::Obj encoder_hints=0)
 
static Image Create (SDF::SDFDoc &doc, const char *buf, size_t buf_size, int width, int height, int bpc, ColorSpace color_space, InputFilter input_format)
 
static Image Create (SDF::SDFDoc &doc, Filters::FilterReader &image_data, int width, int height, int bpc, ColorSpace color_space, InputFilter input_format)
 

Detailed Description

Image class provides common methods for working with PDF images.

Note
PDF::Element contains a similar interface used to access image data. To create the Image object from image PDF::Element, pass the Element's SDF/Cos dictionary to Image constructor (i.e. Image image(element->GetXObject()) )

Definition at line 22 of file Image.h.

Member Enumeration Documentation

Enumerator
e_none 
e_jpeg 
e_jp2 
e_flate 
e_g3 
e_g4 
e_ascii_hex 

Definition at line 255 of file Image.h.

Constructor & Destructor Documentation

pdftron::PDF::Image::Image ( SDF::Obj  image_xobject = 0)

Create an image from an existing image represented as a SDF/Cos object.

Note
To create the Image object from image PDF::Element, pass the Element's SDF/Cos dictionary to Image constructor (i.e. Image image(element->GetXObject()))
pdftron::PDF::Image::Image ( const Image )

Member Function Documentation

static Image pdftron::PDF::Image::Create ( SDF::SDFDoc doc,
const UString filename,
SDF::Obj  encoder_hints = 0 
)
static

Create and embed an Image from an external file taking into account specified compression hints.

By default the function will either pass-through data preserving the original compression or will compress data using Flate compression. It is possible to fine tune compression or to select a different compression algorithm using 'encoder_hints' object.

Parameters
doc- A document to which the image should be added. To obtain SDF::Doc from PDFDoc use PDFDoc::GetSDFDoc() or Obj::GetDoc().
filename- The name of the image file. Currently supported formats are JPEG, PNG, GIF, TIFF, BMP, EMF, and WMF. Other raster formats can be embedded by decompressing image data and using other versions of Image::Create(...) method.
encoder_hints- An optional SDF::Obj containing a hint (or an SDF::Array of hints) that could be used to select a specific compression method and compression parameters. For a concrete example of how to create encoder hints, please take a look at JBIG2Test and AddImage sample projects. The image encoder accepts the following hints:
  • /JBIG2; SDF::Name("JBIG2"), An SDF::Name Object with value equal to "JBIG2". If the image is monochrome (i.e. bpc == 1), the encoder will compress the image using JBIG2Decode filter. Note that JBIG2 compression is not recommended for use on scanned text/financial documents or equivalent since its lossless nature can lead to similar looking numbers or characters being replaced.
  • [/JBIG2 /Threshold 0.6 /SharePages 50] - Compress a monochrome image using lossy JBIG2Decode compression with the given image threshold and by sharing segments from a specified number of pages. The threshold is a floating point number in the range from 0.4 to 0.9. Increasing the threshold value will increase image quality, but may increase the file size. The default value for threshold is 0.85. "SharePages" parameter can be used to specify the maximum number of pages sharing a common 'JBIG2Globals' segment stream. Increasing the value of this parameter improves compression ratio at the expense of memory usage.
  • [/CCITT] - Compress a monochrome (i.e. bpc == 1) image using CCITT Group 4 compression. This algorithm typically produces larger output than JBIG2, but is lossless. This makes it much more suitable for scanned text documents. CCITT is the best option for more general monochrome compression use cases, since JBIG2 has potential to change image content.
  • [/JPEG] - Use JPEG compression with default compression.
  • [/JPEG /Quality 60] - Use JPEG compression with given quality setting. The "Quality" value is expressed on the 0..100 scale.
  • [/JP2] or [/JPEG2000] - Use JPEG2000 compression to compress a RGB or a grayscale image
  • [/Flate] - Use Flate compression with maximum compression at the expense of speed.
  • [/Flate /Level 9] - Use Flate compression using specified compression level. Compression "Level" must be a number between 0 and 9: 1 gives best speed, 9 gives best compression, 0 gives no compression at all (the input data is simply copied a block at a time).
  • /RAW or [/RAW] - The encoder will not use any compression method and the image will be stored in the raw format.
Returns
PDF::Image object representing the embedded image.
Note
For C++ developers: Current document does not take the ownership of the encoder_hints object. Therefore it is a good programming practice to create encoder_hints object on the stack.
static Image pdftron::PDF::Image::Create ( SDF::SDFDoc doc,
const unsigned char *  buf,
size_t  buf_size,
int  width,
int  height,
int  bpc,
ColorSpace  color_space,
SDF::Obj  encoder_hints = 0 
)
static

Create and embed an Image. Embed the raw image data taking into account specified compression hints.

By default the function will compress all images using Flate compression. It is possible to fine tune compression or to select a different compression algorithm using 'encoder_hints' object.

Parameters
doc- A document to which the image should be added. The 'Doc' object can be obtained using Obj::GetDoc() or PDFDoc::GetSDFDoc().
buf- The stream or buffer containing image data. The image data must not be compressed and must follow PDF format for sample representation (please refer to section 4.8.2 'Sample Representation' in PDF Reference Manual for details).
width- The width of the image, in samples.
height- The height of the image, in samples.
bpc- The number of bits used to represent each color component.
color_space- The color space in which image samples are represented.
encoder_hints- An optional parameter that can be used to fine tune compression or to select a different compression algorithm. See Image::Create() for details.
Returns
PDF::Image object representing the embedded image.
static Image pdftron::PDF::Image::Create ( SDF::SDFDoc doc,
Filters::FilterReader image_data,
int  width,
int  height,
int  bpc,
ColorSpace  color_space,
SDF::Obj  encoder_hints = 0 
)
static

Create and embed an Image. Embed the raw image data taking into account specified compression hints.

Note
see Image::Create for details.
static Image pdftron::PDF::Image::Create ( SDF::SDFDoc doc,
const unsigned char *  buf,
size_t  buf_size,
SDF::Obj  encoder_hints = 0 
)
static

Create and embed an Image. Embed the raw image data taking into account specified compression hints.

Note
see Image::Create for details.
static Image pdftron::PDF::Image::Create ( SDF::SDFDoc doc,
Filters::Filter  image_data,
SDF::Obj  encoder_hints = 0 
)
static

Create and embed an Image. Embed the raw image data taking into account specified compression hints.

Note
see Image::Create for details.
PDFNet takes ownership of the filter
static Image pdftron::PDF::Image::Create ( SDF::SDFDoc doc,
const char *  buf,
size_t  buf_size,
int  width,
int  height,
int  bpc,
ColorSpace  color_space,
InputFilter  input_format 
)
static

Directly embed the image that is already compressed using the Image::InputFilter format. The function can be used to pass-through pre-compressed image data.

Parameters
doc- A document to which the image should be added. The 'Doc' object can be obtained using Obj::GetDoc() or PDFDoc::GetSDFDoc().
buf- The stream or buffer containing compressed image data. The compression format must match the input_format parameter.
width- The width of the image, in samples.
height- The height of the image, in samples.
bpc- The number of bits used to represent each color component.
color_space- The color space in which image samples are specified.
input_format- Image::InputFilter describing the format of pre-compressed image data.
encoder_hints- An optional parameter that can be used to fine tune compression or to select a different compression algorithm. See Image::Create() for details.
Returns
PDF::Image object representing the embedded image.
static Image pdftron::PDF::Image::Create ( SDF::SDFDoc doc,
Filters::FilterReader image_data,
int  width,
int  height,
int  bpc,
ColorSpace  color_space,
InputFilter  input_format 
)
static

Embed the raw image data taking into account specified compression hints.

Note
see the above method for details.
static Image pdftron::PDF::Image::CreateImageMask ( SDF::SDFDoc doc,
const char *  buf,
size_t  buf_size,
int  width,
int  height,
SDF::Obj  encoder_hints = 0 
)
static

Create and embed an Image from any GDI+ Bitmap taking into account specified compression hints.

Note
see Image::Create for details.
This method is available only on Windows platforms.
Parameters
doc- A document to which the image should be added. The 'Doc' object can be obtained using Obj::GetDoc() or PDFDoc::GetSDFDoc().
bmp- GDI+ bitmap.
Returns
PDF::Image object representing the embedded image. Create and embed an ImageMask. Embed the raw image data taking into account specified compression hints. The ImageMask can be used as a stencil mask for painting in the current color or as an explicit mask specifying which areas of the image to paint and which to mask out. One of the most important uses of stencil masking is for painting character glyphs represented as bitmaps.
Parameters
doc- A document to which the image should be added. The 'Doc' object can be obtained using Obj::GetDoc() or PDFDoc::GetSDFDoc().
buf- The stream or buffer containing image data stored in 1 bit per sample format. The image data must not be compressed and must follow PDF format for sample representation (please refer to section 4.8.2 'Sample Representation' in PDF Reference Manual for details).
width- The width of the image, in samples.
height- The height of the image, in samples.
encoder_hints- An optional parameter that can be used to fine tune compression or to select a different compression algorithm. See Image::Create() for details.
Returns
PDF::Image object representing the embedded ImageMask.
static Image pdftron::PDF::Image::CreateImageMask ( SDF::SDFDoc doc,
Filters::FilterReader image_data,
int  width,
int  height,
SDF::Obj  encoder_hints = 0 
)
static

Create and embed an ImageMask.

Note
see Image::CreateImageMask for details.
static Image pdftron::PDF::Image::CreateSoftMask ( SDF::SDFDoc doc,
const char *  buf,
size_t  buf_size,
int  width,
int  height,
int  bpc,
SDF::Obj  encoder_hints = 0 
)
static

Create and embed a Soft Mask. Embed the raw image data taking into account specified compression hints. A soft-mask image (see "Soft-Mask Images" in PDF Reference Manual) is used as a source of mask shape or mask opacity values in the transparent imaging model.

Parameters
doc- A document to which the image should be added. The 'Doc' object can be obtained using Obj::GetDoc() or PDFDoc::GetSDFDoc().
buf- The stream or buffer containing image data represented in DeviceGray color space (i.e. one component per sample). The image data must not be compressed and must follow PDF format for sample representation (please refer to section 4.8.2 'Sample Representation' in PDF Reference Manual for details).
width- The width of the image, in samples.
height- The height of the image, in samples.
bpc- The number of bits used to represent each color component.
encoder_hints- An optional parameter that can be used to fine tune compression or to select a different compression algorithm. See Image::Create() for details.
Note
this feature is available only in PDF 1.4 and higher.
static Image pdftron::PDF::Image::CreateSoftMask ( SDF::SDFDoc doc,
Filters::FilterReader image_data,
int  width,
int  height,
int  bpc,
SDF::Obj  encoder_hints = 0 
)
static

Create and embed a Soft Mask. Embed the raw image data taking into account specified compression hints.

Note
see Image::CreateSoftMask for details.
int pdftron::PDF::Image::Export ( const UString filename)

Saves this image to a file.

The output image format (TIFF, JPEG, or PNG) will be automatically selected based on the properties of the embedded image. For example, if the embedded image is using CCITT Fax compression, the output format will be TIFF. Similarly, if the embedded image is using JPEG compression the output format will be JPEG. If your application needs to explicitly control output image format you may want to use ExportAsTiff() or ExportAsPng().

Parameters
filenamestring that specifies the path name for the saved image. The filename should not include the extension which will be appended to the filename string based on the output format.
Returns
the number indicating the selected image format: (0 - PNG, 1 - TIF, 2 - JPEG).
int pdftron::PDF::Image::Export ( Filters::FilterWriter writer)

Saves this image to the output stream. (0 - PNG, 1 - TIF, 2 - JPEG).

Parameters
writerA pointer to FilterWriter used to write to the output stream. If the parameter is null, nothing will be written to the output stream, but the function returns the format identifier.
Returns
the number indicating the selected image format:
Note
see the overloaded Image::Export method for more information.
void pdftron::PDF::Image::ExportAsPng ( const UString filename)

Saves this image to a PNG file.

Parameters
filenamestring that specifies the path name for the saved image. The filename should include the file extension
void pdftron::PDF::Image::ExportAsPng ( Filters::FilterWriter writer)

Saves this image to a PNG output stream.

Parameters
writerFilterWriter used to write to the output stream.
void pdftron::PDF::Image::ExportAsTiff ( const UString filename)

Saves this image to a TIFF file.

Parameters
filenamestring that specifies the path name for the saved image. The filename should include the file extension
void pdftron::PDF::Image::ExportAsTiff ( Filters::FilterWriter writer)

Saves this image to a TIFF output stream.

Parameters
writerFilterWriter used to write to the output stream.
int pdftron::PDF::Image::GetBitsPerComponent ( ) const
Returns
the number of bits used to represent each color component. Only a single value may be specified; the number of bits is the same for all color components. Valid values are 1, 2, 4, 8, and 16.
int pdftron::PDF::Image::GetComponentNum ( ) const
Returns
the number of color components per sample.
SDF::Obj pdftron::PDF::Image::GetDecodeArray ( ) const
Returns
Decode array or NULL if the parameter is not specified. A decode object is an array of numbers describing how to map image samples into the range of values appropriate for the images color space . If ImageMask is true, the array must be either [0 1] or [1 0]; otherwise, its length must be twice the number of color components required by ColorSpace. Default value depends on the color space, See Table 4.36 in PDF Ref. Manual.
ColorSpace pdftron::PDF::Image::GetImageColorSpace ( ) const

Convert PDF image to GDI+ Bitmap.

Returns
GDI+ bitmap from this image. PDFNet creates a GDI+ bitmap that closely matches the original image in terms of the image depth and the number of color channels. PDF color spaces that do not have a counterpart in GDI+ are converted to RGB.
Note
This method is available only on Windows platforms.
Returns
The SDF object representing the color space in which image samples are specified or NULL if:
  • the image is an image mask
  • or is compressed using JPXDecode with missing ColorSpace entry in image dictionary.

The returned color space may be any type of color space except Pattern.

Filters::Filter pdftron::PDF::Image::GetImageData ( ) const
Returns
A stream (filter) containing decoded image data
int pdftron::PDF::Image::GetImageDataSize ( ) const
Returns
the size of image data in bytes
int pdftron::PDF::Image::GetImageHeight ( ) const
Returns
the height of the image, in samples.
GState::RenderingIntent pdftron::PDF::Image::GetImageRenderingIntent ( ) const
Returns
The color rendering intent to be used in rendering the image.
int pdftron::PDF::Image::GetImageWidth ( ) const
Returns
the width of the image, in samples.
SDF::Obj pdftron::PDF::Image::GetMask ( ) const
Returns
an image XObject defining an image mask to be applied to this image (See 'Explicit Masking', 4.8.5), or an array specifying a range of colors to be applied to it as a color key mask (See 'Color Key Masking').

If IsImageMask() return true, this method will return NULL.

SDF::Obj pdftron::PDF::Image::GetSDFObj ( ) const
Returns
the underlying SDF/Cos object
SDF::Obj pdftron::PDF::Image::GetSoftMask ( )
Returns
an image XObject defining a Soft Mask to be applied to this image (See section 7.5.4 'Soft-Mask Images' in PDF Reference Manual), or NULL if the image does not have the soft mask.
bool pdftron::PDF::Image::IsImageInterpolate ( ) const
Returns
a boolean indicating whether image interpolation is to be performed.
bool pdftron::PDF::Image::IsImageMask ( ) const
Returns
a boolean indicating whether the inline image is to be treated as an image mask.
bool pdftron::PDF::Image::IsValid ( ) const
Returns
whether this is a valid raster image. If the function returns false the underlying SDF/Cos object is not a valid raster image and this Image object should be treated as null.
Image& pdftron::PDF::Image::operator= ( const Image )
void pdftron::PDF::Image::SetMask ( Image image_mask)

Set an Explicit Image Mask.

Parameters
image_maskAn Image object which serves as an explicit mask for the base (this) image. The base image and the image mask need not have the same resolution (Width and Height values), but since all images are defined on the unit square in user space, their boundaries on the page will coincide; that is, they will overlay each other. The image mask indicates which places on the page are to be painted and which are to be masked out (left unchanged). Unmasked areas are painted with the corresponding portions of the base image; masked areas are not.
Note
image_mask must be a valid image mask (i.e. image_mask.IsImageMask() must return true.
void pdftron::PDF::Image::SetMask ( SDF::Obj  mask)

Set a Color Key Mask.

Parameters
maskis an Cos/SDF array specifying a range of colors to be masked out. Samples in the image that fall within this range are not painted, allowing the existing background to show through. The effect is similar to that of the video technique known as chroma-key. For details of the array format please refer to section 4.8.5 'Color Key Masking' in PDF Reference Manual.
Note
the current document takes the ownership of the given SDF object.
void pdftron::PDF::Image::SetSoftMask ( Image soft_mask)

Set a Soft Mask.

Parameters
soft_maskis a subsidiary Image object defining a soft-mask image (See section 7.5.4 'Soft-Mask Images' in PDF Reference Manual) to be used as a source of mask shape or mask opacity values in the transparent imaging model. The alpha source parameter in the graphics state determines whether the mask values are interpreted as shape or opacity.

The documentation for this class was generated from the following file: