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#include <PDFDraw.h>
Public Types | |
enum | PixelFormat { e_rgba, e_bgra, e_rgb, e_bgr, e_gray, e_gray_alpha, e_cmyk, e_rgba_demult, e_gray_alpha_demult } |
Pixel format type. More... | |
Public Member Functions | |
PDFDraw (double dpi=92) | |
PDFDraw constructor and destructor. | |
~PDFDraw () | |
void | SetRasterizerType (PDFRasterizer::Type type) |
Sets the core graphics library used for rasterization and rendering. | |
void | SetDPI (double dpi) |
Sets the output image resolution. | |
void | SetImageSize (int width, int height, bool preserve_aspect_ratio=true) |
SetImageSize can be used instead of SetDPI() to adjust page scaling so that image fits into a buffer of given dimensions. | |
void | SetPageBox (Page::Box region) |
Selects the page box/region to rasterize. | |
void | SetFlipYAxis (bool flip_y) |
Flips the vertical (i.e. | |
void | SetRotate (Page::Rotate r) |
Sets the rotation value for this page. | |
void | SetDrawAnnotations (bool render_annots) |
Enable or disable annotation and forms rendering. | |
void | SetAntiAliasing (bool enable_aa) |
Enable or disable anti-aliasing. | |
void | SetImageSmoothing (bool smoothing_enabled=true) |
Enable or disable image smoothing. | |
void | SetCaching (bool enabled=true) |
Enables or disables caching. | |
void | SetGamma (double exp) |
Sets the gamma factor used for anti-aliased rendering. | |
void | SetOCGContext (OCG::Context *ctx) |
Sets the Optional Content Group (OCG) context that should be used when rendering the page. | |
void | SetPrintMode (bool is_printing) |
Tells the rasterizer to render the page 'print' mode. | |
void | SetPageTransparent (bool is_transparent) |
Sets the page color to transparent. | |
void | SetOverprint (bool overprint) |
Enable or disable support for overprint and overprint simulation. | |
void | Export (Page page, const UString &filename, const char *format="PNG", SDF::Obj encoder_params=0) |
A utility method to export the given PDF page to an image file. | |
System::Drawing::Bitmap * | GetBitmap (Page page) |
Returns a GDI+ bitmap for the given page. | |
void | DrawInRect (Page &page, void *hdc, const Rect &rect) |
Draws the contents of the page to a given device context. | |
const UChar * | GetBitmap (Page page, int &out_width, int &out_height, int &out_stride, double &out_dpi, PixelFormat pix_fmt=e_bgra) |
Returns the raw rasterized image data for the given image. | |
void | SetErrorReportProc (PDFRasterizer::ErrorReportProc error_proc, void *data) |
Sets the error handling function to be called in case an error is encountered during page rendering. |
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.
pdftron::PDF::PDFDraw::PDFDraw | ( | double | dpi = 92 |
) |
PDFDraw constructor and destructor.
dpi | - Default resolution used to rasterize pages. If the parameter is not specified, the initial resolution is 92 dots per inch. DPI parameter can be modified at any time using PDFDraw::SetDPI() method. |
pdftron::PDF::PDFDraw::~PDFDraw | ( | ) |
void pdftron::PDF::PDFDraw::SetRasterizerType | ( | PDFRasterizer::Type | 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.
type | Rasterizer type. |
void pdftron::PDF::PDFDraw::SetDPI | ( | double | dpi | ) |
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.
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.
void pdftron::PDF::PDFDraw::SetImageSize | ( | int | width, | |
int | height, | |||
bool | preserve_aspect_ratio = true | |||
) |
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.
width | - The width of the image, in pixels/samples. | |
height | - The height of the image, in pixels/samples. | |
preserve_aspect_ratio | - True to preserve the aspect ratio, false otherwise. By default, preserve_aspect_ratio is true. |
void pdftron::PDF::PDFDraw::SetPageBox | ( | Page::Box | region | ) |
void pdftron::PDF::PDFDraw::SetFlipYAxis | ( | bool | flip_y | ) |
Flips the vertical (i.e.
Y) axis of the image.
flip_y | true to flip the Y axis, false otherwise. For compatibility with most raster formats 'flip_y' is true by default. |
void pdftron::PDF::PDFDraw::SetRotate | ( | Page::Rotate | r | ) |
Sets the rotation value for this page.
angle | Rotation value to be set for a given page. Must be one of the Page::Rotate values. |
void pdftron::PDF::PDFDraw::SetDrawAnnotations | ( | bool | render_annots | ) |
Enable or disable annotation and forms rendering.
By default, all annotations and form fields are rendered.
render_annots | True to draw annotations, false otherwise. |
void pdftron::PDF::PDFDraw::SetAntiAliasing | ( | bool | enable_aa | ) |
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.
void pdftron::PDF::PDFDraw::SetImageSmoothing | ( | bool | smoothing_enabled = true |
) |
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.
smoothing_enabled | True to enable image smoothing, false otherwise. image smoothing is enabled. |
void pdftron::PDF::PDFDraw::SetCaching | ( | bool | enabled = true |
) |
Enables or disables caching.
Caching can improve the rendering performance in cases where the same page will be drawn multiple times.
enabled | - if true PDFRasterizer will cache frequently used graphics objects. |
void pdftron::PDF::PDFDraw::SetGamma | ( | double | exp | ) |
Sets the gamma factor used for anti-aliased rendering.
exp | is the exponent value of gamma function. Typical values are in the range from 0.1 to 3. |
void pdftron::PDF::PDFDraw::SetOCGContext | ( | OCG::Context * | 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.
ctx | Optional Content Group (OCG) context, or NULL if the rasterizer should render all content on the page. |
void pdftron::PDF::PDFDraw::SetPrintMode | ( | bool | 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.
is_printing | set to true if the page should be rendered in print mode. By default, print mode flag is set to false. |
void pdftron::PDF::PDFDraw::SetPageTransparent | ( | bool | is_transparent | ) |
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.
is_transparent | If true, page's backdrop color will be transparent. If false, the page's backdrop will be a opaque white. |
void pdftron::PDF::PDFDraw::SetOverprint | ( | bool | overprint | ) |
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).
By default overprint simulation is enabled.
overprint | If true, overprint support will be enabled. If false, overprint support will be disabled. |
void pdftron::PDF::PDFDraw::Export | ( | Page | page, | |
const UString & | filename, | |||
const char * | format = "PNG" , |
|||
SDF::Obj | encoder_params = 0 | |||
) |
A utility method to export the given PDF page to an image file.
page | The source PDF page. | |
filename | - The name of the output image file. The filename should include the extension suffix (e.g. 'c:/output/myimage.png'). |
By default, the function exports to PNG.
encoder_params | - An optional SDF dictionary object containing key/value pairs representing optional encoder parameters. The following table list possible parameters for corresponding export filters: |
Parameter/Key | Output Format | Description/Value | Example |
Quality | JPEG | The value for compression 'Quality' must be a number between 0 and 100 specifying the tradeoff between compression ratio and loss in image quality. 100 stands for best quality. | hint.PutNumber("Quality", 60); See the Example 2 in PDFDraw sample project. |
Dither | PNG, PNG8, TIFF or TIFF8. | A boolean used to enable or disable dithering. Relevent only for when the image is exported in palettized or monochrome mode. | hint.PutBool("Dither", true); |
ColorSpace | PNG/TIFF for grayscale; TIFF for CMYK. | A name object used to select the rendering and export color space. Currently supported values are "Gray", "RGB, and "CMYK". The output image format must support specified color space, otherwise the parameter will be ignored. An example of image format that supports CMYK is TIFF. Image formats that support grayscale are PNG and TIFF. By default, the image is rendered and exported in RGB color space. | hint.PutName("ColorSpace", "CMYK"); |
BPC | PNG or TIFF. | A number used to specify 'bits per pixel' in the output file. Currently supported values are 1 and 8 (default is 8). To export monochrome (1 bit per pixel) image, use 1 as the value of BPC parameter and use TIFF or PNG as the export format for the image. By default, the image is not dithered when BPC is 1. To enable dithering add 'Dither' option in the export hint. | hint.PutNumber("BPC", 1); |
System::Drawing::Bitmap* pdftron::PDF::PDFDraw::GetBitmap | ( | Page | page | ) |
Returns a GDI+ bitmap for the given page.
page | The source PDF page. |
Draws the contents of the page to a given device context.
page | The source PDF page. | |
hdc | Device context (i.e. HDC structure). | |
rect | The rectangle in the device context inside of which the page will be drawn. |
const UChar* pdftron::PDF::PDFDraw::GetBitmap | ( | Page | page, | |
int & | out_width, | |||
int & | out_height, | |||
int & | out_stride, | |||
double & | out_dpi, | |||
PixelFormat | pix_fmt = e_bgra | |||
) |
Returns the raw rasterized image data for the given image.
page | The source PDF page. | |
out_width | - Filled by the method. The width of the target image in pixels. | |
out_height | - Filled by the method. The height of the target image in pixels (the number of rows). | |
out_stride | - Filled by the method. Stride determines the physical width (in bytes) of one row in memory. If this value is negative the direction of the Y axis is inverted. The absolute value of stride is of importance, because it allows rendering in buffers where rows are padded in memory (e.g. in Windows bitmaps are padded on 4 byte boundaries). | |
out_dpi | - Filled by the method. The output resolution of the image (Dots Per Inch). | |
pix_fmt | - Optional parameter used to specify the desired pixel format. The default pixel format is BGRA. |
void pdftron::PDF::PDFDraw::SetErrorReportProc | ( | PDFRasterizer::ErrorReportProc | error_proc, | |
void * | data | |||
) |
Sets the error handling function to be called in case an error is encountered during page rendering.
error_proc | Error handling callback function (or delegate in .NET) | |
data | Custom data to be passed as a second parameter to 'error_proc'. |